| /* |
| * 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/err.h> |
| #include <openssl/decoder.h> |
| #include "internal/sizes.h" |
| #include "crypto/evp.h" |
| #include "cms_local.h" |
| |
| 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; |
| OSSL_DECODER_CTX *ctx = NULL; |
| |
| if (ptype == V_ASN1_SEQUENCE) { |
| const ASN1_STRING *pstr = pval; |
| const unsigned char *pm = pstr->data; |
| size_t pmlen = (size_t)pstr->length; |
| int selection = OSSL_KEYMGMT_SELECT_ALL_PARAMETERS; |
| |
| ctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "DER", NULL, "EC", |
| selection, libctx, propq); |
| if (ctx == NULL) |
| goto err; |
| |
| if (!OSSL_DECODER_from_data(ctx, &pm, &pmlen)) { |
| ERR_raise(ERR_LIB_CMS, CMS_R_DECODE_ERROR); |
| goto err; |
| } |
| OSSL_DECODER_CTX_free(ctx); |
| return pkey; |
| } else if (ptype == V_ASN1_OBJECT) { |
| const ASN1_OBJECT *poid = pval; |
| char groupname[OSSL_MAX_NAME_SIZE]; |
| |
| /* 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; |
| if (OBJ_obj2txt(groupname, sizeof(groupname), poid, 0) <= 0 |
| || !EVP_PKEY_CTX_set_group_name(pctx, groupname)) { |
| ERR_raise(ERR_LIB_CMS, CMS_R_DECODE_ERROR); |
| goto err; |
| } |
| if (EVP_PKEY_paramgen(pctx, &pkey) <= 0) |
| goto err; |
| EVP_PKEY_CTX_free(pctx); |
| return pkey; |
| } |
| |
| ERR_raise(ERR_LIB_CMS, CMS_R_DECODE_ERROR); |
| return NULL; |
| |
| err: |
| EVP_PKEY_free(pkey); |
| EVP_PKEY_CTX_free(pctx); |
| OSSL_DECODER_CTX_free(ctx); |
| 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; |
| |
| if (!EVP_PKEY_set1_encoded_public_key(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; |
| char name[OSSL_MAX_NAME_SIZE]; |
| |
| if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm)) |
| return 0; |
| |
| if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) { |
| ERR_raise(ERR_LIB_CMS, 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; |
| OBJ_obj2txt(name, sizeof(name), kekalg->algorithm, 0); |
| 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_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)) { |
| ERR_raise(ERR_LIB_CMS, CMS_R_PEER_KEY_ERROR); |
| return 0; |
| } |
| } |
| /* Set ECDH derivation parameters and initialise unwrap context */ |
| if (!ecdh_cms_set_shared_info(pctx, ri)) { |
| ERR_raise(ERR_LIB_CMS, 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 */ |
| |
| penclen = EVP_PKEY_get1_encoded_public_key(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; |
| (void)X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), |
| V_ASN1_UNDEF, NULL); /* cannot fail */ |
| } |
| |
| /* 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_get_type(kdf_md), ecdh_nid)) |
| goto err; |
| /* Get wrap NID */ |
| ctx = CMS_RecipientInfo_kari_get0_ctx(ri); |
| wrap_nid = EVP_CIPHER_CTX_get_type(ctx); |
| 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_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; |
| rv = X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str); |
| if (!rv) |
| ASN1_STRING_free(wrap_str); |
| |
| err: |
| OPENSSL_free(penc); |
| X509_ALGOR_free(wrap_alg); |
| return rv; |
| } |
| |
| int ossl_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); |
| |
| ERR_raise(ERR_LIB_CMS, CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE); |
| return 0; |
| } |
