openssl/crypto/ec/ec_ameth.c
Dr. Stephen Henson f72f00d495 Parameter copy sanity checks.
Don't copy parameters is they're already present in the destination.
Return error if an attempt is made to copy different parameters to
destination. Update documentation.

If key type is not initialised return missing parameters

RT#4149

Reviewed-by: Richard Levitte <levitte@openssl.org>
2016-05-31 13:06:16 +01:00

862 lines
23 KiB
C

/*
* Copyright 2006-2016 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 "internal/cryptlib.h"
#include <openssl/x509.h>
#include <openssl/ec.h>
#include <openssl/bn.h>
#include <openssl/cms.h>
#include <openssl/asn1t.h>
#include "internal/asn1_int.h"
#include "internal/evp_int.h"
#ifndef OPENSSL_NO_CMS
static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
#endif
static int eckey_param2type(int *pptype, void **ppval, EC_KEY *ec_key)
{
const EC_GROUP *group;
int nid;
if (ec_key == NULL || (group = EC_KEY_get0_group(ec_key)) == NULL) {
ECerr(EC_F_ECKEY_PARAM2TYPE, EC_R_MISSING_PARAMETERS);
return 0;
}
if (EC_GROUP_get_asn1_flag(group)
&& (nid = EC_GROUP_get_curve_name(group)))
/* we have a 'named curve' => just set the OID */
{
*ppval = OBJ_nid2obj(nid);
*pptype = V_ASN1_OBJECT;
} else { /* explicit parameters */
ASN1_STRING *pstr = NULL;
pstr = ASN1_STRING_new();
if (pstr == NULL)
return 0;
pstr->length = i2d_ECParameters(ec_key, &pstr->data);
if (pstr->length <= 0) {
ASN1_STRING_free(pstr);
ECerr(EC_F_ECKEY_PARAM2TYPE, ERR_R_EC_LIB);
return 0;
}
*ppval = pstr;
*pptype = V_ASN1_SEQUENCE;
}
return 1;
}
static int eckey_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
{
EC_KEY *ec_key = pkey->pkey.ec;
void *pval = NULL;
int ptype;
unsigned char *penc = NULL, *p;
int penclen;
if (!eckey_param2type(&ptype, &pval, ec_key)) {
ECerr(EC_F_ECKEY_PUB_ENCODE, ERR_R_EC_LIB);
return 0;
}
penclen = i2o_ECPublicKey(ec_key, NULL);
if (penclen <= 0)
goto err;
penc = OPENSSL_malloc(penclen);
if (penc == NULL)
goto err;
p = penc;
penclen = i2o_ECPublicKey(ec_key, &p);
if (penclen <= 0)
goto err;
if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_EC),
ptype, pval, penc, penclen))
return 1;
err:
if (ptype == V_ASN1_OBJECT)
ASN1_OBJECT_free(pval);
else
ASN1_STRING_free(pval);
OPENSSL_free(penc);
return 0;
}
static EC_KEY *eckey_type2param(int ptype, void *pval)
{
EC_KEY *eckey = NULL;
if (ptype == V_ASN1_SEQUENCE) {
ASN1_STRING *pstr = pval;
const unsigned char *pm = NULL;
int pmlen;
pm = pstr->data;
pmlen = pstr->length;
if ((eckey = d2i_ECParameters(NULL, &pm, pmlen)) == NULL) {
ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
goto ecerr;
}
} else if (ptype == V_ASN1_OBJECT) {
ASN1_OBJECT *poid = pval;
EC_GROUP *group;
/*
* type == V_ASN1_OBJECT => the parameters are given by an asn1 OID
*/
if ((eckey = EC_KEY_new()) == NULL) {
ECerr(EC_F_ECKEY_TYPE2PARAM, ERR_R_MALLOC_FAILURE);
goto ecerr;
}
group = EC_GROUP_new_by_curve_name(OBJ_obj2nid(poid));
if (group == NULL)
goto ecerr;
EC_GROUP_set_asn1_flag(group, OPENSSL_EC_NAMED_CURVE);
if (EC_KEY_set_group(eckey, group) == 0)
goto ecerr;
EC_GROUP_free(group);
} else {
ECerr(EC_F_ECKEY_TYPE2PARAM, EC_R_DECODE_ERROR);
goto ecerr;
}
return eckey;
ecerr:
EC_KEY_free(eckey);
return NULL;
}
static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
{
