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openssl/ssl/t1_lib.c
Dr. Stephen Henson ec24630ae2 Modify TLS support for new X25519 API. 
When handling ECDH check to see if the curve is "custom" (X25519 is
currently the only curve of this type) and instead of setting a curve
NID just allocate a key of appropriate type.

Reviewed-by: Rich Salz <rsalz@openssl.org>
2016-08-13 14:11:05 +01:00

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/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <stdlib.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/ocsp.h>
#include <openssl/conf.h>
#include <openssl/x509v3.h>
#include <openssl/dh.h>
#include <openssl/bn.h>
#include "ssl_locl.h"
#include <openssl/ct.h>
static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
const unsigned char *sess_id, int sesslen,
SSL_SESSION **psess);
static int ssl_check_clienthello_tlsext_early(SSL *s);
static int ssl_check_serverhello_tlsext(SSL *s);
SSL3_ENC_METHOD const TLSv1_enc_data = {
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
0,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
SSL3_ENC_METHOD const TLSv1_1_enc_data = {
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
SSL_ENC_FLAG_EXPLICIT_IV,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
SSL3_ENC_METHOD const TLSv1_2_enc_data = {
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
long tls1_default_timeout(void)
{
/*
* 2 hours, the 24 hours mentioned in the TLSv1 spec is way too long for
* http, the cache would over fill
*/
return (60 * 60 * 2);
}
int tls1_new(SSL *s)
{
if (!ssl3_new(s))
return (0);
s->method->ssl_clear(s);
return (1);
}
void tls1_free(SSL *s)
{
OPENSSL_free(s->tlsext_session_ticket);
ssl3_free(s);
}
void tls1_clear(SSL *s)
{
ssl3_clear(s);
if (s->method->version == TLS_ANY_VERSION)
s->version = TLS_MAX_VERSION;
else
s->version = s->method->version;
}
#ifndef OPENSSL_NO_EC
typedef struct {
int nid; /* Curve NID */
int secbits; /* Bits of security (from SP800-57) */
unsigned int flags; /* Flags: currently just field type */
} tls_curve_info;
/*
* Table of curve information.
* Do not delete entries or reorder this array! It is used as a lookup
* table: the index of each entry is one less than the TLS curve id.
*/
static const tls_curve_info nid_list[] = {
{NID_sect163k1, 80, TLS_CURVE_CHAR2}, /* sect163k1 (1) */
{NID_sect163r1, 80, TLS_CURVE_CHAR2}, /* sect163r1 (2) */
{NID_sect163r2, 80, TLS_CURVE_CHAR2}, /* sect163r2 (3) */
{NID_sect193r1, 80, TLS_CURVE_CHAR2}, /* sect193r1 (4) */
{NID_sect193r2, 80, TLS_CURVE_CHAR2}, /* sect193r2 (5) */
{NID_sect233k1, 112, TLS_CURVE_CHAR2}, /* sect233k1 (6) */
{NID_sect233r1, 112, TLS_CURVE_CHAR2}, /* sect233r1 (7) */
{NID_sect239k1, 112, TLS_CURVE_CHAR2}, /* sect239k1 (8) */
{NID_sect283k1, 128, TLS_CURVE_CHAR2}, /* sect283k1 (9) */
{NID_sect283r1, 128, TLS_CURVE_CHAR2}, /* sect283r1 (10) */
{NID_sect409k1, 192, TLS_CURVE_CHAR2}, /* sect409k1 (11) */
{NID_sect409r1, 192, TLS_CURVE_CHAR2}, /* sect409r1 (12) */
{NID_sect571k1, 256, TLS_CURVE_CHAR2}, /* sect571k1 (13) */
{NID_sect571r1, 256, TLS_CURVE_CHAR2}, /* sect571r1 (14) */
{NID_secp160k1, 80, TLS_CURVE_PRIME}, /* secp160k1 (15) */
{NID_secp160r1, 80, TLS_CURVE_PRIME}, /* secp160r1 (16) */
{NID_secp160r2, 80, TLS_CURVE_PRIME}, /* secp160r2 (17) */
{NID_secp192k1, 80, TLS_CURVE_PRIME}, /* secp192k1 (18) */
{NID_X9_62_prime192v1, 80, TLS_CURVE_PRIME}, /* secp192r1 (19) */
{NID_secp224k1, 112, TLS_CURVE_PRIME}, /* secp224k1 (20) */
{NID_secp224r1, 112, TLS_CURVE_PRIME}, /* secp224r1 (21) */
{NID_secp256k1, 128, TLS_CURVE_PRIME}, /* secp256k1 (22) */
{NID_X9_62_prime256v1, 128, TLS_CURVE_PRIME}, /* secp256r1 (23) */
{NID_secp384r1, 192, TLS_CURVE_PRIME}, /* secp384r1 (24) */
{NID_secp521r1, 256, TLS_CURVE_PRIME}, /* secp521r1 (25) */
{NID_brainpoolP256r1, 128, TLS_CURVE_PRIME}, /* brainpoolP256r1 (26) */
{NID_brainpoolP384r1, 192, TLS_CURVE_PRIME}, /* brainpoolP384r1 (27) */
{NID_brainpoolP512r1, 256, TLS_CURVE_PRIME}, /* brainpool512r1 (28) */
{NID_X25519, 128, TLS_CURVE_CUSTOM}, /* X25519 (29) */
};
static const unsigned char ecformats_default[] = {
TLSEXT_ECPOINTFORMAT_uncompressed,
TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
};
/* The default curves */
static const unsigned char eccurves_default[] = {
0, 29, /* X25519 (29) */
0, 23, /* secp256r1 (23) */
0, 25, /* secp521r1 (25) */
0, 24, /* secp384r1 (24) */
};
static const unsigned char eccurves_all[] = {
0, 29, /* X25519 (29) */
0, 23, /* secp256r1 (23) */
0, 25, /* secp521r1 (25) */
0, 24, /* secp384r1 (24) */
0, 26, /* brainpoolP256r1 (26) */
0, 27, /* brainpoolP384r1 (27) */
0, 28, /* brainpool512r1 (28) */
/*
* Remaining curves disabled by default but still permitted if set
* via an explicit callback or parameters.
*/
0, 22, /* secp256k1 (22) */
0, 14, /* sect571r1 (14) */
0, 13, /* sect571k1 (13) */
0, 11, /* sect409k1 (11) */
0, 12, /* sect409r1 (12) */
0, 9, /* sect283k1 (9) */
0, 10, /* sect283r1 (10) */
0, 20, /* secp224k1 (20) */
0, 21, /* secp224r1 (21) */
0, 18, /* secp192k1 (18) */
0, 19, /* secp192r1 (19) */
0, 15, /* secp160k1 (15) */
0, 16, /* secp160r1 (16) */
0, 17, /* secp160r2 (17) */
0, 8, /* sect239k1 (8) */
0, 6, /* sect233k1 (6) */
0, 7, /* sect233r1 (7) */
0, 4, /* sect193r1 (4) */
0, 5, /* sect193r2 (5) */
0, 1, /* sect163k1 (1) */
0, 2, /* sect163r1 (2) */
0, 3, /* sect163r2 (3) */
};
static const unsigned char suiteb_curves[] = {
0, TLSEXT_curve_P_256,
0, TLSEXT_curve_P_384
};
int tls1_ec_curve_id2nid(int curve_id, unsigned int *pflags)
{
const tls_curve_info *cinfo;
/* ECC curves from RFC 4492 and RFC 7027 */
if ((curve_id < 1) || ((unsigned int)curve_id > OSSL_NELEM(nid_list)))
return 0;
cinfo = nid_list + curve_id - 1;
if (pflags)
*pflags = cinfo->flags;
return cinfo->nid;
}
int tls1_ec_nid2curve_id(int nid)
{
size_t i;
for (i = 0; i < OSSL_NELEM(nid_list); i++) {
if (nid_list[i].nid == nid)
return i + 1;
}
return 0;
}
/*
* Get curves list, if "sess" is set return client curves otherwise
* preferred list.
* Sets |num_curves| to the number of curves in the list, i.e.,
* the length of |pcurves| is 2 * num_curves.
* Returns 1 on success and 0 if the client curves list has invalid format.
* The latter indicates an internal error: we should not be accepting such
* lists in the first place.
* TODO(emilia): we should really be storing the curves list in explicitly
* parsed form instead. (However, this would affect binary compatibility
* so cannot happen in the 1.0.x series.)
*/
static int tls1_get_curvelist(SSL *s, int sess,
const unsigned char **pcurves,
size_t *num_curves)
{
size_t pcurveslen = 0;
if (sess) {
*pcurves = s->session->tlsext_ellipticcurvelist;
pcurveslen = s->session->tlsext_ellipticcurvelist_length;
} else {
/* For Suite B mode only include P-256, P-384 */
switch (tls1_suiteb(s)) {
case SSL_CERT_FLAG_SUITEB_128_LOS:
*pcurves = suiteb_curves;
pcurveslen = sizeof(suiteb_curves);
break;
case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
*pcurves = suiteb_curves;
pcurveslen = 2;
break;
case SSL_CERT_FLAG_SUITEB_192_LOS:
*pcurves = suiteb_curves + 2;
pcurveslen = 2;
break;
default:
*pcurves = s->tlsext_ellipticcurvelist;
pcurveslen = s->tlsext_ellipticcurvelist_length;
}
if (!*pcurves) {
*pcurves = eccurves_default;
pcurveslen = sizeof(eccurves_default);
}
}
/* We do not allow odd length arrays to enter the system. */
if (pcurveslen & 1) {
SSLerr(SSL_F_TLS1_GET_CURVELIST, ERR_R_INTERNAL_ERROR);
*num_curves = 0;
return 0;
} else {
*num_curves = pcurveslen / 2;
return 1;
}
}
/* See if curve is allowed by security callback */
static int tls_curve_allowed(SSL *s, const unsigned char *curve, int op)
{
const tls_curve_info *cinfo;
if (curve[0])
return 1;
if ((curve[1] < 1) || ((size_t)curve[1] > OSSL_NELEM(nid_list)))
return 0;
cinfo = &nid_list[curve[1] - 1];
# ifdef OPENSSL_NO_EC2M
if (cinfo->flags & TLS_CURVE_CHAR2)
return 0;
# endif
return ssl_security(s, op, cinfo->secbits, cinfo->nid, (void *)curve);
}
/* Check a curve is one of our preferences */
int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
{
const unsigned char *curves;
size_t num_curves, i;
unsigned int suiteb_flags = tls1_suiteb(s);
if (len != 3 || p[0] != NAMED_CURVE_TYPE)
return 0;
/* Check curve matches Suite B preferences */
if (suiteb_flags) {
unsigned long cid = s->s3->tmp.new_cipher->id;
if (p[1])
return 0;
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256) {
if (p[2] != TLSEXT_curve_P_256)
return 0;
} else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384) {
if (p[2] != TLSEXT_curve_P_384)
return 0;
} else /* Should never happen */
return 0;
}
if (!tls1_get_curvelist(s, 0, &curves, &num_curves))
return 0;
for (i = 0; i < num_curves; i++, curves += 2) {
if (p[1] == curves[0] && p[2] == curves[1])
return tls_curve_allowed(s, p + 1, SSL_SECOP_CURVE_CHECK);
}
return 0;
}
/*-
* For nmatch >= 0, return the NID of the |nmatch|th shared curve or NID_undef
* if there is no match.
* For nmatch == -1, return number of matches
* For nmatch == -2, return the NID of the curve to use for
* an EC tmp key, or NID_undef if there is no match.
*/
int tls1_shared_curve(SSL *s, int nmatch)
{
const unsigned char *pref, *supp;
size_t num_pref, num_supp, i, j;
int k;
/* Can't do anything on client side */
if (s->server == 0)
return -1;
if (nmatch == -2) {
if (tls1_suiteb(s)) {
/*
* For Suite B ciphersuite determines curve: we already know
* these are acceptable due to previous checks.
*/
unsigned long cid = s->s3->tmp.new_cipher->id;
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
return NID_X9_62_prime256v1; /* P-256 */
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
return NID_secp384r1; /* P-384 */
/* Should never happen */
return NID_undef;
}
/* If not Suite B just return first preference shared curve */
nmatch = 0;
}
/*
* Avoid truncation. tls1_get_curvelist takes an int
* but s->options is a long...
*/
if (!tls1_get_curvelist
(s, (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) != 0, &supp,
&num_supp))
/* In practice, NID_undef == 0 but let's be precise. */
return nmatch == -1 ? 0 : NID_undef;
if (!tls1_get_curvelist
(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE), &pref,
&num_pref))
return nmatch == -1 ? 0 : NID_undef;
/*
* If the client didn't send the elliptic_curves extension all of them
* are allowed.
