1 /*-------------------------------------------------------------------------
2 *
3 * cryptohashfuncs.c
4 * Cryptographic hash functions
5 *
6 * Portions Copyright (c) 2018-2021, PostgreSQL Global Development Group
7 *
8 *
9 * IDENTIFICATION
10 * src/backend/utils/adt/cryptohashfuncs.c
11 *
12 *-------------------------------------------------------------------------
13 */
14 #include "postgres.h"
15
16 #include "common/cryptohash.h"
17 #include "common/md5.h"
18 #include "common/sha2.h"
19 #include "utils/builtins.h"
20
21
22 /*
23 * MD5
24 */
25
26 /* MD5 produces a 16 byte (128 bit) hash; double it for hex */
27 #define MD5_HASH_LEN 32
28
29 /*
30 * Create an MD5 hash of a text value and return it as hex string.
31 */
32 Datum
md5_text(PG_FUNCTION_ARGS)33 md5_text(PG_FUNCTION_ARGS)
34 {
35 text *in_text = PG_GETARG_TEXT_PP(0);
36 size_t len;
37 char hexsum[MD5_HASH_LEN + 1];
38
39 /* Calculate the length of the buffer using varlena metadata */
40 len = VARSIZE_ANY_EXHDR(in_text);
41
42 /* get the hash result */
43 if (pg_md5_hash(VARDATA_ANY(in_text), len, hexsum) == false)
44 ereport(ERROR,
45 (errcode(ERRCODE_OUT_OF_MEMORY),
46 errmsg("out of memory")));
47
48 /* convert to text and return it */
49 PG_RETURN_TEXT_P(cstring_to_text(hexsum));
50 }
51
52 /*
53 * Create an MD5 hash of a bytea value and return it as a hex string.
54 */
55 Datum
md5_bytea(PG_FUNCTION_ARGS)56 md5_bytea(PG_FUNCTION_ARGS)
57 {
58 bytea *in = PG_GETARG_BYTEA_PP(0);
59 size_t len;
60 char hexsum[MD5_HASH_LEN + 1];
61
62 len = VARSIZE_ANY_EXHDR(in);
63 if (pg_md5_hash(VARDATA_ANY(in), len, hexsum) == false)
64 ereport(ERROR,
65 (errcode(ERRCODE_OUT_OF_MEMORY),
66 errmsg("out of memory")));
67
68 PG_RETURN_TEXT_P(cstring_to_text(hexsum));
69 }
70
71 /*
72 * Internal routine to compute a cryptohash with the given bytea input.
73 */
74 static inline bytea *
cryptohash_internal(pg_cryptohash_type type,bytea * input)75 cryptohash_internal(pg_cryptohash_type type, bytea *input)
76 {
77 const uint8 *data;
78 const char *typestr = NULL;
79 int digest_len = 0;
80 size_t len;
81 pg_cryptohash_ctx *ctx;
82 bytea *result;
83
84 switch (type)
85 {
86 case PG_SHA224:
87 typestr = "SHA224";
88 digest_len = PG_SHA224_DIGEST_LENGTH;
89 break;
90 case PG_SHA256:
91 typestr = "SHA256";
92 digest_len = PG_SHA256_DIGEST_LENGTH;
93 break;
94 case PG_SHA384:
95 typestr = "SHA384";
96 digest_len = PG_SHA384_DIGEST_LENGTH;
97 break;
98 case PG_SHA512:
99 typestr = "SHA512";
100 digest_len = PG_SHA512_DIGEST_LENGTH;
101 break;
102 case PG_MD5:
103 case PG_SHA1:
104 elog(ERROR, "unsupported cryptohash type %d", type);
105 break;
106 }
107
108 result = palloc0(digest_len + VARHDRSZ);
109 len = VARSIZE_ANY_EXHDR(input);
110 data = (unsigned char *) VARDATA_ANY(input);
111
112 ctx = pg_cryptohash_create(type);
113 if (pg_cryptohash_init(ctx) < 0)
114 elog(ERROR, "could not initialize %s context", typestr);
115 if (pg_cryptohash_update(ctx, data, len) < 0)
116 elog(ERROR, "could not update %s context", typestr);
117 if (pg_cryptohash_final(ctx, (unsigned char *) VARDATA(result),
118 digest_len) < 0)
119 elog(ERROR, "could not finalize %s context", typestr);
120 pg_cryptohash_free(ctx);
121
122 SET_VARSIZE(result, digest_len + VARHDRSZ);
123
124 return result;
125 }
126
127 /*
128 * SHA-2 variants
129 */
130
131 Datum
sha224_bytea(PG_FUNCTION_ARGS)132 sha224_bytea(PG_FUNCTION_ARGS)
133 {
134 bytea *result = cryptohash_internal(PG_SHA224, PG_GETARG_BYTEA_PP(0));
135
136 PG_RETURN_BYTEA_P(result);
137 }
138
139 Datum
sha256_bytea(PG_FUNCTION_ARGS)140 sha256_bytea(PG_FUNCTION_ARGS)
141 {
142 bytea *result = cryptohash_internal(PG_SHA256, PG_GETARG_BYTEA_PP(0));
143
144 PG_RETURN_BYTEA_P(result);
145 }
146
147 Datum
sha384_bytea(PG_FUNCTION_ARGS)148 sha384_bytea(PG_FUNCTION_ARGS)
149 {
150 bytea *result = cryptohash_internal(PG_SHA384, PG_GETARG_BYTEA_PP(0));
151
152 PG_RETURN_BYTEA_P(result);
153 }
154
155 Datum
sha512_bytea(PG_FUNCTION_ARGS)156 sha512_bytea(PG_FUNCTION_ARGS)
157 {
158 bytea *result = cryptohash_internal(PG_SHA512, PG_GETARG_BYTEA_PP(0));
159
160 PG_RETURN_BYTEA_P(result);
161 }
162