svn_checksum.h revision 299742
1/** 2 * @copyright 3 * ==================================================================== 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 * ==================================================================== 21 * @endcopyright 22 * 23 * @file svn_checksum.h 24 * @brief Subversion checksum routines 25 */ 26 27#ifndef SVN_CHECKSUM_H 28#define SVN_CHECKSUM_H 29 30#include <apr.h> /* for apr_size_t */ 31#include <apr_pools.h> /* for apr_pool_t */ 32 33#include "svn_types.h" /* for svn_boolean_t, svn_error_t */ 34 35#ifdef __cplusplus 36extern "C" { 37#endif /* __cplusplus */ 38 39 40/** 41 * Various types of checksums. 42 * 43 * @since New in 1.6. 44 */ 45typedef enum svn_checksum_kind_t 46{ 47 /** The checksum is (or should be set to) an MD5 checksum. */ 48 svn_checksum_md5, 49 50 /** The checksum is (or should be set to) a SHA1 checksum. */ 51 svn_checksum_sha1, 52 53 /** The checksum is (or should be set to) a FNV-1a 32 bit checksum, 54 * in big endian byte order. 55 * @since New in 1.9. */ 56 svn_checksum_fnv1a_32, 57 58 /** The checksum is (or should be set to) a modified FNV-1a 32 bit, 59 * in big endian byte order. 60 * @since New in 1.9. */ 61 svn_checksum_fnv1a_32x4 62} svn_checksum_kind_t; 63 64/** 65 * A generic checksum representation. 66 * 67 * @since New in 1.6. 68 */ 69typedef struct svn_checksum_t 70{ 71 /** The bytes of the checksum. */ 72 const unsigned char *digest; 73 74 /** The type of the checksum. This should never be changed by consumers 75 of the APIs. */ 76 svn_checksum_kind_t kind; 77} svn_checksum_t; 78 79/** 80 * Opaque type for creating checksums of data. 81 */ 82typedef struct svn_checksum_ctx_t svn_checksum_ctx_t; 83 84/** Return a new checksum structure of type @a kind, initialized to the all- 85 * zeros value, allocated in @a pool. 86 * 87 * @since New in 1.6. 88 */ 89svn_checksum_t * 90svn_checksum_create(svn_checksum_kind_t kind, 91 apr_pool_t *pool); 92 93/** Set @a checksum->digest to all zeros, which, by convention, matches 94 * all other checksums. 95 * 96 * @since New in 1.6. 97 */ 98svn_error_t * 99svn_checksum_clear(svn_checksum_t *checksum); 100 101/** Compare checksums @a checksum1 and @a checksum2. If their kinds do not 102 * match or if neither is all zeros, and their content does not match, then 103 * return FALSE; else return TRUE. 104 * 105 * @since New in 1.6. 106 */ 107svn_boolean_t 108svn_checksum_match(const svn_checksum_t *checksum1, 109 const svn_checksum_t *checksum2); 110 111 112/** 113 * Return a deep copy of @a checksum, allocated in @a pool. If @a 114 * checksum is NULL then NULL is returned. 115 * 116 * @since New in 1.6. 117 */ 118svn_checksum_t * 119svn_checksum_dup(const svn_checksum_t *checksum, 120 apr_pool_t *pool); 121 122 123/** Return the hex representation of @a checksum, allocating the string 124 * in @a pool. 125 * 126 * @since New in 1.6. 127 */ 128const char * 129svn_checksum_to_cstring_display(const svn_checksum_t *checksum, 130 apr_pool_t *pool); 131 132 133/** Return the hex representation of @a checksum, allocating the 134 * string in @a pool. If @a checksum->digest is all zeros (that is, 135 * 0, not '0') then return NULL. In 1.7+, @a checksum may be NULL 136 * and NULL will be returned in that case. 137 * 138 * @since New in 1.6. 139 * @note Passing NULL for @a checksum in 1.6 will cause a segfault. 140 */ 141const char * 142svn_checksum_to_cstring(const svn_checksum_t *checksum, 143 apr_pool_t *pool); 144 145 146/** Return a serialized representation of @a checksum, allocated in 147 * @a result_pool. Temporary allocations are performed in @a scratch_pool. 148 * 149 * Note that @a checksum may not be NULL. 150 * 151 * @since New in 1.7. 