2 This file is part of GNUnet.
3 (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors)
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 2, or (at your
8 option) any later version.
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.
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.
20 SHA-512 code by Jean-Luc Cooke <jlcooke@certainkey.com>
22 Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
23 Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
24 Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
28 * @file util/crypto_hash.c
29 * @brief SHA-512 GNUNET_CRYPTO_hash related functions
30 * @author Christian Grothoff
34 #include "gnunet_common.h"
35 #include "gnunet_crypto_lib.h"
36 #include "gnunet_disk_lib.h"
41 * Hash block of given size.
43 * @param block the data to GNUNET_CRYPTO_hash, length is given as a second argument
44 * @param size the length of the data to GNUNET_CRYPTO_hash
45 * @param ret pointer to where to write the hashcode
48 GNUNET_CRYPTO_hash (const void *block, size_t size, GNUNET_HashCode * ret)
50 gcry_md_hash_buffer (GCRY_MD_SHA512, ret, block, size);
55 * Context used when hashing a file.
57 struct GNUNET_CRYPTO_FileHashContext
61 * Function to call upon completion.
63 GNUNET_CRYPTO_HashCompletedCallback callback;
66 * Closure for callback.
73 unsigned char *buffer;
76 * Name of the file we are hashing.
83 struct GNUNET_DISK_FileHandle *fh;
88 struct GNUNET_SCHEDULER_Handle *sched;
106 * Current task for hashing.
108 GNUNET_SCHEDULER_TaskIdentifier task;
119 * Report result of hash computation to callback
120 * and free associated resources.
123 file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
124 const GNUNET_HashCode * res)
126 fhc->callback (fhc->callback_cls, res);
127 GNUNET_free (fhc->filename);
128 if (!GNUNET_DISK_handle_invalid (fhc->fh))
129 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
130 gcry_md_close (fhc->md);
131 GNUNET_free (fhc); /* also frees fhc->buffer */
142 file_hash_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
144 struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
145 GNUNET_HashCode *res;
148 fhc->task = GNUNET_SCHEDULER_NO_TASK;
149 GNUNET_assert (fhc->offset < fhc->fsize);
151 if (fhc->fsize - fhc->offset < delta)
152 delta = fhc->fsize - fhc->offset;
153 if (delta != GNUNET_DISK_file_read (fhc->fh, fhc->buffer, delta))
155 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
156 "read", fhc->filename);
157 file_hash_finish (fhc, NULL);
160 gcry_md_write (fhc->md, fhc->buffer, delta);
161 fhc->offset += delta;
162 if (fhc->offset == fhc->fsize)
164 res = (GNUNET_HashCode *) gcry_md_read (fhc->md, GCRY_MD_SHA512);
165 file_hash_finish (fhc, res);
169 = GNUNET_SCHEDULER_add_after (tc->sched,
170 GNUNET_SCHEDULER_NO_TASK,
171 &file_hash_task, fhc);
176 * Compute the hash of an entire file.
178 * @param sched scheduler to use
179 * @param priority scheduling priority to use
180 * @param filename name of file to hash
181 * @param blocksize number of bytes to process in one task
182 * @param callback function to call upon completion
183 * @param callback_cls closure for callback
184 * @return NULL on (immediate) errror
186 struct GNUNET_CRYPTO_FileHashContext *
187 GNUNET_CRYPTO_hash_file (struct GNUNET_SCHEDULER_Handle *sched,
188 enum GNUNET_SCHEDULER_Priority priority,
189 const char *filename,
191 GNUNET_CRYPTO_HashCompletedCallback callback,
194 struct GNUNET_CRYPTO_FileHashContext *fhc;
196 GNUNET_assert (blocksize > 0);
197 fhc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize);
198 fhc->callback = callback;
199 fhc->callback_cls = callback_cls;
201 fhc->buffer = (unsigned char *) &fhc[1];
202 fhc->filename = GNUNET_strdup (filename);
203 if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
209 fhc->bsize = blocksize;
210 if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fhc->fsize, GNUNET_NO))
212 GNUNET_free (fhc->filename);
216 fhc->fh = GNUNET_DISK_file_open (filename,
217 GNUNET_DISK_OPEN_READ,
218 GNUNET_DISK_PERM_NONE);
221 GNUNET_free (fhc->filename);
226 = GNUNET_SCHEDULER_add_with_priority (sched, priority,
227 &file_hash_task, fhc);
233 * Cancel a file hashing operation.
