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:
if (kekalg)
X509_ALGOR_free(kekalg);
if (der)
OPENSSL_free(der);
return rv;
}
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;
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;
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 paraneters 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)
goto err;
wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
wrap_alg->parameter = ASN1_TYPE_new();
if (!wrap_alg->parameter)
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 = BUF_memdup(ASN1_STRING_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)
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:
if (penc)
OPENSSL_free(penc);
if (wrap_alg)
X509_ALGOR_free(wrap_alg);
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 = BUF_memdup(ASN1_STRING_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:
if (kekalg)
X509_ALGOR_free(kekalg);
if (dukm)
OPENSSL_free(dukm);
return rv;
}
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)
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 paraneters 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
/* Uknown 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)
goto err;
wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
wrap_alg->parameter = ASN1_TYPE_new();
if (!wrap_alg->parameter)
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)
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;
}
