2 * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
27 /* see bearssl_x509.h */
29 br_encode_rsa_pkcs8_der(void *dest
, const br_rsa_private_key
*sk
,
30 const br_rsa_public_key
*pk
, const void *d
, size_t dlen
)
35 * OneAsymmetricKey ::= SEQUENCE {
37 * privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
38 * privateKey PrivateKey,
39 * attributes [0] Attributes OPTIONAL,
41 * [[2: publicKey [1] PublicKey OPTIONAL ]],
45 * We don't include attributes or public key. The 'version' field
46 * is an INTEGER that we will set to 0 (meaning 'v1', compatible
47 * with previous versions of PKCS#8). The 'privateKeyAlgorithm'
48 * structure is an AlgorithmIdentifier whose OID should be
49 * rsaEncryption, with NULL parameters. The 'privateKey' is an
50 * OCTET STRING, whose value is the "raw DER" encoding of the
53 * Since the private key value comes last, this function really
54 * adds a header, which is mostly fixed (only some lengths have
60 * - DER encoding of an INTEGER of value 0 (the 'version' field)
61 * - DER encoding of a PrivateKeyAlgorithmIdentifier that uses
62 * the rsaEncryption OID, and NULL parameters
63 * - An OCTET STRING tag
65 static const unsigned char PK8_HEAD
[] = {
67 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
68 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00,
72 size_t len_raw
, len_seq
;
74 len_raw
= br_encode_rsa_raw_der(NULL
, sk
, pk
, d
, dlen
);
75 len_seq
= (sizeof PK8_HEAD
) + len_of_len(len_raw
) + len_raw
;
77 return 1 + len_of_len(len_seq
) + len_seq
;
83 *buf
++ = 0x30; /* SEQUENCE tag */
84 lenlen
= br_asn1_encode_length(buf
, len_seq
);
87 /* version, privateKeyAlgorithm, privateKey tag */
88 memcpy(buf
, PK8_HEAD
, sizeof PK8_HEAD
);
89 buf
+= sizeof PK8_HEAD
;
92 buf
+= br_asn1_encode_length(buf
, len_raw
);
93 br_encode_rsa_raw_der(buf
, sk
, pk
, d
, dlen
);
95 return 1 + lenlen
+ len_seq
;