openssl/crypto/dh/dh_ameth.c
raja-ashok 9aaecbfc98 TLS1.3 FFDHE Support
Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8178)
2019-06-12 10:18:34 +01:00

920 lines
23 KiB
C

/*
* Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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 "internal/cryptlib.h"
#include <openssl/x509.h>
#include <openssl/asn1.h>
#include "dh_locl.h"
#include <openssl/bn.h>
#include "internal/asn1_int.h"
#include "internal/evp_int.h"
#include <openssl/cms.h>
/*
* i2d/d2i like DH parameter functions which use the appropriate routine for
* PKCS#3 DH or X9.42 DH.
*/
static DH *d2i_dhp(const EVP_PKEY *pkey, const unsigned char **pp,
long length)
{
if (pkey->ameth == &dhx_asn1_meth)
return d2i_DHxparams(NULL, pp, length);
return d2i_DHparams(NULL, pp, length);
}
static int i2d_dhp(const EVP_PKEY *pkey, const DH *a, unsigned char **pp)
{
if (pkey->ameth == &dhx_asn1_meth)
return i2d_DHxparams(a, pp);
return i2d_DHparams(a, pp);
}
static void int_dh_free(EVP_PKEY *pkey)
{
DH_free(pkey->pkey.dh);
}
static int dh_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
{
const unsigned char *p, *pm;
int pklen, pmlen;
int ptype;
const void *pval;
const ASN1_STRING *pstr;
X509_ALGOR *palg;
ASN1_INTEGER *public_key = NULL;
DH *dh = NULL;
if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
if (ptype != V_ASN1_SEQUENCE) {
DHerr(DH_F_DH_PUB_DECODE, DH_R_PARAMETER_ENCODING_ERROR);
goto err;
}
pstr = pval;
pm = pstr->data;
pmlen = pstr->length;
if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL) {
DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
goto err;
}
if ((public_key = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL) {
DHerr(DH_F_DH_PUB_DECODE, DH_R_DECODE_ERROR);
goto err;
}
/* We have parameters now set public key */
if ((dh->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
DHerr(DH_F_DH_PUB_DECODE, DH_R_BN_DECODE_ERROR);
goto err;
}
ASN1_INTEGER_free(public_key);
EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
return 1;
err:
ASN1_INTEGER_free(public_key);
DH_free(dh);
return 0;
}
static int dh_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
{
DH *dh;
int ptype;
unsigned char *penc = NULL;
int penclen;
ASN1_STRING *str;
ASN1_INTEGER *pub_key = NULL;
dh = pkey->pkey.dh;
str = ASN1_STRING_new();
if (str == NULL) {
DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
goto err;
}
str->length = i2d_dhp(pkey, dh, &str->data);
if (str->length <= 0) {
DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
goto err;
}
ptype = V_ASN1_SEQUENCE;
pub_key = BN_to_ASN1_INTEGER(dh->pub_key, NULL);
if (!pub_key)
goto err;
penclen = i2d_ASN1_INTEGER(pub_key, &penc);
ASN1_INTEGER_free(pub_key);
if (penclen <= 0) {
DHerr(DH_F_DH_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
goto err;
}
if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
ptype, str, penc, penclen))
return 1;
err:
OPENSSL_free(penc);
ASN1_STRING_free(str);
return 0;
}
/*
* PKCS#8 DH is defined in PKCS#11 of all places. It is similar to DH in that
* the AlgorithmIdentifier contains the parameters, the private key is
* explicitly included and the pubkey must be recalculated.
