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;
101 * Current task for hashing.
103 GNUNET_SCHEDULER_TaskIdentifier task;
114 * Report result of hash computation to callback
115 * and free associated resources.
118 file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
119 const GNUNET_HashCode * res)
121 fhc->callback (fhc->callback_cls, res);
122 GNUNET_free (fhc->filename);
123 if (!GNUNET_DISK_handle_invalid (fhc->fh))
124 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
125 gcry_md_close (fhc->md);
126 GNUNET_free (fhc); /* also frees fhc->buffer */
137 file_hash_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
139 struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
140 GNUNET_HashCode *res;
143 fhc->task = GNUNET_SCHEDULER_NO_TASK;
144 GNUNET_assert (fhc->offset <= fhc->fsize);
146 if (fhc->fsize - fhc->offset < delta)
147 delta = fhc->fsize - fhc->offset;
148 if (delta != GNUNET_DISK_file_read (fhc->fh, fhc->buffer, delta))
150 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "read", fhc->filename);
151 file_hash_finish (fhc, NULL);
154 gcry_md_write (fhc->md, fhc->buffer, delta);
155 fhc->offset += delta;
156 if (fhc->offset == fhc->fsize)
158 res = (GNUNET_HashCode *) gcry_md_read (fhc->md, GCRY_MD_SHA512);
159 file_hash_finish (fhc, res);
162 fhc->task = GNUNET_SCHEDULER_add_now (&file_hash_task, fhc);
167 * Compute the hash of an entire file.
169 * @param priority scheduling priority to use
170 * @param filename name of file to hash
171 * @param blocksize number of bytes to process in one task
172 * @param callback function to call upon completion
173 * @param callback_cls closure for callback
174 * @return NULL on (immediate) errror
176 struct GNUNET_CRYPTO_FileHashContext *
177 GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
178 const char *filename,
180 GNUNET_CRYPTO_HashCompletedCallback callback,
183 struct GNUNET_CRYPTO_FileHashContext *fhc;
185 GNUNET_assert (blocksize > 0);
187 GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize);
188 fhc->callback = callback;
189 fhc->callback_cls = callback_cls;
190 fhc->buffer = (unsigned char *) &fhc[1];
191 fhc->filename = GNUNET_strdup (filename);
192 if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
198 fhc->bsize = blocksize;
199 if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fhc->fsize, GNUNET_NO))
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);
215 = GNUNET_SCHEDULER_add_with_priority (priority, &file_hash_task, fhc);
221 * Cancel a file hashing operation.
223 * @param fhc operation to cancel (callback must not yet have been invoked)
226 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
228 GNUNET_SCHEDULER_cancel (fhc->task);
229 GNUNET_free (fhc->filename);
230 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
236 /* ***************** binary-ASCII encoding *************** */
239 getValue__ (unsigned char a)
241 if ((a >= '0') && (a <= '9'))
243 if ((a >= 'A') && (a <= 'V'))
244 return (a - 'A' + 10);
249 * Convert GNUNET_CRYPTO_hash to ASCII encoding. The ASCII encoding is rather
250 * GNUnet specific. It was chosen such that it only uses characters
251 * in [0-9A-V], can be produced without complex arithmetics and uses a
252 * small number of characters. The GNUnet encoding uses 103
253 * characters plus a null terminator.
255 * @param block the hash code
256 * @param result where to store the encoding (struct GNUNET_CRYPTO_HashAsciiEncoded can be
257 * safely cast to char*, a '\\0' termination is set).
