silchash.h
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2001 Pekka Riikonen
+ Copyright (C) 1997 - 2007 Pekka Riikonen
This program 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 of the License, or
- (at your option) any later version.
-
+ the Free Software Foundation; version 2 of the License.
+
This program 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
#ifndef SILCHASH_H
#define SILCHASH_H
-/* The default Silc hash object to represent any hash function in SILC. */
+/****h* silccrypt/SILC Hash Interface
+ *
+ * DESCRIPTION
+ *
+ * This is the interface for hash functions which are used to create
+ * message digests. The routines are used in various cryptographic
+ * operations. SILC Hash Interface is used for example by the
+ * SILC HMAC Interface (SilcHmac).
+ *
+ ***/
+
+/****s* silccrypt/SilcHashAPI/SilcHash
+ *
+ * NAME
+ *
+ * typedef struct SilcHashStruct *SilcHash;
+ *
+ * DESCRIPTION
+ *
+ * This context is the actual hash function context and is allocated
+ * by silc_hash_alloc and given as argument usually to all
+ * silc_hash_* functions. It is freed by the silc_hash_free
+ * function.
+ *
+ ***/
+typedef struct SilcHashStruct *SilcHash;
+
+/****s* silccrypt/SilcHashAPI/SilcHashObject
+ *
+ * NAME
+ *
+ * typedef struct { ... } SilcHashObject;
+ *
+ * DESCRIPTION
+ *
+ * This structure represents one hash function. The hash function's
+ * name, digest length and block length are defined in the structure.
+ * This structure is then given as argument to the silc_hash_register.
+ * That function is used to register all hash functions into SILC.
+ * They can be then allocated by the name found in this structure by
+ * calling the silc_hash_alloc.
+ *
+ ***/
typedef struct {
char *name;
- unsigned int hash_len;
- unsigned int block_len;
+ char *oid;
+ SilcUInt16 hash_len;
+ SilcUInt16 block_len;
void (*init)(void *);
- void (*update)(void *, unsigned char *, unsigned int);
+ void (*update)(void *, const unsigned char *, SilcUInt32);
void (*final)(void *, unsigned char *);
- void (*transform)(unsigned long *, unsigned char *);
- unsigned int (*context_len)();
+ void (*transform)(void *, const unsigned char *);
+ SilcUInt32 (*context_len)();
} SilcHashObject;
-/* The main SILC hash structure. Use SilcHash instead of SilcHashStruct.
- Also remember that SilcHash is a pointer. */
-typedef struct SilcHashStruct {
- SilcHashObject *hash;
- void *context;
-
- void (*make_hash)(struct SilcHashStruct *, const unsigned char *,
- unsigned int, unsigned char *);
-} *SilcHash;
-
-extern struct SilcHashListStruct *silc_hash_list;
-
/* Marks for all hash functions. This can be used in silc_hash_unregister
to unregister all hash function at once. */
#define SILC_ALL_HASH_FUNCTIONS ((SilcHashObject *)1)
+/* Default hash functions for silc_hash_register_default(). */
+extern DLLAPI const SilcHashObject silc_default_hash[];
+
+/* Default HASH function in the SILC protocol */
+#define SILC_DEFAULT_HASH "sha1"
+#define SILC_HASH_MAXLEN 64
+
/* Macros */
/* Following macros are used to implement the SILC Hash API. These
#define SILC_HASH_SIM_CONTEXT_LEN "context_len"
/* Macros that can be used to declare SILC Hash API functions. */
-#define SILC_HASH_API_INIT(hash) \
+#define SILC_HASH_API_INIT(hash) \
void silc_##hash##_init(void *context)
-#define SILC_HASH_API_UPDATE(hash) \
-void silc_##hash##_update(void *context, unsigned char *data, \
- unsigned int len)
-#define SILC_HASH_API_FINAL(hash) \
+#define SILC_HASH_API_UPDATE(hash) \
+void silc_##hash##_update(void *context, const unsigned char *data, \
+ SilcUInt32 len)
+#define SILC_HASH_API_FINAL(hash) \
void silc_##hash##_final(void *context, unsigned char *digest)
#define SILC_HASH_API_TRANSFORM(hash) \
-void silc_##hash##_transform(unsigned long *state, \
- unsigned char *buffer)
-#define SILC_HASH_API_CONTEXT_LEN(hash) \
-unsigned int silc_##hash##_context_len()
+void silc_##hash##_transform(void *state, const unsigned char *buffer)
+#define SILC_HASH_API_CONTEXT_LEN(hash) \
+SilcUInt32 silc_##hash##_context_len()
/* Prototypes */
-int silc_hash_register(SilcHashObject *hash);
-int silc_hash_unregister(SilcHashObject *hash);
-int silc_hash_alloc(const unsigned char *name, SilcHash *new_hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_register
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_register(const SilcHashObject *hash);
+ *
+ * DESCRIPTION
+ *
+ * Registers a new hash function into the SILC. This function is used
+ * at the initialization of the SILC. All registered hash functions
+ * should be unregistered with silc_hash_unregister. The `hash' includes
+ * the name of the hash function, digest length and block length. Usually
+ * this function is not called directly. Instead, application can call
+ * the silc_hash_register_default to register all default hash functions
+ * that are builtin the sources. Returns FALSE on error.
