sqlcipher-src 420.0.0+sqlcipher-4.20.0-sqlite-3.54.1-libtomcrypt-1.18.2

The SQLCipher amalgamation for native and wasm32 builds, with a libtomcrypt provider for targets without a system crypto library
Documentation 
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

/* 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.
 */
#include "tomcrypt.h"

/**
  @file der_decode_integer.c
  ASN.1 DER, decode an integer, Tom St Denis
*/


#ifdef LTC_DER

/**
  Read a mp_int integer
  @param in       The DER encoded data
  @param inlen    Size of DER encoded data
  @param num      The first mp_int to decode
  @return CRYPT_OK if successful
*/
int der_decode_integer(const unsigned char *in, unsigned long inlen, void *num)
{
   unsigned long x, y, z;
   int           err;

   LTC_ARGCHK(num    != NULL);
   LTC_ARGCHK(in     != NULL);

   /* min DER INTEGER is 0x02 01 00 == 0 */
   if (inlen < (1 + 1 + 1)) {
      return CRYPT_INVALID_PACKET;
   }

   /* ok expect 0x02 when we AND with 0001 1111 [1F] */
   x = 0;
   if ((in[x++] & 0x1F) != 0x02) {
      return CRYPT_INVALID_PACKET;
   }

   /* now decode the len stuff */
   z = in[x++];

   if ((z & 0x80) == 0x00) {
      /* short form */

      /* will it overflow? */
      if (x + z > inlen) {
         return CRYPT_INVALID_PACKET;
      }

      /* no so read it */
      if ((err = mp_read_unsigned_bin(num, (unsigned char *)in + x, z)) != CRYPT_OK) {
         return err;
      }
   } else {
      /* long form */
      z &= 0x7F;

      /* will number of length bytes overflow? (or > 4) */
      if (((x + z) > inlen) || (z > 4) || (z == 0)) {
         return CRYPT_INVALID_PACKET;
      }

      /* now read it in */
      y = 0;
      while (z--) {
         y = ((unsigned long)(in[x++])) | (y << 8);
      }

      /* now will reading y bytes overrun? */
      if ((x + y) > inlen) {
         return CRYPT_INVALID_PACKET;
      }

      /* no so read it */
      if ((err = mp_read_unsigned_bin(num, (unsigned char *)in + x, y)) != CRYPT_OK) {
         return err;
      }
   }

   /* see if it's negative */
   if (in[x] & 0x80) {
      void *tmp;
      if (mp_init(&tmp) != CRYPT_OK) {
         return CRYPT_MEM;
      }

      if (mp_2expt(tmp, mp_count_bits(num)) != CRYPT_OK || mp_sub(num, tmp, num) != CRYPT_OK) {
         mp_clear(tmp);
         return CRYPT_MEM;
      }
      mp_clear(tmp);
   }

   return CRYPT_OK;

}

#endif

/* ref:         HEAD -> master, tag: v1.18.2 */
/* git commit:  7e7eb695d581782f04b24dc444cbfde86af59853 */
/* commit time: 2018-07-01 22:49:01 +0200 */