diff options
Diffstat (limited to 'ecdsa.c')
| -rw-r--r-- | ecdsa.c | 50 |
1 files changed, 34 insertions, 16 deletions
@@ -942,18 +942,20 @@ hal_error_t hal_ecdsa_key_to_der(const hal_ecdsa_key_t * const key, hal_error_t err; - size_t version_len, hlen, hlen2, hlen3, hlen4; - - if ((err = hal_asn1_encode_integer(version, NULL, &version_len, 0)) != HAL_OK || - (err = hal_asn1_encode_header(ASN1_OCTET_STRING, q_len, NULL, &hlen2, 0)) != HAL_OK || - (err = hal_asn1_encode_header(ASN1_EXPLICIT_0, curve->oid_len, NULL, &hlen3, 0)) != HAL_OK || - (err = hal_asn1_encode_header(ASN1_EXPLICIT_1, (q_len + 1) * 2, NULL, &hlen4, 0)) != HAL_OK) + size_t version_len, hlen, hlen_oct, hlen_oid, hlen_exp0, hlen_bit, hlen_exp1; + + if ((err = hal_asn1_encode_integer(version, NULL, &version_len, 0)) != HAL_OK || + (err = hal_asn1_encode_header(ASN1_OCTET_STRING, q_len, NULL, &hlen_oct, 0)) != HAL_OK || + (err = hal_asn1_encode_header(ASN1_OBJECT_IDENTIFIER, curve->oid_len, NULL, &hlen_oid, 0)) != HAL_OK || + (err = hal_asn1_encode_header(ASN1_EXPLICIT_0, hlen_oid + curve->oid_len, NULL, &hlen_exp0, 0)) != HAL_OK || + (err = hal_asn1_encode_header(ASN1_BIT_STRING, (q_len + 1) * 2, NULL, &hlen_bit, 0)) != HAL_OK || + (err = hal_asn1_encode_header(ASN1_EXPLICIT_1, hlen_bit + (q_len + 1) * 2, NULL, &hlen_exp1, 0)) != HAL_OK) return err; - const size_t vlen = (version_len + - hlen2 + q_len + - hlen3 + curve->oid_len + - hlen4 + (q_len + 1) * 2); + const size_t vlen = (version_len + + hlen_oct + q_len + + hlen_oid + hlen_exp0 + curve->oid_len + + hlen_bit + hlen_exp1 + (q_len + 1) * 2); if ((err = hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)) != HAL_OK) return err; @@ -971,21 +973,27 @@ hal_error_t hal_ecdsa_key_to_der(const hal_ecdsa_key_t * const key, return err; d += version_len; - if ((err = hal_asn1_encode_header(ASN1_OCTET_STRING, q_len, d, NULL, der + der_max - d)) != HAL_OK) + if ((err = hal_asn1_encode_header(ASN1_OCTET_STRING, q_len, d, &hlen, der + der_max - d)) != HAL_OK) return err; - d += hlen2; + d += hlen; fp_to_unsigned_bin(unconst_fp_int(key->d), d + q_len - d_len); d += q_len; - if ((err = hal_asn1_encode_header(ASN1_EXPLICIT_0, curve->oid_len, d, NULL, der + der_max - d)) != HAL_OK) + if ((err = hal_asn1_encode_header(ASN1_EXPLICIT_0, hlen_oid + curve->oid_len, d, &hlen, der + der_max - d)) != HAL_OK) + return err; + d += hlen; + if ((err = hal_asn1_encode_header(ASN1_OBJECT_IDENTIFIER, curve->oid_len, d, &hlen, der + der_max - d)) != HAL_OK) return err; - d += hlen3; + d += hlen; memcpy(d, curve->oid, curve->oid_len); d += curve->oid_len; - if ((err = hal_asn1_encode_header(ASN1_EXPLICIT_1, (q_len + 1) * 2, d, NULL, der + der_max - d)) != HAL_OK) + if ((err = hal_asn1_encode_header(ASN1_EXPLICIT_1, hlen_bit + (q_len + 1) * 2, d, &hlen, der + der_max - d)) != HAL_OK) + return err; + d += hlen; + if ((err = hal_asn1_encode_header(ASN1_EXPLICIT_1, (q_len + 1) * 2, d, &hlen, der + der_max - d)) != HAL_OK) return err; - d += hlen4; + d += hlen; *d++ = 0x00; *d++ = 0x04; fp_to_unsigned_bin(unconst_fp_int(key->d), d + q_len - Qx_len); @@ -1046,6 +1054,11 @@ hal_error_t hal_ecdsa_key_from_der(hal_ecdsa_key_t **key_, if ((err = hal_asn1_decode_header(ASN1_EXPLICIT_0, d, der_end - d, &hlen, &vlen)) != HAL_OK) return err; d += hlen; + if (vlen > der_end - d) + lose(HAL_ERROR_ASN1_PARSE_FAILED); + if ((err = hal_asn1_decode_header(ASN1_OBJECT_IDENTIFIER, d, vlen, &hlen, &vlen)) != HAL_OK) + return err; + d += hlen; for (key->curve = (hal_ecdsa_curve_t) 0; (curve = get_curve(key->curve)) != NULL; key->curve++) if (vlen == curve->oid_len && memcmp(d, curve->oid, vlen) == 0) break; @@ -1056,6 +1069,11 @@ hal_error_t hal_ecdsa_key_from_der(hal_ecdsa_key_t **key_, if ((err = hal_asn1_decode_header(ASN1_EXPLICIT_1, d, der_end - d, &hlen, &vlen)) != HAL_OK) return err; d += hlen; + if (vlen > der_end - d) + lose(HAL_ERROR_ASN1_PARSE_FAILED); + if ((err = hal_asn1_decode_header(ASN1_BIT_STRING, d, vlen, &hlen, &vlen)) != HAL_OK) + return err; + d += hlen; if (vlen < 4 || (vlen & 1) != 0 || *d++ != 0x00 || *d++ != 0x04) lose(HAL_ERROR_ASN1_PARSE_FAILED); vlen = vlen/2 - 1; |