lib/hash.c

   1 /*
   2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include "got_compat.h"
  18
  19 #include <sys/types.h>
  20 #include <sys/queue.h>
  21
  22 #include <errno.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <limits.h>
  27
  28 #include "got_object.h"
  29 #include "got_error.h"
  30
  31 #include "got_lib_hash.h"
  32
  33 struct got_object_id *
  34 got_object_id_dup(struct got_object_id *id1)
  35 {
  36         struct got_object_id *id2;
  37
  38         id2 = malloc(sizeof(*id2));
  39         if (id2 == NULL)
  40                 return NULL;
  41         memcpy(id2, id1, sizeof(*id2));
  42         return id2;
  43 }
  44
  45 int
  46 got_object_id_cmp(const struct got_object_id *id1,
  47     const struct got_object_id *id2)
  48 {
  49         return memcmp(id1->sha1, id2->sha1, SHA1_DIGEST_LENGTH);
  50 }
  51
  52 const struct got_error *
  53 got_object_id_str(char **outbuf, struct got_object_id *id)
  54 {
  55         static const size_t len = GOT_OBJECT_ID_HEX_MAXLEN;
  56
  57         *outbuf = malloc(len);
  58         if (*outbuf == NULL)
  59                 return got_error_from_errno("malloc");
  60
  61         if (got_object_id_hex(id, *outbuf, len) == NULL) {
  62                 free(*outbuf);
  63                 *outbuf = NULL;
  64                 return got_error(GOT_ERR_BAD_OBJ_ID_STR);
  65         }
  66
  67         return NULL;
  68 }
  69
  70 int
  71 got_parse_xdigit(uint8_t *val, const char *hex)
  72 {
  73         char *ep;
  74         long lval;
  75
  76         errno = 0;
  77         lval = strtol(hex, &ep, 16);
  78         if (hex[0] == '\0' || *ep != '\0')
  79                 return 0;
  80         if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
  81                 return 0;
  82
  83         *val = (uint8_t)lval;
  84         return 1;
  85 }
  86
  87 static int
  88 parse_digest(uint8_t *digest, int len, const char *line)
  89 {
  90         uint8_t b = 0;
  91         char hex[3] = {'\0', '\0', '\0'};
  92         int i, j;
  93
  94         for (i = 0; i < len; i++) {
  95                 if (line[0] == '\0' || line[1] == '\0')
  96                         return 0;
  97                 for (j = 0; j < 2; j++) {
  98                         hex[j] = *line;
  99                         line++;
 100                 }
 101                 if (!got_parse_xdigit(&b, hex))
 102                         return 0;
 103                 digest[i] = b;
 104         }
 105
 106         return 1;
 107 }
 108
 109 static char *
 110 digest_to_str(const uint8_t *digest, int len, char *buf)
 111 {
 112         const char hex[] = "0123456789abcdef";
 113         char *p = buf;
 114         int i;
 115
 116         for (i = 0; i < len; i++) {
 117                 *p++ = hex[digest[i] >> 4];
 118                 *p++ = hex[digest[i] & 0xf];
 119         }
 120         *p = '\0';
 121
 122         return buf;
 123 }
 124
 125 char *
 126 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
 127 {
 128         if (size < SHA1_DIGEST_STRING_LENGTH)
 129                 return NULL;
 130         return digest_to_str(digest, SHA1_DIGEST_LENGTH, buf);
 131 }
 132
 133 char *
 134 got_sha256_digest_to_str(const uint8_t *digest, char *buf, size_t size)
 135 {
 136         if (size < SHA256_DIGEST_STRING_LENGTH)
 137                 return NULL;
 138         return digest_to_str(digest, SHA256_DIGEST_LENGTH, buf);
 139 }
 140
 141 int
 142 got_parse_hash_digest(uint8_t *digest, const char *line,
 143     enum got_hash_algorithm algo)
 144 {
 145         switch (algo) {
 146         case GOT_HASH_SHA1:
 147                 return parse_digest(digest, SHA1_DIGEST_LENGTH, line);
 148         case GOT_HASH_SHA256:
 149                 return parse_digest(digest, SHA256_DIGEST_LENGTH, line);
 150         default:
 151                 return 0;
 152         }
 153 }
 154
 155 char *
 156 got_object_id_hex(struct got_object_id *id, char *buf, size_t len)
 157 {
 158         return got_sha1_digest_to_str(id->sha1, buf, len);
 159 }
 160
 161 int
 162 got_parse_object_id(struct got_object_id *id, const char *line,
 163     enum got_hash_algorithm algo)
 164 {
 165         memset(id, 0, sizeof(*id));
 166
 167         /* XXX: temporary until we grow got_object_id */
 168         if (algo != GOT_HASH_SHA1)
 169                 return 0;
 170
 171         return got_parse_hash_digest(id->sha1, line, algo);
 172 }
 173
 174 void
 175 got_hash_init(struct got_hash *hash, enum got_hash_algorithm algo)
 176 {
 177         memset(hash, 0, sizeof(*hash));
 178         hash->algo = algo;
 179
 180         if (algo == GOT_HASH_SHA1)
 181                 SHA1Init(&hash->sha1_ctx);
 182         else if (algo == GOT_HASH_SHA256)
 183                 SHA256Init(&hash->sha256_ctx);
 184 }
 185
 186 void
 187 got_hash_update(struct got_hash *hash, const void *data, size_t len)
 188 {
 189         if (hash->algo == GOT_HASH_SHA1)
 190                 SHA1Update(&hash->sha1_ctx, data, len);
 191         else if (hash->algo == GOT_HASH_SHA256)
 192                 SHA256Update(&hash->sha256_ctx, data, len);
 193 }
 194
 195 void
 196 got_hash_final(struct got_hash *hash, uint8_t *out)
 197 {
 198         if (hash->algo == GOT_HASH_SHA1)
 199                 SHA1Final(out, &hash->sha1_ctx);
 200         else if (hash->algo == GOT_HASH_SHA256)
 201                 SHA256Final(out, &hash->sha256_ctx);
 202 }
 203
 204 void
 205 got_hash_final_object_id(struct got_hash *hash, struct got_object_id *id)
 206 {
 207         memset(id, 0, sizeof(*id));
 208         got_hash_final(hash, id->sha1);
 209 }
 210
 211 int
 212 got_hash_cmp(enum got_hash_algorithm algo, uint8_t *b1, uint8_t *b2)
 213 {
 214         if (algo == GOT_HASH_SHA1)
 215                 return memcmp(b1, b2, SHA1_DIGEST_LENGTH);
 216         else if (algo == GOT_HASH_SHA256)
 217                 return memcmp(b1, b2, SHA256_DIGEST_LENGTH);
 218         return -1;
 219 }