+ *
+ ***/
+SilcBool silc_hash_register(const SilcHashObject *hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_unregister
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_unregister(SilcHashObject *hash);
+ *
+ * DESCRIPTION
+ *
+ * Unregister a hash function from SILC by the SilcHashObject `hash'.
+ * This should be called for all registered hash functions. Returns
+ * FALSE on error.
+ *
+ ***/
+SilcBool silc_hash_unregister(SilcHashObject *hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_register_default
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_register_default(void);
+ *
+ * DESCRIPTION
+ *
+ * Registers all default hash functions into the SILC. These are the
+ * hash functions that are builtin in the sources. See the list of
+ * default hash functions in the silchash.c source file. The application
+ * may use this to register default hash functions if specific hash
+ * function in any specific order is not wanted (application's
+ * configuration usually may decide the order of the registration, in
+ * which case this function should not be used).
+ *
+ ***/
+SilcBool silc_hash_register_default(void);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_unregister_all
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_unregister_all(void);
+ *
+ * DESCRIPTION
+ *
+ * Unregisters all registered hash functions.
+ *
+ ***/
+SilcBool silc_hash_unregister_all(void);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_alloc
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_alloc(const char *name, SilcHash *new_hash);
+ *
+ * DESCRIPTION
+ *
+ * Allocates a new SilcHash object of name of `name'. The new allocated
+ * hash function is returned into `new_hash' pointer. This function
+ * returns FALSE if such hash function does not exist.
+ *
+ ***/
+SilcBool silc_hash_alloc(const char *name, SilcHash *new_hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_alloc_by_oid
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_alloc_by_oid(const char *oid, SilcHash *new_hash);
+ *
+ * DESCRIPTION
+ *
+ * Same as silc_hash_alloc but allocates the hash algorithm by the
+ * hash algorithm OID string indicated by `oid'. Returns FALSE if such
+ * hash function does not exist.
+ *
+ ***/
+SilcBool silc_hash_alloc_by_oid(const char *oid, SilcHash *new_hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_free
+ *
+ * SYNOPSIS
+ *
+ * void silc_hash_free(SilcHash hash);
+ *
+ * DESCRIPTION
+ *
+ * Frees the allocated hash function context.
+ *
+ ***/
void silc_hash_free(SilcHash hash);
-int silc_hash_is_supported(const unsigned char *name);
-char *silc_hash_get_supported();
+
+/****f* silccrypt/SilcHashAPI/silc_hash_is_supported
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_hash_is_supported(const char *name);
+ *
+ * DESCRIPTION
+ *
+ * Returns TRUE if the hash function indicated by the `name' exists.
+ *
+ ***/
+SilcBool silc_hash_is_supported(const char *name);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_get_supported
+ *
+ * SYNOPSIS
+ *
+ * char *silc_hash_get_supported(void);
+ *
+ * DESCRIPTION
+ *
+ * Returns comma (`,') separated list of registered hash functions This
+ * is used for example when sending supported hash function list during
+ * the SILC Key Exchange protocol (SKE). The caller must free the returned
+ * pointer.
+ *
+ ***/
+char *silc_hash_get_supported(void);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_len
+ *
+ * SYNOPSIS
+ *
+ * SilcUInt32 silc_hash_len(SilcHash hash);
+ *
+ * DESCRIPTION
+ *
+ * Returns the length of the message digest the hash function produce.
+ *
+ ***/
+SilcUInt32 silc_hash_len(SilcHash hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_block_len
+ *
+ * SYNOPSIS
+ *
+ * SilcUInt32 silc_hash_block_len(SilcHash hash);
+ *
+ * DESCRIPTION
+ *
+ * Returns the block length of the hash function.
+ *
+ ***/
+SilcUInt32 silc_hash_block_len(SilcHash hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_get_name
+ *
+ * SYNOPSIS
+ *
+ * const char *silc_hash_get_name(SilcHash hash);
+ *
+ * DESCRIPTION
+ *
+ * Returns the name of the hash function indicated by the `hash' context.
+ *
+ ***/
+const char *silc_hash_get_name(SilcHash hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_get_oid
+ *
+ * SYNOPSIS
+ *
+ * const char *silc_hash_get_name(SilcHash hash);
+ *
+ * DESCRIPTION
+ *
+ * Returns the hash OID string. Returns NULL if the hash doesn't have
+ * OID string. Use strlen() to get the OID string length.
+ *
+ ***/
+const char *silc_hash_get_oid(SilcHash hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_make
+ *
+ * SYNOPSIS
+ *
+ * void silc_hash_make(SilcHash hash, const unsigned char *data,
+ * SilcUInt32 len, unsigned char *return_hash);
+ *
+ * DESCRIPTION
+ *
+ * Computes the message digest (hash) out of the data indicated by
+ * `data' of length of `len' bytes. Returns the message digest to the
+ * `return_hash' buffer which must be at least of the size of the
+ * message digest the `hash' produces.
