diff options
Diffstat (limited to 'third_party/bearssl/src/encode_ec_rawder.c')
| -rw-r--r-- | third_party/bearssl/src/encode_ec_rawder.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/third_party/bearssl/src/encode_ec_rawder.c b/third_party/bearssl/src/encode_ec_rawder.c new file mode 100644 index 0000000..5985909 --- /dev/null +++ b/third_party/bearssl/src/encode_ec_rawder.c @@ -0,0 +1,161 @@ +/* + * Copyright (c) 2018 Thomas Pornin <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "inner.h" + +/* see inner.h */ +const unsigned char * +br_get_curve_OID(int curve) +{ + static const unsigned char OID_secp256r1[] = { + 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07 + }; + static const unsigned char OID_secp384r1[] = { + 0x05, 0x2b, 0x81, 0x04, 0x00, 0x22 + }; + static const unsigned char OID_secp521r1[] = { + 0x05, 0x2b, 0x81, 0x04, 0x00, 0x23 + }; + + switch (curve) { + case BR_EC_secp256r1: return OID_secp256r1; + case BR_EC_secp384r1: return OID_secp384r1; + case BR_EC_secp521r1: return OID_secp521r1; + default: + return NULL; + } +} + +/* see inner.h */ +size_t +br_encode_ec_raw_der_inner(void *dest, + const br_ec_private_key *sk, const br_ec_public_key *pk, + int include_curve_oid) +{ + /* + * ASN.1 format: + * + * ECPrivateKey ::= SEQUENCE { + * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1), + * privateKey OCTET STRING, + * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL, + * publicKey [1] BIT STRING OPTIONAL + * } + * + * The tages '[0]' and '[1]' are explicit. The 'ECParameters' + * is a CHOICE; in our case, it will always be an OBJECT IDENTIFIER + * that identifies the curve. + * + * The value of the 'privateKey' field is the raw unsigned big-endian + * encoding of the private key (integer modulo the curve subgroup + * order); there is no INTEGER tag, and the leading bit may be 1. + * Also, leading bytes of value 0x00 are _not_ removed. + * + * The 'publicKey' contents are the raw encoded public key point, + * normally uncompressed (leading byte of value 0x04, followed + * by the unsigned big-endian encodings of the X and Y coordinates, + * padded to the full field length if necessary). + */ + + size_t len_version, len_privateKey, len_parameters, len_publicKey; + size_t len_publicKey_bits, len_seq; + const unsigned char *oid; + + if (include_curve_oid) { + oid = br_get_curve_OID(sk->curve); + if (oid == NULL) { + return 0; + } + } else { + oid = NULL; + } + len_version = 3; + len_privateKey = 1 + len_of_len(sk->xlen) + sk->xlen; + if (include_curve_oid) { + len_parameters = 4 + oid[0]; + } else { + len_parameters = 0; + } + if (pk == NULL) { + len_publicKey = 0; + len_publicKey_bits = 0; + } else { + len_publicKey_bits = 2 + len_of_len(pk->qlen) + pk->qlen; + len_publicKey = 1 + len_of_len(len_publicKey_bits) + + len_publicKey_bits; + } + len_seq = len_version + len_privateKey + len_parameters + len_publicKey; + if (dest == NULL) { + return 1 + len_of_len(len_seq) + len_seq; + } else { + unsigned char *buf; + size_t lenlen; + + buf = dest; + *buf ++ = 0x30; /* SEQUENCE tag */ + lenlen = br_asn1_encode_length(buf, len_seq); + buf += lenlen; + + /* version */ + *buf ++ = 0x02; + *buf ++ = 0x01; + *buf ++ = 0x01; + + /* privateKey */ + *buf ++ = 0x04; + buf += br_asn1_encode_length(buf, sk->xlen); + memcpy(buf, sk->x, sk->xlen); + buf += sk->xlen; + + /* parameters */ + if (include_curve_oid) { + *buf ++ = 0xA0; + *buf ++ = oid[0] + 2; + *buf ++ = 0x06; + memcpy(buf, oid, oid[0] + 1); + buf += oid[0] + 1; + } + + /* publicKey */ + if (pk != NULL) { + *buf ++ = 0xA1; + buf += br_asn1_encode_length(buf, len_publicKey_bits); + *buf ++ = 0x03; + buf += br_asn1_encode_length(buf, pk->qlen + 1); + *buf ++ = 0x00; + memcpy(buf, pk->q, pk->qlen); + /* buf += pk->qlen; */ + } + + return 1 + lenlen + len_seq; + } +} + +/* see bearssl_x509.h */ +size_t +br_encode_ec_raw_der(void *dest, + const br_ec_private_key *sk, const br_ec_public_key *pk) +{ + return br_encode_ec_raw_der_inner(dest, sk, pk, 1); +} |