*/
if (num_supp == 0 && (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) != 0) {
supp = eccurves_all;
num_supp = sizeof(eccurves_all) / 2;
} else if (num_pref == 0 &&
(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) == 0) {
pref = eccurves_all;
num_pref = sizeof(eccurves_all) / 2;
}
k = 0;
for (i = 0; i < num_pref; i++, pref += 2) {
const unsigned char *tsupp = supp;
for (j = 0; j < num_supp; j++, tsupp += 2) {
if (pref[0] == tsupp[0] && pref[1] == tsupp[1]) {
if (!tls_curve_allowed(s, pref, SSL_SECOP_CURVE_SHARED))
continue;
if (nmatch == k) {
int id = (pref[0] << 8) | pref[1];
return tls1_ec_curve_id2nid(id, NULL);
}
k++;
}
}
}
if (nmatch == -1)
return k;
/* Out of range (nmatch > k). */
return NID_undef;
}
int tls1_set_curves(unsigned char **pext, size_t *pextlen,
int *curves, size_t ncurves)
{
unsigned char *clist, *p;
size_t i;
/*
* Bitmap of curves included to detect duplicates: only works while curve
* ids < 32
*/
unsigned long dup_list = 0;
clist = OPENSSL_malloc(ncurves * 2);
if (clist == NULL)
return 0;
for (i = 0, p = clist; i < ncurves; i++) {
unsigned long idmask;
int id;
id = tls1_ec_nid2curve_id(curves[i]);
idmask = 1L << id;
if (!id || (dup_list & idmask)) {
OPENSSL_free(clist);
return 0;
}
dup_list |= idmask;
s2n(id, p);
}
OPENSSL_free(*pext);
*pext = clist;
*pextlen = ncurves * 2;
return 1;
}
# define MAX_CURVELIST 28
typedef struct {
size_t nidcnt;
int nid_arr[MAX_CURVELIST];
} nid_cb_st;
static int nid_cb(const char *elem, int len, void *arg)
{
nid_cb_st *narg = arg;
size_t i;
int nid;
char etmp[20];
if (elem == NULL)
return 0;
if (narg->nidcnt == MAX_CURVELIST)
return 0;
if (len > (int)(sizeof(etmp) - 1))
return 0;
memcpy(etmp, elem, len);
etmp[len] = 0;
nid = EC_curve_nist2nid(etmp);
if (nid == NID_undef)
nid = OBJ_sn2nid(etmp);
if (nid == NID_undef)
nid = OBJ_ln2nid(etmp);
if (nid == NID_undef)
return 0;
for (i = 0; i < narg->nidcnt; i++)
if (narg->nid_arr[i] == nid)
return 0;
narg->nid_arr[narg->nidcnt++] = nid;
return 1;
}
/* Set curves based on a colon separate list */
int tls1_set_curves_list(unsigned char **pext, size_t *pextlen,
const char *str)
{
nid_cb_st ncb;
ncb.nidcnt = 0;
if (!CONF_parse_list(str, ':', 1, nid_cb, &ncb))
return 0;
if (pext == NULL)
return 1;
return tls1_set_curves(pext, pextlen, ncb.nid_arr, ncb.nidcnt);
}
/* For an EC key set TLS id and required compression based on parameters */
static int tls1_set_ec_id(unsigned char *curve_id, unsigned char *comp_id,
EC_KEY *ec)
{
int id;
const EC_GROUP *grp;
if (!ec)
return 0;
/* Determine if it is a prime field */
grp = EC_KEY_get0_group(ec);
if (!grp)
return 0;
/* Determine curve ID */
id = EC_GROUP_get_curve_name(grp);
id = tls1_ec_nid2curve_id(id);
/* If no id return error: we don't support arbitrary explicit curves */
if (id == 0)
return 0;
curve_id[0] = 0;
curve_id[1] = (unsigned char)id;
if (comp_id) {
if (EC_KEY_get0_public_key(ec) == NULL)
return 0;
if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_UNCOMPRESSED) {
*comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
} else {
if ((nid_list[id - 1].flags & TLS_CURVE_TYPE) == TLS_CURVE_PRIME)
*comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
else
*comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
}
}
return 1;
}
/* Check an EC key is compatible with extensions */
static int tls1_check_ec_key(SSL *s,
unsigned char *curve_id, unsigned char *comp_id)
{
const unsigned char *pformats, *pcurves;
size_t num_formats, num_curves, i;
int j;
/*
* If point formats extension present check it, otherwise everything is
* supported (see RFC4492).
*/
if (comp_id && s->session->tlsext_ecpointformatlist) {
pformats = s->session->tlsext_ecpointformatlist;
num_formats = s->session->tlsext_ecpointformatlist_length;
for (i = 0; i < num_formats; i++, pformats++) {
if (*comp_id == *pformats)
break;
}
if (i == num_formats)
return 0;
}
if (!curve_id)
return 1;
/* Check curve is consistent with client and server preferences */
for (j = 0; j <= 1; j++) {
if (!tls1_get_curvelist(s, j, &pcurves, &num_curves))
return 0;
if (j == 1 && num_curves == 0) {
/*
* If we've not received any curves then skip this check.
* RFC 4492 does not require the supported elliptic curves extension
* so if it is not sent we can just choose any curve.
* It is invalid to send an empty list in the elliptic curves
* extension, so num_curves == 0 always means no extension.
*/
break;
}
for (i = 0; i < num_curves; i++, pcurves += 2) {
if (pcurves[0] == curve_id[0] && pcurves[1] == curve_id[1])
break;
}
if (i == num_curves)
return 0;
/* For clients can only check sent curve list */
if (!s->server)
break;
}
return 1;
}
static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
size_t *num_formats)
{
/*
* If we have a custom point format list use it otherwise use default
*/
if (s->tlsext_ecpointformatlist) {
*pformats = s->tlsext_ecpointformatlist;
*num_formats = s->tlsext_ecpointformatlist_length;
} else {
*pformats = ecformats_default;
/* For Suite B we don't support char2 fields */
if (tls1_suiteb(s))
*num_formats = sizeof(ecformats_default) - 1;
else
*num_formats = sizeof(ecformats_default);
}
}
/*
* Check cert parameters compatible with extensions: currently just checks EC
* certificates have compatible curves and compression.
*/
static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
{
unsigned char comp_id, curve_id[2];
EVP_PKEY *pkey;
int rv;
pkey = X509_get0_pubkey(x);
if (!pkey)
return 0;
/* If not EC nothing to do */
if (EVP_PKEY_id(pkey) != EVP_PKEY_EC)
return 1;
rv = tls1_set_ec_id(curve_id, &comp_id, EVP_PKEY_get0_EC_KEY(pkey));
if (!rv)
return 0;
/*
* Can't check curve_id for client certs as we don't have a supported
* curves extension.
*/
rv = tls1_check_ec_key(s, s->server ? curve_id : NULL, &comp_id);
if (!rv)
return 0;
/*
* Special case for suite B. We *MUST* sign using SHA256+P-256 or
* SHA384+P-384, adjust digest if necessary.
*/
if (set_ee_md && tls1_suiteb(s)) {
int check_md;
size_t i;
CERT *c = s->cert;
if (curve_id[0])
return 0;
/* Check to see we have necessary signing algorithm */
if (curve_id[1] == TLSEXT_curve_P_256)
check_md = NID_ecdsa_with_SHA256;
else if (curve_id[1] == TLSEXT_curve_P_384)
check_md = NID_ecdsa_with_SHA384;
else
return 0; /* Should never happen */
for (i = 0; i < c->shared_sigalgslen; i++)
if (check_md == c->shared_sigalgs[i].signandhash_nid)
break;
if (i == c->shared_sigalgslen)
return 0;
if (set_ee_md == 2) {
if (check_md == NID_ecdsa_with_SHA256)
s->s3->tmp.md[SSL_PKEY_ECC] = EVP_sha256();
else
s->s3->tmp.md[SSL_PKEY_ECC] = EVP_sha384();
}
}
return rv;
}
# ifndef OPENSSL_NO_EC
/*
* tls1_check_ec_tmp_key - Check EC temporary key compatibility
* @s: SSL connection
* @cid: Cipher ID we're considering using
*
* Checks that the kECDHE cipher suite we're considering using
* is compatible with the client extensions.
*
* Returns 0 when the cipher can't be used or 1 when it can.
*/
int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
{
/*
* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384, no other
* curves permitted.
*/
if (tls1_suiteb(s)) {
unsigned char curve_id[2];
/* Curve to check determined by ciphersuite */
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
curve_id[1] = TLSEXT_curve_P_256;
else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
curve_id[1] = TLSEXT_curve_P_384;
else
return 0;
curve_id[0] = 0;
/* Check this curve is acceptable */
if (!tls1_check_ec_key(s, curve_id, NULL))
return 0;
return 1;
}
/* Need a shared curve */
if (tls1_shared_curve(s, 0))
return 1;
return 0;
}
# endif /* OPENSSL_NO_EC */
#else
static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
{
return 1;
}
#endif /* OPENSSL_NO_EC */
/*
* List of supported signature algorithms and hashes. Should make this
* customisable at some point, for now include everything we support.
*/
#ifdef OPENSSL_NO_RSA
# define tlsext_sigalg_rsa(md) /* */
#else
# define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
#endif
#ifdef OPENSSL_NO_DSA
# define tlsext_sigalg_dsa(md) /* */
#else
# define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
#endif
#ifdef OPENSSL_NO_EC
# define tlsext_sigalg_ecdsa(md) /* */
#else
# define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
#endif
#define tlsext_sigalg(md) \
tlsext_sigalg_rsa(md) \
tlsext_sigalg_dsa(md) \
tlsext_sigalg_ecdsa(md)
static const unsigned char tls12_sigalgs[] = {
tlsext_sigalg(TLSEXT_hash_sha512)
tlsext_sigalg(TLSEXT_hash_sha384)
tlsext_sigalg(TLSEXT_hash_sha256)
tlsext_sigalg(TLSEXT_hash_sha224)
tlsext_sigalg(TLSEXT_hash_sha1)
#ifndef OPENSSL_NO_GOST
TLSEXT_hash_gostr3411, TLSEXT_signature_gostr34102001,
TLSEXT_hash_gostr34112012_256, TLSEXT_signature_gostr34102012_256,
TLSEXT_hash_gostr34112012_512, TLSEXT_signature_gostr34102012_512
#endif
};
#ifndef OPENSSL_NO_EC
static const unsigned char suiteb_sigalgs[] = {
tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
};
#endif
size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
{
/*
* If Suite B mode use Suite B sigalgs only, ignore any other
* preferences.
*/
#ifndef OPENSSL_NO_EC
switch (tls1_suiteb(s)) {
case SSL_CERT_FLAG_SUITEB_128_LOS:
*psigs = suiteb_sigalgs;
return sizeof(suiteb_sigalgs);
case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
*psigs = suiteb_sigalgs;
return 2;
case SSL_CERT_FLAG_SUITEB_192_LOS:
*psigs = suiteb_sigalgs + 2;
return 2;
}
#endif
/* If server use client authentication sigalgs if not NULL */
if (s->server && s->cert->client_sigalgs) {
*psigs = s->cert->client_sigalgs;
return s->cert->client_sigalgslen;
} else if (s->cert->conf_sigalgs) {
*psigs = s->cert->conf_sigalgs;
return s->cert->conf_sigalgslen;
} else {
*psigs = tls12_sigalgs;
return sizeof(tls12_sigalgs);
}
}
/*
* Check signature algorithm is consistent with sent supported signature
* algorithms and if so return relevant digest.
*/
int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
const unsigned char *sig, EVP_PKEY *pkey)
{
const unsigned char *sent_sigs;
size_t sent_sigslen, i;
int sigalg = tls12_get_sigid(pkey);
/* Should never happen */
if (sigalg == -1)
return -1;
/* Check key type is consistent with signature */
if (sigalg != (int)sig[1]) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
}
#ifndef OPENSSL_NO_EC
if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
unsigned char curve_id[2], comp_id;
/* Check compression and curve matches extensions */
if (!tls1_set_ec_id(curve_id, &comp_id, EVP_PKEY_get0_EC_KEY(pkey)))
return 0;
if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id)) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_CURVE);
return 0;
}
/* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
if (tls1_suiteb(s)) {
if (curve_id[0])
return 0;
if (curve_id[1] == TLSEXT_curve_P_256) {
if (sig[0] != TLSEXT_hash_sha256) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
SSL_R_ILLEGAL_SUITEB_DIGEST);
return 0;
}
} else if (curve_id[1] == TLSEXT_curve_P_384) {
if (sig[0] != TLSEXT_hash_sha384) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
SSL_R_ILLEGAL_SUITEB_DIGEST);
return 0;
}
} else
return 0;
}
} else if (tls1_suiteb(s))
return 0;
#endif
/* Check signature matches a type we sent */
sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
for (i = 0; i < sent_sigslen; i += 2, sent_sigs += 2) {
if (sig[0] == sent_sigs[0] && sig[1] == sent_sigs[1])
break;
}
/* Allow fallback to SHA1 if not strict mode */
if (i == sent_sigslen
&& (sig[0] != TLSEXT_hash_sha1
|| s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
}
*pmd = tls12_get_hash(sig[0]);
if (*pmd == NULL) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_UNKNOWN_DIGEST);
return 0;
}
/* Make sure security callback allows algorithm */
if (!ssl_security(s, SSL_SECOP_SIGALG_CHECK,
EVP_MD_size(*pmd) * 4, EVP_MD_type(*pmd),
(void *)sig)) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
}
/*
* Store the digest used so applications can retrieve it if they wish.
*/
s->s3->tmp.peer_md = *pmd;
return 1;
}
/*
* Set a mask of disabled algorithms: an algorithm is disabled if it isn't
* supported, doesn't appear in supported signature algorithms, isn't supported
* by the enabled protocol versions or by the security level.
*
* This function should only be used for checking which ciphers are supported
* by the client.
*
* Call ssl_cipher_disabled() to check that it's enabled or not.
*/
void ssl_set_client_disabled(SSL *s)
{
s->s3->tmp.mask_a = 0;
s->s3->tmp.mask_k = 0;
ssl_set_sig_mask(&s->s3->tmp.mask_a, s, SSL_SECOP_SIGALG_MASK);
ssl_get_client_min_max_version(s, &s->s3->tmp.min_ver, &s->s3->tmp.max_ver);
# ifndef OPENSSL_NO_PSK
/* with PSK there must be client callback set */
if (!s->psk_client_callback) {
s->s3->tmp.mask_a |= SSL_aPSK;
s->s3->tmp.mask_k |= SSL_PSK;
}
#endif /* OPENSSL_NO_PSK */
#ifndef OPENSSL_NO_SRP
if (!(s->srp_ctx.srp_Mask & SSL_kSRP)) {
s->s3->tmp.mask_a |= SSL_aSRP;
s->s3->tmp.mask_k |= SSL_kSRP;
}
#endif
}
/*
* ssl_cipher_disabled - check that a cipher is disabled or not
* @s: SSL connection that you want to use the cipher on
* @c: cipher to check
* @op: Security check that you want to do
*
* Returns 1 when it's disabled, 0 when enabled.
*/
int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op)
{
if (c->algorithm_mkey & s->s3->tmp.mask_k
|| c->algorithm_auth & s->s3->tmp.mask_a)
return 1;
if (s->s3->tmp.max_ver == 0)
return 1;
if (!SSL_IS_DTLS(s) && ((c->min_tls > s->s3->tmp.max_ver)
|| (c->max_tls < s->s3->tmp.min_ver)))
return 1;
if (SSL_IS_DTLS(s) && (DTLS_VERSION_GT(c->min_dtls, s->s3->tmp.max_ver)
|| DTLS_VERSION_LT(c->max_dtls, s->s3->tmp.min_ver)))
return 1;
return !ssl_security(s, op, c->strength_bits, 0, (void *)c);
}
static int tls_use_ticket(SSL *s)
{
if (s->options & SSL_OP_NO_TICKET)
return 0;
return ssl_security(s, SSL_SECOP_TICKET, 0, 0, NULL);
}
static int compare_uint(const void *p1, const void *p2) {
unsigned int u1 = *((const unsigned int *)p1);
unsigned int u2 = *((const unsigned int *)p2);
if (u1 < u2)
return -1;
else if (u1 > u2)
return 1;
else
return 0;
}
/*
* Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
* more than one extension of the same type in a ClientHello or ServerHello.
