1 /*-------------------------------------------------------------------------
2 *
3 * checksum_helper.c
4 * Compute a checksum of any of various types using common routines
5 *
6 * Portions Copyright (c) 2016-2020, PostgreSQL Global Development Group
7 *
8 * IDENTIFICATION
9 * src/common/checksum_helper.c
10 *
11 *-------------------------------------------------------------------------
12 */
13
14 #ifndef FRONTEND
15 #include "postgres.h"
16 #else
17 #include "postgres_fe.h"
18 #endif
19
20 #include "common/checksum_helper.h"
21
22 /*
23 * If 'name' is a recognized checksum type, set *type to the corresponding
24 * constant and return true. Otherwise, set *type to CHECKSUM_TYPE_NONE and
25 * return false.
26 */
27 bool
pg_checksum_parse_type(char * name,pg_checksum_type * type)28 pg_checksum_parse_type(char *name, pg_checksum_type *type)
29 {
30 pg_checksum_type result_type = CHECKSUM_TYPE_NONE;
31 bool result = true;
32
33 if (pg_strcasecmp(name, "none") == 0)
34 result_type = CHECKSUM_TYPE_NONE;
35 else if (pg_strcasecmp(name, "crc32c") == 0)
36 result_type = CHECKSUM_TYPE_CRC32C;
37 else if (pg_strcasecmp(name, "sha224") == 0)
38 result_type = CHECKSUM_TYPE_SHA224;
39 else if (pg_strcasecmp(name, "sha256") == 0)
40 result_type = CHECKSUM_TYPE_SHA256;
41 else if (pg_strcasecmp(name, "sha384") == 0)
42 result_type = CHECKSUM_TYPE_SHA384;
43 else if (pg_strcasecmp(name, "sha512") == 0)
44 result_type = CHECKSUM_TYPE_SHA512;
45 else
46 result = false;
47
48 *type = result_type;
49 return result;
50 }
51
52 /*
53 * Get the canonical human-readable name corresponding to a checksum type.
54 */
55 char *
pg_checksum_type_name(pg_checksum_type type)56 pg_checksum_type_name(pg_checksum_type type)
57 {
58 switch (type)
59 {
60 case CHECKSUM_TYPE_NONE:
61 return "NONE";
62 case CHECKSUM_TYPE_CRC32C:
63 return "CRC32C";
64 case CHECKSUM_TYPE_SHA224:
65 return "SHA224";
66 case CHECKSUM_TYPE_SHA256:
67 return "SHA256";
68 case CHECKSUM_TYPE_SHA384:
69 return "SHA384";
70 case CHECKSUM_TYPE_SHA512:
71 return "SHA512";
72 }
73
74 Assert(false);
75 return "???";
76 }
77
78 /*
79 * Initialize a checksum context for checksums of the given type.
80 */
81 void
pg_checksum_init(pg_checksum_context * context,pg_checksum_type type)82 pg_checksum_init(pg_checksum_context *context, pg_checksum_type type)
83 {
84 context->type = type;
85
86 switch (type)
87 {
88 case CHECKSUM_TYPE_NONE:
89 /* do nothing */
90 break;
91 case CHECKSUM_TYPE_CRC32C:
92 INIT_CRC32C(context->raw_context.c_crc32c);
93 break;
94 case CHECKSUM_TYPE_SHA224:
95 pg_sha224_init(&context->raw_context.c_sha224);
96 break;
97 case CHECKSUM_TYPE_SHA256:
98 pg_sha256_init(&context->raw_context.c_sha256);
99 break;
100 case CHECKSUM_TYPE_SHA384:
101 pg_sha384_init(&context->raw_context.c_sha384);
102 break;
103 case CHECKSUM_TYPE_SHA512:
104 pg_sha512_init(&context->raw_context.c_sha512);
105 break;
106 }
107 }
108
109 /*
110 * Update a checksum context with new data.
111 */
112 void
pg_checksum_update(pg_checksum_context * context,const uint8 * input,size_t len)113 pg_checksum_update(pg_checksum_context *context, const uint8 *input,
114 size_t len)
115 {
116 switch (context->type)
117 {
118 case CHECKSUM_TYPE_NONE:
119 /* do nothing */
120 break;
121 case CHECKSUM_TYPE_CRC32C:
122 COMP_CRC32C(context->raw_context.c_crc32c, input, len);
123 break;
124 case CHECKSUM_TYPE_SHA224:
125 pg_sha224_update(&context->raw_context.c_sha224, input, len);
126 break;
127 case CHECKSUM_TYPE_SHA256:
128 pg_sha256_update(&context->raw_context.c_sha256, input, len);
129 break;
130 case CHECKSUM_TYPE_SHA384:
131 pg_sha384_update(&context->raw_context.c_sha384, input, len);
132 break;
133 case CHECKSUM_TYPE_SHA512:
134 pg_sha512_update(&context->raw_context.c_sha512, input, len);
135 break;
136 }
137 }
138
139 /*
140 * Finalize a checksum computation and write the result to an output buffer.
141 *
142 * The caller must ensure that the buffer is at least PG_CHECKSUM_MAX_LENGTH
143 * bytes in length. The return value is the number of bytes actually written.
144 */
145 int
pg_checksum_final(pg_checksum_context * context,uint8 * output)146 pg_checksum_final(pg_checksum_context *context, uint8 *output)
147 {
148 int retval = 0;
149
150 StaticAssertStmt(sizeof(pg_crc32c) <= PG_CHECKSUM_MAX_LENGTH,
151 "CRC-32C digest too big for PG_CHECKSUM_MAX_LENGTH");
152 StaticAssertStmt(PG_SHA224_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
153 "SHA224 digest too for PG_CHECKSUM_MAX_LENGTH");
154 StaticAssertStmt(PG_SHA256_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
155 "SHA256 digest too for PG_CHECKSUM_MAX_LENGTH");
156 StaticAssertStmt(PG_SHA384_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
157 "SHA384 digest too for PG_CHECKSUM_MAX_LENGTH");
158 StaticAssertStmt(PG_SHA512_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
159 "SHA512 digest too for PG_CHECKSUM_MAX_LENGTH");
160
161 switch (context->type)
162 {
163 case CHECKSUM_TYPE_NONE:
164 break;
165 case CHECKSUM_TYPE_CRC32C:
166 FIN_CRC32C(context->raw_context.c_crc32c);
167 retval = sizeof(pg_crc32c);
168 memcpy(output, &context->raw_context.c_crc32c, retval);
169 break;
170 case CHECKSUM_TYPE_SHA224:
171 pg_sha224_final(&context->raw_context.c_sha224, output);
172 retval = PG_SHA224_DIGEST_LENGTH;
173 break;
174 case CHECKSUM_TYPE_SHA256:
175 pg_sha256_final(&context->raw_context.c_sha256, output);
176 retval = PG_SHA256_DIGEST_LENGTH;
177 break;
178 case CHECKSUM_TYPE_SHA384:
179 pg_sha384_final(&context->raw_context.c_sha384, output);
180 retval = PG_SHA384_DIGEST_LENGTH;
181 break;
182 case CHECKSUM_TYPE_SHA512:
183 pg_sha512_final(&context->raw_context.c_sha512, output);
184 retval = PG_SHA512_DIGEST_LENGTH;
185 break;
186 }
187
188 Assert(retval <= PG_CHECKSUM_MAX_LENGTH);
189 return retval;
190 }
191