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13 Affero General Public License for more details.
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22 * @file util/crypto_hash_file.c
23 * @brief incremental hashing of files
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
30 #define LOG(kind, ...) GNUNET_log_from (kind, "util-crypto-hash-file", \
33 #define LOG_STRERROR_FILE(kind, syscall, \
34 filename) GNUNET_log_from_strerror_file (kind, \
35 "util-crypto-hash-file", \
41 * Context used when hashing a file.
43 struct GNUNET_CRYPTO_FileHashContext
46 * Function to call upon completion.
48 GNUNET_CRYPTO_HashCompletedCallback callback;
51 * Closure for callback.
58 unsigned char *buffer;
61 * Name of the file we are hashing.
68 struct GNUNET_DISK_FileHandle *fh;
86 * Current task for hashing.
88 struct GNUNET_SCHEDULER_Task *task;
93 enum GNUNET_SCHEDULER_Priority priority;
103 * Report result of hash computation to callback
104 * and free associated resources.
107 file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
108 const struct GNUNET_HashCode *res)
110 fhc->callback (fhc->callback_cls, res);
111 GNUNET_free (fhc->filename);
112 if (! GNUNET_DISK_handle_invalid (fhc->fh))
113 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
114 gcry_md_close (fhc->md);
115 GNUNET_free (fhc); /* also frees fhc->buffer */
125 file_hash_task (void *cls)
127 struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
128 struct GNUNET_HashCode *res;
133 GNUNET_assert (fhc->offset <= fhc->fsize);
135 if (fhc->fsize - fhc->offset < delta)
136 delta = fhc->fsize - fhc->offset;
137 sret = GNUNET_DISK_file_read (fhc->fh,
141 (delta != (size_t) sret))
143 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING,
146 file_hash_finish (fhc,
150 gcry_md_write (fhc->md,
153 fhc->offset += delta;
154 if (fhc->offset == fhc->fsize)
156 res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md,
158 file_hash_finish (fhc, res);
161 fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority,
168 * Compute the hash of an entire file.
170 * @param priority scheduling priority to use
171 * @param filename name of file to hash
172 * @param blocksize number of bytes to process in one task
173 * @param callback function to call upon completion
174 * @param callback_cls closure for @a callback
175 * @return NULL on (immediate) errror
177 struct GNUNET_CRYPTO_FileHashContext *
178 GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
179 const char *filename,
181 GNUNET_CRYPTO_HashCompletedCallback callback,
184 struct GNUNET_CRYPTO_FileHashContext *fhc;
186 GNUNET_assert (blocksize > 0);
188 GNUNET_malloc (sizeof(struct GNUNET_CRYPTO_FileHashContext) + blocksize);
189 fhc->callback = callback;
190 fhc->callback_cls = callback_cls;
191 fhc->buffer = (unsigned char *) &fhc[1];
192 fhc->filename = GNUNET_strdup (filename);
193 if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
199 fhc->bsize = blocksize;
201 GNUNET_DISK_file_size (filename,
206 GNUNET_free (fhc->filename);
210 fhc->fh = GNUNET_DISK_file_open (filename,
211 GNUNET_DISK_OPEN_READ,
212 GNUNET_DISK_PERM_NONE);
215 GNUNET_free (fhc->filename);
219 fhc->priority = priority;
220 fhc->task = GNUNET_SCHEDULER_add_with_priority (priority,
228 * Cancel a file hashing operation.
230 * @param fhc operation to cancel (callback must not yet have been invoked)
233 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
235 GNUNET_SCHEDULER_cancel (fhc->task);
236 GNUNET_free (fhc->filename);
237 GNUNET_break (GNUNET_OK ==
238 GNUNET_DISK_file_close (fhc->fh));
243 /* end of crypto_hash_file.c */