diff options
Diffstat (limited to 'third_party/bearssl/src/encode_ec_pk8der.c')
| -rw-r--r-- | third_party/bearssl/src/encode_ec_pk8der.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/third_party/bearssl/src/encode_ec_pk8der.c b/third_party/bearssl/src/encode_ec_pk8der.c new file mode 100644 index 0000000..53717ce --- /dev/null +++ b/third_party/bearssl/src/encode_ec_pk8der.c @@ -0,0 +1,110 @@ +/* + * 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 bearssl_x509.h */ +size_t +br_encode_ec_pkcs8_der(void *dest, + const br_ec_private_key *sk, const br_ec_public_key *pk) +{ + /* + * ASN.1 format: + * + * OneAsymmetricKey ::= SEQUENCE { + * version Version, + * privateKeyAlgorithm PrivateKeyAlgorithmIdentifier, + * privateKey PrivateKey, + * attributes [0] Attributes OPTIONAL, + * ..., + * [[2: publicKey [1] PublicKey OPTIONAL ]], + * ... + * } + * + * We don't include attributes or public key (the public key + * is included in the private key value instead). The + * 'version' field is an INTEGER that we will set to 0 + * (meaning 'v1', compatible with previous versions of PKCS#8). + * The 'privateKeyAlgorithm' structure is an AlgorithmIdentifier + * whose OID should be id-ecPublicKey, with, as parameters, the + * curve OID. The 'privateKey' is an OCTET STRING, whose value + * is the "raw DER" encoding of the key pair. + */ + + /* + * OID id-ecPublicKey (1.2.840.10045.2.1), DER-encoded (with + * the tag). + */ + static const unsigned char OID_ECPUBKEY[] = { + 0x06, 0x07, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01 + }; + + size_t len_version, len_privateKeyAlgorithm, len_privateKeyValue; + size_t len_privateKey, len_seq; + const unsigned char *oid; + + oid = br_get_curve_OID(sk->curve); + if (oid == NULL) { + return 0; + } + len_version = 3; + len_privateKeyAlgorithm = 2 + sizeof OID_ECPUBKEY + 2 + oid[0]; + len_privateKeyValue = br_encode_ec_raw_der_inner(NULL, sk, pk, 0); + len_privateKey = 1 + len_of_len(len_privateKeyValue) + + len_privateKeyValue; + len_seq = len_version + len_privateKeyAlgorithm + len_privateKey; + + 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 ++ = 0x00; + + /* privateKeyAlgorithm */ + *buf ++ = 0x30; + *buf ++ = (sizeof OID_ECPUBKEY) + 2 + oid[0]; + memcpy(buf, OID_ECPUBKEY, sizeof OID_ECPUBKEY); + buf += sizeof OID_ECPUBKEY; + *buf ++ = 0x06; + memcpy(buf, oid, 1 + oid[0]); + buf += 1 + oid[0]; + + /* privateKey */ + *buf ++ = 0x04; + buf += br_asn1_encode_length(buf, len_privateKeyValue); + br_encode_ec_raw_der_inner(buf, sk, pk, 0); + + return 1 + lenlen + len_seq; + } +} |