260 GNUNET_CRYPTO_hash_to_enc (const GNUNET_HashCode * block,
261 struct GNUNET_CRYPTO_HashAsciiEncoded *result)
264 * 32 characters for encoding (GNUNET_CRYPTO_hash => 32 characters)
266 static char *encTable__ = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
272 GNUNET_assert (block != NULL);
273 GNUNET_assert (result != NULL);
278 while ((rpos < sizeof (GNUNET_HashCode)) || (vbit > 0))
280 if ((rpos < sizeof (GNUNET_HashCode)) && (vbit < 5))
282 bits = (bits << 8) | ((unsigned char *) block)[rpos++]; /* eat 8 more bits */
287 bits <<= (5 - vbit); /* zero-padding */
288 GNUNET_assert (vbit == 2); /* padding by 3: 512+3 mod 5 == 0 */
291 GNUNET_assert (wpos < sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
292 result->encoding[wpos++] = encTable__[(bits >> (vbit - 5)) & 31];
295 GNUNET_assert (wpos == sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
296 GNUNET_assert (vbit == 0);
297 result->encoding[wpos] = '\0';
301 * Convert ASCII encoding back to GNUNET_CRYPTO_hash
303 * @param enc the encoding
304 * @param result where to store the GNUNET_CRYPTO_hash code
305 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
308 GNUNET_CRYPTO_hash_from_string (const char *enc, GNUNET_HashCode * result)
315 if (strlen (enc) != sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1)
316 return GNUNET_SYSERR;
318 vbit = 2; /* padding! */
319 wpos = sizeof (GNUNET_HashCode);
320 rpos = sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1;
321 bits = getValue__ (enc[--rpos]) >> 3;
324 GNUNET_assert (rpos > 0);
325 bits = (getValue__ (enc[--rpos]) << vbit) | bits;
329 ((unsigned char *) result)[--wpos] = (unsigned char) bits;
334 GNUNET_assert (rpos == 0);
335 GNUNET_assert (vbit == 0);
340 * Compute the distance between 2 hashcodes. The computation must be
341 * fast, not involve bits[0] or bits[4] (they're used elsewhere), and be
342 * somewhat consistent. And of course, the result should be a positive
345 * @param a some hash code
346 * @param b some hash code
347 * @return a positive number which is a measure for
348 * hashcode proximity.
351 GNUNET_CRYPTO_hash_distance_u32 (const GNUNET_HashCode * a,
352 const GNUNET_HashCode * b)
354 unsigned int x1 = (a->bits[1] - b->bits[1]) >> 16;
355 unsigned int x2 = (b->bits[1] - a->bits[1]) >> 16;
361 GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
362 GNUNET_HashCode * result)
366 for (i = (sizeof (GNUNET_HashCode) / sizeof (uint32_t)) - 1; i >= 0; i--)
367 result->bits[i] = GNUNET_CRYPTO_random_u32 (mode, UINT32_MAX);
371 GNUNET_CRYPTO_hash_difference (const GNUNET_HashCode * a,
372 const GNUNET_HashCode * b,
373 GNUNET_HashCode * result)
377 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
378 result->bits[i] = b->bits[i] - a->bits[i];
382 GNUNET_CRYPTO_hash_sum (const GNUNET_HashCode * a,
383 const GNUNET_HashCode * delta, GNUNET_HashCode * result)
387 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
388 result->bits[i] = delta->bits[i] + a->bits[i];
393 GNUNET_CRYPTO_hash_xor (const GNUNET_HashCode * a,
394 const GNUNET_HashCode * b, GNUNET_HashCode * result)
398 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
399 result->bits[i] = a->bits[i] ^ b->bits[i];
404 * Convert a hashcode into a key.
407 GNUNET_CRYPTO_hash_to_aes_key (const GNUNET_HashCode * hc,
408 struct GNUNET_CRYPTO_AesSessionKey *skey,
409 struct GNUNET_CRYPTO_AesInitializationVector *iv)
411 GNUNET_assert (sizeof (GNUNET_HashCode) >=
412 GNUNET_CRYPTO_AES_KEY_LENGTH +
413 sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
414 memcpy (skey, hc, GNUNET_CRYPTO_AES_KEY_LENGTH);
416 htonl (GNUNET_CRYPTO_crc32_n (skey, GNUNET_CRYPTO_AES_KEY_LENGTH));
417 memcpy (iv, &((char *) hc)[GNUNET_CRYPTO_AES_KEY_LENGTH],
418 sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
423 * Obtain a bit from a hashcode.
