A local copy of OpenSSL from GitHub
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/*
* Copyright 2006-2020 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 <assert.h>
#include <openssl/cms.h>
#include <openssl/err.h>
#include <openssl/decoder.h>
#include "cms_local.h"
#include "crypto/evp.h"
#ifndef OPENSSL_NO_EC
static EVP_PKEY *pkey_type2param(int ptype, const void *pval,
OSSL_LIB_CTX *libctx, const char *propq)
{
EVP_PKEY *pkey = NULL;
EVP_PKEY_CTX *pctx = NULL;
if (ptype == V_ASN1_SEQUENCE) {
const ASN1_STRING *pstr = pval;
const unsigned char *pm = pstr->data;
int pmlen = pstr->length;
OSSL_DECODER_CTX *ctx = NULL;
BIO *membio = NULL;
/* TODO(3.0): Need to be able to specify here that only params will do */
ctx = OSSL_DECODER_CTX_new_by_EVP_PKEY(&pkey, "DER", "EC", libctx,
propq);
if (ctx == NULL)
goto err;
membio = BIO_new_mem_buf(pm, pmlen);
if (membio == NULL) {
OSSL_DECODER_CTX_free(ctx);
goto err;
}
OSSL_DECODER_from_bio(ctx, membio);
BIO_free(membio);
OSSL_DECODER_CTX_free(ctx);
} else if (ptype == V_ASN1_OBJECT) {
const ASN1_OBJECT *poid = pval;
const char *groupname;
/* type == V_ASN1_OBJECT => the parameters are given by an asn1 OID */
pctx = EVP_PKEY_CTX_new_from_name(libctx, "EC", propq);
if (pctx == NULL || EVP_PKEY_paramgen_init(pctx) <= 0)
goto err;
groupname = OBJ_nid2sn(OBJ_obj2nid(poid));
if (groupname == NULL
|| !EVP_PKEY_CTX_set_group_name(pctx, groupname)) {
CMSerr(0, CMS_R_DECODE_ERROR);
goto err;
}
if (EVP_PKEY_paramgen(pctx, &pkey) <= 0)
goto err;
} else {
CMSerr(0, CMS_R_DECODE_ERROR);
goto err;
}
return pkey;
err:
EVP_PKEY_free(pkey);
EVP_PKEY_CTX_free(pctx);
return NULL;
}
static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
{
const ASN1_OBJECT *aoid;
int atype;
const void *aval;
int rv = 0;
EVP_PKEY *pkpeer = 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) {
EVP_PKEY *pk;
pk = EVP_PKEY_CTX_get0_pkey(pctx);
if (pk == NULL)
goto err;
pkpeer = EVP_PKEY_new();
if (pkpeer == NULL)
goto err;
if (!EVP_PKEY_copy_parameters(pkpeer, pk))
goto err;
} else {
pkpeer = pkey_type2param(atype, aval,
EVP_PKEY_CTX_get0_libctx(pctx),
EVP_PKEY_CTX_get0_propq(pctx));
if (pkpeer == NULL)
goto err;
}
/* We have parameters now set public key */
plen = ASN1_STRING_length(pubkey);
p = ASN1_STRING_get0_data(pubkey);
if (p == NULL || plen == 0)
goto err;
/* TODO(3.0): Terrible name. We need a non-tls specific name */
if (!EVP_PKEY_set1_tls_encodedpoint(pkpeer, p, plen))
goto err;
if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
rv = 1;
err:
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_63) <= 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;
EVP_CIPHER *kekcipher = NULL;
EVP_CIPHER_CTX *kekctx;
const char *name;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
return 0;
if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
CMSerr(0, CMS_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 == NULL)
goto err;
kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
if (kekctx == NULL)
goto err;
name = OBJ_nid2sn(OBJ_obj2nid(kekalg->algorithm));
kekcipher = EVP_CIPHER_fetch(pctx->libctx, name, pctx->propquery);
if (kekcipher == NULL || 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 <= 0)
goto err;
if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
goto err;
der = NULL;
rv = 1;
err:
EVP_CIPHER_free(kekcipher);
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 == NULL)
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 == NULL || pubkey == NULL)
return 0;
if (!ecdh_cms_set_peerkey(pctx, alg, pubkey)) {
CMSerr(0, CMS_R_PEER_KEY_ERROR);
return 0;
}
}
/* Set ECDH derivation parameters and initialise unwrap context */
if (!ecdh_cms_set_shared_info(pctx, ri)) {
CMSerr(0, CMS_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;
const ASN1_OBJECT *aoid;
ASN1_BIT_STRING *pubkey;
ASN1_STRING *wrap_str;
ASN1_OCTET_STRING *ukm;
unsigned char *penc = NULL;
size_t 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 == NULL)
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)) {
/* Set the key */
/* TODO(3.0): Terrible name. Needs a non TLS specific name */
penclen = EVP_PKEY_get1_tls_encodedpoint(pkey, &penc);
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_63;
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 == 0)
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 == NULL || penclen == 0)
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;
}
int cms_ecdh_envelope(CMS_RecipientInfo *ri, int decrypt)
{
assert(decrypt == 0 || decrypt == 1);
if (decrypt == 1)
return ecdh_cms_decrypt(ri);
if (decrypt == 0)
return ecdh_cms_encrypt(ri);
CMSerr(0, CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE);
return 0;
}
#endif
/* ECDSA and DSA implementation is the same */
int cms_ecdsa_dsa_sign(CMS_SignerInfo *si, int verify)
{
assert(verify == 0 || verify == 1);
if (verify == 0) {
int snid, hnid;
X509_ALGOR *alg1, *alg2;
EVP_PKEY *pkey = si->pkey;
CMS_SignerInfo_get0_algs(si, 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;
}