* This function does an initial scan over the extensions block to filter those
* out. It returns 1 if all extensions are unique, and 0 if the extensions
* contain duplicates, could not be successfully parsed, or an internal error
* occurred.
*/
static int tls1_check_duplicate_extensions(const PACKET *packet) {
PACKET extensions = *packet;
size_t num_extensions = 0, i = 0;
unsigned int *extension_types = NULL;
int ret = 0;
/* First pass: count the extensions. */
while (PACKET_remaining(&extensions) > 0) {
unsigned int type;
PACKET extension;
if (!PACKET_get_net_2(&extensions, &type) ||
!PACKET_get_length_prefixed_2(&extensions, &extension)) {
goto done;
}
num_extensions++;
}
if (num_extensions <= 1)
return 1;
extension_types = OPENSSL_malloc(sizeof(unsigned int) * num_extensions);
if (extension_types == NULL) {
SSLerr(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS, ERR_R_MALLOC_FAILURE);
goto done;
}
/* Second pass: gather the extension types. */
extensions = *packet;
for (i = 0; i < num_extensions; i++) {
PACKET extension;
if (!PACKET_get_net_2(&extensions, &extension_types[i]) ||
!PACKET_get_length_prefixed_2(&extensions, &extension)) {
/* This should not happen. */
SSLerr(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS, ERR_R_INTERNAL_ERROR);
goto done;
}
}
if (PACKET_remaining(&extensions) != 0) {
SSLerr(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS, ERR_R_INTERNAL_ERROR);
goto done;
}
/* Sort the extensions and make sure there are no duplicates. */
qsort(extension_types, num_extensions, sizeof(unsigned int), compare_uint);
for (i = 1; i < num_extensions; i++) {
if (extension_types[i - 1] == extension_types[i])
goto done;
}
ret = 1;
done:
OPENSSL_free(extension_types);
return ret;
}
unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf,
unsigned char *limit, int *al)
{
int extdatalen = 0;
unsigned char *orig = buf;
unsigned char *ret = buf;
#ifndef OPENSSL_NO_EC
/* See if we support any ECC ciphersuites */
int using_ecc = 0;
if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s)) {
int i;
unsigned long alg_k, alg_a;
STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++) {
const SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
alg_k = c->algorithm_mkey;
alg_a = c->algorithm_auth;
if ((alg_k & (SSL_kECDHE | SSL_kECDHEPSK))
|| (alg_a & SSL_aECDSA)) {
using_ecc = 1;
break;
}
}
}
#endif
ret += 2;
if (ret >= limit)
return NULL; /* this really never occurs, but ... */
/* Add RI if renegotiating */
if (s->renegotiate) {
int el;
if (!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_renegotiate, ret);
s2n(el, ret);
if (!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
/* Only add RI for SSLv3 */
if (s->client_version == SSL3_VERSION)
goto done;
if (s->tlsext_hostname != NULL) {
/* Add TLS extension servername to the Client Hello message */
unsigned long size_str;
long lenmax;
/*-
* check for enough space.
* 4 for the servername type and extension length
* 2 for servernamelist length
* 1 for the hostname type
* 2 for hostname length
* + hostname length
*/
if ((lenmax = limit - ret - 9) < 0
|| (size_str =
strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
return NULL;
/* extension type and length */
s2n(TLSEXT_TYPE_server_name, ret);
s2n(size_str + 5, ret);
/* length of servername list */
s2n(size_str + 3, ret);
/* hostname type, length and hostname */
*(ret++) = (unsigned char)TLSEXT_NAMETYPE_host_name;
s2n(size_str, ret);
memcpy(ret, s->tlsext_hostname, size_str);
ret += size_str;
}
#ifndef OPENSSL_NO_SRP
/* Add SRP username if there is one */
if (s->srp_ctx.login != NULL) { /* Add TLS extension SRP username to the
* Client Hello message */
int login_len = strlen(s->srp_ctx.login);
if (login_len > 255 || login_len == 0) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
/*-
* check for enough space.
* 4 for the srp type type and extension length
* 1 for the srp user identity
* + srp user identity length
*/
if ((limit - ret - 5 - login_len) < 0)
return NULL;
/* fill in the extension */
s2n(TLSEXT_TYPE_srp, ret);
s2n(login_len + 1, ret);
(*ret++) = (unsigned char)login_len;
memcpy(ret, s->srp_ctx.login, login_len);
ret += login_len;
}
#endif
#ifndef OPENSSL_NO_EC
if (using_ecc) {
/*
* Add TLS extension ECPointFormats to the ClientHello message
*/
long lenmax;
const unsigned char *pcurves, *pformats;
size_t num_curves, num_formats, curves_list_len;
size_t i;
unsigned char *etmp;
tls1_get_formatlist(s, &pformats, &num_formats);
if ((lenmax = limit - ret - 5) < 0)
return NULL;
if (num_formats > (size_t)lenmax)
return NULL;
if (num_formats > 255) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats, ret);
/* The point format list has 1-byte length. */
s2n(num_formats + 1, ret);
*(ret++) = (unsigned char)num_formats;
memcpy(ret, pformats, num_formats);
ret += num_formats;
/*
* Add TLS extension EllipticCurves to the ClientHello message
*/
pcurves = s->tlsext_ellipticcurvelist;
if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves))
return NULL;
if ((lenmax = limit - ret - 6) < 0)
return NULL;
if (num_curves > (size_t)lenmax / 2)
return NULL;
if (num_curves > 65532 / 2) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_elliptic_curves, ret);
etmp = ret + 4;
/* Copy curve ID if supported */
for (i = 0; i < num_curves; i++, pcurves += 2) {
if (tls_curve_allowed(s, pcurves, SSL_SECOP_CURVE_SUPPORTED)) {
*etmp++ = pcurves[0];
*etmp++ = pcurves[1];
}
}
curves_list_len = etmp - ret - 4;
s2n(curves_list_len + 2, ret);
s2n(curves_list_len, ret);
ret += curves_list_len;
}
#endif /* OPENSSL_NO_EC */
if (tls_use_ticket(s)) {
int ticklen;
if (!s->new_session && s->session && s->session->tlsext_tick)
ticklen = s->session->tlsext_ticklen;
else if (s->session && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data) {
ticklen = s->tlsext_session_ticket->length;
s->session->tlsext_tick = OPENSSL_malloc(ticklen);
if (s->session->tlsext_tick == NULL)
return NULL;
memcpy(s->session->tlsext_tick,
s->tlsext_session_ticket->data, ticklen);
s->session->tlsext_ticklen = ticklen;
} else
ticklen = 0;
if (ticklen == 0 && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data == NULL)
goto skip_ext;
/*
* Check for enough room 2 for extension type, 2 for len rest for
* ticket
*/
if ((long)(limit - ret - 4 - ticklen) < 0)
return NULL;
s2n(TLSEXT_TYPE_session_ticket, ret);
s2n(ticklen, ret);
if (ticklen) {
memcpy(ret, s->session->tlsext_tick, ticklen);
ret += ticklen;
}
}
skip_ext:
if (SSL_CLIENT_USE_SIGALGS(s)) {
size_t salglen;
const unsigned char *salg;
unsigned char *etmp;
salglen = tls12_get_psigalgs(s, &salg);
if ((size_t)(limit - ret) < salglen + 6)
return NULL;
s2n(TLSEXT_TYPE_signature_algorithms, ret);
etmp = ret;
/* Skip over lengths for now */
ret += 4;
salglen = tls12_copy_sigalgs(s, ret, salg, salglen);
/* Fill in lengths */
s2n(salglen + 2, etmp);
s2n(salglen, etmp);
ret += salglen;
}
#ifndef OPENSSL_NO_OCSP
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
int i;
long extlen, idlen, itmp;
OCSP_RESPID *id;
idlen = 0;
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++) {
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
itmp = i2d_OCSP_RESPID(id, NULL);
if (itmp <= 0)
return NULL;
idlen += itmp + 2;
}
if (s->tlsext_ocsp_exts) {
extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
if (extlen < 0)
return NULL;
} else
extlen = 0;
if ((long)(limit - ret - 7 - extlen - idlen) < 0)
return NULL;
s2n(TLSEXT_TYPE_status_request, ret);
if (extlen + idlen > 0xFFF0)
return NULL;
s2n(extlen + idlen + 5, ret);
*(ret++) = TLSEXT_STATUSTYPE_ocsp;
s2n(idlen, ret);
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++) {
/* save position of id len */
unsigned char *q = ret;
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
/* skip over id len */
ret += 2;
itmp = i2d_OCSP_RESPID(id, &ret);
/* write id len */
s2n(itmp, q);
}
s2n(extlen, ret);
if (extlen > 0)
i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
}
#endif
#ifndef OPENSSL_NO_HEARTBEATS
if (SSL_IS_DTLS(s)) {
/* Add Heartbeat extension */
if ((limit - ret - 4 - 1) < 0)
return NULL;
s2n(TLSEXT_TYPE_heartbeat, ret);
s2n(1, ret);
/*-
* Set mode:
* 1: peer may send requests
* 2: peer not allowed to send requests
*/
if (s->tlsext_heartbeat & SSL_DTLSEXT_HB_DONT_RECV_REQUESTS)
*(ret++) = SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
else
*(ret++) = SSL_DTLSEXT_HB_ENABLED;
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len) {
/*
* The client advertises an empty extension to indicate its support
* for Next Protocol Negotiation
*/
if (limit - ret - 4 < 0)
return NULL;
s2n(TLSEXT_TYPE_next_proto_neg, ret);
s2n(0, ret);
}
#endif
/*
* finish_md_len is non-zero during a renegotiation, so
* this avoids sending ALPN during the renegotiation
* (see longer comment below)
*/
if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len) {
if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len)
return NULL;
s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret);
s2n(2 + s->alpn_client_proto_list_len, ret);
s2n(s->alpn_client_proto_list_len, ret);
memcpy(ret, s->alpn_client_proto_list, s->alpn_client_proto_list_len);
ret += s->alpn_client_proto_list_len;
s->s3->alpn_sent = 1;
}
#ifndef OPENSSL_NO_SRTP
if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)) {
int el;
/* Returns 0 on success!! */
if (ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_use_srtp, ret);
s2n(el, ret);
if (ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
#endif
custom_ext_init(&s->cert->cli_ext);
/* Add custom TLS Extensions to ClientHello */
if (!custom_ext_add(s, 0, &ret, limit, al))
return NULL;
s2n(TLSEXT_TYPE_encrypt_then_mac, ret);
s2n(0, ret);
#ifndef OPENSSL_NO_CT
if (s->ct_validation_callback != NULL) {
s2n(TLSEXT_TYPE_signed_certificate_timestamp, ret);
s2n(0, ret);
}
#endif
s2n(TLSEXT_TYPE_extended_master_secret, ret);
s2n(0, ret);
/*
* Add padding to workaround bugs in F5 terminators. See
* https://tools.ietf.org/html/draft-agl-tls-padding-03 NB: because this
* code works out the length of all existing extensions it MUST always
* appear last.
*/
if (s->options & SSL_OP_TLSEXT_PADDING) {
int hlen = ret - (unsigned char *)s->init_buf->data;
if (hlen > 0xff && hlen < 0x200) {
hlen = 0x200 - hlen;
if (hlen >= 4)
hlen -= 4;
else
hlen = 0;
s2n(TLSEXT_TYPE_padding, ret);
s2n(hlen, ret);
memset(ret, 0, hlen);
ret += hlen;
}
}
done:
if ((extdatalen = ret - orig - 2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf,
unsigned char *limit, int *al)
{
int extdatalen = 0;
unsigned char *orig = buf;
unsigned char *ret = buf;
#ifndef OPENSSL_NO_NEXTPROTONEG
int next_proto_neg_seen;
#endif
#ifndef OPENSSL_NO_EC
unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
int using_ecc = (alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA);
using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
#endif
ret += 2;
if (ret >= limit)
return NULL; /* this really never occurs, but ... */
if (s->s3->send_connection_binding) {
int el;
if (!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_renegotiate, ret);
s2n(el, ret);
if (!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
/* Only add RI for SSLv3 */
if (s->version == SSL3_VERSION)
goto done;
if (!s->hit && s->servername_done == 1
&& s->session->tlsext_hostname != NULL) {
if ((long)(limit - ret - 4) < 0)
return NULL;
s2n(TLSEXT_TYPE_server_name, ret);
s2n(0, ret);
}
#ifndef OPENSSL_NO_EC
if (using_ecc) {
const unsigned char *plist;
size_t plistlen;
/*
* Add TLS extension ECPointFormats to the ServerHello message
*/
long lenmax;
tls1_get_formatlist(s, &plist, &plistlen);
if ((lenmax = limit - ret - 5) < 0)
return NULL;
if (plistlen > (size_t)lenmax)
return NULL;
if (plistlen > 255) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats, ret);
s2n(plistlen + 1, ret);
*(ret++) = (unsigned char)plistlen;
memcpy(ret, plist, plistlen);
ret += plistlen;
}
/*
* Currently the server should not respond with a SupportedCurves
* extension
*/
#endif /* OPENSSL_NO_EC */
if (s->tlsext_ticket_expected && tls_use_ticket(s)) {
if ((long)(limit - ret - 4) < 0)
return NULL;
s2n(TLSEXT_TYPE_session_ticket, ret);
s2n(0, ret);
} else {
/* if we don't add the above TLSEXT, we can't add a session ticket later */
s->tlsext_ticket_expected = 0;
}
if (s->tlsext_status_expected) {
if ((long)(limit - ret - 4) < 0)
return NULL;
s2n(TLSEXT_TYPE_status_request, ret);
s2n(0, ret);
}
#ifndef OPENSSL_NO_SRTP
if (SSL_IS_DTLS(s) && s->srtp_profile) {
int el;
/* Returns 0 on success!! */
if (ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_use_srtp, ret);
s2n(el, ret);
if (ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
#endif
if (((s->s3->tmp.new_cipher->id & 0xFFFF) == 0x80
|| (s->s3->tmp.new_cipher->id & 0xFFFF) == 0x81)
&& (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG)) {
const unsigned char cryptopro_ext[36] = {
0xfd, 0xe8, /* 65000 */
0x00, 0x20, /* 32 bytes length */
0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17
};
if (limit - ret < 36)
return NULL;
memcpy(ret, cryptopro_ext, 36);
ret += 36;
}
#ifndef OPENSSL_NO_HEARTBEATS
/* Add Heartbeat extension if we've received one */
if (SSL_IS_DTLS(s) && (s->tlsext_heartbeat & SSL_DTLSEXT_HB_ENABLED)) {
if ((limit - ret - 4 - 1) < 0)
return NULL;
s2n(TLSEXT_TYPE_heartbeat, ret);
s2n(1, ret);
/*-
* Set mode:
* 1: peer may send requests
* 2: peer not allowed to send requests
*/
if (s->tlsext_heartbeat & SSL_DTLSEXT_HB_DONT_RECV_REQUESTS)
*(ret++) = SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
else
*(ret++) = SSL_DTLSEXT_HB_ENABLED;
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
next_proto_neg_seen = s->s3->next_proto_neg_seen;
s->s3->next_proto_neg_seen = 0;
if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb) {
const unsigned char *npa;
unsigned int npalen;
int r;
r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen,
s->
ctx->next_protos_advertised_cb_arg);
if (r == SSL_TLSEXT_ERR_OK) {
if ((long)(limit - ret - 4 - npalen) < 0)
return NULL;
s2n(TLSEXT_TYPE_next_proto_neg, ret);
s2n(npalen, ret);
memcpy(ret, npa, npalen);
ret += npalen;
s->s3->next_proto_neg_seen = 1;
}
}
#endif
if (!custom_ext_add(s, 1, &ret, limit, al))
return NULL;
if (s->s3->flags & TLS1_FLAGS_ENCRYPT_THEN_MAC) {
/*
* Don't use encrypt_then_mac if AEAD or RC4 might want to disable
* for other cases too.
