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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Poly1305 authenticator algorithm, RFC75394 *5 * Copyright (C) 2015 Martin Willi6 *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 <linux/unaligned.h>14 15void poly1305_init_generic(struct poly1305_desc_ctx *desc,16 const u8 key[POLY1305_KEY_SIZE])17{18 poly1305_core_setkey(&desc->core_r, key);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;26 desc->rset = 2;27}28EXPORT_SYMBOL_GPL(poly1305_init_generic);29 30void 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) {43 poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf,44 1, 1);45 desc->buflen = 0;46 }47 }48 49 if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {50 poly1305_core_blocks(&desc->h, &desc->core_r, src,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}61EXPORT_SYMBOL_GPL(poly1305_update_generic);62 63void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)64{65 if (unlikely(desc->buflen)) {66 desc->buf[desc->buflen++] = 1;67 memset(desc->buf + desc->buflen, 0,68 POLY1305_BLOCK_SIZE - desc->buflen);69 poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf, 1, 0);70 }71 72 poly1305_core_emit(&desc->h, desc->s, dst);73 *desc = (struct poly1305_desc_ctx){};74}75EXPORT_SYMBOL_GPL(poly1305_final_generic);76 77MODULE_LICENSE("GPL");78MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");79MODULE_DESCRIPTION("Poly1305 authenticator algorithm, RFC7539");80