diff options
Diffstat (limited to 'src/util/crypto_hash_file.c')
-rw-r--r-- | src/util/crypto_hash_file.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/src/util/crypto_hash_file.c b/src/util/crypto_hash_file.c new file mode 100644 index 000000000..2d15fac36 --- /dev/null +++ b/src/util/crypto_hash_file.c | |||
@@ -0,0 +1,215 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2001-2013 Christian Grothoff (and other contributing authors) | ||
4 | |||
5 | GNUnet is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU General Public License as published | ||
7 | by the Free Software Foundation; either version 3, or (at your | ||
8 | 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 | General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU General Public License | ||
16 | along with GNUnet; see the file COPYING. If not, write to the | ||
17 | Free Software Foundation, Inc., 59 Temple Place - Suite 330, | ||
18 | Boston, MA 02111-1307, USA. | ||
19 | |||
20 | */ | ||
21 | |||
22 | /** | ||
23 | * @file util/crypto_hash_file.c | ||
24 | * @brief incremental hashing of files | ||
25 | * @author Christian Grothoff | ||
26 | */ | ||
27 | |||
28 | |||
29 | /** | ||
30 | * Context used when hashing a file. | ||
31 | */ | ||
32 | struct GNUNET_CRYPTO_FileHashContext | ||
33 | { | ||
34 | |||
35 | /** | ||
36 | * Function to call upon completion. | ||
37 | */ | ||
38 | GNUNET_CRYPTO_HashCompletedCallback callback; | ||
39 | |||
40 | /** | ||
41 | * Closure for callback. | ||
42 | */ | ||
43 | void *callback_cls; | ||
44 | |||
45 | /** | ||
46 | * IO buffer. | ||
47 | */ | ||
48 | unsigned char *buffer; | ||
49 | |||
50 | /** | ||
51 | * Name of the file we are hashing. | ||
52 | */ | ||
53 | char *filename; | ||
54 | |||
55 | /** | ||
56 | * File descriptor. | ||
57 | */ | ||
58 | struct GNUNET_DISK_FileHandle *fh; | ||
59 | |||
60 | /** | ||
61 | * Cummulated hash. | ||
62 | */ | ||
63 | gcry_md_hd_t md; | ||
64 | |||
65 | /** | ||
66 | * Size of the file. | ||
67 | */ | ||
68 | uint64_t fsize; | ||
69 | |||
70 | /** | ||
71 | * Current offset. | ||
72 | */ | ||
73 | uint64_t offset; | ||
74 | |||
75 | /** | ||
76 | * Current task for hashing. | ||
77 | */ | ||
78 | struct GNUNET_SCHEDULER_Task * task; | ||
79 | |||
80 | /** | ||
81 | * Priority we use. | ||
82 | */ | ||
83 | enum GNUNET_SCHEDULER_Priority priority; | ||
84 | |||
85 | /** | ||
86 | * Blocksize. | ||
87 | */ | ||
88 | size_t bsize; | ||
89 | |||
90 | }; | ||
91 | |||
92 | |||
93 | /** | ||
94 | * Report result of hash computation to callback | ||
95 | * and free associated resources. | ||
96 | */ | ||
97 | static void | ||
98 | file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc, | ||
99 | const struct GNUNET_HashCode * res) | ||
100 | { | ||
101 | fhc->callback (fhc->callback_cls, res); | ||
102 | GNUNET_free (fhc->filename); | ||
103 | if (!GNUNET_DISK_handle_invalid (fhc->fh)) | ||
104 | GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh)); | ||
105 | gcry_md_close (fhc->md); | ||
106 | GNUNET_free (fhc); /* also frees fhc->buffer */ | ||
107 | } | ||
108 | |||
109 | |||
110 | /** | ||
111 | * File hashing task. | ||
112 | * | ||
113 | * @param cls closure | ||
114 | * @param tc context | ||
115 | */ | ||
116 | static void | ||
117 | file_hash_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) | ||
118 | { | ||
119 | struct GNUNET_CRYPTO_FileHashContext *fhc = cls; | ||
120 | struct GNUNET_HashCode *res; | ||