*/
if (s->s3->tmp.new_cipher->algorithm_mac == SSL_AEAD
|| s->s3->tmp.new_cipher->algorithm_enc == SSL_RC4
|| s->s3->tmp.new_cipher->algorithm_enc == SSL_eGOST2814789CNT
|| s->s3->tmp.new_cipher->algorithm_enc == SSL_eGOST2814789CNT12)
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
else {
s2n(TLSEXT_TYPE_encrypt_then_mac, ret);
s2n(0, ret);
}
}
if (s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) {
s2n(TLSEXT_TYPE_extended_master_secret, ret);
s2n(0, ret);
}
if (s->s3->alpn_selected != NULL) {
const unsigned char *selected = s->s3->alpn_selected;
unsigned int len = s->s3->alpn_selected_len;
if ((long)(limit - ret - 4 - 2 - 1 - len) < 0)
return NULL;
s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret);
s2n(3 + len, ret);
s2n(1 + len, ret);
*ret++ = len;
memcpy(ret, selected, len);
ret += len;
}
done:
if ((extdatalen = ret - orig - 2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
/*
* Save the ALPN extension in a ClientHello.
* pkt: the contents of the ALPN extension, not including type and length.
* al: a pointer to the alert value to send in the event of a failure.
* returns: 1 on success, 0 on error.
*/
static int tls1_alpn_handle_client_hello(SSL *s, PACKET *pkt, int *al)
{
PACKET protocol_list, save_protocol_list, protocol;
*al = SSL_AD_DECODE_ERROR;
if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
|| PACKET_remaining(&protocol_list) < 2) {
return 0;
}
save_protocol_list = protocol_list;
do {
/* Protocol names can't be empty. */
if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
|| PACKET_remaining(&protocol) == 0) {
return 0;
}
} while (PACKET_remaining(&protocol_list) != 0);
if (!PACKET_memdup(&save_protocol_list,
&s->s3->alpn_proposed,
&s->s3->alpn_proposed_len)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
/*
* Process the ALPN extension in a ClientHello.
* al: a pointer to the alert value to send in the event of a failure.
* returns 1 on success, 0 on error.
*/
static int tls1_alpn_handle_client_hello_late(SSL *s, int *al)
{
const unsigned char *selected = NULL;
unsigned char selected_len = 0;
if (s->ctx->alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
int r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
s->s3->alpn_proposed,
s->s3->alpn_proposed_len,
s->ctx->alpn_select_cb_arg);
if (r == SSL_TLSEXT_ERR_OK) {
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
if (s->s3->alpn_selected == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
s->s3->alpn_selected_len = selected_len;
#ifndef OPENSSL_NO_NEXTPROTONEG
/* ALPN takes precedence over NPN. */
s->s3->next_proto_neg_seen = 0;
#endif
} else {
*al = SSL_AD_NO_APPLICATION_PROTOCOL;
return 0;
}
}
return 1;
}
#ifndef OPENSSL_NO_EC
/*-
* ssl_check_for_safari attempts to fingerprint Safari using OS X
* SecureTransport using the TLS extension block in |pkt|.
* Safari, since 10.6, sends exactly these extensions, in this order:
* SNI,
* elliptic_curves
* ec_point_formats
*
* We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
* but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
* Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
* 10.8..10.8.3 (which don't work).
*/
static void ssl_check_for_safari(SSL *s, const PACKET *pkt)
{
unsigned int type;
PACKET sni, tmppkt;
size_t ext_len;
static const unsigned char kSafariExtensionsBlock[] = {
0x00, 0x0a, /* elliptic_curves extension */
0x00, 0x08, /* 8 bytes */
0x00, 0x06, /* 6 bytes of curve ids */
0x00, 0x17, /* P-256 */
0x00, 0x18, /* P-384 */
0x00, 0x19, /* P-521 */
0x00, 0x0b, /* ec_point_formats */
0x00, 0x02, /* 2 bytes */
0x01, /* 1 point format */
0x00, /* uncompressed */
/* The following is only present in TLS 1.2 */
0x00, 0x0d, /* signature_algorithms */
0x00, 0x0c, /* 12 bytes */
0x00, 0x0a, /* 10 bytes */
0x05, 0x01, /* SHA-384/RSA */
0x04, 0x01, /* SHA-256/RSA */
0x02, 0x01, /* SHA-1/RSA */
0x04, 0x03, /* SHA-256/ECDSA */
0x02, 0x03, /* SHA-1/ECDSA */
};
/* Length of the common prefix (first two extensions). */
static const size_t kSafariCommonExtensionsLength = 18;
tmppkt = *pkt;
if (!PACKET_forward(&tmppkt, 2)
|| !PACKET_get_net_2(&tmppkt, &type)
|| !PACKET_get_length_prefixed_2(&tmppkt, &sni)) {
return;
}
if (type != TLSEXT_TYPE_server_name)
return;
ext_len = TLS1_get_client_version(s) >= TLS1_2_VERSION ?
sizeof(kSafariExtensionsBlock) : kSafariCommonExtensionsLength;
s->s3->is_probably_safari = PACKET_equal(&tmppkt, kSafariExtensionsBlock,
ext_len);
}
#endif /* !OPENSSL_NO_EC */
/*
* Parse ClientHello extensions and stash extension info in various parts of
* the SSL object. Verify that there are no duplicate extensions.
*
* Behaviour upon resumption is extension-specific. If the extension has no
* effect during resumption, it is parsed (to verify its format) but otherwise
* ignored.
*
* Consumes the entire packet in |pkt|. Returns 1 on success and 0 on failure.
* Upon failure, sets |al| to the appropriate alert.
*/
static int ssl_scan_clienthello_tlsext(SSL *s, PACKET *pkt, int *al)
{
unsigned int type;
int renegotiate_seen = 0;
PACKET extensions;
*al = SSL_AD_DECODE_ERROR;
s->servername_done = 0;
s->tlsext_status_type = -1;
#ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
#endif
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = NULL;
s->s3->alpn_selected_len = 0;
OPENSSL_free(s->s3->alpn_proposed);
s->s3->alpn_proposed = NULL;
s->s3->alpn_proposed_len = 0;
#ifndef OPENSSL_NO_HEARTBEATS
s->tlsext_heartbeat &= ~(SSL_DTLSEXT_HB_ENABLED |
SSL_DTLSEXT_HB_DONT_SEND_REQUESTS);
#endif
#ifndef OPENSSL_NO_EC
if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
ssl_check_for_safari(s, pkt);
# endif /* !OPENSSL_NO_EC */
/* Clear any signature algorithms extension received */
OPENSSL_free(s->s3->tmp.peer_sigalgs);
s->s3->tmp.peer_sigalgs = NULL;
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
#ifndef OPENSSL_NO_SRP
OPENSSL_free(s->srp_ctx.login);
s->srp_ctx.login = NULL;
#endif
s->srtp_profile = NULL;
if (PACKET_remaining(pkt) == 0)
goto ri_check;
if (!PACKET_as_length_prefixed_2(pkt, &extensions))
return 0;
if (!tls1_check_duplicate_extensions(&extensions))
return 0;
/*
* We parse all extensions to ensure the ClientHello is well-formed but,
* unless an extension specifies otherwise, we ignore extensions upon
* resumption.
*/
while (PACKET_get_net_2(&extensions, &type)) {
PACKET extension;
if (!PACKET_get_length_prefixed_2(&extensions, &extension))
return 0;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 0, type, PACKET_data(&extension),
PACKET_remaining(&extension),
s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_renegotiate) {
if (!ssl_parse_clienthello_renegotiate_ext(s, &extension, al))
return 0;
renegotiate_seen = 1;
} else if (s->version == SSL3_VERSION) {
}
/*-
* The servername extension is treated as follows:
*
* - Only the hostname type is supported with a maximum length of 255.
* - The servername is rejected if too long or if it contains zeros,
* in which case an fatal alert is generated.
* - The servername field is maintained together with the session cache.
* - When a session is resumed, the servername call back invoked in order
* to allow the application to position itself to the right context.
* - The servername is acknowledged if it is new for a session or when
* it is identical to a previously used for the same session.
* Applications can control the behaviour. They can at any time
* set a 'desirable' servername for a new SSL object. This can be the
* case for example with HTTPS when a Host: header field is received and
* a renegotiation is requested. In this case, a possible servername
* presented in the new client hello is only acknowledged if it matches
* the value of the Host: field.
* - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
* if they provide for changing an explicit servername context for the
* session, i.e. when the session has been established with a servername
* extension.
* - On session reconnect, the servername extension may be absent.
*
*/
else if (type == TLSEXT_TYPE_server_name) {
unsigned int servname_type;
PACKET sni, hostname;
if (!PACKET_as_length_prefixed_2(&extension, &sni)
/* ServerNameList must be at least 1 byte long. */
|| PACKET_remaining(&sni) == 0) {
return 0;
}
/*
* Although the server_name extension was intended to be
* extensible to new name types, RFC 4366 defined the
* syntax inextensibility and OpenSSL 1.0.x parses it as
* such.
* RFC 6066 corrected the mistake but adding new name types
* is nevertheless no longer feasible, so act as if no other
* SNI types can exist, to simplify parsing.
*
* Also note that the RFC permits only one SNI value per type,
* i.e., we can only have a single hostname.
*/
if (!PACKET_get_1(&sni, &servname_type)
|| servname_type != TLSEXT_NAMETYPE_host_name
|| !PACKET_as_length_prefixed_2(&sni, &hostname)) {
return 0;
}
if (!s->hit) {
if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (PACKET_contains_zero_byte(&hostname)) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->servername_done = 1;
} else {
/*
* TODO(openssl-team): if the SNI doesn't match, we MUST
* fall back to a full handshake.
*/
s->servername_done = s->session->tlsext_hostname
&& PACKET_equal(&hostname, s->session->tlsext_hostname,
strlen(s->session->tlsext_hostname));
}
}
#ifndef OPENSSL_NO_SRP
else if (type == TLSEXT_TYPE_srp) {
PACKET srp_I;
if (!PACKET_as_length_prefixed_1(&extension, &srp_I))
return 0;
if (PACKET_contains_zero_byte(&srp_I))
return 0;
/*
* TODO(openssl-team): currently, we re-authenticate the user
* upon resumption. Instead, we MUST ignore the login.
*/
if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
#endif
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats) {
PACKET ec_point_format_list;
if (!PACKET_as_length_prefixed_1(&extension,
&ec_point_format_list)
|| PACKET_remaining(&ec_point_format_list) == 0) {
return 0;
}
if (!s->hit) {
if (!PACKET_memdup(&ec_point_format_list,
&s->session->tlsext_ecpointformatlist,
&s->session->tlsext_ecpointformatlist_length)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
} else if (type == TLSEXT_TYPE_elliptic_curves) {
PACKET elliptic_curve_list;
/* Each NamedCurve is 2 bytes and we must have at least 1. */
if (!PACKET_as_length_prefixed_2(&extension,
&elliptic_curve_list)
|| PACKET_remaining(&elliptic_curve_list) == 0
|| (PACKET_remaining(&elliptic_curve_list) % 2) != 0) {
return 0;
}
if (!s->hit) {
if (!PACKET_memdup(&elliptic_curve_list,
&s->session->tlsext_ellipticcurvelist,
&s->session->tlsext_ellipticcurvelist_length)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket) {
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, PACKET_data(&extension),
PACKET_remaining(&extension),
s->tls_session_ticket_ext_cb_arg)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
} else if (type == TLSEXT_TYPE_signature_algorithms) {
PACKET supported_sig_algs;
if (!PACKET_as_length_prefixed_2(&extension, &supported_sig_algs)
|| (PACKET_remaining(&supported_sig_algs) % 2) != 0
|| PACKET_remaining(&supported_sig_algs) == 0) {
return 0;
}
if (!s->hit) {
if (!tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs),
PACKET_remaining(&supported_sig_algs))) {
return 0;
}
}
} else if (type == TLSEXT_TYPE_status_request) {
if (!PACKET_get_1(&extension,
(unsigned int *)&s->tlsext_status_type)) {
return 0;
}
#ifndef OPENSSL_NO_OCSP
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
const unsigned char *ext_data;
PACKET responder_id_list, exts;
if (!PACKET_get_length_prefixed_2(&extension, &responder_id_list))
return 0;
while (PACKET_remaining(&responder_id_list) > 0) {
OCSP_RESPID *id;
PACKET responder_id;
const unsigned char *id_data;
if (!PACKET_get_length_prefixed_2(&responder_id_list,
&responder_id)
|| PACKET_remaining(&responder_id) == 0) {
return 0;
}
if (s->tlsext_ocsp_ids == NULL
&& (s->tlsext_ocsp_ids =
sk_OCSP_RESPID_new_null()) == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
id_data = PACKET_data(&responder_id);
id = d2i_OCSP_RESPID(NULL, &id_data,
PACKET_remaining(&responder_id));
if (id == NULL)
return 0;
if (id_data != PACKET_end(&responder_id)) {
OCSP_RESPID_free(id);
return 0;
}
if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
OCSP_RESPID_free(id);
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
/* Read in request_extensions */
if (!PACKET_as_length_prefixed_2(&extension, &exts))
return 0;
if (PACKET_remaining(&exts) > 0) {
ext_data = PACKET_data(&exts);
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
X509_EXTENSION_free);
s->tlsext_ocsp_exts =
d2i_X509_EXTENSIONS(NULL, &ext_data,
PACKET_remaining(&exts));
if (s->tlsext_ocsp_exts == NULL
|| ext_data != PACKET_end(&exts)) {
return 0;
}
}
} else
#endif
{
/*
* We don't know what to do with any other type so ignore it.