+ *
+ ***/
void silc_hash_make(SilcHash hash, const unsigned char *data,
- unsigned int len, unsigned char *return_hash);
+ SilcUInt32 len, unsigned char *return_hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_init
+ *
+ * SYNOPSIS
+ *
+ * void silc_hash_init(SilcHash hash);
+ *
+ * DESCRIPTION
+ *
+ * Sometimes calling the silc_hash_make might not be the most optimal
+ * case of computing digests. If you have a lot of different data
+ * that you need to put together for computing a digest you may either
+ * put them into a buffer and compute the digest from the buffer by
+ * calling the silc_hash_make, or you can use the silc_hash_init,
+ * silc_hash_update and silc_hash_final to do the digest. This function
+ * prepares the allocated hash function context for this kind of digest
+ * computation. To add the data to be used in the digest computation
+ * call the silc_hash_update function.
+ *
+ ***/
+void silc_hash_init(SilcHash hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_update
+ *
+ * SYNOPSIS
+ *
+ * void silc_hash_update(SilcHash hash, const unsigned char *data,
+ * SilcUInt32 data_len);
+ *
+ * DESCRIPTION
+ *
+ * This function may be called to add data to be used in the digest
+ * computation. This can be called multiple times to add data from
+ * many sources before actually computing the digest. Once you've
+ * added all the data you need you can call the silc_hash_final to
+ * actually produce the message digest value.
+ *
+ * EXAMPLE
+ *
+ * unsigned char digest[20];
+ *
+ * silc_hash_init(hash);
+ * silc_hash_update(hash, data, data_len);
+ * silc_hash_update(hash, more_data, more_data_len);
+ * silc_hash_final(hash, digest);
+ *
+ ***/
+void silc_hash_update(SilcHash hash, const unsigned char *data,
+ SilcUInt32 data_len);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_final
+ *
+ * SYNOPSIS
+ *
+ * void silc_hash_final(SilcHash hash, unsigned char *return_hash);
+ *
+ * DESCRIPTION
+ *
+ * This function is used to produce the final message digest from
+ * the data that has been added to the hash function context by calling
+ * the silc_hash_update function. The digest is copied in to the
+ * `return_hash' pointer which must be at least the size that
+ * the silc_hash_len returns.
+ *
+ ***/
+void silc_hash_final(SilcHash hash, unsigned char *return_hash);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_transform
+ *
+ * SYNOPSIS
+ *
+ * void silc_hash_transform(SilcHash hash, void *state,
+ * const unsigned char *data);
+ *
+ * DESCRIPTION
+ *
+ * This is special function for calling the hash function's internal
+ * digest generation function. The size of the `state' array and the
+ * sizeof the `data' buffer is hash function specific and must be
+ * known by the caller. Usually this function is not needed.
+ *
+ ***/
+void silc_hash_transform(SilcHash hash, void *state,
+ const unsigned char *data);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_fingerprint
+ *
+ * SYNOPSIS
+ *
+ * char *silc_hash_fingerprint(SilcHash hash, const unsigned char *data,
+ * SilcUInt32 data_len);
+ *
+ * DESCRIPTION
+ *
+ * Utility function which can be used to create a textual fingerprint
+ * out of the data indicated by `data' of length of `data_len' bytes.
+ * If `hash' is NULL then SHA1 hash function is used automatically.
+ * The caller must free the returned string.
+ *
+ * Example output could be:
+ * 41BF 5C2E 4149 039A 3917 831F 65C4 0A69 F98B 0A4D
+ *
+ ***/
char *silc_hash_fingerprint(SilcHash hash, const unsigned char *data,
- unsigned int data_len);
+ SilcUInt32 data_len);
+
+/****f* silccrypt/SilcHashAPI/silc_hash_babbleprint
+ *
+ * SYNOPSIS
+ *
+ * char *silc_hash_babbleprint(SilcHash hash, const unsigned char *data,
+ * SilcUInt32 data_len);
+ *
+ * DESCRIPTION
+ *
+ * Utility function which can be used to create a textual babbleprint
+ * out of the data indicated by `data' of length of `data_len' bytes.
+ * If `hash' is NULL then SHA1 hash function is used automatically.
+ * The caller must free the returned string.
+ *
+ * The babbleprint is same as fingerprint but encoded in a form which
+ * makes it easier to pronounce. When verifying fingerprint for example
+ * over a phone call, the babbleprint makes it easier to read the
+ * fingerprint.
+ *
+ * Example output could be:
+ * xiber-zulad-vubug-noban-puvyc-labac-zonos-gedik-novem-rudog-tyxix
+ *
+ ***/
+char *silc_hash_babbleprint(SilcHash hash, const unsigned char *data,
+ SilcUInt32 data_len);
#endif
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