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"
39 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
41 #define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename)
44 * Hash block of given size.
46 * @param block the data to GNUNET_CRYPTO_hash, length is given as a second argument
47 * @param size the length of the data to GNUNET_CRYPTO_hash
48 * @param ret pointer to where to write the hashcode
51 GNUNET_CRYPTO_hash (const void *block, size_t size, GNUNET_HashCode * ret)
53 gcry_md_hash_buffer (GCRY_MD_SHA512, ret, block, size);
58 * Context used when hashing a file.
60 struct GNUNET_CRYPTO_FileHashContext
64 * Function to call upon completion.
66 GNUNET_CRYPTO_HashCompletedCallback callback;
69 * Closure for callback.
76 unsigned char *buffer;
79 * Name of the file we are hashing.
86 struct GNUNET_DISK_FileHandle *fh;
104 * Current task for hashing.
106 GNUNET_SCHEDULER_TaskIdentifier task;
111 enum GNUNET_SCHEDULER_Priority priority;
122 * Report result of hash computation to callback
123 * and free associated resources.
126 file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc,
127 const GNUNET_HashCode * res)
129 fhc->callback (fhc->callback_cls, res);
130 GNUNET_free (fhc->filename);
131 if (!GNUNET_DISK_handle_invalid (fhc->fh))
132 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
133 gcry_md_close (fhc->md);
134 GNUNET_free (fhc); /* also frees fhc->buffer */
145 file_hash_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
147 struct GNUNET_CRYPTO_FileHashContext *fhc = cls;
148 GNUNET_HashCode *res;
151 fhc->task = GNUNET_SCHEDULER_NO_TASK;
152 GNUNET_assert (fhc->offset <= fhc->fsize);
154 if (fhc->fsize - fhc->offset < delta)
155 delta = fhc->fsize - fhc->offset;
156 if (delta != GNUNET_DISK_file_read (fhc->fh, fhc->buffer, delta))
158 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "read", fhc->filename);
159 file_hash_finish (fhc, NULL);
162 gcry_md_write (fhc->md, fhc->buffer, delta);
163 fhc->offset += delta;
164 if (fhc->offset == fhc->fsize)
166 res = (GNUNET_HashCode *) gcry_md_read (fhc->md, GCRY_MD_SHA512);
167 file_hash_finish (fhc, res);
170 fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority,
171 &file_hash_task, fhc);
176 * Compute the hash of an entire file.
178 * @param priority scheduling priority to use
179 * @param filename name of file to hash
180 * @param blocksize number of bytes to process in one task
181 * @param callback function to call upon completion
182 * @param callback_cls closure for callback
183 * @return NULL on (immediate) errror
185 struct GNUNET_CRYPTO_FileHashContext *
186 GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
187 const char *filename, size_t blocksize,
188 GNUNET_CRYPTO_HashCompletedCallback callback,
191 struct GNUNET_CRYPTO_FileHashContext *fhc;
193 GNUNET_assert (blocksize > 0);
195 GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize);
196 fhc->callback = callback;
197 fhc->callback_cls = callback_cls;
198 fhc->buffer = (unsigned char *) &fhc[1];
199 fhc->filename = GNUNET_strdup (filename);
200 if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0))
206 fhc->bsize = blocksize;
207 if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fhc->fsize, GNUNET_NO))
209 GNUNET_free (fhc->filename);
214 GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
215 GNUNET_DISK_PERM_NONE);
218 GNUNET_free (fhc->filename);
222 fhc->priority = priority;
224 GNUNET_SCHEDULER_add_with_priority (priority, &file_hash_task, fhc);
230 * Cancel a file hashing operation.
232 * @param fhc operation to cancel (callback must not yet have been invoked)
235 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc)
237 GNUNET_SCHEDULER_cancel (fhc->task);
238 GNUNET_free (fhc->filename);
239 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh));
245 /* ***************** binary-ASCII encoding *************** */
248 * Get the numeric value corresponding to a character.
250 * @param a a character
251 * @return corresponding numeric value
254 getValue__ (unsigned char a)
256 if ((a >= '0') && (a <= '9'))
258 if ((a >= 'A') && (a <= 'V'))
259 return (a - 'A' + 10);
265 * Convert GNUNET_CRYPTO_hash to ASCII encoding. The ASCII encoding is rather
266 * GNUnet specific. It was chosen such that it only uses characters
267 * in [0-9A-V], can be produced without complex arithmetics and uses a
268 * small number of characters. The GNUnet encoding uses 103
269 * characters plus a null terminator.
271 * @param block the hash code
272 * @param result where to store the encoding (struct GNUNET_CRYPTO_HashAsciiEncoded can be
273 * safely cast to char*, a '\\0' termination is set).