*/
s->tlsext_status_type = -1;
}
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_heartbeat) {
unsigned int hbtype;
if (!PACKET_get_1(&extension, &hbtype)
|| PACKET_remaining(&extension)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
switch (hbtype) {
case 0x01: /* Client allows us to send HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
break;
case 0x02: /* Client doesn't accept HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
break;
default:
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0) {
/*-
* We shouldn't accept this extension on a
* renegotiation.
*
* s->new_session will be set on renegotiation, but we
* probably shouldn't rely that it couldn't be set on
* the initial renegotiation too in certain cases (when
* there's some other reason to disallow resuming an
* earlier session -- the current code won't be doing
* anything like that, but this might change).
*
* A valid sign that there's been a previous handshake
* in this connection is if s->s3->tmp.finish_md_len >
* 0. (We are talking about a check that will happen
* in the Hello protocol round, well before a new
* Finished message could have been computed.)
*/
s->s3->next_proto_neg_seen = 1;
}
#endif
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
s->s3->tmp.finish_md_len == 0) {
if (!tls1_alpn_handle_client_hello(s, &extension, al))
return 0;
}
/* session ticket processed earlier */
#ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)
&& type == TLSEXT_TYPE_use_srtp) {
if (ssl_parse_clienthello_use_srtp_ext(s, &extension, al))
return 0;
}
#endif
else if (type == TLSEXT_TYPE_encrypt_then_mac)
s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
/*
* Note: extended master secret extension handled in
* tls_check_serverhello_tlsext_early()
*/
/*
* If this ClientHello extension was unhandled and this is a
* nonresumed connection, check whether the extension is a custom
* TLS Extension (has a custom_srv_ext_record), and if so call the
* callback and record the extension number so that an appropriate
* ServerHello may be later returned.
*/
else if (!s->hit) {
if (custom_ext_parse(s, 1, type, PACKET_data(&extension),
PACKET_remaining(&extension), al) <= 0)
return 0;
}
}
if (PACKET_remaining(pkt) != 0) {
/* tls1_check_duplicate_extensions should ensure this never happens. */
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
ri_check:
/* Need RI if renegotiating */
if (!renegotiate_seen && s->renegotiate &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
/*
* This function currently has no state to clean up, so it returns directly.
* If parsing fails at any point, the function returns early.
* The SSL object may be left with partial data from extensions, but it must
* then no longer be used, and clearing it up will free the leftovers.
*/
return 1;
}
int ssl_parse_clienthello_tlsext(SSL *s, PACKET *pkt)
{
int al = -1;
custom_ext_init(&s->cert->srv_ext);
if (ssl_scan_clienthello_tlsext(s, pkt, &al) <= 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
if (ssl_check_clienthello_tlsext_early(s) <= 0) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_CLIENTHELLO_TLSEXT);
return 0;
}
return 1;
}
#ifndef OPENSSL_NO_NEXTPROTONEG
/*
* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
* elements of zero length are allowed and the set of elements must exactly
* fill the length of the block.
*/
static char ssl_next_proto_validate(PACKET *pkt)
{
PACKET tmp_protocol;
while (PACKET_remaining(pkt)) {
if (!PACKET_get_length_prefixed_1(pkt, &tmp_protocol)
|| PACKET_remaining(&tmp_protocol) == 0)
return 0;
}
return 1;
}
#endif
static int ssl_scan_serverhello_tlsext(SSL *s, PACKET *pkt, int *al)
{
unsigned int length, type, size;
int tlsext_servername = 0;
int renegotiate_seen = 0;
#ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
#endif
s->tlsext_ticket_expected = 0;
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = NULL;
#ifndef OPENSSL_NO_HEARTBEATS
s->tlsext_heartbeat &= ~(SSL_DTLSEXT_HB_ENABLED |
SSL_DTLSEXT_HB_DONT_SEND_REQUESTS);
#endif
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
if (!PACKET_get_net_2(pkt, &length))
goto ri_check;
if (PACKET_remaining(pkt) != length) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!tls1_check_duplicate_extensions(pkt)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while (PACKET_get_net_2(pkt, &type) && PACKET_get_net_2(pkt, &size)) {
const unsigned char *data;
PACKET spkt;
if (!PACKET_get_sub_packet(pkt, &spkt, size)
|| !PACKET_peek_bytes(&spkt, &data, size))
goto ri_check;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size, s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_renegotiate) {
if (!ssl_parse_serverhello_renegotiate_ext(s, &spkt, al))
return 0;
renegotiate_seen = 1;
} else if (s->version == SSL3_VERSION) {
} else if (type == TLSEXT_TYPE_server_name) {
if (s->tlsext_hostname == NULL || size > 0) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
tlsext_servername = 1;
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats) {
unsigned int ecpointformatlist_length;
if (!PACKET_get_1(&spkt, &ecpointformatlist_length)
|| ecpointformatlist_length != size - 1) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
s->session->tlsext_ecpointformatlist_length = 0;
OPENSSL_free(s->session->tlsext_ecpointformatlist);
if ((s->session->tlsext_ecpointformatlist =
OPENSSL_malloc(ecpointformatlist_length)) == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length =
ecpointformatlist_length;
if (!PACKET_copy_bytes(&spkt,
s->session->tlsext_ecpointformatlist,
ecpointformatlist_length)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
}
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket) {
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, data, size,
s->tls_session_ticket_ext_cb_arg))
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
if (!tls_use_ticket(s) || (size > 0)) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
s->tlsext_ticket_expected = 1;
}
else if (type == TLSEXT_TYPE_status_request) {
/*
* MUST be empty and only sent if we've requested a status
* request message.
*/
if ((s->tlsext_status_type == -1) || (size > 0)) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* Set flag to expect CertificateStatus message */
s->tlsext_status_expected = 1;
}
#ifndef OPENSSL_NO_CT
/*
* Only take it if we asked for it - i.e if there is no CT validation
* callback set, then a custom extension MAY be processing it, so we
* need to let control continue to flow to that.
*/
else if (type == TLSEXT_TYPE_signed_certificate_timestamp &&
s->ct_validation_callback != NULL) {
/* Simply copy it off for later processing */
if (s->tlsext_scts != NULL) {
OPENSSL_free(s->tlsext_scts);
s->tlsext_scts = NULL;
}
s->tlsext_scts_len = size;
if (size > 0) {
s->tlsext_scts = OPENSSL_malloc(size);
if (s->tlsext_scts == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
memcpy(s->tlsext_scts, data, size);
}
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0) {
unsigned char *selected;
unsigned char selected_len;
/* We must have requested it. */
if (s->ctx->next_proto_select_cb == NULL) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* The data must be valid */
if (!ssl_next_proto_validate(&spkt)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
if (s->
ctx->next_proto_select_cb(s, &selected, &selected_len, data,
size,
s->ctx->next_proto_select_cb_arg) !=
SSL_TLSEXT_ERR_OK) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->next_proto_negotiated = OPENSSL_malloc(selected_len);
if (s->next_proto_negotiated == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
memcpy(s->next_proto_negotiated, selected, selected_len);
s->next_proto_negotiated_len = selected_len;
s->s3->next_proto_neg_seen = 1;
}
#endif
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation) {
unsigned len;
/* We must have requested it. */
if (!s->s3->alpn_sent) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/*-
* The extension data consists of:
* uint16 list_length
* uint8 proto_length;
* uint8 proto[proto_length];
*/
if (!PACKET_get_net_2(&spkt, &len)
|| PACKET_remaining(&spkt) != len
|| !PACKET_get_1(&spkt, &len)
|| PACKET_remaining(&spkt) != len) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = OPENSSL_malloc(len);
if (s->s3->alpn_selected == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
if (!PACKET_copy_bytes(&spkt, s->s3->alpn_selected, len)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
s->s3->alpn_selected_len = len;
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_heartbeat) {
unsigned int hbtype;
if (!PACKET_get_1(&spkt, &hbtype)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
switch (hbtype) {
case 0x01: /* Server allows us to send HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
break;
case 0x02: /* Server doesn't accept HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
break;
default:
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
#endif
#ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
if (ssl_parse_serverhello_use_srtp_ext(s, &spkt, al))
return 0;
}
#endif
else if (type == TLSEXT_TYPE_encrypt_then_mac) {
/* Ignore if inappropriate ciphersuite */
if (s->s3->tmp.new_cipher->algorithm_mac != SSL_AEAD
&& s->s3->tmp.new_cipher->algorithm_enc != SSL_RC4)
s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
}
else if (type == TLSEXT_TYPE_extended_master_secret) {
s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
if (!s->hit)
s->session->flags |= SSL_SESS_FLAG_EXTMS;
}
/*
* If this extension type was not otherwise handled, but matches a
* custom_cli_ext_record, then send it to the c callback
*/
else if (custom_ext_parse(s, 0, type, data, size, al) <= 0)
return 0;
}
if (PACKET_remaining(pkt) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && tlsext_servername == 1) {
if (s->tlsext_hostname) {
if (s->session->tlsext_hostname == NULL) {
s->session->tlsext_hostname = OPENSSL_strdup(s->tlsext_hostname);
if (!s->session->tlsext_hostname) {
*al = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
} else {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
ri_check:
/*
* Determine if we need to see RI. Strictly speaking if we want to avoid
* an attack we should *always* see RI even on initial server hello
* because the client doesn't see any renegotiation during an attack.
* However this would mean we could not connect to any server which
* doesn't support RI so for the immediate future tolerate RI absence
*/
if (!renegotiate_seen && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
&& !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
if (s->hit) {
/*
* Check extended master secret extension is consistent with
* original session.
*/
if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
!(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT, SSL_R_INCONSISTENT_EXTMS);
return 0;
}
}
return 1;
}
int ssl_prepare_clienthello_tlsext(SSL *s)
{
s->s3->alpn_sent = 0;
return 1;
}
int ssl_prepare_serverhello_tlsext(SSL *s)
{
return 1;
}
static int ssl_check_clienthello_tlsext_early(SSL *s)
{
int ret = SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
#ifndef OPENSSL_NO_EC
/*
* The handling of the ECPointFormats extension is done elsewhere, namely
* in ssl3_choose_cipher in s3_lib.c.
*/
/*
* The handling of the EllipticCurves extension is done elsewhere, namely
* in ssl3_choose_cipher in s3_lib.c.
*/
#endif
if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
ret =
s->ctx->tlsext_servername_callback(s, &al,
s->ctx->tlsext_servername_arg);
else if (s->initial_ctx != NULL
&& s->initial_ctx->tlsext_servername_callback != 0)
ret =
s->initial_ctx->tlsext_servername_callback(s, &al,
s->
initial_ctx->tlsext_servername_arg);
switch (ret) {
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s, SSL3_AL_WARNING, al);
return 1;
case SSL_TLSEXT_ERR_NOACK:
s->servername_done = 0;
default:
return 1;
}
}
/* Initialise digests to default values */
void ssl_set_default_md(SSL *s)
{
const EVP_MD **pmd = s->s3->tmp.md;
#ifndef OPENSSL_NO_DSA
pmd[SSL_PKEY_DSA_SIGN] = ssl_md(SSL_MD_SHA1_IDX);
#endif
#ifndef OPENSSL_NO_RSA
if (SSL_USE_SIGALGS(s))
pmd[SSL_PKEY_RSA_SIGN] = ssl_md(SSL_MD_SHA1_IDX);
else
pmd[SSL_PKEY_RSA_SIGN] = ssl_md(SSL_MD_MD5_SHA1_IDX);
pmd[SSL_PKEY_RSA_ENC] = pmd[SSL_PKEY_RSA_SIGN];
#endif
#ifndef OPENSSL_NO_EC
pmd[SSL_PKEY_ECC] = ssl_md(SSL_MD_SHA1_IDX);
#endif
#ifndef OPENSSL_NO_GOST
pmd[SSL_PKEY_GOST01] = ssl_md(SSL_MD_GOST94_IDX);
pmd[SSL_PKEY_GOST12_256] = ssl_md(SSL_MD_GOST12_256_IDX);
pmd[SSL_PKEY_GOST12_512] = ssl_md(SSL_MD_GOST12_512_IDX);
#endif
}
int tls1_set_server_sigalgs(SSL *s)
{
int al;
size_t i;
/* Clear any shared signature algorithms */
OPENSSL_free(s->cert->shared_sigalgs);
s->cert->shared_sigalgs = NULL;
s->cert->shared_sigalgslen = 0;
/* Clear certificate digests and validity flags */
for (i = 0; i < SSL_PKEY_NUM; i++) {
s->s3->tmp.md[i] = NULL;
s->s3->tmp.valid_flags[i] = 0;
}
/* If sigalgs received process it. */
if (s->s3->tmp.peer_sigalgs) {
if (!tls1_process_sigalgs(s)) {
SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS, ERR_R_MALLOC_FAILURE);
al = SSL_AD_INTERNAL_ERROR;
goto err;
}
/* Fatal error is no shared signature algorithms */
if (!s->cert->shared_sigalgs) {
SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS,
SSL_R_NO_SHARED_SIGNATURE_ALGORITHMS);
al = SSL_AD_ILLEGAL_PARAMETER;
goto err;
}
} else {
ssl_set_default_md(s);
}
return 1;
err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
/*
* Upon success, returns 1.
