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Diffstat (limited to 'src/util/crypto_hash.c')
| -rw-r--r-- | src/util/crypto_hash.c | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/src/util/crypto_hash.c b/src/util/crypto_hash.c new file mode 100644 index 0000000..63d9654 --- /dev/null +++ b/src/util/crypto_hash.c @@ -0,0 +1,647 @@ +/* + This file is part of GNUnet. + (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 2, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. + + SHA-512 code by Jean-Luc Cooke <jlcooke@certainkey.com> + + Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com> + Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk> + Copyright (c) 2003 Kyle McMartin <kyle@debian.org> +*/ + +/** + * @file util/crypto_hash.c + * @brief SHA-512 GNUNET_CRYPTO_hash related functions + * @author Christian Grothoff + */ + +#include "platform.h" +#include "gnunet_common.h" +#include "gnunet_crypto_lib.h" +#include "gnunet_disk_lib.h" +#include <gcrypt.h> + +#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__) + +#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename) + +/** + * Hash block of given size. + * + * @param block the data to GNUNET_CRYPTO_hash, length is given as a second argument + * @param size the length of the data to GNUNET_CRYPTO_hash + * @param ret pointer to where to write the hashcode + */ +void +GNUNET_CRYPTO_hash (const void *block, size_t size, GNUNET_HashCode * ret) +{ + gcry_md_hash_buffer (GCRY_MD_SHA512, ret, block, size); +} + + +/** + * Context used when hashing a file. + */ +struct GNUNET_CRYPTO_FileHashContext +{ + + /** + * Function to call upon completion. + */ + GNUNET_CRYPTO_HashCompletedCallback callback; + + /** + * Closure for callback. + */ + void *callback_cls; + + /** + * IO buffer. + */ + unsigned char *buffer; + + /** + * Name of the file we are hashing. + */ + char *filename; + + /** + * File descriptor. + */ + struct GNUNET_DISK_FileHandle *fh; + + /** + * Cummulated hash. + */ + gcry_md_hd_t md; + + /** + * Size of the file. + */ + uint64_t fsize; + + /** + * Current offset. + */ + uint64_t offset; + + /** + * Current task for hashing. + */ + GNUNET_SCHEDULER_TaskIdentifier task; + + /** + * Priority we use. + */ + enum GNUNET_SCHEDULER_Priority priority; + + /** + * Blocksize. + */ + size_t bsize; + +}; + + +/** + * Report result of hash computation to callback + * and free associated resources. + */ +static void +file_hash_finish (struct GNUNET_CRYPTO_FileHashContext *fhc, + const GNUNET_HashCode * res) +{ + fhc->callback (fhc->callback_cls, res); + GNUNET_free (fhc->filename); + if (!GNUNET_DISK_handle_invalid (fhc->fh)) + GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh)); + gcry_md_close (fhc->md); + GNUNET_free (fhc); /* also frees fhc->buffer */ +} + + +/** + * File hashing task. + * + * @param cls closure + * @param tc context + */ +static void +file_hash_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_CRYPTO_FileHashContext *fhc = cls; + GNUNET_HashCode *res; + size_t delta; + + fhc->task = GNUNET_SCHEDULER_NO_TASK; + GNUNET_assert (fhc->offset <= fhc->fsize); + delta = fhc->bsize; + if (fhc->fsize - fhc->offset < delta) + delta = fhc->fsize - fhc->offset; + if (delta != GNUNET_DISK_file_read (fhc->fh, fhc->buffer, delta)) + { + LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "read", fhc->filename); + file_hash_finish (fhc, NULL); + return; + } + gcry_md_write (fhc->md, fhc->buffer, delta); + fhc->offset += delta; + if (fhc->offset == fhc->fsize) + { + res = (GNUNET_HashCode *) gcry_md_read (fhc->md, GCRY_MD_SHA512); + file_hash_finish (fhc, res); + return; + } + fhc->task = GNUNET_SCHEDULER_add_with_priority (fhc->priority, + &file_hash_task, fhc); +} + + +/** + * Compute the hash of an entire file. + * + * @param priority scheduling priority to use + * @param filename name of file to hash + * @param blocksize number of bytes to process in one task + * @param callback function to call upon