/* * Copyright 2006-2018 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 */ /* * ECDH and ECDSA low level APIs are deprecated for public use, but still ok * for internal use. */ #include "internal/deprecated.h" #include #include "internal/cryptlib.h" #include #include #include #include #include #include "crypto/asn1.h" #include "crypto/evp.h" #include #include "internal/param_build.h" #include "ec_local.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, const 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) { const 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, const void *pval) { EC_KEY *eckey = NULL; EC_GROUP *group = NULL; if (ptype == V_ASN1_SEQUENCE) { const ASN1_STRING *pstr = pval; const unsigned char *pm = pstr->data; int 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) { const ASN1_OBJECT *poid = pval; /* * 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); EC_GROUP_free(group); return NULL; } static int eckey_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey) { const unsigned char *p = NULL; const 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); if (group == NULL || pa == NULL || pb == NULL) return -2; 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, const PKCS8_PRIV_KEY_INFO *p8) { const unsigned char *p = NULL; const void *pval; int ptype, pklen; EC_KEY *eckey = NULL; const 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 == NULL) 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 = *(pkey->pkey.ec); unsigned char *ep, *p; int eplen, ptype; void *pval; unsigned int old_flags; 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); EC_KEY_set_enc_flags(&ec_key, old_flags | EC_PKEY_NO_PARAMETERS); eplen = i2d_ECPrivateKey(&ec_key, NULL); if (!eplen) { ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB); return 0; } ep = OPENSSL_malloc(eplen); if (ep == NULL) { ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_MALLOC_FAILURE); return 0; } p = ep; if (!i2d_ECPrivateKey(&ec_key, &p)) { OPENSSL_free(ep); ECerr(EC_F_ECKEY_PRIV_ENCODE, ERR_R_EC_LIB); return 0; } if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_X9_62_id_ecPublicKey), 0, ptype, pval, ep, eplen)) { OPENSSL_free(ep); 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) goto err; } if (EC_KEY_set_group(to->pkey.ec, group) == 0) goto err; EC_GROUP_free(group); return 1; err: EC_GROUP_free(group); return 0; } 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 (group_a == NULL || group_b == NULL) return -2; 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 && EC_KEY_get0_public_key(x) != NULL) { 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: if (EVP_PKEY_id(pkey) == EVP_PKEY_SM2) { /* For SM2, the only valid digest-alg is SM3 */ *(int *)arg2 = NID_sm3; return 2; /* Make it mandatory */ } *(int *)arg2 = NID_sha256; return 1; case ASN1_PKEY_CTRL_SET1_TLS_ENCPT: return EC_KEY_oct2key(EVP_PKEY_get0_EC_KEY(pkey), arg2, arg1, NULL); case ASN1_PKEY_CTRL_GET1_TLS_ENCPT: return EC_KEY_key2buf(EVP_PKEY_get0_EC_KEY(pkey), POINT_CONVERSION_UNCOMPRESSED, arg2, NULL); default: return -2; } } static int ec_pkey_check(const EVP_PKEY *pkey) { EC_KEY *eckey = pkey->pkey.ec; /* stay consistent to what EVP_PKEY_check demands */ if (eckey->priv_key == NULL) { ECerr(EC_F_EC_PKEY_CHECK, EC_R_MISSING_PRIVATE_KEY); return 0; } return EC_KEY_check_key(eckey); } static int ec_pkey_public_check(const EVP_PKEY *pkey) { EC_KEY *eckey = pkey->pkey.ec; /* * Note: it unnecessary to check eckey->pub_key here since * it will be checked in EC_KEY_check_key(). In fact, the * EC_KEY_check_key() mainly checks the public key, and checks * the private key optionally (only if there is one). So if * someone passes a whole EC key (public + private), this * will also work... */ return EC_KEY_check_key(eckey); } static int ec_pkey_param_check(const EVP_PKEY *pkey) { EC_KEY *eckey = pkey->pkey.ec; /* stay consistent to what EVP_PKEY_check demands */ if (eckey->group == NULL) { ECerr(EC_F_EC_PKEY_PARAM_CHECK, EC_R_MISSING_PARAMETERS); return 0; } return EC_GROUP_check(eckey->group, NULL); } static size_t ec_pkey_dirty_cnt(const EVP_PKEY *pkey) { return pkey->pkey.ec->dirty_cnt; } static ossl_inline int ecparams_to_params(const EC_KEY *eckey, OSSL_PARAM_BLD *tmpl) { const EC_GROUP *ecg; int curve_nid; if (eckey == NULL) return 0; ecg = EC_KEY_get0_group(eckey); if (ecg == NULL) return 0; curve_nid = EC_GROUP_get_curve_name(ecg); if (curve_nid == NID_undef) { /* explicit parameters */ /* * TODO(3.0): should we support explicit parameters curves? */ return 0; } else { /* named curve */ const char *curve_name = NULL; if ((curve_name = OBJ_nid2sn(curve_nid)) == NULL) return 0; if (!ossl_param_bld_push_utf8_string(tmpl, OSSL_PKEY_PARAM_EC_NAME, curve_name, 