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6 under the terms of the GNU General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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13 Affero General Public License for more details.
17 * @file util/crypto_hash_file.c
18 * @brief incremental hashing of files
19 * @author Christian Grothoff
22 #include "gnunet_util_lib.h"
25 #define LOG(kind,...) GNUNET_log_from (kind, "util-crypto-hash-file", __VA_ARGS__)
27 #define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util-crypto-hash-file", syscall, filename)
31 * Context used when hashing a file.
33 struct GNUNET_CRYPTO_FileHashContext
37 * Function to call upon completion.
39 GNUNET_CRYPTO_HashCompletedCallback callback;
42 * Closure for callback.
49 unsigned char *buffer;
52 * Name of the file we are hashing.
59 struct GNUNET_DISK_FileHandle *fh;
77 * Current task for hashing.
79 struct GNUNET_SCHEDULER_Task * task;
84 enum GNUNET_SCHEDULER_Priority priority;
95 * Report result of hash computation to callback
96 * and free associated resources.
99 file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
100 const struct GNUNET_HashCode * res)
102 fhc->callback (fhc->callback_cls, res);
103 GNUNET_free (fhc->filename);
104 if (!GNUNET_DISK_handle_invalid (fhc->fh))
105 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
106 gcry_md_close (fhc->md);
107 GNUNET_free (fhc); /* also frees fhc->buffer */
117 file_hash_task (void *cls)
119 struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
120 struct GNUNET_HashCode *res;
125 GNUNET_assert (fhc->offset <= fhc->fsize);
127 if (fhc->fsize - fhc->offset < delta)
128 delta = fhc->fsize - fhc->offset;
129 sret = GNUNET_DISK_file_read (fhc->fh,
133 (delta != (size_t) sret) )
135 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING,
138 file_hash_finish (fhc,
142 gcry_md_write (fhc->md,
145 fhc->offset += delta;
146 if (fhc->offset == fhc->fsize)
148 res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md,
150 file_hash_finish (fhc, res);
153 fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority,
160 * Compute the hash of an entire file.
162 * @param priority scheduling priority to use
163 * @param filename name of file to hash
164 * @param blocksize number of bytes to process in one task
165 * @param callback function to call upon completion
166 * @param callback_cls closure for @a callback
167 * @return NULL on (immediate) errror
169 struct GNUNET_CRYPTO_FileHashContext *
170 GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
171 const char *filename,
173 GNUNET_CRYPTO_HashCompletedCallback callback,
176 struct GNUNET_CRYPTO_FileHashContext *fhc;
178 GNUNET_assert (blocksize > 0);
180 GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize);
181 fhc->callback = callback;
182 fhc->callback_cls = callback_cls;
183 fhc->buffer = (unsigned char *) &fhc[1];
184 fhc->filename = GNUNET_strdup (filename);
185 if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
191 fhc->bsize = blocksize;
193 GNUNET_DISK_file_size (filename,
198 GNUNET_free (fhc->filename);
202 fhc->fh = GNUNET_DISK_file_open (filename,
203 GNUNET_DISK_OPEN_READ,
204 GNUNET_DISK_PERM_NONE);
207 GNUNET_free (fhc->filename);
211 fhc->priority = priority;
212 fhc->task = GNUNET_SCHEDULER_add_with_priority (priority,
220 * Cancel a file hashing operation.
222 * @param fhc operation to cancel (callback must not yet have been invoked)
225 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
227 GNUNET_SCHEDULER_cancel (fhc->task);
228 GNUNET_free (fhc->filename);
229 GNUNET_break (GNUNET_OK ==
230 GNUNET_DISK_file_close (fhc->fh));
234 /* end of crypto_hash_file.c */