xref: /freebsd/contrib/bearssl/src/x509/encode_rsa_rawder.c (revision 2aaf9152a852aba9eb2036b95f4948ee77988826)
1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty  * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty  *
4*0957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty  * the following conditions:
11*0957b409SSimon J. Gerraty  *
12*0957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty  *
15*0957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty  * SOFTWARE.
23*0957b409SSimon J. Gerraty  */
24*0957b409SSimon J. Gerraty 
25*0957b409SSimon J. Gerraty #include "inner.h"
26*0957b409SSimon J. Gerraty 
27*0957b409SSimon J. Gerraty /* see bearssl_x509.h */
28*0957b409SSimon J. Gerraty size_t
br_encode_rsa_raw_der(void * dest,const br_rsa_private_key * sk,const br_rsa_public_key * pk,const void * d,size_t dlen)29*0957b409SSimon J. Gerraty br_encode_rsa_raw_der(void *dest, const br_rsa_private_key *sk,
30*0957b409SSimon J. Gerraty 	const br_rsa_public_key *pk, const void *d, size_t dlen)
31*0957b409SSimon J. Gerraty {
32*0957b409SSimon J. Gerraty 	/*
33*0957b409SSimon J. Gerraty 	 * ASN.1 format:
34*0957b409SSimon J. Gerraty 	 *
35*0957b409SSimon J. Gerraty 	 *   RSAPrivateKey ::= SEQUENCE {
36*0957b409SSimon J. Gerraty 	 *       version           Version,
37*0957b409SSimon J. Gerraty 	 *       modulus           INTEGER,  -- n
38*0957b409SSimon J. Gerraty 	 *       publicExponent    INTEGER,  -- e
39*0957b409SSimon J. Gerraty 	 *       privateExponent   INTEGER,  -- d
40*0957b409SSimon J. Gerraty 	 *       prime1            INTEGER,  -- p
41*0957b409SSimon J. Gerraty 	 *       prime2            INTEGER,  -- q
42*0957b409SSimon J. Gerraty 	 *       exponent1         INTEGER,  -- d mod (p-1)
43*0957b409SSimon J. Gerraty 	 *       exponent2         INTEGER,  -- d mod (q-1)
44*0957b409SSimon J. Gerraty 	 *       coefficient       INTEGER,  -- (inverse of q) mod p
45*0957b409SSimon J. Gerraty 	 *       otherPrimeInfos   OtherPrimeInfos OPTIONAL
46*0957b409SSimon J. Gerraty 	 *   }
47*0957b409SSimon J. Gerraty 	 *
48*0957b409SSimon J. Gerraty 	 * The 'version' field is an INTEGER of value 0 (meaning: there
49*0957b409SSimon J. Gerraty 	 * are exactly two prime factors), and 'otherPrimeInfos' will
50*0957b409SSimon J. Gerraty 	 * be absent (because there are exactly two prime factors).
51*0957b409SSimon J. Gerraty 	 */
52*0957b409SSimon J. Gerraty 
53*0957b409SSimon J. Gerraty 	br_asn1_uint num[9];
54*0957b409SSimon J. Gerraty 	size_t u, slen;
55*0957b409SSimon J. Gerraty 
56*0957b409SSimon J. Gerraty 	/*
57*0957b409SSimon J. Gerraty 	 * For all INTEGER values, get the pointer and length for the
58*0957b409SSimon J. Gerraty 	 * data bytes.
59*0957b409SSimon J. Gerraty 	 */
60*0957b409SSimon J. Gerraty 	num[0] = br_asn1_uint_prepare(NULL, 0);
61*0957b409SSimon J. Gerraty 	num[1] = br_asn1_uint_prepare(pk->n, pk->nlen);
62*0957b409SSimon J. Gerraty 	num[2] = br_asn1_uint_prepare(pk->e, pk->elen);
63*0957b409SSimon J. Gerraty 	num[3] = br_asn1_uint_prepare(d, dlen);
64*0957b409SSimon J. Gerraty 	num[4] = br_asn1_uint_prepare(sk->p, sk->plen);
65*0957b409SSimon J. Gerraty 	num[5] = br_asn1_uint_prepare(sk->q, sk->qlen);
66*0957b409SSimon J. Gerraty 	num[6] = br_asn1_uint_prepare(sk->dp, sk->dplen);
67*0957b409SSimon J. Gerraty 	num[7] = br_asn1_uint_prepare(sk->dq, sk->dqlen);
68*0957b409SSimon J. Gerraty 	num[8] = br_asn1_uint_prepare(sk->iq, sk->iqlen);
69*0957b409SSimon J. Gerraty 
70*0957b409SSimon J. Gerraty 	/*
71*0957b409SSimon J. Gerraty 	 * Get the length of the SEQUENCE contents.
72*0957b409SSimon J. Gerraty 	 */
73*0957b409SSimon J. Gerraty 	slen = 0;
74*0957b409SSimon J. Gerraty 	for (u = 0; u < 9; u ++) {
75*0957b409SSimon J. Gerraty 		uint32_t ilen;
76*0957b409SSimon J. Gerraty 
77*0957b409SSimon J. Gerraty 		ilen = num[u].asn1len;
78*0957b409SSimon J. Gerraty 		slen += 1 + len_of_len(ilen) + ilen;
79*0957b409SSimon J. Gerraty 	}
80*0957b409SSimon J. Gerraty 
81*0957b409SSimon J. Gerraty 	if (dest == NULL) {
82*0957b409SSimon J. Gerraty 		return 1 + len_of_len(slen) + slen;
83*0957b409SSimon J. Gerraty 	} else {
84*0957b409SSimon J. Gerraty 		unsigned char *buf;
85*0957b409SSimon J. Gerraty 		size_t lenlen;
86*0957b409SSimon J. Gerraty 
87*0957b409SSimon J. Gerraty 		buf = dest;
88*0957b409SSimon J. Gerraty 		*buf ++ = 0x30;  /* SEQUENCE tag */
89*0957b409SSimon J. Gerraty 		lenlen = br_asn1_encode_length(buf, slen);
90*0957b409SSimon J. Gerraty 		buf += lenlen;
91*0957b409SSimon J. Gerraty 		for (u = 0; u < 9; u ++) {
92*0957b409SSimon J. Gerraty 			buf += br_asn1_encode_uint(buf, num[u]);
93*0957b409SSimon J. Gerraty 		}
94*0957b409SSimon J. Gerraty 		return 1 + lenlen + slen;
95*0957b409SSimon J. Gerraty 	}
96*0957b409SSimon J. Gerraty }
97