*/
static int dh_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
{
const unsigned char *p, *pm;
int pklen, pmlen;
int ptype;
const void *pval;
const ASN1_STRING *pstr;
const X509_ALGOR *palg;
ASN1_INTEGER *privkey = NULL;
DH *dh = NULL;
if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
if (ptype != V_ASN1_SEQUENCE)
goto decerr;
if ((privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)) == NULL)
goto decerr;
pstr = pval;
pm = pstr->data;
pmlen = pstr->length;
if ((dh = d2i_dhp(pkey, &pm, pmlen)) == NULL)
goto decerr;
/* We have parameters now set private key */
if ((dh->priv_key = BN_secure_new()) == NULL
|| !ASN1_INTEGER_to_BN(privkey, dh->priv_key)) {
DHerr(DH_F_DH_PRIV_DECODE, DH_R_BN_ERROR);
goto dherr;
}
/* Calculate public key */
if (!DH_generate_key(dh))
goto dherr;
EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
ASN1_STRING_clear_free(privkey);
return 1;
decerr:
DHerr(DH_F_DH_PRIV_DECODE, EVP_R_DECODE_ERROR);
dherr:
DH_free(dh);
ASN1_STRING_clear_free(privkey);
return 0;
}
static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
ASN1_STRING *params = NULL;
ASN1_INTEGER *prkey = NULL;
unsigned char *dp = NULL;
int dplen;
params = ASN1_STRING_new();
if (params == NULL) {
DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
goto err;
}
params->length = i2d_dhp(pkey, pkey->pkey.dh, &params->data);
if (params->length <= 0) {
DHerr(DH_F_DH_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
goto err;
}
params->type = V_ASN1_SEQUENCE;
/* Get private key into integer */
prkey = BN_to_ASN1_INTEGER(pkey->pkey.dh->priv_key, NULL);
if (!prkey) {
DHerr(DH_F_DH_PRIV_ENCODE, DH_R_BN_ERROR);
goto err;
}
dplen = i2d_ASN1_INTEGER(prkey, &dp);
ASN1_STRING_clear_free(prkey);
prkey = NULL;
if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
V_ASN1_SEQUENCE, params, dp, dplen))
goto err;
return 1;
err:
OPENSSL_free(dp);
ASN1_STRING_free(params);
ASN1_STRING_clear_free(prkey);
return 0;
}
static int dh_param_decode(EVP_PKEY *pkey,
const unsigned char **pder, int derlen)
{
DH *dh;
if ((dh = d2i_dhp(pkey, pder, derlen)) == NULL) {
DHerr(DH_F_DH_PARAM_DECODE, ERR_R_DH_LIB);
return 0;
}
EVP_PKEY_assign(pkey, pkey->ameth->pkey_id, dh);
return 1;
}
static int dh_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
{
return i2d_dhp(pkey, pkey->pkey.dh, pder);
}
static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
{
int reason = ERR_R_BUF_LIB;
const char *ktype = NULL;
BIGNUM *priv_key, *pub_key;
if (ptype == 2)
priv_key = x->priv_key;
else
priv_key = NULL;
if (ptype > 0)
pub_key = x->pub_key;
else
pub_key = NULL;
if (x->p == NULL || (ptype == 2 && priv_key == NULL)
|| (ptype > 0 && pub_key == NULL)) {
reason = ERR_R_PASSED_NULL_PARAMETER;
goto err;
}
if (ptype == 2)
ktype = "DH Private-Key";
else if (ptype == 1)
ktype = "DH Public-Key";
else
ktype = "DH Parameters";
BIO_indent(bp, indent, 128);
if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
goto err;
indent += 4;
if (!ASN1_bn_print(bp, "private-key:", priv_key, NULL, indent))
goto err;
if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
goto err;
if (!ASN1_bn_print(bp, "prime:", x->p, NULL, indent))
goto err;
if (!ASN1_bn_print(bp, "generator:", x->g, NULL, indent))
goto err;
if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, NULL, indent))
goto err;
if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, NULL, indent))
goto err;
if (x->seed) {
int i;
BIO_indent(bp, indent, 128);
BIO_puts(bp, "seed:");
for (i = 0; i < x->seedlen; i++) {
if ((i % 15) == 0) {
if (BIO_puts(bp, "\n") <= 0
|| !BIO_indent(bp, indent + 4, 128))
goto err;
}
if (BIO_printf(bp, "%02x%s", x->seed[i],
((i + 1) == x->seedlen) ? "" : ":") <= 0)
goto err;
}
if (BIO_write(bp, "\n", 1) <= 0)
return 0;
}
if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, NULL, indent))
goto err;
if (x->length != 0) {
BIO_indent(bp, indent, 128);
if (BIO_printf(bp, "recommended-private-length: %d bits\n",
(int)x->length) <= 0)
goto err;
}
return 1;
err:
DHerr(DH_F_DO_DH_PRINT, reason);
return 0;
}
static int int_dh_size(const EVP_PKEY *pkey)
{
return DH_size(pkey->pkey.dh);
}
static int dh_bits(const EVP_PKEY *pkey)
{
return BN_num_bits(pkey->pkey.dh->p);
}
static int dh_security_bits(const EVP_PKEY *pkey)
{
return DH_security_bits(pkey->pkey.dh);
}
static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
{
if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
return 0;
else if (a->ameth == &dhx_asn1_meth) {
if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
return 0;
}
return 1;
}
static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
{
BIGNUM *a;
/*
* If source is read only just copy the pointer, so
* we don't have to reallocate it.
