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comparison libtomcrypt/src/pk/asn1/der/sequence/der_decode_subject_public_key_info.c @ 1471:6dba84798cd5

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Update to libtomcrypt 1.18.1, merged with Dropbear changes
author Matt Johnston <matt@ucc.asn.au>
date Fri, 09 Feb 2018 21:44:05 +0800
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children e9dba7abd939
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1470:8bba51a55704 1471:6dba84798cd5
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 */
9 #include "tomcrypt.h"
10 /**
11 @file der_decode_subject_public_key_info.c
12 ASN.1 DER, encode a Subject Public Key structure --nmav
13 */
14
15 #ifdef LTC_DER
16
17 /* AlgorithmIdentifier := SEQUENCE {
18 * algorithm OBJECT IDENTIFIER,
19 * parameters ANY DEFINED BY algorithm
20 * }
21 *
22 * SubjectPublicKeyInfo := SEQUENCE {
23 * algorithm AlgorithmIdentifier,
24 * subjectPublicKey BIT STRING
25 * }
26 */
27 /**
28 Decode a subject public key info
29 @param in The input buffer
30 @param inlen The length of the input buffer
31 @param algorithm One out of the enum #public_key_algorithms
32 @param public_key The buffer for the public key
33 @param public_key_len [in/out] The length of the public key buffer and the written length
34 @param parameters_type The parameters' type out of the enum ltc_asn1_type
35 @param parameters The parameters to include
36 @param parameters_len The number of parameters to include
37 @return CRYPT_OK on success
38 */
39 int der_decode_subject_public_key_info(const unsigned char *in, unsigned long inlen,
40 unsigned int algorithm, void* public_key, unsigned long* public_key_len,
41 unsigned long parameters_type, ltc_asn1_list* parameters, unsigned long parameters_len)
42 {
43 int err;
44 unsigned long len;
45 oid_st oid;
46 unsigned char *tmpbuf;
47 unsigned long tmpoid[16];
48 ltc_asn1_list alg_id[2];
49 ltc_asn1_list subject_pubkey[2];
50
51 LTC_ARGCHK(in != NULL);
52 LTC_ARGCHK(inlen != 0);
53 LTC_ARGCHK(public_key_len != NULL);
54
55 err = pk_get_oid(algorithm, &oid);
56 if (err != CRYPT_OK) {
57 return err;
58 }
59
60 /* see if the OpenSSL DER format RSA public key will work */
61 tmpbuf = XCALLOC(1, inlen);
62 if (tmpbuf == NULL) {
63 err = CRYPT_MEM;
64 goto LBL_ERR;
65 }
66
67 /* this includes the internal hash ID and optional params (NULL in this case) */
68 LTC_SET_ASN1(alg_id, 0, LTC_ASN1_OBJECT_IDENTIFIER, tmpoid, sizeof(tmpoid)/sizeof(tmpoid[0]));
69 LTC_SET_ASN1(alg_id, 1, (ltc_asn1_type)parameters_type, parameters, parameters_len);
70
71 /* the actual format of the SSL DER key is odd, it stores a RSAPublicKey
72 * in a **BIT** string ... so we have to extract it then proceed to convert bit to octet
73 */
74 LTC_SET_ASN1(subject_pubkey, 0, LTC_ASN1_SEQUENCE, alg_id, 2);
75 LTC_SET_ASN1(subject_pubkey, 1, LTC_ASN1_RAW_BIT_STRING, tmpbuf, inlen*8U);
76
77 err=der_decode_sequence(in, inlen, subject_pubkey, 2UL);
78 if (err != CRYPT_OK) {
79 goto LBL_ERR;
80 }
81
82 if ((alg_id[0].size != oid.OIDlen) ||
83 XMEMCMP(oid.OID, alg_id[0].data, oid.OIDlen * sizeof(oid.OID[0]))) {
84 /* OID mismatch */
85 err = CRYPT_PK_INVALID_TYPE;
86 goto LBL_ERR;
87 }
88
89 len = subject_pubkey[1].size/8;
90 if (*public_key_len > len) {
91 XMEMCPY(public_key, subject_pubkey[1].data, len);
92 *public_key_len = len;
93 } else {
94 *public_key_len = len;
95 err = CRYPT_BUFFER_OVERFLOW;
96 goto LBL_ERR;
97 }
98
99 err = CRYPT_OK;
100
101 LBL_ERR:
102
103 XFREE(tmpbuf);
104
105 return err;
106 }
107
108 #endif
109
110 /* ref: $Format:%D$ */
111 /* git commit: $Format:%H$ */
112 /* commit time: $Format:%ai$ */