| /* |
| * Copyright 2006-2022 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/dh.h> |
| #include <openssl/err.h> |
| #include <openssl/core_names.h> |
| #include "internal/sizes.h" |
| #include "crypto/evp.h" |
| #include "cms_local.h" |
| |
| 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; |
| BIGNUM *bnpub = NULL; |
| const unsigned char *p; |
| unsigned char *buf = NULL; |
| 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 == NULL || !EVP_PKEY_is_a(pk, "DHX")) |
| goto err; |
| |
| /* Get public key */ |
| plen = ASN1_STRING_length(pubkey); |
| p = ASN1_STRING_get0_data(pubkey); |
| if (p == NULL || plen == 0) |
| goto err; |
| |
| if ((public_key = d2i_ASN1_INTEGER(NULL, &p, plen)) == NULL) |
| goto err; |
| /* |
| * Pad to full p parameter size as that is checked by |
| * EVP_PKEY_set1_encoded_public_key() |
| */ |
| plen = EVP_PKEY_get_size(pk); |
| if ((bnpub = ASN1_INTEGER_to_BN(public_key, NULL)) == NULL) |
| goto err; |
| if ((buf = OPENSSL_malloc(plen)) == NULL) |
| goto err; |
| if (BN_bn2binpad(bnpub, buf, plen) < 0) |
| goto err; |
| |
| pkpeer = EVP_PKEY_new(); |
| if (pkpeer == NULL |
| || !EVP_PKEY_copy_parameters(pkpeer, pk) |
| || !EVP_PKEY_set1_encoded_public_key(pkpeer, buf, plen)) |
| goto err; |
| |
| if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0) |
| rv = 1; |
| err: |
| ASN1_INTEGER_free(public_key); |
| BN_free(bnpub); |
| OPENSSL_free(buf); |
| EVP_PKEY_free(pkpeer); |
| 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; |
| EVP_CIPHER *kekcipher = NULL; |
| EVP_CIPHER_CTX *kekctx; |
| char name[OSSL_MAX_NAME_SIZE]; |
| |
| 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) { |
| ERR_raise(ERR_LIB_CMS, CMS_R_KDF_PARAMETER_ERROR); |
| goto err; |
| } |
| |
| if (EVP_PKEY_CTX_set_dh_kdf_type(pctx, EVP_PKEY_DH_KDF_X9_42) <= 0 |
| || 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 == NULL) |
| goto err; |
| kekctx = CMS_RecipientInfo_kari_get0_ctx(ri); |
| if (kekctx == NULL) |
| goto err; |
| |
| if (OBJ_obj2txt(name, sizeof(name), kekalg->algorithm, 0) <= 0) |
| goto err; |
| |
| kekcipher = EVP_CIPHER_fetch(pctx->libctx, name, pctx->propquery); |
| if (kekcipher == NULL |
| || EVP_CIPHER_get_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_get_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_get_type(kekcipher))) |
| <= 0) |
| goto err; |
| |
| if (ukm != NULL) { |
| dukmlen = ASN1_STRING_length(ukm); |
| dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen); |
| if (dukm == NULL) |
| 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); |
| EVP_CIPHER_free(kekcipher); |
| OPENSSL_free(dukm); |
| return rv; |
| } |
| |
| static int dh_cms_decrypt(CMS_RecipientInfo *ri) |
| { |
| EVP_PKEY_CTX *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 (!dh_cms_set_peerkey(pctx, alg, pubkey)) { |
| ERR_raise(ERR_LIB_CMS, CMS_R_PEER_KEY_ERROR); |
| return 0; |
| } |
| } |
| /* Set DH derivation parameters and initialise unwrap context */ |
| if (!dh_cms_set_shared_info(pctx, ri)) { |
| ERR_raise(ERR_LIB_CMS, CMS_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 == 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; |
| |
| /* Is everything uninitialised? */ |
| X509_ALGOR_get0(&aoid, NULL, NULL, talg); |
| if (aoid == OBJ_nid2obj(NID_undef)) { |
| BIGNUM *bn_pub_key = NULL; |
| ASN1_INTEGER *pubk; |
| |
| if (!EVP_PKEY_get_bn_param(pkey, OSSL_PKEY_PARAM_PUB_KEY, &bn_pub_key)) |
| goto err; |
| |
| pubk = BN_to_ASN1_INTEGER(bn_pub_key, NULL); |
| BN_free(bn_pub_key); |
| if (pubk == NULL) |
| 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; |
| (void)X509_ALGOR_set0(talg, OBJ_nid2obj(NID_dhpublicnumber), |
| V_ASN1_UNDEF, NULL); /* cannot fail */ |
| } |
| |
| /* See if custom parameters set */ |
| kdf_type = EVP_PKEY_CTX_get_dh_kdf_type(pctx); |
| if (kdf_type <= 0 || !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_get_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_get_type(ctx); |
| if (EVP_PKEY_CTX_set0_dh_kdf_oid(pctx, OBJ_nid2obj(wrap_nid)) <= 0) |
| goto err; |
| keylen = EVP_CIPHER_CTX_get_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 != NULL) { |
| dukmlen = ASN1_STRING_length(ukm); |
| dukm = OPENSSL_memdup(ASN1_STRING_get0_data(ukm), dukmlen); |
| if (dukm == NULL) |
| 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 == 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; |
| rv = X509_ALGOR_set0(talg, OBJ_nid2obj(NID_id_smime_alg_ESDH), |
| V_ASN1_SEQUENCE, wrap_str); |
| if (!rv) |
| ASN1_STRING_free(wrap_str); |
| |
| err: |
| OPENSSL_free(penc); |
| X509_ALGOR_free(wrap_alg); |
| OPENSSL_free(dukm); |
| return rv; |
| } |
| |
| int ossl_cms_dh_envelope(CMS_RecipientInfo *ri, int decrypt) |
| { |
| assert(decrypt == 0 || decrypt == 1); |
| |
| if (decrypt == 1) |
| return dh_cms_decrypt(ri); |
| |
| if (decrypt == 0) |
| return dh_cms_encrypt(ri); |
| |
| ERR_raise(ERR_LIB_CMS, CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE); |
| return 0; |
| } |