*/
if (src == NULL)
a = NULL;
else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
&& !BN_get_flags(src, BN_FLG_MALLOCED))
a = (BIGNUM *)src;
else if ((a = BN_dup(src)) == NULL)
return 0;
BN_clear_free(*dst);
*dst = a;
return 1;
}
static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
{
if (is_x942 == -1)
is_x942 = ! !from->q;
if (!int_dh_bn_cpy(&to->p, from->p))
return 0;
if (!int_dh_bn_cpy(&to->g, from->g))
return 0;
if (is_x942) {
if (!int_dh_bn_cpy(&to->q, from->q))
return 0;
if (!int_dh_bn_cpy(&to->j, from->j))
return 0;
OPENSSL_free(to->seed);
to->seed = NULL;
to->seedlen = 0;
if (from->seed) {
to->seed = OPENSSL_memdup(from->seed, from->seedlen);
if (!to->seed)
return 0;
to->seedlen = from->seedlen;
}
} else
to->length = from->length;
return 1;
}
DH *DHparams_dup(const DH *dh)
{
DH *ret;
ret = DH_new();
if (ret == NULL)
return NULL;
if (!int_dh_param_copy(ret, dh, -1)) {
DH_free(ret);
return NULL;
}
return ret;
}
static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
{
if (to->pkey.dh == NULL) {
to->pkey.dh = DH_new();
if (to->pkey.dh == NULL)
return 0;
}
return int_dh_param_copy(to->pkey.dh, from->pkey.dh,
from->ameth == &dhx_asn1_meth);
}
static int dh_missing_parameters(const EVP_PKEY *a)
{
if (a->pkey.dh == NULL || a->pkey.dh->p == NULL || a->pkey.dh->g == NULL)
return 1;
return 0;
}
static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
if (dh_cmp_parameters(a, b) == 0)
return 0;
if (BN_cmp(b->pkey.dh->pub_key, a->pkey.dh->pub_key) != 0)
return 0;
else
return 1;
}
static int dh_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return do_dh_print(bp, pkey->pkey.dh, indent, 0);
}
static int dh_public_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return do_dh_print(bp, pkey->pkey.dh, indent, 1);
}
static int dh_private_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return do_dh_print(bp, pkey->pkey.dh, indent, 2);
}
int DHparams_print(BIO *bp, const DH *x)
{
return do_dh_print(bp, x, 4, 0);
}
#ifndef OPENSSL_NO_CMS
static int dh_cms_decrypt(CMS_RecipientInfo *ri);
static int dh_cms_encrypt(CMS_RecipientInfo *ri);
#endif
static int dh_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
switch (op) {
case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
return dh_buf2key(EVP_PKEY_get0_DH(pkey), arg2, arg1);
case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
return dh_key2buf(EVP_PKEY_get0_DH(pkey), arg2);
default:
return -2;
}
}
static int dhx_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
switch (op) {
#ifndef OPENSSL_NO_CMS
case ASN1_PKEY_CTRL_CMS_ENVELOPE:
if (arg1 == 1)
return dh_cms_decrypt(arg2);
else if (arg1 == 0)
return dh_cms_encrypt(arg2);
return -2;
case ASN1_PKEY_CTRL_CMS_RI_TYPE:
*(int *)arg2 = CMS_RECIPINFO_AGREE;
return 1;
#endif
default:
return -2;
}
}
static int dh_pkey_public_check(const EVP_PKEY *pkey)
{
DH *dh = pkey->pkey.dh;
if (dh->pub_key == NULL) {
DHerr(DH_F_DH_PKEY_PUBLIC_CHECK, DH_R_MISSING_PUBKEY);
return 0;
}
return DH_check_pub_key_ex(dh, dh->pub_key);
}
static int dh_pkey_param_check(const EVP_PKEY *pkey)
{
DH *dh = pkey->pkey.dh;
return DH_check_ex(dh);
}
const EVP_PKEY_ASN1_METHOD dh_asn1_meth = {
EVP_PKEY_DH,
EVP_PKEY_DH,
0,
"DH",
"OpenSSL PKCS#3 DH method",
dh_pub_decode,
dh_pub_encode,
dh_pub_cmp,
dh_public_print,
dh_priv_decode,
dh_priv_encode,
dh_private_print,
int_dh_size,
dh_bits,
dh_security_bits,
dh_param_decode,
dh_param_encode,
dh_missing_parameters,
dh_copy_parameters,
dh_cmp_parameters,
dh_param_print,
0,
int_dh_free,
dh_pkey_ctrl,
0, 0, 0, 0, 0,
0,
dh_pkey_public_check,
dh_pkey_param_check
};
const EVP_PKEY_ASN1_METHOD dhx_asn1_meth = {
EVP_PKEY_DHX,
EVP_PKEY_DHX,
0,
"X9.42 DH",
"OpenSSL X9.42 DH method",
dh_pub_decode,
dh_pub_encode,
