Mercurial > dropbear

annotate libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c @ 382:0cbe8f6dbf9e

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f) to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 02:41:05 +0000
parents 1b9e69c058d2
children f849a5ca2efc
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
2 *
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 * LibTomCrypt is a library that provides various cryptographic
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4 * algorithms in a highly modular and flexible manner.
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 *
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 * The library is free for all purposes without any express
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7 * guarantee it works.
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 *
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
9 * Tom St Denis, [email protected], http://libtomcrypt.com
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11 #include "tomcrypt.h"
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 /**
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14 @file der_length_integer.c
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
15 ASN.1 DER, get length of encoding, Tom St Denis
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16 */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 #ifdef LTC_DER
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20 /**
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21 Gets length of DER encoding of num
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
22 @param num The int to get the size of
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 @param outlen [out] The length of the DER encoding for the given integer
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 @return CRYPT_OK if successful
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 */
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
26 int der_length_integer(void *num, unsigned long *outlen)
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27 {
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 unsigned long z, len;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 int leading_zero;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
30
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
31 LTC_ARGCHK(num != NULL);
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
32 LTC_ARGCHK(outlen != NULL);
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
34 if (mp_cmp_d(num, 0) != LTC_MP_LT) {
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35 /* positive */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
36
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
37 /* we only need a leading zero if the msb of the first byte is one */
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
38 if ((mp_count_bits(num) & 7) == 0 || mp_iszero(num) == LTC_MP_YES) {
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
39 leading_zero = 1;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
40 } else {
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
41 leading_zero = 0;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
42 }
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
43
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
44 /* size for bignum */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
45 z = len = leading_zero + mp_unsigned_bin_size(num);
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
46 } else {
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
47 /* it's negative */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
48 /* find power of 2 that is a multiple of eight and greater than count bits */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
49 leading_zero = 0;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
50 z = mp_count_bits(num);
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
51 z = z + (8 - (z & 7));
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
52 if (((mp_cnt_lsb(num)+1)==mp_count_bits(num)) && ((mp_count_bits(num)&7)==0)) --z;
285
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
53 len = z = z >> 3;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
54 }
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
55
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
56 /* now we need a length */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
57 if (z < 128) {
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
58 /* short form */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
59 ++len;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
60 } else {
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
61 /* long form (relies on z != 0), assumes length bytes < 128 */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
62 ++len;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
63
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
64 while (z) {
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
65 ++len;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
66 z >>= 8;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
67 }
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
68 }
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
69
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
70 /* we need a 0x02 to indicate it's INTEGER */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
71 ++len;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
72
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
73 /* return length */
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
74 *outlen = len;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
75 return CRYPT_OK;
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
76 }
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
77
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
78 #endif
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
79
1b9e69c058d2 propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3)
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
80 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/integer/der_length_integer.c,v $ */
382
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
81 /* $Revision: 1.4 $ */
0cbe8f6dbf9e propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
Matt Johnston <matt@ucc.asn.au>
parents: 285
diff changeset
82 /* $Date: 2006/04/22 01:22:55 $ */