MySQL 8.4.3
Source Code Documentation
sql_digest.h
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17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
23
24#ifndef SQL_DIGEST_H
25#define SQL_DIGEST_H
26
27#include <string.h>
28#include <sys/types.h>
29
30#include "my_inttypes.h" // IWYU pragma: keep
31
32class String;
33
34#define MAX_DIGEST_STORAGE_SIZE (1024 * 1024)
35
36/**
37 Write SHA-256 hash value in a string to be used
38 as DIGEST for the statement.
39*/
40#define DIGEST_HASH_TO_STRING(_hash, _str) \
41 (void)sprintf(_str, \
42 "%02x%02x%02x%02x%02x%02x%02x%02x" \
43 "%02x%02x%02x%02x%02x%02x%02x%02x" \
44 "%02x%02x%02x%02x%02x%02x%02x%02x" \
45 "%02x%02x%02x%02x%02x%02x%02x%02x", \
46 _hash[0], _hash[1], _hash[2], _hash[3], _hash[4], _hash[5], \
47 _hash[6], _hash[7], _hash[8], _hash[9], _hash[10], _hash[11], \
48 _hash[12], _hash[13], _hash[14], _hash[15], _hash[16], \
49 _hash[17], _hash[18], _hash[19], _hash[20], _hash[21], \
50 _hash[22], _hash[23], _hash[24], _hash[25], _hash[26], \
51 _hash[27], _hash[28], _hash[29], _hash[30], _hash[31])
52
53/// SHA-256 = 32 bytes of binary = 64 printable characters.
54#define DIGEST_HASH_TO_STRING_LENGTH 64
55
56/*
57 Various hashes considered for digests.
58
59 MD5:
60 - 128 bits
61 - used up to MySQL 5.7
62 - abandoned in MySQL 8.0, non FIPS compliant.
63
64 SHA1:
65 - 160 bits
66 - non FIPS compliant in strict mode
67 - not used
68
69 SHA2-224
70 - 224 bits
71 - non FIPS compliant in strict mode
72 - not used
73
74 SHA2-256
75 - 256 bits
76 - FIPS compliant
77 - Used starting with MySQL 8.0
78
79 SHA2-384
80 - 384 bits
81
82 SHA2-512
83 - 512 bits
84*/
85
86/**
87 DIGEST hash size, in bytes.
88 256 bits, for SHA256.
89*/
90#define DIGEST_HASH_SIZE 32
91
93
94/**
95 Structure to store token count/array for a statement
96 on which digest is to be calculated.
97*/
99 bool m_full;
101 unsigned char m_hash[DIGEST_HASH_SIZE];
102 /** Character set number. */
104 /**
105 Token array.
106 Token array is an array of bytes to store tokens received during parsing.
107 Following is the way token array is formed.
108 ... &lt;non-id-token&gt; &lt;non-id-token&gt; &lt;id-token&gt;
109 &lt;id_len&gt; &lt;id_text&gt; ... For Example: SELECT * FROM T1;
110 &lt;SELECT_TOKEN&gt; &lt;*&gt; &lt;FROM_TOKEN&gt; &lt;ID_TOKEN&gt; &lt;2&gt;
111 &lt;T1&gt;
112
113 @note Only the first @c m_byte_count bytes are initialized,
114 out of @c m_token_array_length.
115 */
116 unsigned char *m_token_array;
117 /* Length of the token array to be considered for DIGEST_TEXT calculation. */
119
120 sql_digest_storage() { reset(nullptr, 0); }
121
122 inline void reset(unsigned char *token_array, size_t length) {
123 m_token_array = token_array;
125 reset();
126 }
127
128 inline void reset() {
129 m_full = false;
130 m_byte_count = 0;
132 memset(m_hash, 0, DIGEST_HASH_SIZE);
133 }
134
135 inline bool is_empty() { return (m_byte_count == 0); }
136
137 inline void copy(const sql_digest_storage *from) {
138 /*
139 Keep in mind this is a dirty copy of something that may change,
140 as the thread producing the digest is executing concurrently,
141 without any lock enforced.
142 */
143 const size_t byte_count_copy = m_token_array_length < from->m_byte_count
145 : from->m_byte_count;
146
147 if (byte_count_copy > 0) {
148 m_full = from->m_full;
149 m_byte_count = byte_count_copy;
152 memcpy(m_hash, from->m_hash, DIGEST_HASH_SIZE);
153 } else {
154 m_full = false;
155 m_byte_count = 0;
157 }
158 }
159};
161
162/**
163 Compute a digest hash.
164 @param digest_storage The digest
165 @param [out] hash The computed digest hash. This parameter is a buffer of size
166 @c DIGEST_HASH_SIZE.
167*/
168void compute_digest_hash(const sql_digest_storage *digest_storage,
169 unsigned char *hash);
170
171/**
172 Compute a digest text.
173 A 'digest text' is a textual representation of a query,
174 where:
175 - comments are removed,
176 - non significant spaces are removed,
177 - literal values are replaced with a special '?' marker,
178 - lists of values are collapsed using a shorter notation
179 @param digest_storage The digest
180 @param [out] digest_text The digest text
181*/
182void compute_digest_text(const sql_digest_storage *digest_storage,
183 String *digest_text);
184
185#endif
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:167
Some integer typedefs for easier portability.
bool length(const dd::Spatial_reference_system *srs, const Geometry *g1, double *length, bool *null) noexcept
Computes the length of linestrings and multilinestrings.
Definition: length.cc:76
void compute_digest_hash(const sql_digest_storage *digest_storage, unsigned char *hash)
Compute a digest hash.
Definition: sql_digest.cc:160
void compute_digest_text(const sql_digest_storage *digest_storage, String *digest_text)
Compute a digest text.
Definition: sql_digest.cc:171
ulong get_max_digest_length()
Definition: sql_digest.cc:51
#define DIGEST_HASH_SIZE
DIGEST hash size, in bytes.
Definition: sql_digest.h:90
Structure to store token count/array for a statement on which digest is to be calculated.
Definition: sql_digest.h:98
void copy(const sql_digest_storage *from)
Definition: sql_digest.h:137
uint m_charset_number
Character set number.
Definition: sql_digest.h:103
sql_digest_storage()
Definition: sql_digest.h:120
size_t m_byte_count
Definition: sql_digest.h:100
unsigned char m_hash[DIGEST_HASH_SIZE]
Definition: sql_digest.h:101
bool m_full
Definition: sql_digest.h:99
unsigned char * m_token_array
Token array.
Definition: sql_digest.h:116
void reset(unsigned char *token_array, size_t length)
Definition: sql_digest.h:122
bool is_empty()
Definition: sql_digest.h:135
void reset()
Definition: sql_digest.h:128
size_t m_token_array_length
Definition: sql_digest.h:118