GNUnet  0.11.x
crypto_hash_file.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2001-2013 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  GNUnet is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19 
20  */
26 #include "platform.h"
27 #include "gnunet_util_lib.h"
28 #include <gcrypt.h>
29 
30 #define LOG(kind, ...) GNUNET_log_from (kind, "util-crypto-hash-file", \
31  __VA_ARGS__)
32 
33 #define LOG_STRERROR_FILE(kind, syscall, \
34  filename) GNUNET_log_from_strerror_file (kind, \
35  "util-crypto-hash-file", \
36  syscall, \
37  filename)
38 
39 
44 {
49 
53  void *callback_cls;
54 
58  unsigned char *buffer;
59 
63  char *filename;
64 
69 
73  gcry_md_hd_t md;
74 
78  uint64_t fsize;
79 
83  uint64_t offset;
84 
89 
94 
98  size_t bsize;
99 };
100 
101 
106 static void
108  const struct GNUNET_HashCode *res)
109 {
110  fhc->callback (fhc->callback_cls, res);
111  GNUNET_free (fhc->filename);
112  if (! GNUNET_DISK_handle_invalid (fhc->fh))
114  gcry_md_close (fhc->md);
115  GNUNET_free (fhc); /* also frees fhc->buffer */
116 }
117 
118 
124 static void
125 file_hash_task (void *cls)
126 {
127  struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
128  struct GNUNET_HashCode *res;
129  size_t delta;
130  ssize_t sret;
131 
132  fhc->task = NULL;
133  GNUNET_assert (fhc->offset <= fhc->fsize);
134  delta = fhc->bsize;
135  if (fhc->fsize - fhc->offset < delta)
136  delta = fhc->fsize - fhc->offset;
137  sret = GNUNET_DISK_file_read (fhc->fh,
138  fhc->buffer,
139  delta);
140  if ((sret < 0) ||
141  (delta != (size_t) sret))
142  {
144  "read",
145  fhc->filename);
146  file_hash_finish (fhc,
147  NULL);
148  return;
149  }
150  gcry_md_write (fhc->md,
151  fhc->buffer,
152  delta);
153  fhc->offset += delta;
154  if (fhc->offset == fhc->fsize)
155  {
156  res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md,
157  GCRY_MD_SHA512);
158  file_hash_finish (fhc, res);
159  return;
160  }
163  fhc);
164 }
165 
166 
179  const char *filename,
180  size_t blocksize,
182  void *callback_cls)
183 {
184  struct GNUNET_CRYPTO_FileHashContext *fhc;
185 
186  GNUNET_assert (blocksize > 0);
187  fhc =
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))
194  {
195  GNUNET_break (0);
196  GNUNET_free (fhc);
197  return NULL;
198  }
199  fhc->bsize = blocksize;
200  if (GNUNET_OK !=
201  GNUNET_DISK_file_size (filename,
202  &fhc->fsize,
203  GNUNET_NO,
204  GNUNET_YES))
205  {
206  GNUNET_free (fhc->filename);
207  GNUNET_free (fhc);
208  return NULL;
209  }
210  fhc->fh = GNUNET_DISK_file_open (filename,
213  if (! fhc->fh)
214  {
215  GNUNET_free (fhc->filename);
216  GNUNET_free (fhc);
217  return NULL;
218  }
219  fhc->priority = priority;
220  fhc->task = GNUNET_SCHEDULER_add_with_priority (priority,
222  fhc);
223  return fhc;
224 }
225 
226 
232 void
234 {
236  GNUNET_free (fhc->filename);
238  GNUNET_DISK_file_close (fhc->fh));
239  GNUNET_free (fhc);
240 }
241 
242 
243 /* end of crypto_hash_file.c */
Open the file for reading.
struct GNUNET_SCHEDULER_Task * task
Current task for hashing.
int GNUNET_DISK_file_close(struct GNUNET_DISK_FileHandle *h)
Close an open file.
Definition: disk.c:1345
struct GNUNET_DISK_FileHandle * fh
File descriptor.
static struct GNUNET_TIME_Relative delta
Definition: speedup.c:35
void(* GNUNET_CRYPTO_HashCompletedCallback)(void *cls, const struct GNUNET_HashCode *res)
Function called once the hash computation over the specified file has completed.
ssize_t GNUNET_DISK_file_read(const struct GNUNET_DISK_FileHandle *h, void *result, size_t len)
Read the contents of a binary file into a buffer.
Definition: disk.c:732
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
static void file_hash_finish(struct GNUNET_CRYPTO_FileHashContext *fhc, const struct GNUNET_HashCode *res)
Report result of hash computation to callback and free associated resources.
Nobody is allowed to do anything to the file.
#define GNUNET_NO
Definition: gnunet_common.h:78
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
GNUNET_SCHEDULER_Priority
Valid task priorities.
struct GNUNET_CRYPTO_FileHashContext * GNUNET_CRYPTO_hash_file(enum GNUNET_SCHEDULER_Priority priority, const char *filename, size_t blocksize, GNUNET_CRYPTO_HashCompletedCallback callback, void *callback_cls)
Compute the hash of an entire file.
#define GNUNET_strdup(a)
Wrapper around GNUNET_xstrdup_.
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
gcry_md_hd_t md
Cummulated hash.
int GNUNET_DISK_handle_invalid(const struct GNUNET_DISK_FileHandle *h)
Checks whether a handle is invalid.
Definition: disk.c:192
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_with_priority(enum GNUNET_SCHEDULER_Priority prio, GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run with a specified priority.
Definition: scheduler.c:1207
#define LOG_STRERROR_FILE(kind, syscall, filename)
unsigned char * buffer
IO buffer.
A 512-bit hashcode.
static int res
char * filename
Name of the file we are hashing.
uint64_t fsize
Size of the file.
Context used when hashing a file.
int GNUNET_DISK_file_size(const char *filename, uint64_t *size, int include_symbolic_links, int single_file_mode)
Get the size of the file (or directory) of the given file (in bytes).
Definition: disk.c:257
enum GNUNET_SCHEDULER_Priority priority
Priority we use.
Entry in list of pending tasks.
Definition: scheduler.c:134
GNUNET_CRYPTO_HashCompletedCallback callback
Function to call upon completion.
#define GNUNET_YES
Definition: gnunet_common.h:77
static void file_hash_task(void *cls)
File hashing task.
struct GNUNET_DISK_FileHandle * GNUNET_DISK_file_open(const char *fn, enum GNUNET_DISK_OpenFlags flags, enum GNUNET_DISK_AccessPermissions perm)
Open a file.
Definition: disk.c:1268
Handle used to access files (and pipes).
uint64_t offset
Current offset.
#define GNUNET_malloc(size)
Wrapper around malloc.
void * callback_cls
Closure for callback.
#define GNUNET_free(ptr)
Wrapper around free.
void GNUNET_CRYPTO_hash_file_cancel(struct GNUNET_CRYPTO_FileHashContext *fhc)
Cancel a file hashing operation.
void * GNUNET_SCHEDULER_cancel(struct GNUNET_SCHEDULER_Task *task)
Cancel the task with the specified identifier.
Definition: scheduler.c:966