* Upon failure, returns 0 and sets |al| to the appropriate fatal alert.
*/
int ssl_check_clienthello_tlsext_late(SSL *s, int *al)
{
s->tlsext_status_expected = 0;
/*
* If status request then ask callback what to do. Note: this must be
* called after servername callbacks in case the certificate has changed,
* and must be called after the cipher has been chosen because this may
* influence which certificate is sent
*/
if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb) {
int ret;
CERT_PKEY *certpkey;
certpkey = ssl_get_server_send_pkey(s);
/* If no certificate can't return certificate status */
if (certpkey != NULL) {
/*
* Set current certificate to one we will use so SSL_get_certificate
* et al can pick it up.
*/
s->cert->key = certpkey;
ret = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
switch (ret) {
/* We don't want to send a status request response */
case SSL_TLSEXT_ERR_NOACK:
s->tlsext_status_expected = 0;
break;
/* status request response should be sent */
case SSL_TLSEXT_ERR_OK:
if (s->tlsext_ocsp_resp)
s->tlsext_status_expected = 1;
break;
/* something bad happened */
case SSL_TLSEXT_ERR_ALERT_FATAL:
default:
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
}
if (!tls1_alpn_handle_client_hello_late(s, al)) {
return 0;
}
return 1;
}
int ssl_check_serverhello_tlsext(SSL *s)
{
int ret = SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
#ifndef OPENSSL_NO_EC
/*
* If we are client and using an elliptic curve cryptography cipher
* suite, then if server returns an EC point formats lists extension it
* must contain uncompressed.
*/
unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
if ((s->tlsext_ecpointformatlist != NULL)
&& (s->tlsext_ecpointformatlist_length > 0)
&& (s->session->tlsext_ecpointformatlist != NULL)
&& (s->session->tlsext_ecpointformatlist_length > 0)
&& ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
/* we are using an ECC cipher */
size_t i;
unsigned char *list;
int found_uncompressed = 0;
list = s->session->tlsext_ecpointformatlist;
for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++) {
if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed) {
found_uncompressed = 1;
break;
}
}
if (!found_uncompressed) {
SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,
SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
return -1;
}
}
ret = SSL_TLSEXT_ERR_OK;
#endif /* OPENSSL_NO_EC */
if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
ret =
s->ctx->tlsext_servername_callback(s, &al,
s->ctx->tlsext_servername_arg);
else if (s->initial_ctx != NULL
&& s->initial_ctx->tlsext_servername_callback != 0)
ret =
s->initial_ctx->tlsext_servername_callback(s, &al,
s->
initial_ctx->tlsext_servername_arg);
/*
* Ensure we get sensible values passed to tlsext_status_cb in the event
* that we don't receive a status message
*/
OPENSSL_free(s->tlsext_ocsp_resp);
s->tlsext_ocsp_resp = NULL;
s->tlsext_ocsp_resplen = -1;
switch (ret) {
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s, SSL3_AL_WARNING, al);
return 1;
case SSL_TLSEXT_ERR_NOACK:
s->servername_done = 0;
default:
return 1;
}
}
int ssl_parse_serverhello_tlsext(SSL *s, PACKET *pkt)
{
int al = -1;
if (s->version < SSL3_VERSION)
return 1;
if (ssl_scan_serverhello_tlsext(s, pkt, &al) <= 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
if (ssl_check_serverhello_tlsext(s) <= 0) {
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_SERVERHELLO_TLSEXT);
return 0;
}
return 1;
}
/*-
* Since the server cache lookup is done early on in the processing of the
* ClientHello and other operations depend on the result some extensions
* need to be handled at the same time.
*
* Two extensions are currently handled, session ticket and extended master
* secret.
*
* session_id: ClientHello session ID.
* ext: ClientHello extensions (including length prefix)
* ret: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* If s->tls_session_secret_cb is set then we are expecting a pre-shared key
* ciphersuite, in which case we have no use for session tickets and one will
* never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
*
* Returns:
* -1: fatal error, either from parsing or decrypting the ticket.
* 0: no ticket was found (or was ignored, based on settings).
* 1: a zero length extension was found, indicating that the client supports
* session tickets but doesn't currently have one to offer.
* 2: either s->tls_session_secret_cb was set, or a ticket was offered but
* couldn't be decrypted because of a non-fatal error.
* 3: a ticket was successfully decrypted and *ret was set.
*
* Side effects:
* Sets s->tlsext_ticket_expected to 1 if the server will have to issue
* a new session ticket to the client because the client indicated support
* (and s->tls_session_secret_cb is NULL) but the client either doesn't have
* a session ticket or we couldn't use the one it gave us, or if
* s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
* Otherwise, s->tlsext_ticket_expected is set to 0.
*
* For extended master secret flag is set if the extension is present.
*
*/
int tls_check_serverhello_tlsext_early(SSL *s, const PACKET *ext,
const PACKET *session_id,
SSL_SESSION **ret)
{
unsigned int i;
PACKET local_ext = *ext;
int retv = -1;
int have_ticket = 0;
int use_ticket = tls_use_ticket(s);
*ret = NULL;
s->tlsext_ticket_expected = 0;
s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
/*
* If tickets disabled behave as if no ticket present to permit stateful
* resumption.
*/
if ((s->version <= SSL3_VERSION))
return 0;
if (!PACKET_get_net_2(&local_ext, &i)) {
retv = 0;
goto end;
}
while (PACKET_remaining(&local_ext) >= 4) {
unsigned int type, size;
if (!PACKET_get_net_2(&local_ext, &type)
|| !PACKET_get_net_2(&local_ext, &size)) {
/* Shouldn't ever happen */
retv = -1;
goto end;
}
if (PACKET_remaining(&local_ext) < size) {
retv = 0;
goto end;
}
if (type == TLSEXT_TYPE_session_ticket && use_ticket) {
int r;
const unsigned char *etick;
/* Duplicate extension */
if (have_ticket != 0) {
retv = -1;
goto end;
}
have_ticket = 1;
if (size == 0) {
/*
* The client will accept a ticket but doesn't currently have
* one.
*/
s->tlsext_ticket_expected = 1;
retv = 1;
continue;
}
if (s->tls_session_secret_cb) {
/*
* Indicate that the ticket couldn't be decrypted rather than
* generating the session from ticket now, trigger
* abbreviated handshake based on external mechanism to
* calculate the master secret later.
*/
retv = 2;
continue;
}
if (!PACKET_get_bytes(&local_ext, &etick, size)) {
/* Shouldn't ever happen */
retv = -1;
goto end;
}
r = tls_decrypt_ticket(s, etick, size, PACKET_data(session_id),
PACKET_remaining(session_id), ret);
switch (r) {
case 2: /* ticket couldn't be decrypted */
s->tlsext_ticket_expected = 1;
retv = 2;
break;
case 3: /* ticket was decrypted */
retv = r;
break;
case 4: /* ticket decrypted but need to renew */
s->tlsext_ticket_expected = 1;
retv = 3;
break;
default: /* fatal error */
retv = -1;
break;
}
continue;
} else {
if (type == TLSEXT_TYPE_extended_master_secret)
s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
if (!PACKET_forward(&local_ext, size)) {
retv = -1;
goto end;
}
}
}
if (have_ticket == 0)
retv = 0;
end:
return retv;
}
/*-
* tls_decrypt_ticket attempts to decrypt a session ticket.
*
* etick: points to the body of the session ticket extension.
* eticklen: the length of the session tickets extension.
* sess_id: points at the session ID.
* sesslen: the length of the session ID.
* psess: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* Returns:
* -2: fatal error, malloc failure.
* -1: fatal error, either from parsing or decrypting the ticket.
* 2: the ticket couldn't be decrypted.
* 3: a ticket was successfully decrypted and *psess was set.
* 4: same as 3, but the ticket needs to be renewed.
*/
static int tls_decrypt_ticket(SSL *s, const unsigned char *etick,
int eticklen, const unsigned char *sess_id,
int sesslen, SSL_SESSION **psess)
{
SSL_SESSION *sess;
unsigned char *sdec;
const unsigned char *p;
int slen, mlen, renew_ticket = 0, ret = -1;
unsigned char tick_hmac[EVP_MAX_MD_SIZE];
HMAC_CTX *hctx = NULL;
EVP_CIPHER_CTX *ctx;
SSL_CTX *tctx = s->initial_ctx;
/* Need at least keyname + iv + some encrypted data */
if (eticklen < 48)
return 2;
/* Initialize session ticket encryption and HMAC contexts */
hctx = HMAC_CTX_new();
if (hctx == NULL)
return -2;
ctx = EVP_CIPHER_CTX_new();
if (ctx == NULL) {
ret = -2;
goto err;
}
if (tctx->tlsext_ticket_key_cb) {
unsigned char *nctick = (unsigned char *)etick;
int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
ctx, hctx, 0);
if (rv < 0)
goto err;
if (rv == 0) {
ret = 2;
goto err;
}
if (rv == 2)
renew_ticket = 1;
} else {
/* Check key name matches */
if (memcmp(etick, tctx->tlsext_tick_key_name,
sizeof(tctx->tlsext_tick_key_name)) != 0) {
ret = 2;
goto err;
}
if (HMAC_Init_ex(hctx, tctx->tlsext_tick_hmac_key,
sizeof(tctx->tlsext_tick_hmac_key),
EVP_sha256(), NULL) <= 0
|| EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL,
tctx->tlsext_tick_aes_key,
etick + sizeof(tctx->tlsext_tick_key_name)) <= 0) {
goto err;
}
}
/*
* Attempt to process session ticket, first conduct sanity and integrity
* checks on ticket.
*/
mlen = HMAC_size(hctx);
if (mlen < 0) {
goto err;
}
eticklen -= mlen;
/* Check HMAC of encrypted ticket */
if (HMAC_Update(hctx, etick, eticklen) <= 0
|| HMAC_Final(hctx, tick_hmac, NULL) <= 0) {
goto err;
}
HMAC_CTX_free(hctx);
if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) {
EVP_CIPHER_CTX_free(ctx);
return 2;
}
/* Attempt to decrypt session data */
/* Move p after IV to start of encrypted ticket, update length */
p = etick + 16 + EVP_CIPHER_CTX_iv_length(ctx);
eticklen -= 16 + EVP_CIPHER_CTX_iv_length(ctx);
sdec = OPENSSL_malloc(eticklen);
if (sdec == NULL
|| EVP_DecryptUpdate(ctx, sdec, &slen, p, eticklen) <= 0) {
EVP_CIPHER_CTX_free(ctx);
OPENSSL_free(sdec);
return -1;
}
if (EVP_DecryptFinal(ctx, sdec + slen, &mlen) <= 0) {
EVP_CIPHER_CTX_free(ctx);
OPENSSL_free(sdec);
return 2;
}
slen += mlen;
EVP_CIPHER_CTX_free(ctx);
ctx = NULL;
p = sdec;
sess = d2i_SSL_SESSION(NULL, &p, slen);
OPENSSL_free(sdec);
if (sess) {
/*
* The session ID, if non-empty, is used by some clients to detect
* that the ticket has been accepted. So we copy it to the session
* structure. If it is empty set length to zero as required by
* standard.
*/
if (sesslen)
memcpy(sess->session_id, sess_id, sesslen);
sess->session_id_length = sesslen;
*psess = sess;
if (renew_ticket)
return 4;
else
return 3;
}
ERR_clear_error();
/*
* For session parse failure, indicate that we need to send a new ticket.
