From 48bb9d0cf5de06cfb483aea66ff5a2c7aa3eb46f Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Tue, 20 Sep 2022 16:06:13 +0900 Subject: [PATCH 08/29] fips: fix checking on hash algorithm used in ECDSA Previously we checked against the "preferred" hash algorithm based on the curve, instead of the one actually used. Signed-off-by: Daiki Ueno --- lib/crypto-backend.h | 12 ++++--- lib/nettle/pk.c | 33 ++++++++--------- lib/pubkey.c | 5 ++- tests/fips-test.c | 86 ++++++++++++++++++++++++++++++++++++++++++-- 4 files changed, 111 insertions(+), 25 deletions(-) --- a/lib/crypto-backend.h +++ b/lib/crypto-backend.h @@ -245,15 +245,17 @@ typedef enum { GNUTLS_PK_FLAG_PROVABLE = 1, GNUTLS_PK_FLAG_REPRODUCIBLE = 2, GNUTLS_PK_FLAG_RSA_PSS_FIXED_SALT_LENGTH = 4 } gnutls_pk_flag_t; -#define FIX_SIGN_PARAMS(params, flags, dig) do { \ - if ((flags) & GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE) { \ - (params).flags |= GNUTLS_PK_FLAG_REPRODUCIBLE; \ - (params).dsa_dig = (dig); \ - } \ +#define FIX_SIGN_PARAMS(params, flags, dig) do { \ + if ((flags) & GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE) { \ + (params).flags |= GNUTLS_PK_FLAG_REPRODUCIBLE; \ + } \ + if ((params).pk == GNUTLS_PK_DSA || (params).pk == GNUTLS_PK_ECDSA) { \ + (params).dsa_dig = (dig); \ + } \ } while (0) void gnutls_pk_params_release(gnutls_pk_params_st * p); void gnutls_pk_params_clear(gnutls_pk_params_st * p); void gnutls_pk_params_init(gnutls_pk_params_st * p); --- a/lib/nettle/pk.c +++ b/lib/nettle/pk.c @@ -1102,29 +1102,29 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm dsa_signature_init(&sig); me = _gnutls_dsa_q_to_hash(pk_params, &hash_len); + if (hash_len > vdata->size) { + gnutls_assert(); + _gnutls_debug_log + ("Security level of algorithm requires hash %s(%d) or better\n", + _gnutls_mac_get_name(me), hash_len); + hash_len = vdata->size; + } + /* Only SHA-2 is allowed in FIPS 140-3 */ - switch (me->id) { + switch (DIG_TO_MAC(sign_params->dsa_dig)) { case GNUTLS_MAC_SHA256: case GNUTLS_MAC_SHA384: case GNUTLS_MAC_SHA512: case GNUTLS_MAC_SHA224: break; default: not_approved = true; } - if (hash_len > vdata->size) { - gnutls_assert(); - _gnutls_debug_log - ("Security level of algorithm requires hash %s(%d) or better\n", - _gnutls_mac_get_name(me), hash_len); - hash_len = vdata->size; - } - mpz_init(k); if (_gnutls_get_lib_state() == LIB_STATE_SELFTEST || (sign_params->flags & GNUTLS_PK_FLAG_REPRODUCIBLE)) { ret = _gnutls_ecdsa_compute_k(k, curve_id, @@ -1543,11 +1543,10 @@ _wrap_nettle_pk_verify(gnutls_pk_algorit { struct ecc_point pub; struct dsa_signature sig; int curve_id = pk_params->curve; const struct ecc_curve *curve; - const mac_entry_st *me; curve = get_supported_nist_curve(curve_id); if (curve == NULL) { ret = gnutls_assert_val(GNUTLS_E_ECC_UNSUPPORTED_CURVE); goto cleanup; @@ -1569,28 +1568,28 @@ _wrap_nettle_pk_verify(gnutls_pk_algorit } memcpy(sig.r, tmp[0], SIZEOF_MPZT); memcpy(sig.s, tmp[1], SIZEOF_MPZT); - me = _gnutls_dsa_q_to_hash(pk_params, &hash_len); + (void)_gnutls_dsa_q_to_hash(pk_params, &hash_len); + + if (hash_len > vdata->size) + hash_len = vdata->size; /* SHA-1 is allowed for SigVer in FIPS 140-3 in legacy * mode */ - switch (me->id) { + switch (DIG_TO_MAC(sign_params->dsa_dig)) { case GNUTLS_MAC_SHA1: case GNUTLS_MAC_SHA256: case GNUTLS_MAC_SHA384: case GNUTLS_MAC_SHA512: case GNUTLS_MAC_SHA224: break; default: not_approved = true; } - if (hash_len > vdata->size) - hash_len = vdata->size; - ret = ecdsa_verify(&pub, hash_len, vdata->data, &sig); if (ret == 0) { gnutls_assert(); @@ -2388,12 +2387,14 @@ static int pct_test(gnutls_pk_algorithm_ memcpy(&spki, ¶ms->spki, sizeof(spki)); if (algo == GNUTLS_PK_DSA || algo == GNUTLS_PK_EC) { unsigned hash_len; + const mac_entry_st *me; - _gnutls_dsa_q_to_hash(params, &hash_len); + me = _gnutls_dsa_q_to_hash(params, &hash_len); + spki.dsa_dig = MAC_TO_DIG(me->id); gen_data = gnutls_malloc(hash_len); gnutls_rnd(GNUTLS_RND_NONCE, gen_data, hash_len); ddata.data = (void*)gen_data; ddata.size = hash_len; --- a/lib/pubkey.c +++ b/lib/pubkey.c @@ -1983,11 +1983,11 @@ gnutls_pubkey_import_dsa_raw(gnutls_pubk /* Updates the gnutls_x509_spki_st parameters based on the signature * information, and reports any incompatibilities between the existing * parameters (if any) with the signature algorithm */ static int fixup_spki_params(const gnutls_pk_params_st *key_params, const gnutls_sign_entry_st *se, - const mac_entry_st *me, gnutls_x509_spki_st *params) + const mac_entry_st *me, gnutls_x509_spki_st *params) { unsigned bits; if (se->pk != key_params->algo) { if (!sign_supports_priv_pk_algorithm(se, key_params->algo)) { @@ -2016,10 +2016,13 @@ int fixup_spki_params(const gnutls_pk_pa params->salt_size = ret; } if (params->rsa_pss_dig != se->hash) return gnutls_assert_val(GNUTLS_E_CONSTRAINT_ERROR); + } else if (params->pk == GNUTLS_PK_DSA || + params->pk == GNUTLS_PK_ECDSA) { + params->dsa_dig = se->hash; } return 0; } --- a/tests/fips-test.c +++ b/tests/fips-test.c @@ -78,12 +78,26 @@ static const uint8_t rsa2342_sha1_sig_da static const gnutls_datum_t rsa2342_sha1_sig = { .data = (unsigned char *)rsa2342_sha1_sig_data, .size = sizeof(rsa2342_sha1_sig_data), }; +static const uint8_t ecc256_sha1_sig_data[] = { + 0x30, 0x45, 0x02, 0x21, 0x00, 0x9a, 0x28, 0xc9, 0xbf, 0xc8, 0x70, 0x4f, + 0x27, 0x2d, 0xe1, 0x66, 0xc4, 0xa5, 0xc6, 0xf2, 0xdc, 0x33, 0xb9, 0x41, + 0xdf, 0x78, 0x98, 0x8a, 0x22, 0x4d, 0x29, 0x37, 0xa0, 0x0f, 0x6f, 0xd4, + 0xed, 0x02, 0x20, 0x0b, 0x15, 0xca, 0x30, 0x09, 0x2d, 0x55, 0x44, 0xb4, + 0x1d, 0x3f, 0x48, 0x7a, 0xc3, 0xd1, 0x2a, 0xc1, 0x0e, 0x47, 0xfa, 0xe6, + 0xe9, 0x0f, 0x03, 0xe2, 0x01, 0x4e, 0xe4, 0x73, 0x37, 0xa7, 0x90, +}; + +static const gnutls_datum_t ecc256_sha1_sig = { + .data = (unsigned char *)ecc256_sha1_sig_data, + .size = sizeof(ecc256_sha1_sig_data), +}; + static void -rsa_import_keypair(gnutls_privkey_t *privkey, gnutls_pubkey_t *pubkey, +import_keypair(gnutls_privkey_t *privkey, gnutls_pubkey_t *pubkey, const char *filename) { const char *srcdir; char path[256]; gnutls_datum_t tmp; @@ -422,11 +436,11 @@ void doit(void) gnutls_x509_privkey_deinit(xprivkey); FIPS_POP_CONTEXT(ERROR); /* Import 2432-bit RSA key; not a security