/*
This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2001-2013 GNUnet e.V.
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
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, 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
+ * @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 "gnunet_strings_lib.h"
#include <gcrypt.h>
#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
/**
* 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 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 in @a block
* @param ret pointer to where to write the hashcode
*/
void
-GNUNET_CRYPTO_hash (const void *block, size_t size, GNUNET_HashCode * ret)
+GNUNET_CRYPTO_hash (const void *block,
+ size_t size,
+ struct 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
* safely cast to char*, a '\\0' termination is set).
*/
void
-GNUNET_CRYPTO_hash_to_enc (const GNUNET_HashCode * block,
+GNUNET_CRYPTO_hash_to_enc (const struct 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';
+ char *np;
+
+ np = GNUNET_STRINGS_data_to_string ((const unsigned char *) block,
+ sizeof (struct GNUNET_HashCode),
+ (char*) result,
+ sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1);
+ GNUNET_assert (NULL != np);
+ *np = '\0';
}
/**
- * Convert ASCII encoding back to GNUNET_CRYPTO_hash
+ * Convert ASCII encoding back to hash code.
*
* @param enc the encoding
- * @param result where to store the GNUNET_CRYPTO_hash code
- * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
+ * @param enclen number of characters in @a enc (without 0-terminator, which can be missing)
+ * @param result where to store the hash code
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if result has the wrong encoding
*/
int
-GNUNET_CRYPTO_hash_from_string (const char *enc, GNUNET_HashCode * result)
+GNUNET_CRYPTO_hash_from_string2 (const char *enc,
+ size_t enclen,
+ struct GNUNET_HashCode *result)
{
- unsigned int rpos;
- unsigned int wpos;
- unsigned int bits;
- unsigned int vbit;
- int ret;
-
- if (strlen (enc) != 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;
+ char upper_enc[enclen];
+ char *up_ptr = upper_enc;
+
+ GNUNET_STRINGS_utf8_toupper (enc, up_ptr);
+
+ return GNUNET_STRINGS_string_to_data (upper_enc, enclen,
+ (unsigned char*) result,
+ sizeof (struct GNUNET_HashCode));
}
/**
+ * @ingroup hash
+ *
* 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
* hashcode proximity.
*/
unsigned int
-GNUNET_CRYPTO_hash_distance_u32 (const GNUNET_HashCode * a,
- const GNUNET_HashCode * b)
+GNUNET_CRYPTO_hash_distance_u32 (const struct GNUNET_HashCode *a,
+ const struct GNUNET_HashCode *b)
{
unsigned int x1 = (a->bits[1] - b->bits[1]) >> 16;
unsigned int x2 = (b->bits[1] - a->bits[1]) >> 16;
*/
void
GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
- GNUNET_HashCode * result)
+ struct GNUNET_HashCode *result)
{
int i;
- for (i = (sizeof (GNUNET_HashCode) / sizeof (uint32_t)) - 1; i >= 0; i--)
+ for (i = (sizeof (struct GNUNET_HashCode) / sizeof (uint32_t)) - 1; i >= 0; i--)
result->bits[i] = GNUNET_CRYPTO_random_u32 (mode, UINT32_MAX);
}
* @param result set to b - a
*/
void
-GNUNET_CRYPTO_hash_difference (const GNUNET_HashCode * a,
- const GNUNET_HashCode * b,
- GNUNET_HashCode * result)
+GNUNET_CRYPTO_hash_difference (const struct GNUNET_HashCode *a,
+ const struct GNUNET_HashCode *b,
+ struct GNUNET_HashCode *result)
{
int i;
- for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
+ for (i = (sizeof (struct GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
result->bits[i] = b->bits[i] - a->bits[i];
}
* @param result set to a + delta
*/
void
-GNUNET_CRYPTO_hash_sum (const GNUNET_HashCode * a,
- const GNUNET_HashCode * delta, GNUNET_HashCode * result)
+GNUNET_CRYPTO_hash_sum (const struct GNUNET_HashCode * a,
+ const struct GNUNET_HashCode * delta, struct GNUNET_HashCode * result)
{
int i;
- for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
+ for (i = (sizeof (struct GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
result->bits[i] = delta->bits[i] + a->bits[i];
}
* @param result set to a ^ b
*/
void
-GNUNET_CRYPTO_hash_xor (const GNUNET_HashCode * a, const GNUNET_HashCode * b,
- GNUNET_HashCode * result)
+GNUNET_CRYPTO_hash_xor (const struct GNUNET_HashCode *a,
+ const struct GNUNET_HashCode *b,
+ struct GNUNET_HashCode *result)
{
int i;
- for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
+ for (i = (sizeof (struct GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
result->bits[i] = a->bits[i] ^ b->bits[i];
}
* @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_CRYPTO_hash_to_aes_key (const struct GNUNET_HashCode *hc,
+ struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
+ struct GNUNET_CRYPTO_SymmetricInitializationVector *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));
+ GNUNET_assert (GNUNET_YES ==
+ GNUNET_CRYPTO_kdf (skey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
+ "Hash key derivation", strlen ("Hash key derivation"),
+ hc, sizeof (struct GNUNET_HashCode),
+ NULL, 0));
+ GNUNET_assert (GNUNET_YES ==
+ GNUNET_CRYPTO_kdf (iv, sizeof (struct GNUNET_CRYPTO_SymmetricInitializationVector),
+ "Initialization vector derivation", strlen ("Initialization vector derivation"),
+ hc, sizeof (struct GNUNET_HashCode),
+ NULL, 0));
}
* @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_CRYPTO_hash_get_bit (const struct GNUNET_HashCode * code, unsigned int bit)
{
- GNUNET_assert (bit < 8 * sizeof (GNUNET_HashCode));
+ GNUNET_assert (bit < 8 * sizeof (struct 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
+ * `struct GNUNET_HashCode`s. 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!).
