1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
*/
#include "tomcrypt.h"
/**
@file rsa_import.c
Import a LTC_PKCS RSA key, Tom St Denis
*/
#ifdef LTC_MRSA
/**
Import an RSAPublicKey or RSAPrivateKey [two-prime only, only support >= 1024-bit keys, defined in LTC_PKCS #1 v2.1]
@param in The packet to import from
@param inlen It's length (octets)
@param key [out] Destination for newly imported key
@return CRYPT_OK if successful, upon error allocated memory is freed
*/
int rsa_import(const unsigned char *in, unsigned long inlen, rsa_key *key)
{
int err;
void *zero;
unsigned char *tmpbuf;
unsigned long t, x, y, z, tmpoid[16];
ltc_asn1_list ssl_pubkey_hashoid[2];
ltc_asn1_list ssl_pubkey[2];
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(key != NULL);
LTC_ARGCHK(ltc_mp.name != NULL);
/* init key */
if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ,
&key->dP, &key->qP, &key->p, &key->q, NULL)) != CRYPT_OK) {
return err;
}
/* see if the OpenSSL DER format RSA public key will work */
tmpbuf = XCALLOC(1, MAX_RSA_SIZE*8);
if (tmpbuf == NULL) {
err = CRYPT_MEM;
goto LBL_ERR;
}
/* this includes the internal hash ID and optional params (NULL in this case) */
LTC_SET_ASN1(ssl_pubkey_hashoid, 0, LTC_ASN1_OBJECT_IDENTIFIER, tmpoid, sizeof(tmpoid)/sizeof(tmpoid[0]));
LTC_SET_ASN1(ssl_pubkey_hashoid, 1, LTC_ASN1_NULL, NULL, 0);
/* the actual format of the SSL DER key is odd, it stores a RSAPublicKey in a **BIT** string ... so we have to extract it
then proceed to convert bit to octet
*/
LTC_SET_ASN1(ssl_pubkey, 0, LTC_ASN1_SEQUENCE, &ssl_pubkey_hashoid, 2);
LTC_SET_ASN1(ssl_pubkey, 1, LTC_ASN1_BIT_STRING, tmpbuf, MAX_RSA_SIZE*8);
if (der_decode_sequence(in, inlen,
ssl_pubkey, 2UL) == CRYPT_OK) {
/* ok now we have to reassemble the BIT STRING to an OCTET STRING. Thanks OpenSSL... */
for (t = y = z = x = 0; x < ssl_pubkey[1].size; x++) {
y = (y << 1) | tmpbuf[x];
if (++z == 8) {
tmpbuf[t++] = (unsigned char)y;
y = 0;
z = 0;
}
}
/* now it should be SEQUENCE { INTEGER, INTEGER } */
if ((err = der_decode_sequence_multi(tmpbuf, t,
LTC_ASN1_INTEGER, 1UL, key->N,
LTC_ASN1_INTEGER, 1UL, key->e,
LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
XFREE(tmpbuf);
goto LBL_ERR;
}
XFREE(tmpbuf);
key->type = PK_PUBLIC;
return CRYPT_OK;
}
XFREE(tmpbuf);
/* not SSL public key, try to match against LTC_PKCS #1 standards */
if ((err = der_decode_sequence_multi(in, inlen,
LTC_ASN1_INTEGER, 1UL, key->N,
LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
goto LBL_ERR;
}
if (mp_cmp_d(key->N, 0) == LTC_MP_EQ) {
if ((err = mp_init(&zero)) != CRYPT_OK) {
goto LBL_ERR;
}
/* it's a private key */
if ((err = der_decode_sequence_multi(in, inlen,
LTC_ASN1_INTEGER, 1UL, zero,
LTC_ASN1_INTEGER, 1UL, key->N,
LTC_ASN1_INTEGER, 1UL, key->e,
LTC_ASN1_INTEGER, 1UL, key->d,
LTC_ASN1_INTEGER, 1UL, key->p,
LTC_ASN1_INTEGER, 1UL, key->q,
LTC_ASN1_INTEGER, 1UL, key->dP,
LTC_ASN1_INTEGER, 1UL, key->dQ,
LTC_ASN1_INTEGER, 1UL, key->qP,
LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
mp_clear(zero);
goto LBL_ERR;
}
mp_clear(zero);
key->type = PK_PRIVATE;
} else if (mp_cmp_d(key->N, 1) == LTC_MP_EQ) {
/* we don't support multi-prime RSA */
err = CRYPT_PK_INVALID_TYPE;
goto LBL_ERR;
} else {
/* it's a public key and we lack e */
if ((err = der_decode_sequence_multi(in, inlen,
LTC_ASN1_INTEGER, 1UL, key->N,
LTC_ASN1_INTEGER, 1UL, key->e,
LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
goto LBL_ERR;
}
key->type = PK_PUBLIC;
}
return CRYPT_OK;
LBL_ERR:
mp_clear_multi(key->d, key->e, key->N, key->dQ, key->dP, key->qP, key->p, key->q, NULL);
return err;
}
#endif /* LTC_MRSA */
/* $Source$ */
/* $Revision$ */
/* $Date$ */
|
