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comparison src/pk/rsa/rsa_import.c @ 191:1c15b283127b libtomcrypt-orig

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Import of libtomcrypt 1.02 with manual path rename rearrangement etc
author Matt Johnston <matt@ucc.asn.au>
date Fri, 06 May 2005 13:23:02 +0000
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children 39d5d58461d6
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143:5d99163f7e32 191:1c15b283127b
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 * Tom St Denis, [email protected], http://libtomcrypt.org
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file rsa_import.c
15 Import a PKCS RSA key, Tom St Denis
16 */
17
18 #ifdef MRSA
19
20 /**
21 Import an RSAPublicKey or RSAPrivateKey [two-prime only, defined in PKCS #1 v2.1]
22 @param in The packet to import from
23 @param inlen It's length (octets)
24 @param key [out] Destination for newly imported key
25 @return CRYPT_OK if successful, upon error allocated memory is freed
26 */
27 int rsa_import(const unsigned char *in, unsigned long inlen, rsa_key *key)
28 {
29 unsigned long x, y;
30 int err;
31
32 LTC_ARGCHK(in != NULL);
33 LTC_ARGCHK(key != NULL);
34
35 /* init key */
36 if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ, &key->dP, &key->qP,
37 &key->p, &key->q, NULL)) != MP_OKAY) {
38 return mpi_to_ltc_error(err);
39 }
40
41 /* check the header */
42 if (inlen < 4) {
43 return CRYPT_INVALID_PACKET;
44 }
45
46 /* should be 0x30 0x8{1|2} LL LL */
47 if ((in[0] != 0x30) || ((in[1] != 0x81) && (in[1] != 0x82))) {
48 return CRYPT_INVALID_PACKET;
49 }
50
51 /* ok all the ASN.1 params are fine so far, let's move up */
52 x = ((unsigned long)in[2]);
53 y = 0;
54 if ((in[1] & ~0x80) == 2) {
55 x = (x << 8) + ((unsigned long)in[3]) + 1;
56 in += 1;
57 y = 1;
58 }
59 in += 3; /* advance input */
60 x += 3; /* size of packet according to header */
61 y += 3; /* used input */
62
63 if (x != inlen) {
64 return CRYPT_INVALID_PACKET;
65 }
66
67 /* decrement inlen by the header size */
68 inlen -= y;
69
70 /* read first number, it's either N or 0 [0 == private key] */
71 x = inlen;
72 if ((err = der_get_multi_integer(in, &x, &key->N, NULL)) != CRYPT_OK) {
73 goto LBL_ERR;
74 }
75
76 /* advance */
77 inlen -= x;
78 in += x;
79
80 if (mp_cmp_d(&key->N, 0) == MP_EQ) {
81 /* it's a private key */
82 if ((err = der_get_multi_integer(in, &inlen, &key->N, &key->e,
83 &key->d, &key->p, &key->q, &key->dP,
84 &key->dQ, &key->qP, NULL)) != CRYPT_OK) {
85 goto LBL_ERR;
86 }
87
88 key->type = PK_PRIVATE;
89 } else if (mp_cmp_d(&key->N, 1) == MP_EQ) {
90 /* we don't support multi-prime RSA */
91 err = CRYPT_PK_INVALID_TYPE;
92 goto LBL_ERR;
93 } else {
94 /* it's a public key and we lack e */
95 if ((err = der_get_multi_integer(in, &inlen, &key->e, NULL)) != CRYPT_OK) {
96 goto LBL_ERR;
97 }
98
99 /* free up some ram */
100 mp_clear_multi(&key->p, &key->q, &key->qP, &key->dP, &key->dQ, NULL);
101
102 key->type = PK_PUBLIC;
103 }
104 return CRYPT_OK;
105 LBL_ERR:
106 mp_clear_multi(&key->d, &key->e, &key->N, &key->dQ, &key->dP,
107 &key->qP, &key->p, &key->q, NULL);
108 return err;
109 }
110
111 #endif /* MRSA */
112