const unsigned char *p = NULL;
void *pval;
int ptype, pklen;
EC_KEY *eckey = NULL;
X509_ALGOR *palg;
if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
eckey = eckey_type2param(ptype, pval);
if (!eckey) {
ECerr(EC_F_ECKEY_PUB_DECODE, ERR_R_EC_LIB);
return 0;
}
/* We have parameters now set public key */
if (!o2i_ECPublicKey(&eckey, &p, pklen)) {
ECerr(EC_F_ECKEY_PUB_DECODE, EC_R_DECODE_ERROR);
goto ecerr;
}
EVP_PKEY_assign_EC_KEY(pkey, eckey);
return 1;
ecerr:
EC_KEY_free(eckey);
return 0;
}
static int eckey_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
int r;
const EC_GROUP *group = EC_KEY_get0_group(b->pkey.ec);
const EC_POINT *pa = EC_KEY_get0_public_key(a->pkey.ec),
*pb = EC_KEY_get0_public_key(b->pkey.ec);
r = EC_POINT_cmp(group, pa, pb, NULL);
if (r == 0)
return 1;
if (r == 1)
return 0;
return -2;
}
static int eckey_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)
{
const unsigned char *p = NULL;
void *pval;
int ptype, pklen;
EC_KEY *eckey = NULL;
X509_ALGOR *palg;
if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))
return 0;
X509_ALGOR_get0(NULL, &ptype, &pval, palg);
eckey = eckey_type2param(ptype, pval);
if (!eckey)
goto ecliberr;
/* We have parameters now set private key */
if (!d2i_ECPrivateKey(&eckey, &p, pklen)) {
ECerr(EC_F_ECKEY_PRIV_DECODE, EC_R_DECODE_ERROR);
goto ecerr;
}
EVP_PKEY_assign_EC_KEY(pkey, eckey);
return 1;
ecliberr:
ECerr(EC_F_ECKEY_PRIV_DECODE, ERR_R_EC_LIB);
ecerr:
EC_KEY_free(eckey);
return 0;
}
static int eckey_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
EC_KEY *ec_key;
unsigned char *ep, *p;
int eplen, ptype;
void *pval;
unsigned int tmp_flags, old_flags;
ec_key = pkey->pkey.ec;
if (!eckey_param2type(&ptype, &pval, ec_key)) {
ECerr(EC_F_ECKEY_PRIV_ENCODE, EC_R_DECODE_ERROR);
return 0;
}
/* set the private key */
/*
* do not include the parameters in the SEC1 private key see PKCS#11
* 12.11
*/
old_flags = EC_KEY_get_enc_flags(ec_key);
tmp_flags = old_flags | EC_PKEY_NO_PARAMETERS;
EC_KEY_set_enc_flags(ec_key, tmp_flags);
eplen = i2d_ECPrivateKey(ec_key, NULL);
if (!eplen) {
EC_KEY_set_enc_flags(ec_key, old_flags);
ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
return 0;
}
ep = OPENSSL_malloc(eplen);
if (ep == NULL) {
EC_KEY_set_enc_flags(ec_key, old_flags);
ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
return 0;
}
p = ep;
if (!i2d_ECPrivateKey(ec_key, &p)) {
EC_KEY_set_enc_flags(ec_key, old_flags);
OPENSSL_free(ep);
ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB);
return 0;
}
/* restore old encoding flags */
EC_KEY_set_enc_flags(ec_key, old_flags);
if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0,
ptype, pval, ep, eplen))
return 0;
return 1;
}
static int int_ec_size(const EVP_PKEY *pkey)
{
return ECDSA_size(pkey->pkey.ec);
}
static int ec_bits(const EVP_PKEY *pkey)
{
return EC_GROUP_order_bits(EC_KEY_get0_group(pkey->pkey.ec));
}
static int ec_security_bits(const EVP_PKEY *pkey)
{
int ecbits = ec_bits(pkey);
if (ecbits >= 512)
return 256;
if (ecbits >= 384)
return 192;
if (ecbits >= 256)
return 128;
if (ecbits >= 224)
return 112;
if (ecbits >= 160)
return 80;
return ecbits / 2;
}
static int ec_missing_parameters(const EVP_PKEY *pkey)
{
if (pkey->pkey.ec == NULL || EC_KEY_get0_group(pkey->pkey.ec) == NULL)
return 1;
return 0;
}
