cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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poly1305_generic.c (3754B)

      1/*
      2 * Poly1305 authenticator algorithm, RFC7539
      3 *
      4 * Copyright (C) 2015 Martin Willi
      5 *
      6 * Based on public domain code by Andrew Moon and Daniel J. Bernstein.
      7 *
      8 * This program is free software; you can redistribute it and/or modify
      9 * it under the terms of the GNU General Public License as published by
     10 * the Free Software Foundation; either version 2 of the License, or
     11 * (at your option) any later version.
     12 */
     13
     14#include <crypto/algapi.h>
     15#include <crypto/internal/hash.h>
     16#include <crypto/internal/poly1305.h>
     17#include <linux/crypto.h>
     18#include <linux/kernel.h>
     19#include <linux/module.h>
     20#include <asm/unaligned.h>
     21
     22static int crypto_poly1305_init(struct shash_desc *desc)
     23{
     24	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
     25
     26	poly1305_core_init(&dctx->h);
     27	dctx->buflen = 0;
     28	dctx->rset = 0;
     29	dctx->sset = false;
     30
     31	return 0;
     32}
     33
     34static unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
     35					       const u8 *src, unsigned int srclen)
     36{
     37	if (!dctx->sset) {
     38		if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) {
     39			poly1305_core_setkey(&dctx->core_r, src);
     40			src += POLY1305_BLOCK_SIZE;
     41			srclen -= POLY1305_BLOCK_SIZE;
     42			dctx->rset = 2;
     43		}
     44		if (srclen >= POLY1305_BLOCK_SIZE) {
     45			dctx->s[0] = get_unaligned_le32(src +  0);
     46			dctx->s[1] = get_unaligned_le32(src +  4);
     47			dctx->s[2] = get_unaligned_le32(src +  8);
     48			dctx->s[3] = get_unaligned_le32(src + 12);
     49			src += POLY1305_BLOCK_SIZE;
     50			srclen -= POLY1305_BLOCK_SIZE;
     51			dctx->sset = true;
     52		}
     53	}
     54	return srclen;
     55}
     56
     57static void poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
     58			    unsigned int srclen)
     59{
     60	unsigned int datalen;
     61
     62	if (unlikely(!dctx->sset)) {
     63		datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
     64		src += srclen - datalen;
     65		srclen = datalen;
     66	}
     67
     68	poly1305_core_blocks(&dctx->h, &dctx->core_r, src,
     69			     srclen / POLY1305_BLOCK_SIZE, 1);
     70}
     71
     72static int crypto_poly1305_update(struct shash_desc *desc,
     73				  const u8 *src, unsigned int srclen)
     74{
     75	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
     76	unsigned int bytes;
     77
     78	if (unlikely(dctx->buflen)) {
     79		bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
     80		memcpy(dctx->buf + dctx->buflen, src, bytes);
     81		src += bytes;
     82		srclen -= bytes;
     83		dctx->buflen += bytes;
     84
     85		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
     86			poly1305_blocks(dctx, dctx->buf,
     87					POLY1305_BLOCK_SIZE);
     88			dctx->buflen = 0;
     89		}
     90	}
     91
     92	if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
     93		poly1305_blocks(dctx, src, srclen);
     94		src += srclen - (srclen % POLY1305_BLOCK_SIZE);
     95		srclen %= POLY1305_BLOCK_SIZE;
     96	}
     97
     98	if (unlikely(srclen)) {
     99		dctx->buflen = srclen;
    100		memcpy(dctx->buf, src, srclen);
    101	}
    102
    103	return 0;
    104}
    105
    106static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
    107{
    108	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
    109
    110	if (unlikely(!dctx->sset))
    111		return -ENOKEY;
    112
    113	poly1305_final_generic(dctx, dst);
    114	return 0;
    115}
    116
    117static struct shash_alg poly1305_alg = {
    118	.digestsize	= POLY1305_DIGEST_SIZE,
    119	.init		= crypto_poly1305_init,
    120	.update		= crypto_poly1305_update,
    121	.final		= crypto_poly1305_final,
    122	.descsize	= sizeof(struct poly1305_desc_ctx),
    123	.base		= {
    124		.cra_name		= "poly1305",
    125		.cra_driver_name	= "poly1305-generic",
    126		.cra_priority		= 100,
    127		.cra_blocksize		= POLY1305_BLOCK_SIZE,
    128		.cra_module		= THIS_MODULE,
    129	},
    130};
    131
    132static int __init poly1305_mod_init(void)
    133{
    134	return crypto_register_shash(&poly1305_alg);
    135}
    136
    137static void __exit poly1305_mod_exit(void)
    138{
    139	crypto_unregister_shash(&poly1305_alg);
    140}
    141
    142subsys_initcall(poly1305_mod_init);
    143module_exit(poly1305_mod_exit);
    144
    145MODULE_LICENSE("GPL");
    146MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
    147MODULE_DESCRIPTION("Poly1305 authenticator");
    148MODULE_ALIAS_CRYPTO("poly1305");
    149MODULE_ALIAS_CRYPTO("poly1305-generic");