[linux-block.git] / lib / crypto / poly1305.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Poly1305 authenticator algorithm, RFC7539
 *
 * Copyright (C) 2015 Martin Willi
 *
 * Based on public domain code by Andrew Moon and Daniel J. Bernstein.
 */

#include <crypto/internal/poly1305.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/unaligned.h>

void poly1305_init_generic(struct poly1305_desc_ctx *desc,
			   const u8 key[POLY1305_KEY_SIZE])
{
	poly1305_core_setkey(&desc->core_r, key);
	desc->s[0] = get_unaligned_le32(key + 16);
	desc->s[1] = get_unaligned_le32(key + 20);
	desc->s[2] = get_unaligned_le32(key + 24);
	desc->s[3] = get_unaligned_le32(key + 28);
	poly1305_core_init(&desc->h);
	desc->buflen = 0;
	desc->sset = true;
	desc->rset = 2;
}
EXPORT_SYMBOL_GPL(poly1305_init_generic);

void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
			     unsigned int nbytes)
{
	unsigned int bytes;

	if (unlikely(desc->buflen)) {
		bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
		memcpy(desc->buf + desc->buflen, src, bytes);
		src += bytes;
		nbytes -= bytes;
		desc->buflen += bytes;

		if (desc->buflen == POLY1305_BLOCK_SIZE) {
			poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf,
					     1, 1);
			desc->buflen = 0;
		}
	}

	if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
		poly1305_core_blocks(&desc->h, &desc->core_r, src,
				     nbytes / POLY1305_BLOCK_SIZE, 1);
		src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
		nbytes %= POLY1305_BLOCK_SIZE;
	}

	if (unlikely(nbytes)) {
		desc->buflen = nbytes;
		memcpy(desc->buf, src, nbytes);
	}
}
EXPORT_SYMBOL_GPL(poly1305_update_generic);

void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)
{
	if (unlikely(desc->buflen)) {
		desc->buf[desc->buflen++] = 1;
		memset(desc->buf + desc->buflen, 0,
		       POLY1305_BLOCK_SIZE - desc->buflen);
		poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf, 1, 0);
	}

	poly1305_core_emit(&desc->h, desc->s, dst);
	*desc = (struct poly1305_desc_ctx){};
}
EXPORT_SYMBOL_GPL(poly1305_final_generic);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
Commit	Line	Data
48ea8c6e AB	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Poly1305 authenticator algorithm, RFC7539
	4	*
	5	* Copyright (C) 2015 Martin Willi
	6	*
	7	* Based on public domain code by Andrew Moon and Daniel J. Bernstein.
	8	*/
	9
	10	#include <crypto/internal/poly1305.h>
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <asm/unaligned.h>
	14
8d195e7a AB	15	void poly1305_init_generic(struct poly1305_desc_ctx *desc,
8d195e7a AB	16	const u8 key[POLY1305_KEY_SIZE])
a1d93064	17	{
1c08a104	18	poly1305_core_setkey(&desc->core_r, key);
a1d93064 AB	19	desc->s[0] = get_unaligned_le32(key + 16);
	20	desc->s[1] = get_unaligned_le32(key + 20);
	21	desc->s[2] = get_unaligned_le32(key + 24);
	22	desc->s[3] = get_unaligned_le32(key + 28);
	23	poly1305_core_init(&desc->h);
	24	desc->buflen = 0;
	25	desc->sset = true;
1c08a104	26	desc->rset = 2;
a1d93064 AB	27	}
	28	EXPORT_SYMBOL_GPL(poly1305_init_generic);
	29
	30	void poly1305_update_generic(struct poly1305_desc_ctx desc, const u8 src,
	31	unsigned int nbytes)
	32	{
	33	unsigned int bytes;
	34
	35	if (unlikely(desc->buflen)) {
	36	bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
	37	memcpy(desc->buf + desc->buflen, src, bytes);
	38	src += bytes;
	39	nbytes -= bytes;
	40	desc->buflen += bytes;
	41
	42	if (desc->buflen == POLY1305_BLOCK_SIZE) {
1c08a104 JD	43	poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf,
1c08a104 JD	44	1, 1);
a1d93064 AB	45	desc->buflen = 0;
	46	}
	47	}
	48
	49	if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
1c08a104	50	poly1305_core_blocks(&desc->h, &desc->core_r, src,
a1d93064 AB	51	nbytes / POLY1305_BLOCK_SIZE, 1);
	52	src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
	53	nbytes %= POLY1305_BLOCK_SIZE;
	54	}
	55
	56	if (unlikely(nbytes)) {
	57	desc->buflen = nbytes;
	58	memcpy(desc->buf, src, nbytes);
	59	}
	60	}
	61	EXPORT_SYMBOL_GPL(poly1305_update_generic);
	62
	63	void poly1305_final_generic(struct poly1305_desc_ctx desc, u8 dst)
	64	{
a1d93064 AB	65	if (unlikely(desc->buflen)) {
	66	desc->buf[desc->buflen++] = 1;
	67	memset(desc->buf + desc->buflen, 0,
	68	POLY1305_BLOCK_SIZE - desc->buflen);
1c08a104	69	poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf, 1, 0);
a1d93064 AB	70	}
a1d93064 AB	71
1c08a104	72	poly1305_core_emit(&desc->h, desc->s, dst);
a1d93064 AB	73	*desc = (struct poly1305_desc_ctx){};
	74	}
	75	EXPORT_SYMBOL_GPL(poly1305_final_generic);
	76
48ea8c6e AB	77	MODULE_LICENSE("GPL");
48ea8c6e AB	78	MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");