README: remove duplicate download link & mention related softw.
[pgsql.git] / contrib / pgcrypto / crypt-gensalt.c
blob740f3612532b0719985beb0629d9b2d769f6170f
1 /*
2 * Written by Solar Designer and placed in the public domain.
3 * See crypt_blowfish.c for more information.
5 * contrib/pgcrypto/crypt-gensalt.c
7 * This file contains salt generation functions for the traditional and
8 * other common crypt(3) algorithms, except for bcrypt which is defined
9 * entirely in crypt_blowfish.c.
11 * Put bcrypt generator also here as crypt-blowfish.c
12 * may not be compiled always. -- marko
15 #include "postgres.h"
17 #include "px-crypt.h"
19 typedef unsigned int BF_word;
21 static unsigned char _crypt_itoa64[64 + 1] =
22 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
24 char *
25 _crypt_gensalt_traditional_rn(unsigned long count,
26 const char *input, int size, char *output, int output_size)
28 if (size < 2 || output_size < 2 + 1 || (count && count != 25))
30 if (output_size > 0)
31 output[0] = '\0';
32 return NULL;
35 output[0] = _crypt_itoa64[(unsigned int) input[0] & 0x3f];
36 output[1] = _crypt_itoa64[(unsigned int) input[1] & 0x3f];
37 output[2] = '\0';
39 return output;
42 char *
43 _crypt_gensalt_extended_rn(unsigned long count,
44 const char *input, int size, char *output, int output_size)
46 unsigned long value;
48 /* Even iteration counts make it easier to detect weak DES keys from a look
49 * at the hash, so they should be avoided */
50 if (size < 3 || output_size < 1 + 4 + 4 + 1 ||
51 (count && (count > 0xffffff || !(count & 1))))
53 if (output_size > 0)
54 output[0] = '\0';
55 return NULL;
58 if (!count)
59 count = 725;
61 output[0] = '_';
62 output[1] = _crypt_itoa64[count & 0x3f];
63 output[2] = _crypt_itoa64[(count >> 6) & 0x3f];
64 output[3] = _crypt_itoa64[(count >> 12) & 0x3f];
65 output[4] = _crypt_itoa64[(count >> 18) & 0x3f];
66 value = (unsigned long) (unsigned char) input[0] |
67 ((unsigned long) (unsigned char) input[1] << 8) |
68 ((unsigned long) (unsigned char) input[2] << 16);
69 output[5] = _crypt_itoa64[value & 0x3f];
70 output[6] = _crypt_itoa64[(value >> 6) & 0x3f];
71 output[7] = _crypt_itoa64[(value >> 12) & 0x3f];
72 output[8] = _crypt_itoa64[(value >> 18) & 0x3f];
73 output[9] = '\0';
75 return output;
78 char *
79 _crypt_gensalt_md5_rn(unsigned long count,
80 const char *input, int size, char *output, int output_size)
82 unsigned long value;
84 if (size < 3 || output_size < 3 + 4 + 1 || (count && count != 1000))
86 if (output_size > 0)
87 output[0] = '\0';
88 return NULL;
91 output[0] = '$';
92 output[1] = '1';
93 output[2] = '$';
94 value = (unsigned long) (unsigned char) input[0] |
95 ((unsigned long) (unsigned char) input[1] << 8) |
96 ((unsigned long) (unsigned char) input[2] << 16);
97 output[3] = _crypt_itoa64[value & 0x3f];
98 output[4] = _crypt_itoa64[(value >> 6) & 0x3f];
99 output[5] = _crypt_itoa64[(value >> 12) & 0x3f];
100 output[6] = _crypt_itoa64[(value >> 18) & 0x3f];
101 output[7] = '\0';
103 if (size >= 6 && output_size >= 3 + 4 + 4 + 1)
105 value = (unsigned long) (unsigned char) input[3] |
106 ((unsigned long) (unsigned char) input[4] << 8) |
107 ((unsigned long) (unsigned char) input[5] << 16);
108 output[7] = _crypt_itoa64[value & 0x3f];
109 output[8] = _crypt_itoa64[(value >> 6) & 0x3f];
110 output[9] = _crypt_itoa64[(value >> 12) & 0x3f];
111 output[10] = _crypt_itoa64[(value >> 18) & 0x3f];
112 output[11] = '\0';
115 return output;
120 static unsigned char BF_itoa64[64 + 1] =
121 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
123 static void
124 BF_encode(char *dst, const BF_word *src, int size)
126 const unsigned char *sptr = (const unsigned char *) src;
127 const unsigned char *end = sptr + size;
128 unsigned char *dptr = (unsigned char *) dst;
129 unsigned int c1,
134 c1 = *sptr++;
135 *dptr++ = BF_itoa64[c1 >> 2];
136 c1 = (c1 & 0x03) << 4;
137 if (sptr >= end)
139 *dptr++ = BF_itoa64[c1];
140 break;
143 c2 = *sptr++;
144 c1 |= c2 >> 4;
145 *dptr++ = BF_itoa64[c1];
146 c1 = (c2 & 0x0f) << 2;
147 if (sptr >= end)
149 *dptr++ = BF_itoa64[c1];
150 break;
153 c2 = *sptr++;
154 c1 |= c2 >> 6;
155 *dptr++ = BF_itoa64[c1];
156 *dptr++ = BF_itoa64[c2 & 0x3f];
157 } while (sptr < end);
160 char *
161 _crypt_gensalt_blowfish_rn(unsigned long count,
162 const char *input, int size, char *output, int output_size)
164 if (size < 16 || output_size < 7 + 22 + 1 ||
165 (count && (count < 4 || count > 31)))
167 if (output_size > 0)
168 output[0] = '\0';
169 return NULL;
172 if (!count)
173 count = 5;
175 output[0] = '$';
176 output[1] = '2';
177 output[2] = 'a';
178 output[3] = '$';
179 output[4] = '0' + count / 10;
180 output[5] = '0' + count % 10;
181 output[6] = '$';
183 BF_encode(&output[7], (const BF_word *) input, 16);
184 output[7 + 22] = '\0';
186 return output;