235 * @param fhc operation to cancel (callback must not yet have been invoked)
238 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
240 GNUNET_SCHEDULER_cancel (fhc->sched,
242 GNUNET_free (fhc->filename);
243 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
249 /* ***************** binary-ASCII encoding *************** */
252 getValue__ (unsigned char a)
254 if ((a >= '0') && (a <= '9'))
256 if ((a >= 'A') && (a <= 'V'))
257 return (a - 'A' + 10);
262 * Convert GNUNET_CRYPTO_hash to ASCII encoding. The ASCII encoding is rather
263 * GNUnet specific. It was chosen such that it only uses characters
264 * in [0-9A-V], can be produced without complex arithmetics and uses a
265 * small number of characters. The GNUnet encoding uses 102
266 * characters plus a null terminator.
268 * @param block the hash code
269 * @param result where to store the encoding (struct GNUNET_CRYPTO_HashAsciiEncoded can be
270 * safely cast to char*, a '\\0' termination is set).
273 GNUNET_CRYPTO_hash_to_enc (const GNUNET_HashCode * block,
274 struct GNUNET_CRYPTO_HashAsciiEncoded *result)
277 * 32 characters for encoding (GNUNET_CRYPTO_hash => 32 characters)
279 static char *encTable__ = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
285 GNUNET_assert (block != NULL);
286 GNUNET_assert (result != NULL);
291 while ((rpos < sizeof (GNUNET_HashCode)) || (vbit > 0))
293 if ((rpos < sizeof (GNUNET_HashCode)) && (vbit < 5))
295 bits = (bits << 8) | ((unsigned char *) block)[rpos++]; /* eat 8 more bits */
300 bits <<= (5 - vbit); /* zero-padding */
301 GNUNET_assert (vbit == 2); /* padding by 3: 512+3 mod 5 == 0 */
304 GNUNET_assert (wpos <
305 sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
306 result->encoding[wpos++] = encTable__[(bits >> (vbit - 5)) & 31];
309 GNUNET_assert (wpos == sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
310 GNUNET_assert (vbit == 0);
311 result->encoding[wpos] = '\0';
315 * Convert ASCII encoding back to GNUNET_CRYPTO_hash
317 * @param enc the encoding
318 * @param result where to store the GNUNET_CRYPTO_hash code
319 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
322 GNUNET_CRYPTO_hash_from_string (const char *enc, GNUNET_HashCode * result)
329 if (strlen (enc) != sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1)
330 return GNUNET_SYSERR;
332 vbit = 2; /* padding! */
333 wpos = sizeof (GNUNET_HashCode);
334 rpos = sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1;
335 bits = getValue__ (enc[--rpos]) >> 3;
338 GNUNET_assert (rpos > 0);
339 bits = (getValue__ (enc[--rpos]) << vbit) | bits;
343 ((unsigned char *) result)[--wpos] = (unsigned char) bits;
348 GNUNET_assert (rpos == 0);
349 GNUNET_assert (vbit == 0);
354 * Compute the distance between 2 hashcodes. The computation must be
355 * fast, not involve bits[0] or bits[4] (they're used elsewhere), and be
356 * somewhat consistent. And of course, the result should be a positive
359 * @param a some hash code
360 * @param b some hash code
361 * @return a positive number which is a measure for
362 * hashcode proximity.
365 GNUNET_CRYPTO_hash_distance_u32 (const GNUNET_HashCode * a,
366 const GNUNET_HashCode * b)
368 unsigned int x1 = (a->bits[1] - b->bits[1]) >> 16;
369 unsigned int x2 = (b->bits[1] - a->bits[1]) >> 16;
374 GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
375 GNUNET_HashCode * result)
378 for (i = (sizeof (GNUNET_HashCode) / sizeof (uint32_t)) - 1; i >= 0; i--)
379 result->bits[i] = GNUNET_CRYPTO_random_u32 (mode, UINT32_MAX);
383 GNUNET_CRYPTO_hash_difference (const GNUNET_HashCode * a,
384 const GNUNET_HashCode * b,
385 GNUNET_HashCode * result)
388 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0;
390 result->bits[i] = b->bits[i] - a->bits[i];
394 GNUNET_CRYPTO_hash_sum (const GNUNET_HashCode * a,
395 const GNUNET_HashCode * delta,
396 GNUNET_HashCode * result)
399 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0;
401 result->bits[i] = delta->bits[i] + a->bits[i];
406 GNUNET_CRYPTO_hash_xor (const GNUNET_HashCode * a,
407 const GNUNET_HashCode * b,
408 GNUNET_HashCode * result)
411 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0;
413 result->bits[i] = a->bits[i] ^ b->bits[i];
418 * Convert a hashcode into a key.