276 GNUNET_CRYPTO_hash_to_enc (const GNUNET_HashCode * block,
277 struct GNUNET_CRYPTO_HashAsciiEncoded *result)
280 * 32 characters for encoding (GNUNET_CRYPTO_hash => 32 characters)
282 static char *encTable__ = "0123456789ABCDEFGHIJKLMNOPQRSTUV";
288 GNUNET_assert (block != NULL);
289 GNUNET_assert (result != NULL);
294 while ((rpos < sizeof (GNUNET_HashCode)) || (vbit > 0))
296 if ((rpos < sizeof (GNUNET_HashCode)) && (vbit < 5))
298 bits = (bits << 8) | ((unsigned char *) block)[rpos++]; /* eat 8 more bits */
303 bits <<= (5 - vbit); /* zero-padding */
304 GNUNET_assert (vbit == 2); /* padding by 3: 512+3 mod 5 == 0 */
307 GNUNET_assert (wpos < sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
308 result->encoding[wpos++] = encTable__[(bits >> (vbit - 5)) & 31];
311 GNUNET_assert (wpos == sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
312 GNUNET_assert (vbit == 0);
313 result->encoding[wpos] = '\0';
318 * Convert ASCII encoding back to GNUNET_CRYPTO_hash
320 * @param enc the encoding
321 * @param result where to store the GNUNET_CRYPTO_hash code
322 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
325 GNUNET_CRYPTO_hash_from_string (const char *enc, GNUNET_HashCode * result)
333 if (strlen (enc) != sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1)
334 return GNUNET_SYSERR;
336 vbit = 2; /* padding! */
337 wpos = sizeof (GNUNET_HashCode);
338 rpos = sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1;
339 bits = (ret = getValue__ (enc[--rpos])) >> 3;
341 return GNUNET_SYSERR;
344 GNUNET_assert (rpos > 0);
345 bits = ((ret = getValue__ (enc[--rpos])) << vbit) | bits;
347 return GNUNET_SYSERR;
351 ((unsigned char *) result)[--wpos] = (unsigned char) bits;
356 GNUNET_assert (rpos == 0);
357 GNUNET_assert (vbit == 0);
363 * Compute the distance between 2 hashcodes. The computation must be
364 * fast, not involve bits[0] or bits[4] (they're used elsewhere), and be
365 * somewhat consistent. And of course, the result should be a positive
368 * @param a some hash code
369 * @param b some hash code
370 * @return a positive number which is a measure for
371 * hashcode proximity.
374 GNUNET_CRYPTO_hash_distance_u32 (const GNUNET_HashCode * a,
375 const GNUNET_HashCode * b)
377 unsigned int x1 = (a->bits[1] - b->bits[1]) >> 16;
378 unsigned int x2 = (b->bits[1] - a->bits[1]) >> 16;
385 * Create a random hash code.
387 * @param mode desired quality level
388 * @param result hash code that is randomized
391 GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
392 GNUNET_HashCode * result)
396 for (i = (sizeof (GNUNET_HashCode) / sizeof (uint32_t)) - 1; i >= 0; i--)
397 result->bits[i] = GNUNET_CRYPTO_random_u32 (mode, UINT32_MAX);
402 * compute result(delta) = b - a
404 * @param a some hash code
405 * @param b some hash code
406 * @param result set to b - a
409 GNUNET_CRYPTO_hash_difference (const GNUNET_HashCode * a,
410 const GNUNET_HashCode * b,
411 GNUNET_HashCode * result)
415 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
416 result->bits[i] = b->bits[i] - a->bits[i];
421 * compute result(b) = a + delta
423 * @param a some hash code
424 * @param delta some hash code
425 * @param result set to a + delta
428 GNUNET_CRYPTO_hash_sum (const GNUNET_HashCode * a,
429 const GNUNET_HashCode * delta, GNUNET_HashCode * result)
433 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
434 result->bits[i] = delta->bits[i] + a->bits[i];
439 * compute result = a ^ b
441 * @param a some hash code
442 * @param b some hash code
443 * @param result set to a ^ b
446 GNUNET_CRYPTO_hash_xor (const GNUNET_HashCode * a, const GNUNET_HashCode * b,
447 GNUNET_HashCode * result)
451 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
452 result->bits[i] = a->bits[i] ^ b->bits[i];
457 * Convert a hashcode into a key.
459 * @param hc hash code that serves to generate the key
460 * @param skey set to a valid session key
461 * @param iv set to a valid initialization vector
464 GNUNET_CRYPTO_hash_to_aes_key (const GNUNET_HashCode * hc,
465 struct GNUNET_CRYPTO_AesSessionKey *skey,
466 struct GNUNET_CRYPTO_AesInitializationVector *iv)
468 GNUNET_assert (sizeof (GNUNET_HashCode) >=
469 GNUNET_CRYPTO_AES_KEY_LENGTH +
470 sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
471 memcpy (skey, hc, GNUNET_CRYPTO_AES_KEY_LENGTH);
473 htonl (GNUNET_CRYPTO_crc32_n (skey, GNUNET_CRYPTO_AES_KEY_LENGTH));
474 memcpy (iv, &((char *) hc)[GNUNET_CRYPTO_AES_KEY_LENGTH],
475 sizeof (struct GNUNET_CRYPTO_AesInitializationVector));
480 * Obtain a bit from a hashcode.