static int ec_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
{
EC_GROUP *group = EC_GROUP_dup(EC_KEY_get0_group(from->pkey.ec));
if (group == NULL)
return 0;
if (to->pkey.ec == NULL) {
to->pkey.ec = EC_KEY_new();
if (to->pkey.ec == NULL)
return 0;
}
if (EC_KEY_set_group(to->pkey.ec, group) == 0)
return 0;
EC_GROUP_free(group);
return 1;
}
static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
{
const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
*group_b = EC_KEY_get0_group(b->pkey.ec);
if (EC_GROUP_cmp(group_a, group_b, NULL))
return 0;
else
return 1;
}
static void int_ec_free(EVP_PKEY *pkey)
{
EC_KEY_free(pkey->pkey.ec);
}
typedef enum {
EC_KEY_PRINT_PRIVATE,
EC_KEY_PRINT_PUBLIC,
EC_KEY_PRINT_PARAM
} ec_print_t;
static int do_EC_KEY_print(BIO *bp, const EC_KEY *x, int off, ec_print_t ktype)
{
const char *ecstr;
unsigned char *priv = NULL, *pub = NULL;
size_t privlen = 0, publen = 0;
int ret = 0;
const EC_GROUP *group;
if (x == NULL || (group = EC_KEY_get0_group(x)) == NULL) {
ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
if (ktype != EC_KEY_PRINT_PARAM) {
publen = EC_KEY_key2buf(x, EC_KEY_get_conv_form(x), &pub, NULL);
if (publen == 0)
goto err;
}
if (ktype == EC_KEY_PRINT_PRIVATE && EC_KEY_get0_private_key(x) != NULL) {
privlen = EC_KEY_priv2buf(x, &priv);
if (privlen == 0)
goto err;
}
if (ktype == EC_KEY_PRINT_PRIVATE)
ecstr = "Private-Key";
else if (ktype == EC_KEY_PRINT_PUBLIC)
ecstr = "Public-Key";
else
ecstr = "ECDSA-Parameters";
if (!BIO_indent(bp, off, 128))
goto err;
if (BIO_printf(bp, "%s: (%d bit)\n", ecstr,
EC_GROUP_order_bits(group)) <= 0)
goto err;
if (privlen != 0) {
if (BIO_printf(bp, "%*spriv:\n", off, "") <= 0)
goto err;
if (ASN1_buf_print(bp, priv, privlen, off + 4) == 0)
goto err;
}
if (publen != 0) {
if (BIO_printf(bp, "%*spub:\n", off, "") <= 0)
goto err;
if (ASN1_buf_print(bp, pub, publen, off + 4) == 0)
goto err;
}
if (!ECPKParameters_print(bp, group, off))
goto err;
ret = 1;
err:
if (!ret)
ECerr(EC_F_DO_EC_KEY_PRINT, ERR_R_EC_LIB);
OPENSSL_clear_free(priv, privlen);
OPENSSL_free(pub);
return ret;
}
static int eckey_param_decode(EVP_PKEY *pkey,
const unsigned char **pder, int derlen)
{
EC_KEY *eckey;
if ((eckey = d2i_ECParameters(NULL, pder, derlen)) == NULL) {
ECerr(EC_F_ECKEY_PARAM_DECODE, ERR_R_EC_LIB);
return 0;
}
EVP_PKEY_assign_EC_KEY(pkey, eckey);
return 1;
}
static int eckey_param_encode(const EVP_PKEY *pkey, unsigned char **pder)
{
return i2d_ECParameters(pkey->pkey.ec, pder);
}
static int eckey_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PARAM);
}
static int eckey_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PUBLIC);
}
static int eckey_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return do_EC_KEY_print(bp, pkey->pkey.ec, indent, EC_KEY_PRINT_PRIVATE);
}
static int old_ec_priv_decode(EVP_PKEY *pkey,
const unsigned char **pder, int derlen)
{
EC_KEY *ec;
if ((ec = d2i_ECPrivateKey(NULL, pder, derlen)) == NULL) {
ECerr(EC_F_OLD_EC_PRIV_DECODE, EC_R_DECODE_ERROR);
return 0;
}
EVP_PKEY_assign_EC_KEY(pkey, ec);
return 1;
}
static int old_ec_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)
{
return i2d_ECPrivateKey(pkey->pkey.ec, pder);
}
static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
switch (op) {
case ASN1_PKEY_CTRL_PKCS7_SIGN:
if (arg1 == 0) {