function */ FIPS_PUSH_CONTEXT(); - rsa_import_keypair(&privkey, &pubkey, "rsa-2432.pem"); + import_keypair(&privkey, &pubkey, "rsa-2432.pem"); FIPS_POP_CONTEXT(INITIAL); /* Create a signature with 2432-bit RSA and SHA256; approved */ FIPS_PUSH_CONTEXT(); ret = gnutls_privkey_sign_data(privkey, GNUTLS_DIG_SHA256, 0, @@ -468,11 +482,11 @@ void doit(void) gnutls_pubkey_deinit(pubkey); gnutls_privkey_deinit(privkey); /* Import 512-bit RSA key; not a security function */ FIPS_PUSH_CONTEXT(); - rsa_import_keypair(&privkey, &pubkey, "rsa-512.pem"); + import_keypair(&privkey, &pubkey, "rsa-512.pem"); FIPS_POP_CONTEXT(INITIAL); /* Create a signature with 512-bit RSA and SHA256; not approved */ FIPS_PUSH_CONTEXT(); ret = gnutls_privkey_sign_data(privkey, GNUTLS_DIG_SHA256, 0, @@ -491,10 +505,76 @@ void doit(void) } FIPS_POP_CONTEXT(NOT_APPROVED); gnutls_free(signature.data); gnutls_pubkey_deinit(pubkey); gnutls_privkey_deinit(privkey); + + /* Import ECDSA key; not a security function */ + FIPS_PUSH_CONTEXT(); + import_keypair(&privkey, &pubkey, "ecc256.pem"); + FIPS_POP_CONTEXT(INITIAL); + + /* Create a signature with ECDSA and SHA256; approved */ + FIPS_PUSH_CONTEXT(); + ret = gnutls_privkey_sign_data2(privkey, GNUTLS_SIGN_ECDSA_SHA256, 0, + &data, &signature); + if (ret < 0) { + fail("gnutls_privkey_sign_data2 failed\n"); + } + FIPS_POP_CONTEXT(APPROVED); + + /* Verify a signature with ECDSA and SHA256; approved */ + FIPS_PUSH_CONTEXT(); + ret = gnutls_pubkey_verify_data2(pubkey, GNUTLS_SIGN_ECDSA_SHA256, 0, + &data, &signature); + if (ret < 0) { + fail("gnutls_pubkey_verify_data2 failed\n"); + } + FIPS_POP_CONTEXT(APPROVED); + gnutls_free(signature.data); + + /* Create a signature with ECDSA and SHA256 (old API); approved */ + FIPS_PUSH_CONTEXT(); + ret = gnutls_privkey_sign_data(privkey, GNUTLS_DIG_SHA256, 0, + &data, &signature); + if (ret < 0) { + fail("gnutls_privkey_sign_data failed\n"); + } + FIPS_POP_CONTEXT(APPROVED); + gnutls_free(signature.data); + + /* Create a signature with ECDSA and SHA-1; not approved */ + FIPS_PUSH_CONTEXT(); + ret = gnutls_privkey_sign_data2(privkey, GNUTLS_SIGN_ECDSA_SHA1, 0, + &data, &signature); + if (ret < 0) { + fail("gnutls_privkey_sign_data2 failed\n"); + } + FIPS_POP_CONTEXT(NOT_APPROVED); + + /* Verify a signature created with ECDSA and SHA-1; approved */ + FIPS_PUSH_CONTEXT(); + ret = gnutls_pubkey_verify_data2(pubkey, GNUTLS_SIGN_ECDSA_SHA1, + GNUTLS_VERIFY_ALLOW_SIGN_WITH_SHA1, &data, + &ecc256_sha1_sig); + if (ret < 0) { + fail("gnutls_pubkey_verify_data2 failed\n"); + } + FIPS_POP_CONTEXT(APPROVED); + gnutls_free(signature.data); + + /* Create a signature with ECDSA and SHA-1 (old API); not approved */ + FIPS_PUSH_CONTEXT(); + ret = gnutls_privkey_sign_data(privkey, GNUTLS_DIG_SHA1, 0, + &data, &signature); + if (ret < 0) { + fail("gnutls_privkey_sign_data failed\n"); + } + FIPS_POP_CONTEXT(NOT_APPROVED); + gnutls_free(signature.data); + gnutls_pubkey_deinit(pubkey); + gnutls_privkey_deinit(privkey); /* Test RND functions */ FIPS_PUSH_CONTEXT(); ret = gnutls_rnd(GNUTLS_RND_RANDOM, key16, sizeof(key16)); if (ret < 0) {