*/
return 2;
err:
EVP_CIPHER_CTX_free(ctx);
HMAC_CTX_free(hctx);
return ret;
}
/* Tables to translate from NIDs to TLS v1.2 ids */
typedef struct {
int nid;
int id;
} tls12_lookup;
static const tls12_lookup tls12_md[] = {
{NID_md5, TLSEXT_hash_md5},
{NID_sha1, TLSEXT_hash_sha1},
{NID_sha224, TLSEXT_hash_sha224},
{NID_sha256, TLSEXT_hash_sha256},
{NID_sha384, TLSEXT_hash_sha384},
{NID_sha512, TLSEXT_hash_sha512},
{NID_id_GostR3411_94, TLSEXT_hash_gostr3411},
{NID_id_GostR3411_2012_256, TLSEXT_hash_gostr34112012_256},
{NID_id_GostR3411_2012_512, TLSEXT_hash_gostr34112012_512},
};
static const tls12_lookup tls12_sig[] = {
{EVP_PKEY_RSA, TLSEXT_signature_rsa},
{EVP_PKEY_DSA, TLSEXT_signature_dsa},
{EVP_PKEY_EC, TLSEXT_signature_ecdsa},
{NID_id_GostR3410_2001, TLSEXT_signature_gostr34102001},
{NID_id_GostR3410_2012_256, TLSEXT_signature_gostr34102012_256},
{NID_id_GostR3410_2012_512, TLSEXT_signature_gostr34102012_512}
};
static int tls12_find_id(int nid, const tls12_lookup *table, size_t tlen)
{
size_t i;
for (i = 0; i < tlen; i++) {
if (table[i].nid == nid)
return table[i].id;
}
return -1;
}
static int tls12_find_nid(int id, const tls12_lookup *table, size_t tlen)
{
size_t i;
for (i = 0; i < tlen; i++) {
if ((table[i].id) == id)
return table[i].nid;
}
return NID_undef;
}
int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk,
const EVP_MD *md)
{
int sig_id, md_id;
if (!md)
return 0;
md_id = tls12_find_id(EVP_MD_type(md), tls12_md, OSSL_NELEM(tls12_md));
if (md_id == -1)
return 0;
sig_id = tls12_get_sigid(pk);
if (sig_id == -1)
return 0;
p[0] = (unsigned char)md_id;
p[1] = (unsigned char)sig_id;
return 1;
}
int tls12_get_sigid(const EVP_PKEY *pk)
{
return tls12_find_id(EVP_PKEY_id(pk), tls12_sig, OSSL_NELEM(tls12_sig));
}
typedef struct {
int nid;
int secbits;
int md_idx;
unsigned char tlsext_hash;
} tls12_hash_info;
static const tls12_hash_info tls12_md_info[] = {
{NID_md5, 64, SSL_MD_MD5_IDX, TLSEXT_hash_md5},
{NID_sha1, 80, SSL_MD_SHA1_IDX, TLSEXT_hash_sha1},
{NID_sha224, 112, SSL_MD_SHA224_IDX, TLSEXT_hash_sha224},
{NID_sha256, 128, SSL_MD_SHA256_IDX, TLSEXT_hash_sha256},
{NID_sha384, 192, SSL_MD_SHA384_IDX, TLSEXT_hash_sha384},
{NID_sha512, 256, SSL_MD_SHA512_IDX, TLSEXT_hash_sha512},
{NID_id_GostR3411_94, 128, SSL_MD_GOST94_IDX, TLSEXT_hash_gostr3411},
{NID_id_GostR3411_2012_256, 128, SSL_MD_GOST12_256_IDX, TLSEXT_hash_gostr34112012_256},
{NID_id_GostR3411_2012_512, 256, SSL_MD_GOST12_512_IDX, TLSEXT_hash_gostr34112012_512},
};
static const tls12_hash_info *tls12_get_hash_info(unsigned char hash_alg)
{
unsigned int i;
if (hash_alg == 0)
return NULL;
for (i=0; i < OSSL_NELEM(tls12_md_info); i++)
{
if (tls12_md_info[i].tlsext_hash == hash_alg)
return tls12_md_info + i;
}
return NULL;
}
const EVP_MD *tls12_get_hash(unsigned char hash_alg)
{
const tls12_hash_info *inf;
if (hash_alg == TLSEXT_hash_md5 && FIPS_mode())
return NULL;
inf = tls12_get_hash_info(hash_alg);
if (!inf)
return NULL;
return ssl_md(inf->md_idx);
}
static int tls12_get_pkey_idx(unsigned char sig_alg)
{
switch (sig_alg) {
#ifndef OPENSSL_NO_RSA
case TLSEXT_signature_rsa:
return SSL_PKEY_RSA_SIGN;
#endif
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
return SSL_PKEY_DSA_SIGN;
#endif
#ifndef OPENSSL_NO_EC
case TLSEXT_signature_ecdsa:
return SSL_PKEY_ECC;
#endif
# ifndef OPENSSL_NO_GOST
case TLSEXT_signature_gostr34102001:
return SSL_PKEY_GOST01;
case TLSEXT_signature_gostr34102012_256:
return SSL_PKEY_GOST12_256;
case TLSEXT_signature_gostr34102012_512:
return SSL_PKEY_GOST12_512;
# endif
}
return -1;
}
/* Convert TLS 1.2 signature algorithm extension values into NIDs */
static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid,
int *psignhash_nid, const unsigned char *data)
{
int sign_nid = NID_undef, hash_nid = NID_undef;
if (!phash_nid && !psign_nid && !psignhash_nid)
return;
if (phash_nid || psignhash_nid) {
hash_nid = tls12_find_nid(data[0], tls12_md, OSSL_NELEM(tls12_md));
if (phash_nid)
*phash_nid = hash_nid;
}
if (psign_nid || psignhash_nid) {
sign_nid = tls12_find_nid(data[1], tls12_sig, OSSL_NELEM(tls12_sig));
if (psign_nid)
*psign_nid = sign_nid;
}
if (psignhash_nid) {
if (sign_nid == NID_undef || hash_nid == NID_undef
|| OBJ_find_sigid_by_algs(psignhash_nid, hash_nid,
sign_nid) <= 0)
*psignhash_nid = NID_undef;
}
}
/* Check to see if a signature algorithm is allowed */
static int tls12_sigalg_allowed(SSL *s, int op, const unsigned char *ptmp)
{
/* See if we have an entry in the hash table and it is enabled */
const tls12_hash_info *hinf = tls12_get_hash_info(ptmp[0]);
if (hinf == NULL || ssl_md(hinf->md_idx) == NULL)
return 0;
/* See if public key algorithm allowed */
if (tls12_get_pkey_idx(ptmp[1]) == -1)
return 0;
/* Finally see if security callback allows it */
return ssl_security(s, op, hinf->secbits, hinf->nid, (void *)ptmp);
}
/*
* Get a mask of disabled public key algorithms based on supported signature
* algorithms. For example if no signature algorithm supports RSA then RSA is
* disabled.
*/
void ssl_set_sig_mask(uint32_t *pmask_a, SSL *s, int op)
{
const unsigned char *sigalgs;
size_t i, sigalgslen;
int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
/*
* Now go through all signature algorithms seeing if we support any for
* RSA, DSA, ECDSA. Do this for all versions not just TLS 1.2. To keep
* down calls to security callback only check if we have to.
*/
sigalgslen = tls12_get_psigalgs(s, &sigalgs);
for (i = 0; i < sigalgslen; i += 2, sigalgs += 2) {
switch (sigalgs[1]) {
#ifndef OPENSSL_NO_RSA
case TLSEXT_signature_rsa:
if (!have_rsa && tls12_sigalg_allowed(s, op, sigalgs))
have_rsa = 1;
break;
#endif
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
if (!have_dsa && tls12_sigalg_allowed(s, op, sigalgs))
have_dsa = 1;
break;
#endif
#ifndef OPENSSL_NO_EC
case TLSEXT_signature_ecdsa:
if (!have_ecdsa && tls12_sigalg_allowed(s, op, sigalgs))
have_ecdsa = 1;
break;
#endif
}
}
if (!have_rsa)
*pmask_a |= SSL_aRSA;
if (!have_dsa)
*pmask_a |= SSL_aDSS;
if (!have_ecdsa)
*pmask_a |= SSL_aECDSA;
}
size_t tls12_copy_sigalgs(SSL *s, unsigned char *out,
const unsigned char *psig, size_t psiglen)
{
unsigned char *tmpout = out;
size_t i;
for (i = 0; i < psiglen; i += 2, psig += 2) {
if (tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, psig)) {
*tmpout++ = psig[0];
*tmpout++ = psig[1];
}
}
return tmpout - out;
}
/* Given preference and allowed sigalgs set shared sigalgs */
static int tls12_shared_sigalgs(SSL *s, TLS_SIGALGS *shsig,
const unsigned char *pref, size_t preflen,
const unsigned char *allow, size_t allowlen)
{
const unsigned char *ptmp, *atmp;
size_t i, j, nmatch = 0;
for (i = 0, ptmp = pref; i < preflen; i += 2, ptmp += 2) {
/* Skip disabled hashes or signature algorithms */
if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SHARED, ptmp))
continue;
for (j = 0, atmp = allow; j < allowlen; j += 2, atmp += 2) {
if (ptmp[0] == atmp[0] && ptmp[1] == atmp[1]) {
nmatch++;
if (shsig) {
shsig->rhash = ptmp[0];
shsig->rsign = ptmp[1];
tls1_lookup_sigalg(&shsig->hash_nid,
&shsig->sign_nid,
&shsig->signandhash_nid, ptmp);
shsig++;
}
break;
}
}
}
return nmatch;
}
/* Set shared signature algorithms for SSL structures */
static int tls1_set_shared_sigalgs(SSL *s)
{
const unsigned char *pref, *allow, *conf;
size_t preflen, allowlen, conflen;
size_t nmatch;
TLS_SIGALGS *salgs = NULL;
CERT *c = s->cert;
unsigned int is_suiteb = tls1_suiteb(s);
OPENSSL_free(c->shared_sigalgs);
c->shared_sigalgs = NULL;
c->shared_sigalgslen = 0;
/* If client use client signature algorithms if not NULL */
if (!s->server && c->client_sigalgs && !is_suiteb) {
conf = c->client_sigalgs;
conflen = c->client_sigalgslen;
} else if (c->conf_sigalgs && !is_suiteb) {
conf = c->conf_sigalgs;
conflen = c->conf_sigalgslen;
} else
conflen = tls12_get_psigalgs(s, &conf);
if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb) {
pref = conf;
preflen = conflen;
allow = s->s3->tmp.peer_sigalgs;
allowlen = s->s3->tmp.peer_sigalgslen;
} else {
allow = conf;
allowlen = conflen;
pref = s->s3->tmp.peer_sigalgs;
preflen = s->s3->tmp.peer_sigalgslen;
}
nmatch = tls12_shared_sigalgs(s, NULL, pref, preflen, allow, allowlen);
if (nmatch) {
salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS));
if (salgs == NULL)
return 0;
nmatch = tls12_shared_sigalgs(s, salgs, pref, preflen, allow, allowlen);
} else {
salgs = NULL;
}
c->shared_sigalgs = salgs;
c->shared_sigalgslen = nmatch;
return 1;
}
/* Set preferred digest for each key type */
int tls1_save_sigalgs(SSL *s, const unsigned char *data, int dsize)
{
CERT *c = s->cert;
/* Extension ignored for inappropriate versions */
if (!SSL_USE_SIGALGS(s))
return 1;
/* Should never happen */
if (!c)
return 0;
OPENSSL_free(s->s3->tmp.peer_sigalgs);
s->s3->tmp.peer_sigalgs = OPENSSL_malloc(dsize);
if (s->s3->tmp.peer_sigalgs == NULL)
return 0;
s->s3->tmp.peer_sigalgslen = dsize;
memcpy(s->s3->tmp.peer_sigalgs, data, dsize);
return 1;
}
int tls1_process_sigalgs(SSL *s)
{
int idx;
size_t i;
const EVP_MD *md;
const EVP_MD **pmd = s->s3->tmp.md;
uint32_t *pvalid = s->s3->tmp.valid_flags;
CERT *c = s->cert;
TLS_SIGALGS *sigptr;
if (!tls1_set_shared_sigalgs(s))
return 0;
for (i = 0, sigptr = c->shared_sigalgs;
i < c->shared_sigalgslen; i++, sigptr++) {
idx = tls12_get_pkey_idx(sigptr->rsign);
if (idx > 0 && pmd[idx] == NULL) {
md = tls12_get_hash(sigptr->rhash);
pmd[idx] = md;
pvalid[idx] = CERT_PKEY_EXPLICIT_SIGN;
if (idx == SSL_PKEY_RSA_SIGN) {
pvalid[SSL_PKEY_RSA_ENC] = CERT_PKEY_EXPLICIT_SIGN;
pmd[SSL_PKEY_RSA_ENC] = md;
}
}
}
/*
* In strict mode leave unset digests as NULL to indicate we can't use
* the certificate for signing.
*/
if (!(s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
/*
* Set any remaining keys to default values. NOTE: if alg is not
* supported it stays as NULL.
*/
#ifndef OPENSSL_NO_DSA
if (pmd[SSL_PKEY_DSA_SIGN] == NULL)
pmd[SSL_PKEY_DSA_SIGN] = EVP_sha1();
#endif
#ifndef OPENSSL_NO_RSA
if (pmd[SSL_PKEY_RSA_SIGN] == NULL) {
pmd[SSL_PKEY_RSA_SIGN] = EVP_sha1();
pmd[SSL_PKEY_RSA_ENC] = EVP_sha1();
}
#endif
#ifndef OPENSSL_NO_EC
if (pmd[SSL_PKEY_ECC] == NULL)
pmd[SSL_PKEY_ECC] = EVP_sha1();
#endif
# ifndef OPENSSL_NO_GOST
if (pmd[SSL_PKEY_GOST01] == NULL)
pmd[SSL_PKEY_GOST01] = EVP_get_digestbynid(NID_id_GostR3411_94);
if (pmd[SSL_PKEY_GOST12_256] == NULL)
pmd[SSL_PKEY_GOST12_256] = EVP_get_digestbynid(NID_id_GostR3411_2012_256);
if (pmd[SSL_PKEY_GOST12_512] == NULL)
pmd[SSL_PKEY_GOST12_512] = EVP_get_digestbynid(NID_id_GostR3411_2012_512);
# endif
}
return 1;
}
int SSL_get_sigalgs(SSL *s, int idx,
int *psign, int *phash, int *psignhash,
unsigned char *rsig, unsigned char *rhash)
{
const unsigned char *psig = s->s3->tmp.peer_sigalgs;
if (psig == NULL)
return 0;
if (idx >= 0) {
idx <<= 1;
if (idx >= (int)s->s3->tmp.peer_sigalgslen)
return 0;
psig += idx;
if (rhash)
*rhash = psig[0];
if (rsig)
*rsig = psig[1];
tls1_lookup_sigalg(phash, psign, psignhash, psig);
}
return s->s3->tmp.peer_sigalgslen / 2;
}
int SSL_get_shared_sigalgs(SSL *s, int idx,
int *psign, int *phash, int *psignhash,
unsigned char *rsig, unsigned char *rhash)
{
TLS_SIGALGS *shsigalgs = s->cert->shared_sigalgs;
if (!shsigalgs || idx >= (int)s->cert->shared_sigalgslen)
return 0;
shsigalgs += idx;
if (phash)
*phash = shsigalgs->hash_nid;
if (psign)
*psign = shsigalgs->sign_nid;
if (psignhash)
*psignhash = shsigalgs->signandhash_nid;
if (rsig)
*rsig = shsigalgs->rsign;
if (rhash)
*rhash = shsigalgs->rhash;
return s->cert->shared_sigalgslen;
}
#define MAX_SIGALGLEN (TLSEXT_hash_num * TLSEXT_signature_num * 2)
typedef struct {
size_t sigalgcnt;
int sigalgs[MAX_SIGALGLEN];
} sig_cb_st;
static void get_sigorhash(int *psig, int *phash, const char *str)
{
if (strcmp(str, "RSA") == 0) {
*psig = EVP_PKEY_RSA;
} else if (strcmp(str, "DSA") == 0) {
*psig = EVP_PKEY_DSA;
} else if (strcmp(str, "ECDSA") == 0) {
*psig = EVP_PKEY_EC;
} else {
*phash = OBJ_sn2nid(str);
if (*phash == NID_undef)
*phash = OBJ_ln2nid(str);
}
}
static int sig_cb(const char *elem, int len, void *arg)
{
sig_cb_st *sarg = arg;
size_t i;
char etmp[20], *p;
int sig_alg = NID_undef, hash_alg = NID_undef;
if (elem == NULL)
return 0;
if (sarg->sigalgcnt == MAX_SIGALGLEN)
return 0;
if (len > (int)(sizeof(etmp) - 1))
return 0;
memcpy(etmp, elem, len);
etmp[len] = 0;
p = strchr(etmp, '+');
if (!p)
return 0;
*p = 0;
p++;
if (!*p)
return 0;
get_sigorhash(&sig_alg, &hash_alg, etmp);
get_sigorhash(&sig_alg, &hash_alg, p);
if (sig_alg == NID_undef || hash_alg == NID_undef)
return 0;
for (i = 0; i < sarg->sigalgcnt; i += 2) {
if (sarg->sigalgs[i] == sig_alg && sarg->sigalgs[i + 1] == hash_alg)
return 0;
}
sarg->sigalgs[sarg->sigalgcnt++] = hash_alg;
sarg->sigalgs[sarg->sigalgcnt++] = sig_alg;
return 1;
}
/*
* Set supported signature algorithms based on a colon separated list of the
* form sig+hash e.g. RSA+SHA512:DSA+SHA512
*/
int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
{
sig_cb_st sig;
sig.sigalgcnt = 0;
if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
return 0;
if (c == NULL)
return 1;
return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
}
int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen,
int client)
{
unsigned char *sigalgs, *sptr;
int rhash, rsign;
size_t i;
if (salglen & 1)
return 0;
sigalgs = OPENSSL_malloc(salglen);
if (sigalgs == NULL)
return 0;
for (i = 0, sptr = sigalgs; i < salglen; i += 2) {
rhash = tls12_find_id(*psig_nids++, tls12_md, OSSL_NELEM(tls12_md));
rsign = tls12_find_id(*psig_nids++, tls12_sig, OSSL_NELEM(tls12_sig));
if (rhash == -1 || rsign == -1)
goto err;
*sptr++ = rhash;
*sptr++ = rsign;
}
if (client) {
OPENSSL_free(c->client_sigalgs);
c->client_sigalgs = sigalgs;
c->client_sigalgslen = salglen;
} else {
OPENSSL_free(c->conf_sigalgs);
c->conf_sigalgs = sigalgs;
c->conf_sigalgslen = salglen;
}
return 1;
err:
OPENSSL_free(sigalgs);
return 0;
}
static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
{
int sig_nid;
size_t i;
if (default_nid == -1)
return 1;
sig_nid = X509_get_signature_nid(x);
if (default_nid)
return sig_nid == default_nid ? 1 : 0;
for (i = 0; i < c->shared_sigalgslen; i++)
if (sig_nid == c->shared_sigalgs[i].signandhash_nid)
return 1;
return 0;
}
/* Check to see if a certificate issuer name matches list of CA names */
static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
{
X509_NAME *nm;
int i;
nm = X509_get_issuer_name(x);
for (i = 0; i < sk_X509_NAME_num(names); i++) {
if (!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
return 1;
}
return 0;
}
/*
* Check certificate chain is consistent with TLS extensions and is usable by
* server. This servers two purposes: it allows users to check chains before
* passing them to the server and it allows the server to check chains before
* attempting to use them.