int snid, hnid;
X509_ALGOR *alg1, *alg2;
PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);
if (alg1 == NULL || alg1->algorithm == NULL)
return -1;
hnid = OBJ_obj2nid(alg1->algorithm);
if (hnid == NID_undef)
return -1;
if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
return -1;
X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
}
return 1;
#ifndef OPENSSL_NO_CMS
case ASN1_PKEY_CTRL_CMS_SIGN:
if (arg1 == 0) {
int snid, hnid;
X509_ALGOR *alg1, *alg2;
CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
if (alg1 == NULL || alg1->algorithm == NULL)
return -1;
hnid = OBJ_obj2nid(alg1->algorithm);
if (hnid == NID_undef)
return -1;
if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
return -1;
X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
}
return 1;
case ASN1_PKEY_CTRL_CMS_ENVELOPE:
if (arg1 == 1)
return ecdh_cms_decrypt(arg2);
else if (arg1 == 0)
return ecdh_cms_encrypt(arg2);
return -2;
case ASN1_PKEY_CTRL_CMS_RI_TYPE:
*(int *)arg2 = CMS_RECIPINFO_AGREE;
return 1;
#endif
case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
*(int *)arg2 = NID_sha256;
return 2;
default:
return -2;
}
}
const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
EVP_PKEY_EC,
EVP_PKEY_EC,
0,
"EC",
"OpenSSL EC algorithm",
eckey_pub_decode,
eckey_pub_encode,
eckey_pub_cmp,
eckey_pub_print,
eckey_priv_decode,
eckey_priv_encode,
eckey_priv_print,
int_ec_size,
ec_bits,
ec_security_bits,
eckey_param_decode,
eckey_param_encode,
ec_missing_parameters,
ec_copy_parameters,
ec_cmp_parameters,
eckey_param_print,
0,
int_ec_free,
ec_pkey_ctrl,
old_ec_priv_decode,
old_ec_priv_encode
};
#ifndef OPENSSL_NO_CMS
static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
{
ASN1_OBJECT *aoid;
int atype;
void *aval;
int rv = 0;
EVP_PKEY *pkpeer = NULL;
EC_KEY *ecpeer = NULL;
const unsigned char *p;
int plen;
X509_ALGOR_get0(&aoid, &atype, &aval, alg);
if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
goto err;
/* If absent parameters get group from main key */
if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL) {
const EC_GROUP *grp;
EVP_PKEY *pk;
pk = EVP_PKEY_CTX_get0_pkey(pctx);
if (!pk)
goto err;
grp = EC_KEY_get0_group(pk->pkey.ec);
ecpeer = EC_KEY_new();
if (ecpeer == NULL)
goto err;
if (!EC_KEY_set_group(ecpeer, grp))
goto err;
} else {
ecpeer = eckey_type2param(atype, aval);
if (!ecpeer)
goto err;
}
/* We have parameters now set public key */
plen = ASN1_STRING_length(pubkey);
p = ASN1_STRING_data(pubkey);
if (!p || !plen)
goto err;
if (!o2i_ECPublicKey(&ecpeer, &p, plen))
goto err;
pkpeer = EVP_PKEY_new();
if (pkpeer == NULL)
goto err;
EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
rv = 1;
err:
EC_KEY_free(ecpeer);
EVP_PKEY_free(pkpeer);
return rv;
}
/* Set KDF parameters based on KDF NID */
static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
{
int kdf_nid, kdfmd_nid, cofactor;
const EVP_MD *kdf_md;
if (eckdf_nid == NID_undef)
return 0;
/* Lookup KDF type, cofactor mode and digest */
if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
return 0;
if (kdf_nid == NID_dh_std_kdf)
cofactor = 0;
else if (kdf_nid == NID_dh_cofactor_kdf)
cofactor = 1;
else
return 0;
if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
return 0;
if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
return 0;