dh_pub_cmp,
dh_public_print,
dh_priv_decode,
dh_priv_encode,
dh_private_print,
int_dh_size,
dh_bits,
dh_security_bits,
dh_param_decode,
dh_param_encode,
dh_missing_parameters,
dh_copy_parameters,
dh_cmp_parameters,
dh_param_print,
0,
int_dh_free,
dhx_pkey_ctrl,
0, 0, 0, 0, 0,
0,
dh_pkey_public_check,
dh_pkey_param_check
};
#ifndef OPENSSL_NO_CMS
static int dh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
{
const ASN1_OBJECT *aoid;
int atype;
const void *aval;
ASN1_INTEGER *public_key = NULL;
int rv = 0;
EVP_PKEY *pkpeer = NULL, *pk = NULL;
DH *dhpeer = NULL;
const unsigned char *p;
int plen;
X509_ALGOR_get0(&aoid, &atype, &aval, alg);
if (OBJ_obj2nid(aoid) != NID_dhpublicnumber)
goto err;
/* Only absent parameters allowed in RFC XXXX */
if (atype != V_ASN1_UNDEF && atype == V_ASN1_NULL)
goto err;
pk = EVP_PKEY_CTX_get0_pkey(pctx);
if (!pk)
goto err;
if (pk->type != EVP_PKEY_DHX)
goto err;
/* Get parameters from parent key */
dhpeer = DHparams_dup(pk->pkey.dh);
/* We have parameters now set public key */
plen = ASN1_STRING_length(pubkey);
p = ASN1_STRING_get0_data(pubkey);
if (!p || !plen)
goto err;
if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) {
DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_DECODE_ERROR);
goto err;
}
/* We have parameters now set public key */
if ((dhpeer->pub_key = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) {
DHerr(DH_F_DH_CMS_SET_PEERKEY, DH_R_BN_DECODE_ERROR);
goto err;
}
pkpeer = EVP_PKEY_new();
if (pkpeer == NULL)
goto err;
EVP_PKEY_assign(pkpeer, pk->ameth->pkey_id, dhpeer);
dhpeer = NULL;
if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
rv = 1;
err:
ASN1_INTEGER_free(public_key);
EVP_PKEY_free(pkpeer);
DH_free(dhpeer);
return rv;
}
static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
{
int rv = 0;
X509_ALGOR *alg, *kekalg = NULL;
ASN1_OCTET_STRING *ukm;
const unsigned char *p;
unsigned char *dukm = NULL;
size_t dukmlen = 0;
int keylen, plen;
const EVP_CIPHER *kekcipher;
EVP_CIPHER_CTX *kekctx;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
goto err;
/*
* For DH we only have one OID permissible. If ever any more get defined
* we will need something cleverer.
*/
if (OBJ_obj2nid(alg->algorithm) != NID_id_smime_alg_ESDH) {
DHerr(DH_F_DH_CMS_SET_SHARED_INFO, DH_R_KDF_PARAMETER_ERROR);
goto err;
}
if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0)
goto err;
if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, EVP_sha1()) <= 0)
goto err;
if (alg->parameter->type != V_ASN1_SEQUENCE)
goto err;
p = alg->parameter->value.sequence->data;
plen = alg->parameter->value.sequence->length;
kekalg = d2i_X509_ALGOR(NULL, &p, plen);
if (!kekalg)
goto err;
kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
if (!kekctx)
goto err;
kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
goto err;
if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
goto err;
if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
goto err;
keylen = EVP_CIPHER_CTX_key_length(kekctx);
if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
goto err;
/* Use OBJ_nid2obj to ensure we use built in OID that isn't freed */
if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx,
OBJ_nid2obj(EVP_CIPHER_type(kekcipher)))
<= 0)
goto err;
if (ukm) {
dukmlen = ASN1_STRING_length(ukm);
dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
if (!dukm)
goto err;
}
if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
goto err;
dukm = NULL;
rv = 1;
err:
X509_ALGOR_free(kekalg);
OPENSSL_free(dukm);
return rv;
}
static int dh_cms_decrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pctx)
return 0;
/* See if we need to set peer key */
if (!EVP_PKEY_CTX_get0_peerkey(pctx)) {
X509_ALGOR *alg;