*/
/* Flags which need to be set for a certificate when stict mode not set */
#define CERT_PKEY_VALID_FLAGS \
(CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
/* Strict mode flags */
#define CERT_PKEY_STRICT_FLAGS \
(CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
| CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
int idx)
{
int i;
int rv = 0;
int check_flags = 0, strict_mode;
CERT_PKEY *cpk = NULL;
CERT *c = s->cert;
uint32_t *pvalid;
unsigned int suiteb_flags = tls1_suiteb(s);
/* idx == -1 means checking server chains */
if (idx != -1) {
/* idx == -2 means checking client certificate chains */
if (idx == -2) {
cpk = c->key;
idx = cpk - c->pkeys;
} else
cpk = c->pkeys + idx;
pvalid = s->s3->tmp.valid_flags + idx;
x = cpk->x509;
pk = cpk->privatekey;
chain = cpk->chain;
strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
/* If no cert or key, forget it */
if (!x || !pk)
goto end;
} else {
if (!x || !pk)
return 0;
idx = ssl_cert_type(x, pk);
if (idx == -1)
return 0;
pvalid = s->s3->tmp.valid_flags + idx;
if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
check_flags = CERT_PKEY_STRICT_FLAGS;
else
check_flags = CERT_PKEY_VALID_FLAGS;
strict_mode = 1;
}
if (suiteb_flags) {
int ok;
if (check_flags)
check_flags |= CERT_PKEY_SUITEB;
ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
if (ok == X509_V_OK)
rv |= CERT_PKEY_SUITEB;
else if (!check_flags)
goto end;
}
/*
* Check all signature algorithms are consistent with signature
* algorithms extension if TLS 1.2 or later and strict mode.
*/
if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode) {
int default_nid;
unsigned char rsign = 0;
if (s->s3->tmp.peer_sigalgs)
default_nid = 0;
/* If no sigalgs extension use defaults from RFC5246 */
else {
switch (idx) {
case SSL_PKEY_RSA_ENC:
case SSL_PKEY_RSA_SIGN:
rsign = TLSEXT_signature_rsa;
default_nid = NID_sha1WithRSAEncryption;
break;
case SSL_PKEY_DSA_SIGN:
rsign = TLSEXT_signature_dsa;
default_nid = NID_dsaWithSHA1;
break;
case SSL_PKEY_ECC:
rsign = TLSEXT_signature_ecdsa;
default_nid = NID_ecdsa_with_SHA1;
break;
case SSL_PKEY_GOST01:
rsign = TLSEXT_signature_gostr34102001;
default_nid = NID_id_GostR3411_94_with_GostR3410_2001;
break;
case SSL_PKEY_GOST12_256:
rsign = TLSEXT_signature_gostr34102012_256;
default_nid = NID_id_tc26_signwithdigest_gost3410_2012_256;
break;
case SSL_PKEY_GOST12_512:
rsign = TLSEXT_signature_gostr34102012_512;
default_nid = NID_id_tc26_signwithdigest_gost3410_2012_512;
break;
default:
default_nid = -1;
break;
}
}
/*
* If peer sent no signature algorithms extension and we have set
* preferred signature algorithms check we support sha1.
*/
if (default_nid > 0 && c->conf_sigalgs) {
size_t j;
const unsigned char *p = c->conf_sigalgs;
for (j = 0; j < c->conf_sigalgslen; j += 2, p += 2) {
if (p[0] == TLSEXT_hash_sha1 && p[1] == rsign)
break;
}
if (j == c->conf_sigalgslen) {
if (check_flags)
goto skip_sigs;
else
goto end;
}
}
/* Check signature algorithm of each cert in chain */
if (!tls1_check_sig_alg(c, x, default_nid)) {
if (!check_flags)
goto end;
} else
rv |= CERT_PKEY_EE_SIGNATURE;
rv |= CERT_PKEY_CA_SIGNATURE;
for (i = 0; i < sk_X509_num(chain); i++) {
if (!tls1_check_sig_alg(c, sk_X509_value(chain, i), default_nid)) {
if (check_flags) {
rv &= ~CERT_PKEY_CA_SIGNATURE;
break;
} else
goto end;
}
}
}
/* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
else if (check_flags)
rv |= CERT_PKEY_EE_SIGNATURE | CERT_PKEY_CA_SIGNATURE;
skip_sigs:
/* Check cert parameters are consistent */
if (tls1_check_cert_param(s, x, check_flags ? 1 : 2))
rv |= CERT_PKEY_EE_PARAM;
else if (!check_flags)
goto end;
if (!s->server)
rv |= CERT_PKEY_CA_PARAM;
/* In strict mode check rest of chain too */
else if (strict_mode) {
rv |= CERT_PKEY_CA_PARAM;
for (i = 0; i < sk_X509_num(chain); i++) {
X509 *ca = sk_X509_value(chain, i);
if (!tls1_check_cert_param(s, ca, 0)) {
if (check_flags) {
rv &= ~CERT_PKEY_CA_PARAM;
break;
} else
goto end;
}
}
}
if (!s->server && strict_mode) {
STACK_OF(X509_NAME) *ca_dn;
int check_type = 0;
switch (EVP_PKEY_id(pk)) {
case EVP_PKEY_RSA:
check_type = TLS_CT_RSA_SIGN;
break;
case EVP_PKEY_DSA:
check_type = TLS_CT_DSS_SIGN;
break;
case EVP_PKEY_EC:
check_type = TLS_CT_ECDSA_SIGN;
break;
}
if (check_type) {
const unsigned char *ctypes;
int ctypelen;
if (c->ctypes) {
ctypes = c->ctypes;
ctypelen = (int)c->ctype_num;
} else {
ctypes = (unsigned char *)s->s3->tmp.ctype;
ctypelen = s->s3->tmp.ctype_num;
}
for (i = 0; i < ctypelen; i++) {
if (ctypes[i] == check_type) {
rv |= CERT_PKEY_CERT_TYPE;
break;
}
}
if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
goto end;
} else
rv |= CERT_PKEY_CERT_TYPE;
ca_dn = s->s3->tmp.ca_names;
if (!sk_X509_NAME_num(ca_dn))
rv |= CERT_PKEY_ISSUER_NAME;
if (!(rv & CERT_PKEY_ISSUER_NAME)) {
if (ssl_check_ca_name(ca_dn, x))
rv |= CERT_PKEY_ISSUER_NAME;
}
if (!(rv & CERT_PKEY_ISSUER_NAME)) {
for (i = 0; i < sk_X509_num(chain); i++) {
X509 *xtmp = sk_X509_value(chain, i);
if (ssl_check_ca_name(ca_dn, xtmp)) {
rv |= CERT_PKEY_ISSUER_NAME;
break;
}
}
}
if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
goto end;
} else
rv |= CERT_PKEY_ISSUER_NAME | CERT_PKEY_CERT_TYPE;
if (!check_flags || (rv & check_flags) == check_flags)
rv |= CERT_PKEY_VALID;
end:
if (TLS1_get_version(s) >= TLS1_2_VERSION) {
if (*pvalid & CERT_PKEY_EXPLICIT_SIGN)
rv |= CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
else if (s->s3->tmp.md[idx] != NULL)
rv |= CERT_PKEY_SIGN;
} else
rv |= CERT_PKEY_SIGN | CERT_PKEY_EXPLICIT_SIGN;
/*
* When checking a CERT_PKEY structure all flags are irrelevant if the
* chain is invalid.
*/
if (!check_flags) {
if (rv & CERT_PKEY_VALID)
*pvalid = rv;
else {
/* Preserve explicit sign flag, clear rest */
*pvalid &= CERT_PKEY_EXPLICIT_SIGN;
return 0;
}
}
return rv;
}
/* Set validity of certificates in an SSL structure */
void tls1_set_cert_validity(SSL *s)
{
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_ENC);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_SIGN);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST01);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_256);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_512);
}
/* User level utiity function to check a chain is suitable */
int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
{
return tls1_check_chain(s, x, pk, chain, -1);
}
#ifndef OPENSSL_NO_DH
DH *ssl_get_auto_dh(SSL *s)
{
int dh_secbits = 80;
if (s->cert->dh_tmp_auto == 2)
return DH_get_1024_160();
if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aPSK)) {
if (s->s3->tmp.new_cipher->strength_bits == 256)
dh_secbits = 128;
else
dh_secbits = 80;
} else {
CERT_PKEY *cpk = ssl_get_server_send_pkey(s);
dh_secbits = EVP_PKEY_security_bits(cpk->privatekey);
}
if (dh_secbits >= 128) {
DH *dhp = DH_new();
BIGNUM *p, *g;
if (dhp == NULL)
return NULL;
g = BN_new();
if (g != NULL)
BN_set_word(g, 2);
if (dh_secbits >= 192)
p = BN_get_rfc3526_prime_8192(NULL);
else
p = BN_get_rfc3526_prime_3072(NULL);
if (p == NULL || g == NULL || !DH_set0_pqg(dhp, p, NULL, g)) {
DH_free(dhp);
BN_free(p);
BN_free(g);
return NULL;
}
return dhp;
}
if (dh_secbits >= 112)
return DH_get_2048_224();
return DH_get_1024_160();
}
#endif
static int ssl_security_cert_key(SSL *s, SSL_CTX *ctx, X509 *x, int op)
{
int secbits = -1;
EVP_PKEY *pkey = X509_get0_pubkey(x);
if (pkey) {
/*
* If no parameters this will return -1 and fail using the default
* security callback for any non-zero security level. This will
* reject keys which omit parameters but this only affects DSA and
* omission of parameters is never (?) done in practice.
*/
secbits = EVP_PKEY_security_bits(pkey);
}
if (s)
return ssl_security(s, op, secbits, 0, x);
else
return ssl_ctx_security(ctx, op, secbits, 0, x);
}
static int ssl_security_cert_sig(SSL *s, SSL_CTX *ctx, X509 *x, int op)
{
/* Lookup signature algorithm digest */
int secbits = -1, md_nid = NID_undef, sig_nid;
/* Don't check signature if self signed */
if ((X509_get_extension_flags(x) & EXFLAG_SS) != 0)
return 1;
sig_nid = X509_get_signature_nid(x);
if (sig_nid && OBJ_find_sigid_algs(sig_nid, &md_nid, NULL)) {
const EVP_MD *md;
if (md_nid && (md = EVP_get_digestbynid(md_nid)))
secbits = EVP_MD_size(md) * 4;
}
if (s)
return ssl_security(s, op, secbits, md_nid, x);
else
return ssl_ctx_security(ctx, op, secbits, md_nid, x);
}
int ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee)
{
if (vfy)
vfy = SSL_SECOP_PEER;
if (is_ee) {
if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_EE_KEY | vfy))
return SSL_R_EE_KEY_TOO_SMALL;
} else {
if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_CA_KEY | vfy))
return SSL_R_CA_KEY_TOO_SMALL;
}
if (!ssl_security_cert_sig(s, ctx, x, SSL_SECOP_CA_MD | vfy))
return SSL_R_CA_MD_TOO_WEAK;
return 1;
}
/*
* Check security of a chain, if sk includes the end entity certificate then
* x is NULL. If vfy is 1 then we are verifying a peer chain and not sending
* one to the peer. Return values: 1 if ok otherwise error code to use
*/
int ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *x, int vfy)
{
int rv, start_idx, i;
if (x == NULL) {
x = sk_X509_value(sk, 0);
start_idx = 1;
} else
start_idx = 0;
rv = ssl_security_cert(s, NULL, x, vfy, 1);
if (rv != 1)
return rv;
for (i = start_idx; i < sk_X509_num(sk); i++) {
x = sk_X509_value(sk, i);
rv = ssl_security_cert(s, NULL, x, vfy, 0);
if (rv != 1)
return rv;
}
return 1;
}
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