kdf_md = EVP_get_digestbynid(kdfmd_nid);
if (!kdf_md)
return 0;
if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
return 0;
return 1;
}
static int ecdh_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 *der = NULL;
int plen, keylen;
const EVP_CIPHER *kekcipher;
EVP_CIPHER_CTX *kekctx;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
return 0;
if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
return 0;
}
if (alg->parameter->type != V_ASN1_SEQUENCE)
return 0;
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_ecdh_kdf_outlen(pctx, keylen) <= 0)
goto err;
plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
if (!plen)
goto err;
if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
goto err;
der = NULL;
rv = 1;
err:
X509_ALGOR_free(kekalg);
OPENSSL_free(der);
return rv;
}
static int ecdh_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 (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
return 0;
}
}
/* Set ECDH derivation parameters and initialise unwrap context */
if (!ecdh_cms_set_shared_info(pctx, ri)) {
ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
return 0;
}
return 1;
}
static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
EVP_PKEY *pkey;
EVP_CIPHER_CTX *ctx;
int keylen;
X509_ALGOR *talg, *wrap_alg = NULL;
ASN1_OBJECT *aoid;
ASN1_BIT_STRING *pubkey;
ASN1_STRING *wrap_str;
ASN1_OCTET_STRING *ukm;
unsigned char *penc = NULL;
int penclen;
int rv = 0;
int ecdh_nid, kdf_type, kdf_nid, 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)) {
EC_KEY *eckey = pkey->pkey.ec;
/* Set the key */
unsigned char *p;
penclen = i2o_ECPublicKey(eckey, NULL);
if (penclen <= 0)
goto err;
penc = OPENSSL_malloc(penclen);
if (penc == NULL)
goto err;
p = penc;
penclen = i2o_ECPublicKey(eckey, &p);
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_X9_62_id_ecPublicKey),
V_ASN1_UNDEF, NULL);
}
/* See if custom parameters set */
kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
if (kdf_type <= 0)
goto err;
if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
goto err;
ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
if (ecdh_nid < 0)
goto err;
else if (ecdh_nid == 0)
ecdh_nid = NID_dh_std_kdf;
else if (ecdh_nid == 1)
ecdh_nid = NID_dh_cofactor_kdf;
if (kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
goto err;
} else
/* Unknown KDF */
goto err;
if (kdf_md == NULL) {
/* Fixme later for better MD */
kdf_md = EVP_sha1();
if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
goto err;
}
if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
goto err;
/* Lookup NID for KDF+cofactor+digest */
if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
goto err;
/* Get wrap NID */
ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
wrap_nid = EVP_CIPHER_CTX_type(ctx);
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_ecdh_kdf_outlen(pctx, keylen) <= 0)
goto err;
penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
if (!penclen)
goto err;
if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
goto err;
penc = NULL;
/*
* Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
* of another AlgorithmIdentifier.
*/
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(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
rv = 1;
err:
OPENSSL_free(penc);
X509_ALGOR_free(wrap_alg);
return rv;
}
#endif