completion + * @param callback_cls closure for callback + * @return NULL on (immediate) errror + */ +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) +{ + struct GNUNET_CRYPTO_FileHashContext *fhc; + + GNUNET_assert (blocksize > 0); + fhc = + GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_FileHashContext) + blocksize); + fhc->callback = callback; + fhc->callback_cls = callback_cls; + fhc->buffer = (unsigned char *) &fhc[1]; + fhc->filename = GNUNET_strdup (filename); + if (GPG_ERR_NO_ERROR != gcry_md_open (&fhc->md, GCRY_MD_SHA512, 0)) + { + GNUNET_break (0); + GNUNET_free (fhc); + return NULL; + } + fhc->bsize = blocksize; + if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fhc->fsize, GNUNET_NO)) + { + GNUNET_free (fhc->filename); + GNUNET_free (fhc); + return NULL; + } + fhc->fh = + GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ, + GNUNET_DISK_PERM_NONE); + if (!fhc->fh) + { + GNUNET_free (fhc->filename); + GNUNET_free (fhc); + return NULL; + } + fhc->priority = priority; + fhc->task = + GNUNET_SCHEDULER_add_with_priority (priority, &file_hash_task, fhc); + return fhc; +} + + +/** + * Cancel a file hashing operation. + * + * @param fhc operation to cancel (callback must not yet have been invoked) + */ +void +GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc) +{ + GNUNET_SCHEDULER_cancel (fhc->task); + GNUNET_free (fhc->filename); + GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fhc->fh)); + GNUNET_free (fhc); +} + + + +/* ***************** binary-ASCII encoding *************** */ + +/** + * Get the numeric value corresponding to a character. + * + * @param a a character + * @return corresponding numeric value + */ +static unsigned int +getValue__ (unsigned char a) +{ + if ((a >= '0') && (a <= '9')) + return a - '0'; + if ((a >= 'A') && (a <= 'V')) + return (a - 'A' + 10); + return -1; +} + + +/** + * Convert GNUNET_CRYPTO_hash to ASCII encoding. The ASCII encoding is rather + * GNUnet specific. It was chosen such that it only uses characters + * in [0-9A-V], can be produced without complex arithmetics and uses a + * small number of characters. The GNUnet encoding uses 103 + * characters plus a null terminator. + * + * @param block the hash code + * @param result where to store the encoding (struct GNUNET_CRYPTO_HashAsciiEncoded can be + * safely cast to char*, a '\\0' termination is set). + */ +void +GNUNET_CRYPTO_hash_to_enc (const GNUNET_HashCode * block, + struct GNUNET_CRYPTO_HashAsciiEncoded *result) +{ + /** + * 32 characters for encoding (GNUNET_CRYPTO_hash => 32 characters) + */ + static char *encTable__ = "0123456789ABCDEFGHIJKLMNOPQRSTUV"; + unsigned int wpos; + unsigned int rpos; + unsigned int bits; + unsigned int vbit; + + GNUNET_assert (block != NULL); + GNUNET_assert (result != NULL); + vbit = 0; + wpos = 0; + rpos = 0; + bits = 0; + while ((rpos < sizeof (GNUNET_HashCode)) || (vbit > 0)) + { + if ((rpos < sizeof (GNUNET_HashCode)) && (vbit < 5)) + { + bits = (bits << 8) | ((unsigned char *) block)[rpos++]; /* eat 8 more bits */ + vbit += 8; + } + if (vbit < 5) + { + bits <<= (5 - vbit); /* zero-padding */ + GNUNET_assert (vbit == 2); /* padding by 3: 512+3 mod 5 == 0 */ + vbit = 5; + } + GNUNET_assert (wpos < sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1); + result->encoding[wpos++] = encTable__[(bits >> (vbit - 5)) & 31]; + vbit -= 5; + } + GNUNET_assert (wpos == sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1); + GNUNET_assert (vbit == 0); + result->encoding[wpos] = '\0'; +} + + +/** + * Convert ASCII encoding back to GNUNET_CRYPTO_hash + * + * @param enc the encoding + * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing) + * @param result where to store the GNUNET_CRYPTO_hash code + * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding + */ +int +GNUNET_CRYPTO_hash_from_string2 (const char *enc, size_t enclen, + GNUNET_HashCode * result) +{ + unsigned int rpos; + unsigned int wpos; + unsigned int bits; + unsigned