* @return the number of bits that match
*/
unsigned int
-GNUNET_CRYPTO_hash_matching_bits (const GNUNET_HashCode * first,
- const GNUNET_HashCode * second)
+GNUNET_CRYPTO_hash_matching_bits (const struct GNUNET_HashCode * first,
+ const struct GNUNET_HashCode * second)
{
unsigned int i;
- for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++)
+ for (i = 0; i < sizeof (struct 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;
+ return sizeof (struct GNUNET_HashCode) * 8;
}
* @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)
+GNUNET_CRYPTO_hash_cmp (const struct GNUNET_HashCode *h1,
+ const struct GNUNET_HashCode *h2)
{
unsigned int *i1;
unsigned int *i2;
i1 = (unsigned int *) h1;
i2 = (unsigned int *) h2;
- for (i = (sizeof (GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
+ for (i = (sizeof (struct GNUNET_HashCode) / sizeof (unsigned int)) - 1; i >= 0; i--)
{
if (i1[i] > i2[i])
return 1;
/**
- * Find out which of the two GNUNET_CRYPTO_hash codes is closer to target
+ * Find out which of the two `struct GNUNET_HashCode`s is closer to target
* in the XOR metric (Kademlia).
*
* @param h1 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)
+GNUNET_CRYPTO_hash_xorcmp (const struct GNUNET_HashCode *h1,
+ const struct GNUNET_HashCode *h2,
+ const struct GNUNET_HashCode *target)
{
int i;
unsigned int d1;
unsigned int d2;
- for (i = sizeof (GNUNET_HashCode) / sizeof (unsigned int) - 1; i >= 0; i--)
+ for (i = sizeof (struct 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];
* @param key authentication key
* @param rkey root key
* @param salt salt
- * @param salt_len size of the salt
+ * @param salt_len size of the @a 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 struct GNUNET_CRYPTO_SymmetricSessionKey *rkey,
const void *salt, size_t salt_len, ...)
{
va_list argp;
* @param key authentication key
* @param rkey root key
* @param salt salt
- * @param salt_len size of the salt
+ * @param salt_len size of the @a 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 struct GNUNET_CRYPTO_SymmetricSessionKey *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);
+ GNUNET_CRYPTO_kdf_v (key->key, sizeof (key->key),
+ salt, salt_len,
+ rkey, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
+ argp);
}
*
* @param key secret key
* @param plaintext input plaintext
- * @param plaintext_len length of plaintext
+ * @param plaintext_len length of @a 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)
+ struct GNUNET_HashCode *hmac)
{
- gcry_md_hd_t md;
+ static int once;
+ static 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));
+ if (! once)
+ {
+ once = 1;
+ GNUNET_assert (GPG_ERR_NO_ERROR ==
+ gcry_md_open (&md, GCRY_MD_SHA512, GCRY_MD_FLAG_HMAC));
+ }
+ else
+ {
+ gcry_md_reset (md);
+ }
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);
+ GNUNET_assert (NULL != mc);
+ GNUNET_memcpy (hmac->bits, mc, sizeof (hmac->bits));
+}
+
+
+/**
+ * Context for cummulative hashing.
+ */
+struct GNUNET_HashContext
+{
+ /**
+ * Internal state of the hash function.
+ */
+ gcry_md_hd_t hd;
+};
+
+
+/**
+ * Start incremental hashing operation.
+ *
+ * @return context for incremental hash computation
+ */
+struct GNUNET_HashContext *
+GNUNET_CRYPTO_hash_context_start ()
+{
+ struct GNUNET_HashContext *hc;
+
+ hc = GNUNET_new (struct GNUNET_HashContext);
+ GNUNET_assert (0 ==
+ gcry_md_open (&hc->hd,
+ GCRY_MD_SHA512,
+ 0));
+ return hc;
+}
+
+
+/**
+ * Add data to be hashed.
+ *
+ * @param hc cummulative hash context
+ * @param buf data to add
+ * @param size number of bytes in @a buf
+ */
+void
+GNUNET_CRYPTO_hash_context_read (struct GNUNET_HashContext *hc,
+ const void *buf,
+ size_t size)
+{
+ gcry_md_write (hc->hd, buf, size);
+}
+
+
+/**
+ * Finish the hash computation.
+ *
+ * @param hc hash context to use
+ * @param r_hash where to write the latest / final hash code
+ */
+void
+GNUNET_CRYPTO_hash_context_finish (struct GNUNET_HashContext *hc,
+ struct GNUNET_HashCode *r_hash)
+{
+ const void *res = gcry_md_read (hc->hd, 0);
+
+ GNUNET_assert (NULL != res);
+ if (NULL != r_hash)
+ GNUNET_memcpy (r_hash,
+ res,
+ sizeof (struct GNUNET_HashCode));
+ GNUNET_CRYPTO_hash_context_abort (hc);
+}
+
+
+/**
+ * Abort hashing, do not bother calculating final result.
+ *
+ * @param hc hash context to destroy
+ */
+void
+GNUNET_CRYPTO_hash_context_abort (struct GNUNET_HashContext *hc)
+{
+ gcry_md_close (hc->hd);
+ GNUNET_free (hc);
}