-fix

[oweals/gnunet.git] / src / include / gnunet_crypto_lib.h

diff --git a/src/include/gnunet_crypto_lib.h b/src/include/gnunet_crypto_lib.h
index 04b460446455266590e7c37712d66ab40f445890..777ddd97e6a811259ab30ee9d5fc40dda801e486 100644 (file)
--- a/src/include/gnunet_crypto_lib.h
+++ b/src/include/gnunet_crypto_lib.h
@@ -1,6 +1,6 @@
 /*
      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
@@ -138,6 +138,26 @@ struct GNUNET_CRYPTO_HashAsciiEncoded
 
 
 
+
+/**
+ * @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
  */
@@ -346,6 +366,7 @@ GNUNET_CRYPTO_random_permute (enum GNUNET_CRYPTO_Quality mode, unsigned int n);
 void
 GNUNET_CRYPTO_aes_create_session_key (struct GNUNET_CRYPTO_AesSessionKey *key);
 
+
 /**
  * Check that a new session key is well-formed.
  *
@@ -432,7 +453,19 @@ GNUNET_CRYPTO_hash_to_enc (const GNUNET_HashCode * block,
 
 
 /**
- * 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)
@@ -445,15 +478,52 @@ GNUNET_CRYPTO_hash_from_string2 (const char *enc, size_t enclen,
 
 
 /**
- * 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
@@ -481,6 +551,42 @@ void
 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)
  *