int vbit; + int ret; + + if (enclen != sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1) + return GNUNET_SYSERR; + + vbit = 2; /* padding! */ + wpos = sizeof (GNUNET_HashCode); + rpos = sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1; + bits = (ret = getValue__ (enc[--rpos])) >> 3; + if (-1 == ret) + return GNUNET_SYSERR; + while (wpos > 0) + { + GNUNET_assert (rpos > 0); + bits = ((ret = getValue__ (enc[--rpos])) << vbit) | bits; + if (-1 == ret) + return GNUNET_SYSERR; + vbit += 5; + if (vbit >= 8) + { + ((unsigned char *) result)[--wpos] = (unsigned char) bits; + bits >>= 8; + vbit -= 8; + } + } + GNUNET_assert (rpos == 0); + GNUNET_assert (vbit == 0); + return GNUNET_OK; +} + + +/** + * Compute the distance between 2 hashcodes. The computation must be + * fast, not involve bits[0] or bits[4] (they're used elsewhere), and be + * somewhat consistent. And of course, the result should be a positive + * number. + * + * @param a some hash code + * @param b some hash code + * @return a positive number which is a measure for + * hashcode proximity. + */ +unsigned int +GNUNET_CRYPTO_hash_distance_u32 (const GNUNET_HashCode * a, + const GNUNET_HashCode * b) +{ + unsigned int x1 = (a->bits[1] - b->bits[1]) >> 16; + unsigned int x2 = (b->bits[1] - a->bits[1]) >> 16; + + return (x1 * x2); +} + + +/** + * Create a random hash code. + * + * @param mode desired quality level + * @param result hash code that is randomized + */ +void +GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode, + GNUNET_HashCode * result) +{ + int i; + + for (i = (sizeof (GNUNET_HashCode) / sizeof (uint32_t)) - 1; i >= 0; i--) + result->bits[i] = GNUNET_CRYPTO_random_u32 (mode, UINT32_MAX); +} + + +/** + * compute result(delta) = b - a + * + * @param a some hash code + * @param b some hash code + * @param result set to b - a + */ +void +GNUNET_CRYPTO_hash_difference (const GNUNET_HashCode * a, + const GNUNET_HashCode * b, + GNUNET_HashCode * result) +{ + int i; + + for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--) + result->bits[i] = b->bits[i] - a->bits[i]; +} + + +/** + * compute result(b) = a + delta + * + * @param a some hash code + * @param delta some hash code + * @param result set to a + delta + */ +void +GNUNET_CRYPTO_hash_sum (const GNUNET_HashCode * a, + const GNUNET_HashCode * delta, GNUNET_HashCode * result) +{ + int i; + + for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--) + result->bits[i] = delta->bits[i] + a->bits[i]; +} + + +/** + * compute result = a ^ b + * + * @param a some hash code + * @param b some hash code + * @param result set to a ^ b + */ +void +GNUNET_CRYPTO_hash_xor (const GNUNET_HashCode * a, const GNUNET_HashCode * b, + GNUNET_HashCode * result) +{ + int i; + + for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--) + result->bits[i] = a->bits[i] ^ b->bits[i]; +} + + +/** + * Convert a hashcode into a key. + * + * @param hc hash code that serves to generate the key + * @param skey set to a valid session key + * @param iv set to a valid initialization vector + */ +void +GNUNET_CRYPTO_hash_to_aes_key (const GNUNET_HashCode * hc, + struct GNUNET_CRYPTO_AesSessionKey *skey, + struct GNUNET_CRYPTO_AesInitializationVector *iv) +{ + GNUNET_assert (sizeof (GNUNET_HashCode) >= + GNUNET_CRYPTO_AES_KEY_LENGTH + + sizeof (struct GNUNET_CRYPTO_AesInitializationVector)); + memcpy (skey, hc, GNUNET_CRYPTO_AES_KEY_LENGTH); + skey->crc32 = + htonl (GNUNET_CRYPTO_crc32_n (skey, GNUNET_CRYPTO_AES_KEY_LENGTH)); + memcpy (iv, &((char *) hc)[GNUNET_CRYPTO_AES_KEY_LENGTH], + sizeof (struct GNUNET_CRYPTO_AesInitializationVector)); +} + + +/** + * Obtain a bit from a hashcode. + * @param code the GNUNET_CRYPTO_hash to index bit-wise + * @param bit index into the hashcode, [0...511] + * @return Bit \a bit from hashcode \a code, -1 for invalid index + */ +int +GNUNET_CRYPTO_hash_get_bit (const GNUNET_HashCode * code, unsigned int bit) +{ + GNUNET_assert (bit < 8 * sizeof (GNUNET_HashCode)); + return (((unsigned char *) code)[bit >> 3] & (1 << (bit & 7))) > 0; +} + + +/** + * Determine how many low order bits match in two + * GNUNET_HashCodes. i.e. - 010011 and 011111 share + * the first two lowest order bits, and therefore the + * return value is two (NOT XOR distance, nor how many + * bits match absolutely!). + * + * @param first the first hashcode + * @param second the hashcode to compare first to + * + * @return the number of bits that match + */ +unsigned int +GNUNET_CRYPTO_hash_matching_bits (const GNUNET_HashCode * first, + const GNUNET_HashCode * second) +{ + unsigned int i; + + for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++) + if (GNUNET_CRYPTO_hash_get_bit (first, i) != + GNUNET_CRYPTO_hash_get_bit (second, i)) + return i; + return sizeof (GNUNET_HashCode) * 8; +} + + +/** + * Compare function for HashCodes, producing a total ordering + * of all hashcodes. + * + * @param h1 some hash code + * @param h2 some hash code + * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2. + */ +int +GNUNET_CRYPTO_hash_cmp (const GNUNET_HashCode * h1, const GNUNET_HashCode * h2) +{ + unsigned int *i1; + unsigned int *i2; + int i; + + i1 = (unsigned int *) h1; + i2 = (unsigned int *) h2; + for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--) + { + if (i1[i] > i2[i]) + return 1; + if (i1[i] < i2[i]) + return -1; + } + return 0; +} + + +/** + * Find out which of the two GNUNET_CRYPTO_hash codes is closer to target + * in the XOR metric (Kademlia). + * + * @param h1 some hash code + * @param h2 some hash code + * @param target some hash code + * @return -1 if h1 is closer, 1 if h2 is closer and 0 if h1==h2. + */ +int +GNUNET_CRYPTO_hash_xorcmp (const GNUNET_HashCode * h1, + const GNUNET_HashCode * h2, + const GNUNET_HashCode * target) +{ + int i; + unsigned int d1; + unsigned int d2; + + for (i = sizeof (GNUNET_HashCode) / sizeof (unsigned int) - 1; i >= 0; i--) + { + d1 = ((unsigned int *) h1)[i] ^ ((unsigned int *) target)[i]; + d2 = ((unsigned int *) h2)[i] ^ ((unsigned int *) target)[i]; + if (d1 > d2) + return 1; + else if (d1 < d2) + return -1; + } + return 0; +} + + +/** + * @brief Derive an authentication key + * @param key authentication key + * @param rkey root key + * @param salt salt + * @param salt_len size of the salt + * @param ... pair of void * & size_t for context chunks, terminated by NULL + */ +void +GNUNET_CRYPTO_hmac_derive_key (struct GNUNET_CRYPTO_AuthKey *key, + const struct GNUNET_CRYPTO_AesSessionKey *rkey, + const void *salt, size_t salt_len, ...) +{ + va_list argp; + + va_start (argp, salt_len); + GNUNET_CRYPTO_hmac_derive_key_v (key, rkey, salt, salt_len, argp); + va_end (argp); +} + + +/** + * @brief Derive an authentication key + * @param key authentication key + * @param rkey root key + * @param salt salt + * @param salt_len size of the salt + * @param argp pair of void * & size_t for context chunks, terminated by NULL + */ +void +GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key, + const struct GNUNET_CRYPTO_AesSessionKey *rkey, + const void *salt, size_t salt_len, + va_list argp) +{ + GNUNET_CRYPTO_kdf_v (key->key, sizeof (key->key), salt, salt_len, rkey->key, + sizeof (rkey->key), argp); +} + + +/** + * Calculate HMAC of a message (RFC 2104) + * + * @param key secret key + * @param plaintext input plaintext + * @param plaintext_len length of plaintext + * @param hmac where to store the hmac + */ +void +GNUNET_CRYPTO_hmac (const struct GNUNET_CRYPTO_AuthKey *key, + const void *plaintext, size_t plaintext_len, + GNUNET_HashCode * hmac) +{ + gcry_md_hd_t md; + const unsigned char *mc; + + GNUNET_assert (GPG_ERR_NO_ERROR == + gcry_md_open (&md, GCRY_MD_SHA512, GCRY_MD_FLAG_HMAC)); + gcry_md_setkey (md, key->key, sizeof (key->key)); + gcry_md_write (md, plaintext, plaintext_len); + mc = gcry_md_read (md, GCRY_MD_SHA512); + if (mc != NULL) + memcpy (hmac->bits, mc, sizeof (hmac->bits)); + gcry_md_close (md); +} + + +/* end of crypto_hash.c */ |