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 15 void 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 } 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) { 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 } 61 EXPORT_SYMBOL_GPL(poly1305_update_generic); 62 63 void 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 } 75 EXPORT_SYMBOL_GPL(poly1305_final_generic); 76 77 MODULE_LICENSE("GPL"); 78 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); 79 MODULE_DESCRIPTION("Poly1305 authenticator algorithm, RFC7539"); 80