424 * @param code the GNUNET_CRYPTO_hash to index bit-wise
425 * @param bit index into the hashcode, [0...511]
426 * @return Bit \a bit from hashcode \a code, -1 for invalid index
429 GNUNET_CRYPTO_hash_get_bit (const GNUNET_HashCode * code, unsigned int bit)
431 GNUNET_assert (bit < 8 * sizeof (GNUNET_HashCode));
432 return (((unsigned char *) code)[bit >> 3] & (1 << (bit & 7))) > 0;
436 * Determine how many low order bits match in two
437 * GNUNET_HashCodes. i.e. - 010011 and 011111 share
438 * the first two lowest order bits, and therefore the
439 * return value is two (NOT XOR distance, nor how many
440 * bits match absolutely!).
442 * @param first the first hashcode
443 * @param second the hashcode to compare first to
445 * @return the number of bits that match
448 GNUNET_CRYPTO_hash_matching_bits (const GNUNET_HashCode * first,
449 const GNUNET_HashCode * second)
453 for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++)
454 if (GNUNET_CRYPTO_hash_get_bit (first, i) !=
455 GNUNET_CRYPTO_hash_get_bit (second, i))
457 return sizeof (GNUNET_HashCode) * 8;
462 * Compare function for HashCodes, producing a total ordering
464 * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
467 GNUNET_CRYPTO_hash_cmp (const GNUNET_HashCode * h1, const GNUNET_HashCode * h2)
473 i1 = (unsigned int *) h1;
474 i2 = (unsigned int *) h2;
475 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
487 * Find out which of the two GNUNET_CRYPTO_hash codes is closer to target
488 * in the XOR metric (Kademlia).
489 * @return -1 if h1 is closer, 1 if h2 is closer and 0 if h1==h2.
492 GNUNET_CRYPTO_hash_xorcmp (const GNUNET_HashCode * h1,
493 const GNUNET_HashCode * h2,
494 const GNUNET_HashCode * target)
500 for (i = sizeof (GNUNET_HashCode) / sizeof (unsigned int) - 1; i >= 0; i--)
502 d1 = ((unsigned int *) h1)[i] ^ ((unsigned int *) target)[i];
503 d2 = ((unsigned int *) h2)[i] ^ ((unsigned int *) target)[i];
514 * @brief Derive an authentication key
515 * @param key authentication key
516 * @param rkey root key
518 * @param salt_len size of the salt
519 * @param ... pair of void * & size_t for context chunks, terminated by NULL
522 GNUNET_CRYPTO_hmac_derive_key (struct GNUNET_CRYPTO_AuthKey *key,
523 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
524 const void *salt, size_t salt_len, ...)
528 va_start (argp, salt_len);
529 GNUNET_CRYPTO_hmac_derive_key_v (key, rkey, salt, salt_len, argp);
535 * @brief Derive an authentication key
536 * @param key authentication key
537 * @param rkey root key
539 * @param salt_len size of the salt
540 * @param argp pair of void * & size_t for context chunks, terminated by NULL
543 GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key,
544 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
546 size_t salt_len, va_list argp)
548 GNUNET_CRYPTO_kdf_v (key->key,
550 salt, salt_len, rkey->key, sizeof (rkey->key), argp);
555 * Calculate HMAC of a message (RFC 2104)
557 * @param key secret key
558 * @param plaintext input plaintext
559 * @param plaintext_len length of plaintext
560 * @param hmac where to store the hmac
563 GNUNET_CRYPTO_hmac (const struct GNUNET_CRYPTO_AuthKey *key,
564 const void *plaintext,
565 size_t plaintext_len, GNUNET_HashCode * hmac)
568 const unsigned char *mc;
570 GNUNET_assert (GPG_ERR_NO_ERROR == gcry_md_open (&md,
573 gcry_md_setkey (md, key->key, sizeof (key->key));
574 gcry_md_write (md, plaintext, plaintext_len);
575 mc = gcry_md_read (md, GCRY_MD_SHA512);
577 memcpy (hmac->bits, mc, sizeof (hmac->bits));
582 /* end of crypto_hash.c */