/*
This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 Christian Grothoff (and other contributing authors)
+ (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2012 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
+
+/**
+ * @brief 256-bit hashcode
+ */
+struct GNUNET_CRYPTO_ShortHashCode
+{
+ uint32_t bits[256 / 8 / sizeof (uint32_t)]; /* = 8 */
+};
+
+
+/**
+ * @brief 0-terminated ASCII encoding of a 'struct GNUNET_ShortHashCode'.
+ */
+struct GNUNET_CRYPTO_ShortHashAsciiEncoded
+{
+ unsigned char short_encoding[53];
+};
+
+
+
/**
* @brief an RSA signature
*/
void
GNUNET_CRYPTO_aes_create_session_key (struct GNUNET_CRYPTO_AesSessionKey *key);
+
/**
* Check that a new session key is well-formed.
*
/**
- * Convert ASCII encoding back to GNUNET_CRYPTO_hash
+ * Convert short hash to ASCII encoding.
+ *
+ * @param block the hash code
+ * @param result where to store the encoding (struct GNUNET_CRYPTO_ShortHashAsciiEncoded can be
+ * safely cast to char*, a '\\0' termination is set).
+ */
+void
+GNUNET_CRYPTO_short_hash_to_enc (const struct GNUNET_CRYPTO_ShortHashCode * block,
+ struct GNUNET_CRYPTO_ShortHashAsciiEncoded *result);
+
+
+/**
+ * Convert ASCII encoding back to a 'GNUNET_HashCode'
*
* @param enc the encoding
* @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
/**
- * Convert ASCII encoding back to GNUNET_CRYPTO_hash
+ * Convert ASCII encoding back to a 'struct GNUNET_CRYPTO_ShortHash'
+ *
* @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_short_hash_from_string2 (const char *enc, size_t enclen,
+ struct GNUNET_CRYPTO_ShortHashCode * result);
+
+
+/**
+ * Convert ASCII encoding back to GNUNET_HashCode
+ *
+ * @param enc the encoding
+ * @param result where to store the hash code
+ * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
+ */
#define GNUNET_CRYPTO_hash_from_string(enc, result) \
GNUNET_CRYPTO_hash_from_string2 (enc, strlen(enc), result)
+/**
+ * Convert ASCII encoding back to a 'struct GNUNET_CRYPTO_ShortHash'
+ *
+ * @param enc the encoding
+ * @param result where to store the GNUNET_CRYPTO_ShortHash
+ * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
+ */
+#define GNUNET_CRYPTO_short_hash_from_string(enc, result) \
+ GNUNET_CRYPTO_short_hash_from_string2 (enc, strlen(enc), result)
+
+
+/**
+ * Compare function for ShortHashCodes, 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_short_hash_cmp (const struct GNUNET_CRYPTO_ShortHashCode * h1,
+ const struct GNUNET_CRYPTO_ShortHashCode * h2);
+
/**
* Compute the distance between 2 hashcodes.
* The computation must be fast, not involve
GNUNET_CRYPTO_hash (const void *block, size_t size, GNUNET_HashCode * ret);
+/**
+ * Compute short (256-bit) hash of a given block.
+ *
+ * @param block the data to hash
+ * @param size size of the block
+ * @param ret pointer to where to write the hashcode
+ */
+void
+GNUNET_CRYPTO_short_hash (const void *block, size_t size,
+ struct GNUNET_CRYPTO_ShortHashCode * ret);
+
+
+/**
+ * Double short (256-bit) hash to create a long hash.
+ *
+ * @param sh short hash to double
+ * @param dh where to store the (doubled) long hash (not really a hash)
+ */
+void
+GNUNET_CRYPTO_short_hash_double (const struct GNUNET_CRYPTO_ShortHashCode *sh,
+ struct GNUNET_HashCode *dh);
+
+
+/**
+ * Truncate doubled short hash back to a short hash.
+ *
+ * @param dh doubled short hash to reduce again
+ * @param sh where to store the short hash
+ * @return GNUNET_OK on success, GNUNET_SYSERR if this was not a
+ * doubled short hash
+ */
+int
+GNUNET_CRYPTO_short_hash_from_truncation (const struct GNUNET_HashCode *dh,
+ struct GNUNET_CRYPTO_ShortHashCode *sh);
+
+
/**
* Calculate HMAC of a message (RFC 2104)
*
void
GNUNET_CRYPTO_random_disable_entropy_gathering (void);
-/**
- * Convert binary data 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.
- * Does not append 0-terminator, but returns a pointer to the place where
- * it should be placed, if needed.
- *
- * @param data data to encode
- * @param size size of data (in bytes)
- * @param out buffer to fill
- * @param out_size size of the buffer. Must be large enough to hold
- * ((size*8) + (((size*8) % 5) > 0 ? 5 - ((size*8) % 5) : 0)) / 5
- * @return pointer to the next byte in 'out' or NULL on error.
- */
-char *
-GNUNET_CRYPTO_data_to_string (unsigned char *data, size_t size,
- char *out, size_t out_size);
-
-/**
- * Convert ASCII encoding back to data
- * out_size must match exactly the size of the data before it was encoded.
- *
- * @param enc the encoding
- * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
- * @param out location where to store the decoded data
- * @param out_size sizeof the output buffer
- * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
- */
-int
-GNUNET_CRYPTO_string_to_data (const char *enc, size_t enclen,
- unsigned char *out, size_t out_size);
#if 0 /* keep Emacsens' auto-indent happy */
{
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