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, const u8 *key) 16 { 17 poly1305_core_setkey(&desc->core_r, key); 18 desc->s[0] = get_unaligned_le32(key + 16); 19 desc->s[1] = get_unaligned_le32(key + 20); 20 desc->s[2] = get_unaligned_le32(key + 24); 21 desc->s[3] = get_unaligned_le32(key + 28); 22 poly1305_core_init(&desc->h); 23 desc->buflen = 0; 24 desc->sset = true; 25 desc->rset = 2; 26 } 27 EXPORT_SYMBOL_GPL(poly1305_init_generic); 28 29 void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src, 30 unsigned int nbytes) 31 { 32 unsigned int bytes; 33 34 if (unlikely(desc->buflen)) { 35 bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen); 36 memcpy(desc->buf + desc->buflen, src, bytes); 37 src += bytes; 38 nbytes -= bytes; 39 desc->buflen += bytes; 40 41 if (desc->buflen == POLY1305_BLOCK_SIZE) { 42 poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf, 43 1, 1); 44 desc->buflen = 0; 45 } 46 } 47 48 if (likely(nbytes >= POLY1305_BLOCK_SIZE)) { 49 poly1305_core_blocks(&desc->h, &desc->core_r, src, 50 nbytes / POLY1305_BLOCK_SIZE, 1); 51 src += nbytes - (nbytes % POLY1305_BLOCK_SIZE); 52 nbytes %= POLY1305_BLOCK_SIZE; 53 } 54 55 if (unlikely(nbytes)) { 56 desc->buflen = nbytes; 57 memcpy(desc->buf, src, nbytes); 58 } 59 } 60 EXPORT_SYMBOL_GPL(poly1305_update_generic); 61 62 void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst) 63 { 64 if (unlikely(desc->buflen)) { 65 desc->buf[desc->buflen++] = 1; 66 memset(desc->buf + desc->buflen, 0, 67 POLY1305_BLOCK_SIZE - desc->buflen); 68 poly1305_core_blocks(&desc->h, &desc->core_r, desc->buf, 1, 0); 69 } 70 71 poly1305_core_emit(&desc->h, desc->s, dst); 72 *desc = (struct poly1305_desc_ctx){}; 73 } 74 EXPORT_SYMBOL_GPL(poly1305_final_generic); 75 76 MODULE_LICENSE("GPL"); 77 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); 78