Mercurial > dropbear
annotate src/pk/rsa/rsa_exptmod.c @ 192:9cc34777b479 libtomcrypt
propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9)
to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 08 May 2005 06:36:47 +0000 |
parents | 1c15b283127b |
children | 39d5d58461d6 |
rev | line source |
---|---|
191
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
2 * |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
3 * LibTomCrypt is a library that provides various cryptographic |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
4 * algorithms in a highly modular and flexible manner. |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
5 * |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
6 * The library is free for all purposes without any express |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
7 * guarantee it works. |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
8 * |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
9 * Tom St Denis, [email protected], http://libtomcrypt.org |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
10 */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
11 #include "tomcrypt.h" |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
12 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
13 /** |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
14 @file rsa_exptmod.c |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
15 RSA PKCS exptmod, Tom St Denis |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
16 */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
17 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
18 #ifdef MRSA |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
19 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
20 /** |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
21 Compute an RSA modular exponentiation |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
22 @param in The input data to send into RSA |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
23 @param inlen The length of the input (octets) |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
24 @param out [out] The destination |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
25 @param outlen [in/out] The max size and resulting size of the output |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
26 @param which Which exponent to use, e.g. PK_PRIVATE or PK_PUBLIC |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
27 @param key The RSA key to use |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
28 @return CRYPT_OK if successful |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
29 */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
30 int rsa_exptmod(const unsigned char *in, unsigned long inlen, |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
31 unsigned char *out, unsigned long *outlen, int which, |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
32 rsa_key *key) |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
33 { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
34 mp_int tmp, tmpa, tmpb; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
35 unsigned long x; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
36 int err; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
37 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
38 LTC_ARGCHK(in != NULL); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
39 LTC_ARGCHK(out != NULL); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
40 LTC_ARGCHK(outlen != NULL); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
41 LTC_ARGCHK(key != NULL); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
42 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
43 /* is the key of the right type for the operation? */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
44 if (which == PK_PRIVATE && (key->type != PK_PRIVATE)) { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
45 return CRYPT_PK_NOT_PRIVATE; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
46 } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
47 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
48 /* must be a private or public operation */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
49 if (which != PK_PRIVATE && which != PK_PUBLIC) { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
50 return CRYPT_PK_INVALID_TYPE; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
51 } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
52 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
53 /* init and copy into tmp */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
54 if ((err = mp_init_multi(&tmp, &tmpa, &tmpb, NULL)) != MP_OKAY) { return mpi_to_ltc_error(err); } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
55 if ((err = mp_read_unsigned_bin(&tmp, (unsigned char *)in, (int)inlen)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
56 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
57 /* sanity check on the input */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
58 if (mp_cmp(&key->N, &tmp) == MP_LT) { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
59 err = CRYPT_PK_INVALID_SIZE; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
60 goto done; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
61 } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
62 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
63 /* are we using the private exponent and is the key optimized? */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
64 if (which == PK_PRIVATE) { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
65 /* tmpa = tmp^dP mod p */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
66 if ((err = mp_exptmod(&tmp, &key->dP, &key->p, &tmpa)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
67 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
68 /* tmpb = tmp^dQ mod q */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
69 if ((err = mp_exptmod(&tmp, &key->dQ, &key->q, &tmpb)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
70 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
71 /* tmp = (tmpa - tmpb) * qInv (mod p) */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
72 if ((err = mp_sub(&tmpa, &tmpb, &tmp)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
73 if ((err = mp_mulmod(&tmp, &key->qP, &key->p, &tmp)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
74 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
75 /* tmp = tmpb + q * tmp */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
76 if ((err = mp_mul(&tmp, &key->q, &tmp)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
77 if ((err = mp_add(&tmp, &tmpb, &tmp)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
78 } else { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
79 /* exptmod it */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
80 if ((err = mp_exptmod(&tmp, &key->e, &key->N, &tmp)) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
81 } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
82 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
83 /* read it back */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
84 x = (unsigned long)mp_unsigned_bin_size(&key->N); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
85 if (x > *outlen) { |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
86 err = CRYPT_BUFFER_OVERFLOW; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
87 goto done; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
88 } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
89 *outlen = x; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
90 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
91 /* convert it */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
92 zeromem(out, x); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
93 if ((err = mp_to_unsigned_bin(&tmp, out+(x-mp_unsigned_bin_size(&tmp)))) != MP_OKAY) { goto error; } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
94 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
95 /* clean up and return */ |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
96 err = CRYPT_OK; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
97 goto done; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
98 error: |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
99 err = mpi_to_ltc_error(err); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
100 done: |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
101 mp_clear_multi(&tmp, &tmpa, &tmpb, NULL); |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
102 return err; |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
103 } |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
104 |
1c15b283127b
Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff
changeset
|
105 #endif |