0)) return 0; } return 1; } static int ec_pkey_export_to(const EVP_PKEY *from, void *to_keydata, EVP_KEYMGMT *to_keymgmt) { const EC_KEY *eckey = NULL; const EC_GROUP *ecg = NULL; unsigned char *pub_key_buf = NULL; size_t pub_key_buflen; OSSL_PARAM_BLD tmpl; OSSL_PARAM *params = NULL; const BIGNUM *priv_key = NULL; const EC_POINT *pub_point = NULL; int rv = 0; if (from == NULL || (eckey = from->pkey.ec) == NULL || (ecg = EC_KEY_get0_group(eckey)) == NULL) return 0; /* * If the EC_KEY method is foreign, then we can't be sure of anything, * and can therefore not export or pretend to export. */ if (EC_KEY_get_method(eckey) != EC_KEY_OpenSSL()) return 0; ossl_param_bld_init(&tmpl); /* export the domain parameters */ if (!ecparams_to_params(eckey, &tmpl)) return 0; priv_key = EC_KEY_get0_private_key(eckey); pub_point = EC_KEY_get0_public_key(eckey); /* public_key must be present, priv_key is optional */ if (pub_point == NULL) return 0; /* convert pub_point to a octet string according to the SECG standard */ if ((pub_key_buflen = EC_POINT_point2buf(ecg, pub_point, POINT_CONVERSION_COMPRESSED, &pub_key_buf, NULL)) == 0) return 0; if (!ossl_param_bld_push_octet_string(&tmpl, OSSL_PKEY_PARAM_PUB_KEY, pub_key_buf, pub_key_buflen)) goto err; if (priv_key != NULL) { size_t sz; int ecbits; int ecdh_cofactor_mode; /* * Key import/export should never leak the bit length of the secret * scalar in the key. * * For this reason, on export we use padded BIGNUMs with fixed length. * * When importing we also should make sure that, even if short lived, * the newly created BIGNUM is marked with the BN_FLG_CONSTTIME flag as * soon as possible, so that any processing of this BIGNUM might opt for * constant time implementations in the backend. * * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have * to preallocate the BIGNUM internal buffer to a fixed public size big * enough that operations performed during the processing never trigger * a realloc which would leak the size of the scalar through memory * accesses. * * Fixed Length * ------------ * * The order of the large prime subgroup of the curve is our choice for * a fixed public size, as that is generally the upper bound for * generating a private key in EC cryptosystems and should fit all valid * secret scalars. * * For padding on export we just use the bit length of the order * converted to bytes (rounding up). * * For preallocating the BIGNUM storage we look at the number of "words" * required for the internal representation of the order, and we * preallocate 2 extra "words" in case any of the subsequent processing * might temporarily overflow the order length. */ ecbits = EC_GROUP_order_bits(ecg); if (ecbits <= 0) goto err; sz = (ecbits + 7 ) / 8; if (!ossl_param_bld_push_BN_pad(&tmpl, OSSL_PKEY_PARAM_PRIV_KEY, priv_key, sz)) goto err; /* * The ECDH Cofactor Mode is defined only if the EC_KEY actually * contains a private key, so we check for the flag and export it only * in this case. */ ecdh_cofactor_mode = (EC_KEY_get_flags(eckey) & EC_FLAG_COFACTOR_ECDH) ? 1 : 0; /* Export the ECDH_COFACTOR_MODE parameter */ if (!ossl_param_bld_push_int(&tmpl, OSSL_PKEY_PARAM_USE_COFACTOR_ECDH, ecdh_cofactor_mode)) goto err; } params = ossl_param_bld_to_param(&tmpl); /* We export, the provider imports */ rv = evp_keymgmt_import(to_keymgmt, to_keydata, OSSL_KEYMGMT_SELECT_ALL, params); err: ossl_param_bld_free(params); OPENSSL_free(pub_key_buf); return rv; } 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, 0, 0, 0, ec_pkey_check, ec_pkey_public_check, ec_pkey_param_check, 0, /* set_priv_key */ 0, /* set_pub_key */ 0, /* get_priv_key */ 0, /* get_pub_key */ ec_pkey_dirty_cnt, ec_pkey_export_to }; #if !defined(OPENSSL_NO_SM2) const EVP_PKEY_ASN1_METHOD sm2_asn1_meth = { EVP_PKEY_SM2, EVP_PKEY_EC, ASN1_PKEY_ALIAS }; #endif int EC_KEY_print(BIO *bp, const EC_KEY *x, int off) { int private = EC_KEY_get0_private_key(x) != NULL; return do_EC_KEY_print(bp, x, off, private ? EC_KEY_PRINT_PRIVATE : EC_KEY_PRINT_PUBLIC); } int ECParameters_print(BIO *bp, const EC_KEY *x) { return do_EC_KEY_print(bp, x, 4, EC_KEY_PRINT_PARAM); } #ifndef OPENSSL_NO_CMS 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; 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 == NULL) 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_get0_data(pubkey); if (p == NULL || plen == 0) 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_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; 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; const 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_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) 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