ASN1_BIT_STRING *pubkey;
if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
NULL, NULL, NULL))
return 0;
if (!alg || !pubkey)
return 0;
if (!dh_cms_set_peerkey(pctx, alg, pubkey)) {
DHerr(DH_F_DH_CMS_DECRYPT, DH_R_PEER_KEY_ERROR);
return 0;
}
}
/* Set DH derivation parameters and initialise unwrap context */
if (!dh_cms_set_shared_info(pctx, ri)) {
DHerr(DH_F_DH_CMS_DECRYPT, DH_R_SHARED_INFO_ERROR);
return 0;
}
return 1;
}
static int dh_cms_encrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
EVP_PKEY *pkey;
EVP_CIPHER_CTX *ctx;
int keylen;
X509_ALGOR *talg, *wrap_alg = NULL;
const ASN1_OBJECT *aoid;
ASN1_BIT_STRING *pubkey;
ASN1_STRING *wrap_str;
ASN1_OCTET_STRING *ukm;
unsigned char *penc = NULL, *dukm = NULL;
int penclen;
size_t dukmlen = 0;
int rv = 0;
int kdf_type, wrap_nid;
const EVP_MD *kdf_md;
pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pctx)
return 0;
/* Get ephemeral key */
pkey = EVP_PKEY_CTX_get0_pkey(pctx);
if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
NULL, NULL, NULL))
goto err;
X509_ALGOR_get0(&aoid, NULL, NULL, talg);
/* Is everything uninitialised? */
if (aoid == OBJ_nid2obj(NID_undef)) {
ASN1_INTEGER *pubk = BN_to_ASN1_INTEGER(pkey->pkey.dh->pub_key, NULL);
if (!pubk)
goto err;
/* Set the key */
penclen = i2d_ASN1_INTEGER(pubk, &penc);
ASN1_INTEGER_free(pubk);
if (penclen <= 0)
goto err;
ASN1_STRING_set0(pubkey, penc, penclen);
pubkey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
pubkey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
penc = NULL;
X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber),
V_ASN1_UNDEF, NULL);
}
/* See if custom parameters set */
kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx);
if (kdf_type <= 0)
goto err;
if (!EVP_PKEY_CTX_get_dh_kdf_md(pctx, &kdf_md))
goto err;
if (kdf_type == EVP_PKEY_DH_KDF_NONE) {
kdf_type = EVP_PKEY_DH_KDF_X9_42;
if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, kdf_type) <= 0)
goto err;
} else if (kdf_type != EVP_PKEY_DH_KDF_X9_42)
/* Unknown KDF */
goto err;
if (kdf_md == NULL) {
/* Only SHA1 supported */
kdf_md = EVP_sha1();
if (EVP_PKEY_CTX_set_dh_kdf_md(pctx, kdf_md) <= 0)
goto err;
} else if (EVP_MD_type(kdf_md) != NID_sha1)
/* Unsupported digest */
goto err;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
goto err;
/* Get wrap NID */
ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
wrap_nid = EVP_CIPHER_CTX_type(ctx);
if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0)
goto err;
keylen = EVP_CIPHER_CTX_key_length(ctx);
/* Package wrap algorithm in an AlgorithmIdentifier */
wrap_alg = X509_ALGOR_new();
if (wrap_alg == NULL)
goto err;
wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
wrap_alg->parameter = ASN1_TYPE_new();
if (wrap_alg->parameter == NULL)
goto err;
if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
goto err;
if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
ASN1_TYPE_free(wrap_alg->parameter);
wrap_alg->parameter = NULL;
}
if (EVP_PKEY_CTX_set_dh_kdf_outlen(pctx, keylen) <= 0)
goto err;
if (ukm) {
dukmlen = ASN1_STRING_length(ukm);
dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen);
if (!dukm)
goto err;
}
if (EVP_PKEY_CTX_set0_dh_kdf_ukm(pctx, dukm, dukmlen) <= 0)
goto err;
dukm = NULL;
/*
* Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
* of another AlgorithmIdentifier.
*/
penc = NULL;
penclen = i2d_X509_ALGOR(wrap_alg, &penc);
if (!penc || !penclen)
goto err;
wrap_str = ASN1_STRING_new();
if (wrap_str == NULL)
goto err;
ASN1_STRING_set0(wrap_str, penc, penclen);
penc = NULL;
X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH),
V_ASN1_SEQUENCE, wrap_str);
rv = 1;
err:
OPENSSL_free(penc);
X509_ALGOR_free(wrap_alg);
return rv;
}
#endif