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md5_common.c
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1/*-------------------------------------------------------------------------
2 *
3 * md5_common.c
4 * Routines shared between all MD5 implementations used for encrypted
5 * passwords.
6 *
7 * Sverre H. Huseby <sverrehu@online.no>
8 *
9 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
10 * Portions Copyright (c) 1994, Regents of the University of California
11 *
12 * IDENTIFICATION
13 * src/common/md5_common.c
14 *
15 *-------------------------------------------------------------------------
16 */
17
18#ifndef FRONTEND
19#include "postgres.h"
20#else
21#include "postgres_fe.h"
22#endif
23
24#include "common/cryptohash.h"
25#include "common/md5.h"
26
27static void
28bytesToHex(uint8 b[16], char *s)
29{
30 static const char *hex = "0123456789abcdef";
31 int q,
32 w;
33
34 for (q = 0, w = 0; q < 16; q++)
35 {
36 s[w++] = hex[(b[q] >> 4) & 0x0F];
37 s[w++] = hex[b[q] & 0x0F];
38 }
39 s[w] = '\0';
40}
41
42/*
43 * pg_md5_hash
44 *
45 * Calculates the MD5 sum of the bytes in a buffer.
46 *
47 * SYNOPSIS #include "md5.h"
48 * bool pg_md5_hash(const void *buff, size_t len, char *hexsum,
49 * const char **errstr)
50 *
51 * INPUT buff the buffer containing the bytes that you want
52 * the MD5 sum of.
53 * len number of bytes in the buffer.
54 *
55 * OUTPUT hexsum the MD5 sum as a '\0'-terminated string of
56 * hexadecimal digits. an MD5 sum is 16 bytes long.
57 * each byte is represented by two hexadecimal
58 * characters. you thus need to provide an array
59 * of 33 characters, including the trailing '\0'.
60 *
61 * errstr filled with a constant-string error message
62 * on failure return; NULL on success.
63 *
64 * RETURNS false on failure (out of memory for internal buffers
65 * or MD5 computation failure) or true on success.
66 *
67 * STANDARDS MD5 is described in RFC 1321.
68 *
69 * AUTHOR Sverre H. Huseby <sverrehu@online.no>
70 *
71 */
72
73bool
74pg_md5_hash(const void *buff, size_t len, char *hexsum, const char **errstr)
75{
78
79 *errstr = NULL;
81 if (ctx == NULL)
82 {
83 *errstr = pg_cryptohash_error(NULL); /* returns OOM */
84 return false;
85 }
86
87 if (pg_cryptohash_init(ctx) < 0 ||
88 pg_cryptohash_update(ctx, buff, len) < 0 ||
89 pg_cryptohash_final(ctx, sum, sizeof(sum)) < 0)
90 {
91 *errstr = pg_cryptohash_error(ctx);
93 return false;
94 }
95
96 bytesToHex(sum, hexsum);
98 return true;
99}
100
101/*
102 * pg_md5_binary
103 *
104 * As above, except that the MD5 digest is returned as a binary string
105 * (of size MD5_DIGEST_LENGTH) rather than being converted to ASCII hex.
106 */
107bool
108pg_md5_binary(const void *buff, size_t len, void *outbuf, const char **errstr)
109{
111
112 *errstr = NULL;
114 if (ctx == NULL)
115 {
116 *errstr = pg_cryptohash_error(NULL); /* returns OOM */
117 return false;
118 }
119
120 if (pg_cryptohash_init(ctx) < 0 ||
121 pg_cryptohash_update(ctx, buff, len) < 0 ||
122 pg_cryptohash_final(ctx, outbuf, MD5_DIGEST_LENGTH) < 0)
123 {
124 *errstr = pg_cryptohash_error(ctx);
126 return false;
127 }
128
130 return true;
131}
132
133
134/*
135 * Computes MD5 checksum of "passwd" (a null-terminated string) followed
136 * by "salt" (which need not be null-terminated).
137 *
138 * Output format is "md5" followed by a 32-hex-digit MD5 checksum.
139 * Hence, the output buffer "buf" must be at least 36 bytes long.
140 *
141 * Returns true if okay, false on error with *errstr providing some
142 * error context.
143 */
144bool
145pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
146 char *buf, const char **errstr)
147{
148 size_t passwd_len = strlen(passwd);
149
150 /* +1 here is just to avoid risk of unportable malloc(0) */
151 char *crypt_buf = malloc(passwd_len + salt_len + 1);
152 bool ret;
153
154 if (!crypt_buf)
155 {
156 *errstr = _("out of memory");
157 return false;
158 }
159
160 /*
161 * Place salt at the end because it may be known by users trying to crack
162 * the MD5 output.
163 */
164 memcpy(crypt_buf, passwd, passwd_len);
165 memcpy(crypt_buf + passwd_len, salt, salt_len);
166
167 strcpy(buf, "md5");
168 ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3, errstr);
169
170 free(crypt_buf);
171
172 return ret;
173}
uint8_t uint8
Definition: c.h:486
const char * pg_cryptohash_error(pg_cryptohash_ctx *ctx)
Definition: cryptohash.c:254
int pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len)
Definition: cryptohash.c:136
pg_cryptohash_ctx * pg_cryptohash_create(pg_cryptohash_type type)
Definition: cryptohash.c:74
int pg_cryptohash_init(pg_cryptohash_ctx *ctx)
Definition: cryptohash.c:100
void pg_cryptohash_free(pg_cryptohash_ctx *ctx)
Definition: cryptohash.c:238
int pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
Definition: cryptohash.c:172
@ PG_MD5
Definition: cryptohash.h:21
#define _(x)
Definition: elog.c:90
#define free(a)
Definition: header.h:65
#define malloc(a)
Definition: header.h:50
int b
Definition: isn.c:69
#define MD5_DIGEST_LENGTH
Definition: md5.h:20
bool pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len, char *buf, const char **errstr)
Definition: md5_common.c:145
bool pg_md5_hash(const void *buff, size_t len, char *hexsum, const char **errstr)
Definition: md5_common.c:74
bool pg_md5_binary(const void *buff, size_t len, void *outbuf, const char **errstr)
Definition: md5_common.c:108
static void bytesToHex(uint8 b[16], char *s)
Definition: md5_common.c:28
const void size_t len
static char * buf
Definition: pg_test_fsync.c:72