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13 Affero General Public License for more details.
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16 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * @file util/crypto_hash_file.c
21 * @brief incremental hashing of files
22 * @author Christian Grothoff
25 #include "gnunet_util_lib.h"
28 #define LOG(kind,...) GNUNET_log_from (kind, "util-crypto-hash-file", __VA_ARGS__)
30 #define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util-crypto-hash-file", syscall, filename)
34 * Context used when hashing a file.
36 struct GNUNET_CRYPTO_FileHashContext
40 * Function to call upon completion.
42 GNUNET_CRYPTO_HashCompletedCallback callback;
45 * Closure for callback.
52 unsigned char *buffer;
55 * Name of the file we are hashing.
62 struct GNUNET_DISK_FileHandle *fh;
80 * Current task for hashing.
82 struct GNUNET_SCHEDULER_Task * task;
87 enum GNUNET_SCHEDULER_Priority priority;
98 * Report result of hash computation to callback
99 * and free associated resources.
102 file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
103 const struct GNUNET_HashCode * res)
105 fhc->callback (fhc->callback_cls, res);
106 GNUNET_free (fhc->filename);
107 if (!GNUNET_DISK_handle_invalid (fhc->fh))
108 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
109 gcry_md_close (fhc->md);
110 GNUNET_free (fhc); /* also frees fhc->buffer */
120 file_hash_task (void *cls)
122 struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
123 struct GNUNET_HashCode *res;
128 GNUNET_assert (fhc->offset <= fhc->fsize);
130 if (fhc->fsize - fhc->offset < delta)
131 delta = fhc->fsize - fhc->offset;
132 sret = GNUNET_DISK_file_read (fhc->fh,
136 (delta != (size_t) sret) )
138 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING,
141 file_hash_finish (fhc,
145 gcry_md_write (fhc->md,
148 fhc->offset += delta;
149 if (fhc->offset == fhc->fsize)
151 res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md,
153 file_hash_finish (fhc, res);
156 fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority,
163 * Compute the hash of an entire file.
165 * @param priority scheduling priority to use
166 * @param filename name of file to hash
167 * @param blocksize number of bytes to process in one task
168 * @param callback function to call upon completion
169 * @param callback_cls closure for @a callback
170 * @return NULL on (immediate) errror
172 struct GNUNET_CRYPTO_FileHashContext *
173 GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
174 const char *filename,
176 GNUNET_CRYPTO_HashCompletedCallback callback,
179 struct GNUNET_CRYPTO_FileHashContext *fhc;
181 GNUNET_assert (blocksize > 0);
183 GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize);
184 fhc->callback = callback;
185 fhc->callback_cls = callback_cls;
186 fhc->buffer = (unsigned char *) &fhc[1];
187 fhc->filename = GNUNET_strdup (filename);
188 if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
194 fhc->bsize = blocksize;
196 GNUNET_DISK_file_size (filename,
201 GNUNET_free (fhc->filename);
205 fhc->fh = GNUNET_DISK_file_open (filename,
206 GNUNET_DISK_OPEN_READ,
207 GNUNET_DISK_PERM_NONE);
210 GNUNET_free (fhc->filename);
214 fhc->priority = priority;
215 fhc->task = GNUNET_SCHEDULER_add_with_priority (priority,
223 * Cancel a file hashing operation.
225 * @param fhc operation to cancel (callback must not yet have been invoked)
228 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
230 GNUNET_SCHEDULER_cancel (fhc->task);
231 GNUNET_free (fhc->filename);
232 GNUNET_break (GNUNET_OK ==
233 GNUNET_DISK_file_close (fhc->fh));
237 /* end of crypto_hash_file.c */