152 */ 153const char * 154svn_checksum_serialize(const svn_checksum_t *checksum, 155 apr_pool_t *result_pool, 156 apr_pool_t *scratch_pool); 157 158 159/** Return @a checksum from the serialized format at @a data. The checksum 160 * will be allocated in @a result_pool, with any temporary allocations 161 * performed in @a scratch_pool. 162 * 163 * @since New in 1.7. 164 */ 165svn_error_t * 166svn_checksum_deserialize(const svn_checksum_t **checksum, 167 const char *data, 168 apr_pool_t *result_pool, 169 apr_pool_t *scratch_pool); 170 171 172/** Parse the hex representation @a hex of a checksum of kind @a kind and 173 * set @a *checksum to the result, allocating in @a pool. 174 * 175 * If @a hex is @c NULL or is the all-zeros checksum, then set @a *checksum 176 * to @c NULL. 177 * 178 * @since New in 1.6. 179 */ 180svn_error_t * 181svn_checksum_parse_hex(svn_checksum_t **checksum, 182 svn_checksum_kind_t kind, 183 const char *hex, 184 apr_pool_t *pool); 185 186/** 187 * Return in @a *checksum the checksum of type @a kind for the bytes beginning 188 * at @a data, and going for @a len. @a *checksum is allocated in @a pool. 189 * 190 * @since New in 1.6. 191 */ 192svn_error_t * 193svn_checksum(svn_checksum_t **checksum, 194 svn_checksum_kind_t kind, 195 const void *data, 196 apr_size_t len, 197 apr_pool_t *pool); 198 199 200/** 201 * Return in @a pool a newly allocated checksum populated with the checksum 202 * of type @a kind for the empty string. 203 * 204 * @since New in 1.6. 205 */ 206svn_checksum_t * 207svn_checksum_empty_checksum(svn_checksum_kind_t kind, 208 apr_pool_t *pool); 209 210 211/** 212 * Create a new @c svn_checksum_ctx_t structure, allocated from @a pool for 213 * calculating checksums of type @a kind. @see svn_checksum_final() 214 * 215 * @since New in 1.6. 216 */ 217svn_checksum_ctx_t * 218svn_checksum_ctx_create(svn_checksum_kind_t kind, 219 apr_pool_t *pool); 220 221/** 222 * Update the checksum represented by @a ctx, with @a len bytes starting at 223 * @a data. 224 * 225 * @since New in 1.6. 226 */ 227svn_error_t * 228svn_checksum_update(svn_checksum_ctx_t *ctx, 229 const void *data, 230 apr_size_t len); 231 232 233/** 234 * Finalize the checksum used when creating @a ctx, and put the resultant 235 * checksum in @a *checksum, allocated in @a pool. 236 * 237 * @since New in 1.6. 238 */ 239svn_error_t * 240svn_checksum_final(svn_checksum_t **checksum, 241 const svn_checksum_ctx_t *ctx, 242 apr_pool_t *pool); 243 244 245/** 246 * Return the digest size of @a checksum. 247 * 248 * @since New in 1.6. 249 */ 250apr_size_t 251svn_checksum_size(const svn_checksum_t *checksum); 252 253/** 254 * Return @c TRUE iff @a checksum matches the checksum for the empty 255 * string. 256 * 257 * @since New in 1.8. 258 */ 259svn_boolean_t 260svn_checksum_is_empty_checksum(svn_checksum_t *checksum); 261 262 263/** 264 * Return an error of type #SVN_ERR_CHECKSUM_MISMATCH for @a actual and 265 * @a expected checksums which do not match. Use @a fmt, and the following 266 * parameters to populate the error message. 267 * 268 * @note This function does not actually check for the mismatch, it just 269 * constructs the error. 270 * 271 * @a scratch_pool is used for temporary allocations; the returned error 272 * will be allocated in its own pool (as is typical). 273 * 274 * @since New in 1.7. 275 */ 276svn_error_t * 277svn_checksum_mismatch_err(const svn_checksum_t *expected, 278 const svn_checksum_t *actual, 279 apr_pool_t *scratch_pool, 280 const char *fmt, 281 ...) 282 __attribute__ ((format(printf, 4, 5))); 283 284#ifdef __cplusplus 285} 286#endif /* __cplusplus */ 287 288#endif /* SVN_CHECKSUM_H */ 289