/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Common values for SHA-1 algorithms
 */

#ifndef _CRYPTO_SHA1_H
#define _CRYPTO_SHA1_H

#include <linux/types.h>

#define SHA1_DIGEST_SIZE        20
#define SHA1_BLOCK_SIZE         64
#define SHA1_STATE_SIZE         offsetof(struct sha1_state, buffer)

#define SHA1_H0		0x67452301UL
#define SHA1_H1		0xefcdab89UL
#define SHA1_H2		0x98badcfeUL
#define SHA1_H3		0x10325476UL
#define SHA1_H4		0xc3d2e1f0UL

extern const u8 sha1_zero_message_hash[SHA1_DIGEST_SIZE];

struct sha1_state {
	u32 state[SHA1_DIGEST_SIZE / 4];
	u64 count;
	u8 buffer[SHA1_BLOCK_SIZE];
};

/* State for the SHA-1 compression function */
struct sha1_block_state {
	u32 h[SHA1_DIGEST_SIZE / 4];
};

/**
 * struct sha1_ctx - Context for hashing a message with SHA-1
 * @state: the compression function state
 * @bytecount: number of bytes processed so far
 * @buf: partial block buffer; bytecount % SHA1_BLOCK_SIZE bytes are valid
 */
struct sha1_ctx {
	struct sha1_block_state state;
	u64 bytecount;
	u8 buf[SHA1_BLOCK_SIZE];
};

/**
 * sha1_init() - Initialize a SHA-1 context for a new message
 * @ctx: the context to initialize
 *
 * If you don't need incremental computation, consider sha1() instead.
 *
 * Context: Any context.
 */
void sha1_init(struct sha1_ctx *ctx);

/**
 * sha1_update() - Update a SHA-1 context with message data
 * @ctx: the context to update; must have been initialized
 * @data: the message data
 * @len: the data length in bytes
 *
 * This can be called any number of times.
 *
 * Context: Any context.
 */
void sha1_update(struct sha1_ctx *ctx, const u8 *data, size_t len);

/**
 * sha1_final() - Finish computing a SHA-1 message digest
 * @ctx: the context to finalize; must have been initialized
 * @out: (output) the resulting SHA-1 message digest
 *
 * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
 *
 * Context: Any context.
 */
void sha1_final(struct sha1_ctx *ctx, u8 out[at_least SHA1_DIGEST_SIZE]);

/**
 * sha1() - Compute SHA-1 message digest in one shot
 * @data: the message data
 * @len: the data length in bytes
 * @out: (output) the resulting SHA-1 message digest
 *
 * Context: Any context.
 */
void sha1(const u8 *data, size_t len, u8 out[at_least SHA1_DIGEST_SIZE]);

/**
 * struct hmac_sha1_key - Prepared key for HMAC-SHA1
 * @istate: private
 * @ostate: private
 */
struct hmac_sha1_key {
	struct sha1_block_state istate;
	struct sha1_block_state ostate;
};

/**
 * struct hmac_sha1_ctx - Context for computing HMAC-SHA1 of a message
 * @sha_ctx: private
 * @ostate: private
 */
struct hmac_sha1_ctx {
	struct sha1_ctx sha_ctx;
	struct sha1_block_state ostate;
};

/**
 * hmac_sha1_preparekey() - Prepare a key for HMAC-SHA1
 * @key: (output) the key structure to initialize
 * @raw_key: the raw HMAC-SHA1 key
 * @raw_key_len: the key length in bytes.  All key lengths are supported.
 *
 * Note: the caller is responsible for zeroizing both the struct hmac_sha1_key
 * and the raw key once they are no longer needed.
 *
 * Context: Any context.
 */
void hmac_sha1_preparekey(struct hmac_sha1_key *key,
			  const u8 *raw_key, size_t raw_key_len);

/**
 * hmac_sha1_init() - Initialize an HMAC-SHA1 context for a new message
 * @ctx: (output) the HMAC context to initialize
 * @key: the prepared HMAC key
 *
 * If you don't need incremental computation, consider hmac_sha1() instead.
 *
 * Context: Any context.
 */
void hmac_sha1_init(struct hmac_sha1_ctx *ctx, const struct hmac_sha1_key *key);

/**
 * hmac_sha1_init_usingrawkey() - Initialize an HMAC-SHA1 context for a new
 *				  message, using a raw key
 * @ctx: (output) the HMAC context to initialize
 * @raw_key: the raw HMAC-SHA1 key
 * @raw_key_len: the key length in bytes.  All key lengths are supported.
 *
 * If you don't need incremental computation, consider hmac_sha1_usingrawkey()
 * instead.
 *
 * Context: Any context.
 */
void hmac_sha1_init_usingrawkey(struct hmac_sha1_ctx *ctx,
				const u8 *raw_key, size_t raw_key_len);

/**
 * hmac_sha1_update() - Update an HMAC-SHA1 context with message data
 * @ctx: the HMAC context to update; must have been initialized
 * @data: the message data
 * @data_len: the data length in bytes
 *
 * This can be called any number of times.
 *
 * Context: Any context.
 */
static inline void hmac_sha1_update(struct hmac_sha1_ctx *ctx,
				    const u8 *data, size_t data_len)
{
	sha1_update(&ctx->sha_ctx, data, data_len);
}

/**
 * hmac_sha1_final() - Finish computing an HMAC-SHA1 value
 * @ctx: the HMAC context to finalize; must have been initialized
 * @out: (output) the resulting HMAC-SHA1 value
 *
 * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
 *
 * Context: Any context.
 */
void hmac_sha1_final(struct hmac_sha1_ctx *ctx,
		     u8 out[at_least SHA1_DIGEST_SIZE]);

/**
 * hmac_sha1() - Compute HMAC-SHA1 in one shot, using a prepared key
 * @key: the prepared HMAC key
 * @data: the message data
 * @data_len: the data length in bytes
 * @out: (output) the resulting HMAC-SHA1 value
 *
 * If you're using the key only once, consider using hmac_sha1_usingrawkey().
 *
 * Context: Any context.
 */
void hmac_sha1(const struct hmac_sha1_key *key,
	       const u8 *data, size_t data_len,
	       u8 out[at_least SHA1_DIGEST_SIZE]);

/**
 * hmac_sha1_usingrawkey() - Compute HMAC-SHA1 in one shot, using a raw key
 * @raw_key: the raw HMAC-SHA1 key
 * @raw_key_len: the key length in bytes.  All key lengths are supported.
 * @data: the message data
 * @data_len: the data length in bytes
 * @out: (output) the resulting HMAC-SHA1 value
 *
 * If you're using the key multiple times, prefer to use hmac_sha1_preparekey()
 * followed by multiple calls to hmac_sha1() instead.
 *
 * Context: Any context.
 */
void hmac_sha1_usingrawkey(const u8 *raw_key, size_t raw_key_len,
			   const u8 *data, size_t data_len,
			   u8 out[at_least SHA1_DIGEST_SIZE]);

#endif /* _CRYPTO_SHA1_H */