121 | size_t delta; | ||
122 | |||
123 | fhc->task = NULL; | ||
124 | GNUNET_assert (fhc->offset <= fhc->fsize); | ||
125 | delta = fhc->bsize; | ||
126 | if (fhc->fsize - fhc->offset < delta) | ||
127 | delta = fhc->fsize - fhc->offset; | ||
128 | if (delta != GNUNET_DISK_file_read (fhc->fh, fhc->buffer, delta)) | ||
129 | { | ||
130 | LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "read", fhc->filename); | ||
131 | file_hash_finish (fhc, NULL); | ||
132 | return; | ||
133 | } | ||
134 | gcry_md_write (fhc->md, fhc->buffer, delta); | ||
135 | fhc->offset += delta; | ||
136 | if (fhc->offset == fhc->fsize) | ||
137 | { | ||
138 | res = (struct GNUNET_HashCode *) gcry_md_read (fhc->md, GCRY_MD_SHA512); | ||
139 | file_hash_finish (fhc, res); | ||
140 | return; | ||
141 | } | ||
142 | fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority, | ||
143 | &file_hash_task, fhc); | ||
144 | } | ||
145 | |||
146 | |||
147 | /** | ||
148 | * Compute the hash of an entire file. | ||
149 | * | ||
150 | * @param priority scheduling priority to use | ||
151 | * @param filename name of file to hash | ||
152 | * @param blocksize number of bytes to process in one task | ||
153 | * @param callback function to call upon completion | ||
154 | * @param callback_cls closure for callback | ||
155 | * @return NULL on (immediate) errror | ||
156 | */ | ||
157 | struct GNUNET_CRYPTO_FileHashContext * | ||
158 | GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority, | ||
159 | const char *filename, size_t blocksize, | ||
160 | GNUNET_CRYPTO_HashCompletedCallback callback, | ||
161 | void *callback_cls) | ||
162 | { | ||
163 | struct GNUNET_CRYPTO_FileHashContext *fhc; | ||
164 | |||
165 | GNUNET_assert (blocksize > 0); | ||
166 | fhc = | ||
167 | GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize); | ||
168 | fhc->callback = callback; | ||
169 | fhc->callback_cls = callback_cls; | ||
170 | fhc->buffer = (unsigned char *) &fhc[1]; | ||
171 | fhc->filename = GNUNET_strdup (filename); | ||
172 | if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0)) | ||
173 | { | ||
174 | GNUNET_break (0); | ||
175 | GNUNET_free (fhc); | ||
176 | return NULL; | ||
177 | } | ||
178 | fhc->bsize = blocksize; | ||
179 | if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fhc->fsize, GNUNET_NO, GNUNET_YES)) | ||
180 | { | ||
181 | GNUNET_free (fhc->filename); | ||
182 | GNUNET_free (fhc); | ||
183 | return NULL; | ||
184 | } | ||
185 | fhc->fh = | ||
186 | GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ, | ||
187 | GNUNET_DISK_PERM_NONE); | ||
188 | if (!fhc->fh) | ||
189 | { | ||
190 | GNUNET_free (fhc->filename); | ||
191 | GNUNET_free (fhc); | ||
192 | return NULL; | ||
193 | } | ||
194 | fhc->priority = priority; | ||
195 | fhc->task = | ||
196 | GNUNET_SCHEDULER_add_with_priority (priority, &file_hash_task, fhc); | ||
197 | return fhc; | ||
198 | } | ||
199 | |||
200 | |||
201 | /** | ||
202 | * Cancel a file hashing operation. | ||
203 | * | ||
204 | * @param fhc operation to cancel (callback must not yet have been invoked) | ||
205 | */ | ||
206 | void | ||
207 | GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc) | ||
208 | { | ||
209 | GNUNET_SCHEDULER_cancel (fhc->task); | ||
210 | GNUNET_free (fhc->filename); | ||
211 | GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh)); | ||
212 | GNUNET_free (fhc); | ||
213 | } | ||
214 | |||
215 | /* end of crypto_hash_file.c */ | ||