bird/lib/sha1.h
2015-11-24 13:47:28 +01:00

86 lines
2.8 KiB
C

/*
* BIRD Library -- SHA-1 Hash Function (FIPS 180-1, RFC 3174) and HMAC-SHA-1
*
* (c) 2015 CZ.NIC z.s.p.o.
*
* Based on the code from libucw-6.4
* (c) 2008--2009 Martin Mares <mj@ucw.cz>
*
* Based on the code from libgcrypt-1.2.3, which is
* (c) 1998, 2001, 2002, 2003 Free Software Foundation, Inc.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_SHA1_H_
#define _BIRD_SHA1_H_
#include "nest/bird.h"
#define SHA1_SIZE 20 /* Size of the SHA1 hash in its binary representation */
#define SHA1_HEX_SIZE 41 /* Buffer length for a string containing SHA1 in hexadecimal format. */
#define SHA1_BLOCK_SIZE 64 /* SHA1 splits input to blocks of this size. */
/*
* Internal SHA1 state.
* You should use it just as an opaque handle only.
*/
struct sha1_context {
u32 h0, h1, h2, h3, h4;
byte buf[SHA1_BLOCK_SIZE];
uint nblocks;
uint count;
};
void sha1_init(struct sha1_context *ctx); /* Initialize new algorithm run in the @ctx context. **/
/*
* Push another @len bytes of data pointed to by @buf onto the SHA1 hash
* currently in @ctx. You can call this any times you want on the same hash (and
* you do not need to reinitialize it by @sha1_init()). It has the same effect
* as concatenating all the data together and passing them at once.
*/
void sha1_update(struct sha1_context *ctx, const byte *buf, uint len);
/*
* No more @sha1_update() calls will be done. This terminates the hash and
* returns a pointer to it.
*
* Note that the pointer points into data in the @ctx context. If it ceases to
* exist, the pointer becomes invalid.
*/
byte *sha1_final(struct sha1_context *ctx);
/*
* A convenience one-shot function for SHA1 hash. It is equivalent to this
* snippet of code:
*
* sha1_context ctx;
* sha1_init(&ctx);
* sha1_update(&ctx, buffer, length);
* memcpy(outbuf, sha1_final(&ctx), SHA1_SIZE);
*/
void sha1_hash_buffer(byte *outbuf, const byte *buffer, uint length);
/*
* SHA1 HMAC message authentication. If you provide @key and @data, the result
* will be stored in @outbuf.
*/
void sha1_hmac(byte *outbuf, const byte *key, uint keylen, const byte *data, uint datalen);
/*
* The HMAC also exists in a stream version in a way analogous to the plain
* SHA1. Pass this as a context.
*/
struct sha1_hmac_context {
struct sha1_context ictx;
struct sha1_context octx;
};
void sha1_hmac_init(struct sha1_hmac_context *ctx, const byte *key, uint keylen); /* Initialize HMAC with context @ctx and the given key. See sha1_init(). */
void sha1_hmac_update(struct sha1_hmac_context *ctx, const byte *data, uint datalen); /* Hash another @datalen bytes of data. See sha1_update(). */
byte *sha1_hmac_final(struct sha1_hmac_context *ctx); /* Terminate the HMAC and return a pointer to the allocated hash. See sha1_final(). */
#endif /* _BIRD_SHA1_H_ */