421 GNUNET_CRYPTO_hash_to_aes_key (const GNUNET_HashCode * hc,
422 struct GNUNET_CRYPTO_AesSessionKey *skey,
423 struct GNUNET_CRYPTO_AesInitializationVector
426 GNUNET_assert (sizeof (GNUNET_HashCode) >=
427 GNUNET_CRYPTO_AES_KEY_LENGTH +
428 sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
429 memcpy (skey, hc, GNUNET_CRYPTO_AES_KEY_LENGTH);
431 htonl (GNUNET_CRYPTO_crc32_n (skey, GNUNET_CRYPTO_AES_KEY_LENGTH));
432 memcpy (iv, &((char *) hc)[GNUNET_CRYPTO_AES_KEY_LENGTH],
433 sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
438 * Obtain a bit from a hashcode.
439 * @param code the GNUNET_CRYPTO_hash to index bit-wise
440 * @param bit index into the hashcode, [0...511]
441 * @return Bit \a bit from hashcode \a code, -1 for invalid index
444 GNUNET_CRYPTO_hash_get_bit (const GNUNET_HashCode * code,
447 GNUNET_assert (bit < 8 * sizeof (GNUNET_HashCode));
448 return (((unsigned char *) code)[bit >> 3] & (1 << (bit & 7))) > 0;
452 * Determine how many low order bits match in two
453 * GNUNET_HashCodes. i.e. - 010011 and 011111 share
454 * the first two lowest order bits, and therefore the
455 * return value is two (NOT XOR distance, nor how many
456 * bits match absolutely!).
458 * @param first the first hashcode
459 * @param second the hashcode to compare first to
461 * @return the number of bits that match
464 GNUNET_CRYPTO_hash_matching_bits(const GNUNET_HashCode *first,
465 const GNUNET_HashCode *second)
469 for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++)
470 if (GNUNET_CRYPTO_hash_get_bit (first, i) != GNUNET_CRYPTO_hash_get_bit (second, i))
472 return sizeof (GNUNET_HashCode) * 8;
477 * Compare function for HashCodes, producing a total ordering
479 * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
482 GNUNET_CRYPTO_hash_cmp (const GNUNET_HashCode * h1,
483 const GNUNET_HashCode * h2)
489 i1 = (unsigned int *) h1;
490 i2 = (unsigned int *) h2;
491 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0;
504 * Find out which of the two GNUNET_CRYPTO_hash codes is closer to target
505 * in the XOR metric (Kademlia).
506 * @return -1 if h1 is closer, 1 if h2 is closer and 0 if h1==h2.
509 GNUNET_CRYPTO_hash_xorcmp (const GNUNET_HashCode * h1,
510 const GNUNET_HashCode * h2,
511 const GNUNET_HashCode * target)
517 for (i = sizeof (GNUNET_HashCode) / sizeof (unsigned int) - 1; i >= 0; i--)
519 d1 = ((unsigned int *) h1)[i] ^ ((unsigned int *) target)[i];
520 d2 = ((unsigned int *) h2)[i] ^ ((unsigned int *) target)[i];
531 * @brief Derive an authentication key
532 * @param key authentication key
533 * @param rkey root key
535 * @param salt_len size of the salt
536 * @param ... pair of void * & size_t for context chunks, terminated by NULL
539 GNUNET_CRYPTO_hmac_derive_key(struct GNUNET_CRYPTO_AuthKey *key,
540 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
547 va_start (argp, salt_len);
548 GNUNET_CRYPTO_hmac_derive_key_v (key, rkey, salt, salt_len, argp);
554 * @brief Derive an authentication key
555 * @param key authentication key
556 * @param rkey root key
558 * @param salt_len size of the salt
559 * @param argp pair of void * & size_t for context chunks, terminated by NULL
562 GNUNET_CRYPTO_hmac_derive_key_v(struct GNUNET_CRYPTO_AuthKey *key,
563 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
568 GNUNET_CRYPTO_kdf_v (key->key,
578 * Calculate HMAC of a message (RFC 2104)
580 * @param key secret key
581 * @param plaintext input plaintext
582 * @param plaintext_len length of plaintext
583 * @param hmac where to store the hmac
586 GNUNET_CRYPTO_hmac (const struct GNUNET_CRYPTO_AuthKey *key,
587 const void *plaintext,
588 size_t plaintext_len,
589 GNUNET_HashCode *hmac)
592 const unsigned char *mc;
594 GNUNET_assert (GPG_ERR_NO_ERROR == gcry_md_open (&md,
597 gcry_md_setkey (md, key->key, sizeof(key->key));
598 gcry_md_write (md, plaintext, plaintext_len);
599 mc = gcry_md_read (md, GCRY_MD_SHA512);
601 memcpy (hmac->bits, mc, sizeof(hmac->bits));
606 /* end of crypto_hash.c */