nostril/sha256.h
William Casarin 009af9ed5b initial commit
Signed-off-by: William Casarin <jb55@jb55.com>
2022-04-14 07:52:29 -07:00

156 lines
4.0 KiB
C

#ifndef CCAN_CRYPTO_SHA256_H
#define CCAN_CRYPTO_SHA256_H
/** Output length for `wally_sha256` */
#define SHA256_LEN 32
/* BSD-MIT - see LICENSE file for details */
/* #include "config.h" */
#include <stdint.h>
#include <stdlib.h>
/* Uncomment this to use openssl's SHA256 routines (and link with -lcrypto) */
/*#define CCAN_CRYPTO_SHA256_USE_OPENSSL 1*/
#ifdef CCAN_CRYPTO_SHA256_USE_OPENSSL
#include <openssl/sha.h>
#endif
/**
* struct sha256 - structure representing a completed SHA256.
* @u.u8: an unsigned char array.
* @u.u32: a 32-bit integer array.
*
* Other fields may be added to the union in future.
*/
struct sha256 {
union {
uint32_t u32[8];
unsigned char u8[32];
} u;
};
/**
* sha256 - return sha256 of an object.
* @sha256: the sha256 to fill in
* @p: pointer to memory,
* @size: the number of bytes pointed to by @p
*
* The bytes pointed to by @p is SHA256 hashed into @sha256. This is
* equivalent to sha256_init(), sha256_update() then sha256_done().
*/
void sha256(struct sha256 *sha, const void *p, size_t size);
/**
* struct sha256_ctx - structure to store running context for sha256
*/
struct sha256_ctx {
#ifdef CCAN_CRYPTO_SHA256_USE_OPENSSL
SHA256_CTX c;
#else
uint32_t s[8];
union {
uint32_t u32[16];
unsigned char u8[64];
} buf;
size_t bytes;
#endif
};
/**
* sha256_init - initialize an SHA256 context.
* @ctx: the sha256_ctx to initialize
*
* This must be called before sha256_update or sha256_done, or
* alternately you can assign SHA256_INIT.
*
* If it was already initialized, this forgets anything which was
* hashed before.
*
* Example:
* static void hash_all(const char **arr, struct sha256 *hash)
* {
* size_t i;
* struct sha256_ctx ctx;
*
* sha256_init(&ctx);
* for (i = 0; arr[i]; i++)
* sha256_update(&ctx, arr[i], strlen(arr[i]));
* sha256_done(&ctx, hash);
* }
*/
void sha256_init(struct sha256_ctx *ctx);
/**
* SHA256_INIT - initializer for an SHA256 context.
*
* This can be used to statically initialize an SHA256 context (instead
* of sha256_init()).
*
* Example:
* static void hash_all(const char **arr, struct sha256 *hash)
* {
* size_t i;
* struct sha256_ctx ctx = SHA256_INIT;
*
* for (i = 0; arr[i]; i++)
* sha256_update(&ctx, arr[i], strlen(arr[i]));
* sha256_done(&ctx, hash);
* }
*/
#ifdef CCAN_CRYPTO_SHA256_USE_OPENSSL
#define SHA256_INIT \
{ { { 0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, \
0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul }, \
0x0, 0x0, \
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, \
0x0, 0x20 } }
#else
#define SHA256_INIT \
{ { 0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul, \
0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul }, \
{ { 0 } }, 0 }
#endif
/**
* sha256_update - include some memory in the hash.
* @ctx: the sha256_ctx to use
* @p: pointer to memory,
* @size: the number of bytes pointed to by @p
*
* You can call this multiple times to hash more data, before calling
* sha256_done().
*/
void sha256_update(struct sha256_ctx *ctx, const void *p, size_t size);
/**
* sha256_done - finish SHA256 and return the hash
* @ctx: the sha256_ctx to complete
* @res: the hash to return.
*
* Note that @ctx is *destroyed* by this, and must be reinitialized.
* To avoid that, pass a copy instead.
*/
void sha256_done(struct sha256_ctx *sha256, struct sha256 *res);
/* Add various types to an SHA256 hash */
void sha256_u8(struct sha256_ctx *ctx, uint8_t v);
void sha256_u16(struct sha256_ctx *ctx, uint16_t v);
void sha256_u32(struct sha256_ctx *ctx, uint32_t v);
void sha256_u64(struct sha256_ctx *ctx, uint64_t v);
/* Add as little-endian */
void sha256_le16(struct sha256_ctx *ctx, uint16_t v);
void sha256_le32(struct sha256_ctx *ctx, uint32_t v);
void sha256_le64(struct sha256_ctx *ctx, uint64_t v);
/* Add as big-endian */
void sha256_be16(struct sha256_ctx *ctx, uint16_t v);
void sha256_be32(struct sha256_ctx *ctx, uint32_t v);
void sha256_be64(struct sha256_ctx *ctx, uint64_t v);
#endif /* CCAN_CRYPTO_SHA256_H */