481 * @param code the GNUNET_CRYPTO_hash to index bit-wise
482 * @param bit index into the hashcode, [0...511]
483 * @return Bit \a bit from hashcode \a code, -1 for invalid index
486 GNUNET_CRYPTO_hash_get_bit (const GNUNET_HashCode * code, unsigned int bit)
488 GNUNET_assert (bit < 8 * sizeof (GNUNET_HashCode));
489 return (((unsigned char *) code)[bit >> 3] & (1 << (bit & 7))) > 0;
494 * Determine how many low order bits match in two
495 * GNUNET_HashCodes. i.e. - 010011 and 011111 share
496 * the first two lowest order bits, and therefore the
497 * return value is two (NOT XOR distance, nor how many
498 * bits match absolutely!).
500 * @param first the first hashcode
501 * @param second the hashcode to compare first to
503 * @return the number of bits that match
506 GNUNET_CRYPTO_hash_matching_bits (const GNUNET_HashCode * first,
507 const GNUNET_HashCode * second)
511 for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++)
512 if (GNUNET_CRYPTO_hash_get_bit (first, i) !=
513 GNUNET_CRYPTO_hash_get_bit (second, i))
515 return sizeof (GNUNET_HashCode) * 8;
520 * Compare function for HashCodes, producing a total ordering
523 * @param h1 some hash code
524 * @param h2 some hash code
525 * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
528 GNUNET_CRYPTO_hash_cmp (const GNUNET_HashCode * h1, const GNUNET_HashCode * h2)
534 i1 = (unsigned int *) h1;
535 i2 = (unsigned int *) h2;
536 for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
548 * Find out which of the two GNUNET_CRYPTO_hash codes is closer to target
549 * in the XOR metric (Kademlia).
551 * @param h1 some hash code
552 * @param h2 some hash code
553 * @param target some hash code
554 * @return -1 if h1 is closer, 1 if h2 is closer and 0 if h1==h2.
557 GNUNET_CRYPTO_hash_xorcmp (const GNUNET_HashCode * h1,
558 const GNUNET_HashCode * h2,
559 const GNUNET_HashCode * target)
565 for (i = sizeof (GNUNET_HashCode) / sizeof (unsigned int) - 1; i >= 0; i--)
567 d1 = ((unsigned int *) h1)[i] ^ ((unsigned int *) target)[i];
568 d2 = ((unsigned int *) h2)[i] ^ ((unsigned int *) target)[i];
579 * @brief Derive an authentication key
580 * @param key authentication key
581 * @param rkey root key
583 * @param salt_len size of the salt
584 * @param ... pair of void * & size_t for context chunks, terminated by NULL
587 GNUNET_CRYPTO_hmac_derive_key (struct GNUNET_CRYPTO_AuthKey *key,
588 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
589 const void *salt, size_t salt_len, ...)
593 va_start (argp, salt_len);
594 GNUNET_CRYPTO_hmac_derive_key_v (key, rkey, salt, salt_len, argp);
600 * @brief Derive an authentication key
601 * @param key authentication key
602 * @param rkey root key
604 * @param salt_len size of the salt
605 * @param argp pair of void * & size_t for context chunks, terminated by NULL
608 GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key,
609 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
610 const void *salt, size_t salt_len,
613 GNUNET_CRYPTO_kdf_v (key->key, sizeof (key->key), salt, salt_len, rkey->key,
614 sizeof (rkey->key), argp);
619 * Calculate HMAC of a message (RFC 2104)
621 * @param key secret key
622 * @param plaintext input plaintext
623 * @param plaintext_len length of plaintext
624 * @param hmac where to store the hmac
627 GNUNET_CRYPTO_hmac (const struct GNUNET_CRYPTO_AuthKey *key,
628 const void *plaintext, size_t plaintext_len,
629 GNUNET_HashCode * hmac)
632 const unsigned char *mc;
634 GNUNET_assert (GPG_ERR_NO_ERROR ==
635 gcry_md_open (&md, GCRY_MD_SHA512, GCRY_MD_FLAG_HMAC));
636 gcry_md_setkey (md, key->key, sizeof (key->key));
637 gcry_md_write (md, plaintext, plaintext_len);
638 mc = gcry_md_read (md, GCRY_MD_SHA512);
640 memcpy (hmac->bits, mc, sizeof (hmac->bits));
645 /* end of crypto_hash.c */