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| 2 | |
| 3 | * Poly1305 authenticator algorithm, RFC7539
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| 4 | *
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| 5 | * Copyright (C) 2015 Martin Willi
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| 6 | *
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| 7 | * Based on public domain code by Andrew Moon and Daniel J. Bernstein.
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| 8 |
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| 9 |
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| 10 | #include <crypto/internal/poly1305.h>
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| 11 | #include <linux/export.h>
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| 12 | #include <linux/kernel.h>
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| 13 | #include <linux/module.h>
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| 14 | #include <linux/string.h>
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| 15 | #include <linux/unaligned.h>
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| 16 |
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| 17 | #ifdef CONFIG_CRYPTO_LIB_POLY1305_ARCH
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| 18 | #include "poly1305.h"
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| 19 | #else
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| 20 | #define poly1305_block_init poly1305_block_init_generic
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| 21 | #define poly1305_blocks poly1305_blocks_generic
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| 22 | #define poly1305_emit poly1305_emit_generic
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| 23 | #endif
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| 24 |
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| 25 | void poly1305_init(struct poly1305_desc_ctx *desc,
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| 26 | const u8 key[POLY1305_KEY_SIZE])
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| 27 | {
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| 28 | desc->s[0] = get_unaligned_le32(key + 16);
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| 29 | desc->s[1] = get_unaligned_le32(key + 20);
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| 30 | desc->s[2] = get_unaligned_le32(key + 24);
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| 31 | desc->s[3] = get_unaligned_le32(key + 28);
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| 32 | desc->buflen = 0;
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| 33 | poly1305_block_init(&desc->state, key);
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| 34 | }
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| 35 | EXPORT_SYMBOL(poly1305_init);
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| 36 |
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| 37 | void poly1305_update(struct poly1305_desc_ctx *desc, const u8 *src,
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| 38 | size_t nbytes)
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| 39 | {
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| 40 | if (nbytes >= POLY1305_BLOCK_SIZE - desc->buflen) {
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| 41 | size_t bulk_len;
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| 42 |
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| 43 | if (desc->buflen) {
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| 44 | size_t l = POLY1305_BLOCK_SIZE - desc->buflen;
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| 45 |
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| 46 | memcpy(&desc->buf[desc->buflen], src, l);
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| 47 | src += l;
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| 48 | nbytes -= l;
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| 49 |
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| 50 | poly1305_blocks(&desc->state, desc->buf,
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| 51 | POLY1305_BLOCK_SIZE, 1);
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| 52 | desc->buflen = 0;
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| 53 | }
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| 54 |
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| 55 | bulk_len = round_down(nbytes, POLY1305_BLOCK_SIZE);
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| 56 | nbytes %= POLY1305_BLOCK_SIZE;
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| 57 |
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| 58 | if (bulk_len) {
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| 59 | poly1305_blocks(&desc->state, src, bulk_len, 1);
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| 60 | src += bulk_len;
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| 61 | }
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| 62 | }
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| 63 | if (nbytes) {
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| 64 | memcpy(&desc->buf[desc->buflen], src, nbytes);
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| 65 | desc->buflen += nbytes;
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| 66 | }
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| 67 | }
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| 68 | EXPORT_SYMBOL(poly1305_update);
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| 69 |
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| 70 | void poly1305_final(struct poly1305_desc_ctx *desc, u8 *dst)
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| 71 | {
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| 72 | if (unlikely(desc->buflen)) {
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| 73 | desc->buf[desc->buflen++] = 1;
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| 74 | memset(desc->buf + desc->buflen, 0,
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| 75 | POLY1305_BLOCK_SIZE - desc->buflen);
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| 76 | poly1305_blocks(&desc->state, desc->buf, POLY1305_BLOCK_SIZE,
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| 77 | 0);
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| 78 | }
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| 79 |
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| 80 | poly1305_emit(&desc->state.h, dst, desc->s);
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| 81 | memzero_explicit(desc, sizeof(*desc));
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| 82 | }
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| 83 | EXPORT_SYMBOL(poly1305_final);
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| 84 |
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| 85 | #ifdef poly1305_mod_init_arch
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| 86 | static int __init poly1305_mod_init(void)
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| 87 | {
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| 88 | poly1305_mod_init_arch();
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| 89 | return 0;
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| 90 | }
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| 91 | subsys_initcall(poly1305_mod_init);
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| 92 |
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| 93 | static void __exit poly1305_mod_exit(void)
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| 94 | {
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| 95 | }
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| 96 | module_exit(poly1305_mod_exit);
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| 97 | #endif
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| 98 |
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| 99 | MODULE_LICENSE("GPL");
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| 100 | MODULE_DESCRIPTION("Poly1305 authenticator algorithm, RFC7539");
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