![Eric Biggers](/assets/img/avatar_default.png)
Since Poly1305 requires a nonce per invocation, the Linux kernel implementations of Poly1305 don't use the crypto API's keying mechanism and instead expect the key and nonce as the first 32 bytes of the data. But ->setkey() is still defined as a stub returning an error code. This prevents Poly1305 from being used through AF_ALG and will also break it completely once we start enforcing that all crypto API users (not just AF_ALG) call ->setkey() if present. Fix it by removing crypto_poly1305_setkey(), leaving ->setkey as NULL. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
207 lines
5.6 KiB
C
207 lines
5.6 KiB
C
/*
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* Poly1305 authenticator algorithm, RFC7539, SIMD glue code
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*
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* Copyright (C) 2015 Martin Willi
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <crypto/algapi.h>
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#include <crypto/internal/hash.h>
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#include <crypto/poly1305.h>
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#include <linux/crypto.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/fpu/api.h>
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#include <asm/simd.h>
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struct poly1305_simd_desc_ctx {
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struct poly1305_desc_ctx base;
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/* derived key u set? */
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bool uset;
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#ifdef CONFIG_AS_AVX2
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/* derived keys r^3, r^4 set? */
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bool wset;
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#endif
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/* derived Poly1305 key r^2 */
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u32 u[5];
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/* ... silently appended r^3 and r^4 when using AVX2 */
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};
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asmlinkage void poly1305_block_sse2(u32 *h, const u8 *src,
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const u32 *r, unsigned int blocks);
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asmlinkage void poly1305_2block_sse2(u32 *h, const u8 *src, const u32 *r,
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unsigned int blocks, const u32 *u);
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#ifdef CONFIG_AS_AVX2
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asmlinkage void poly1305_4block_avx2(u32 *h, const u8 *src, const u32 *r,
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unsigned int blocks, const u32 *u);
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static bool poly1305_use_avx2;
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#endif
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static int poly1305_simd_init(struct shash_desc *desc)
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{
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struct poly1305_simd_desc_ctx *sctx = shash_desc_ctx(desc);
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sctx->uset = false;
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#ifdef CONFIG_AS_AVX2
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sctx->wset = false;
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#endif
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return crypto_poly1305_init(desc);
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}
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static void poly1305_simd_mult(u32 *a, const u32 *b)
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{
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u8 m[POLY1305_BLOCK_SIZE];
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memset(m, 0, sizeof(m));
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/* The poly1305 block function adds a hi-bit to the accumulator which
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* we don't need for key multiplication; compensate for it. */
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a[4] -= 1 << 24;
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poly1305_block_sse2(a, m, b, 1);
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}
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static unsigned int poly1305_simd_blocks(struct poly1305_desc_ctx *dctx,
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const u8 *src, unsigned int srclen)
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{
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struct poly1305_simd_desc_ctx *sctx;
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unsigned int blocks, datalen;
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BUILD_BUG_ON(offsetof(struct poly1305_simd_desc_ctx, base));
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sctx = container_of(dctx, struct poly1305_simd_desc_ctx, base);
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if (unlikely(!dctx->sset)) {
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datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
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src += srclen - datalen;
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srclen = datalen;
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}
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#ifdef CONFIG_AS_AVX2
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if (poly1305_use_avx2 && srclen >= POLY1305_BLOCK_SIZE * 4) {
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if (unlikely(!sctx->wset)) {
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if (!sctx->uset) {
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memcpy(sctx->u, dctx->r, sizeof(sctx->u));
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poly1305_simd_mult(sctx->u, dctx->r);
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sctx->uset = true;
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}
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memcpy(sctx->u + 5, sctx->u, sizeof(sctx->u));
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poly1305_simd_mult(sctx->u + 5, dctx->r);
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memcpy(sctx->u + 10, sctx->u + 5, sizeof(sctx->u));
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poly1305_simd_mult(sctx->u + 10, dctx->r);
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sctx->wset = true;
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}
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blocks = srclen / (POLY1305_BLOCK_SIZE * 4);
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poly1305_4block_avx2(dctx->h, src, dctx->r, blocks, sctx->u);
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src += POLY1305_BLOCK_SIZE * 4 * blocks;
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srclen -= POLY1305_BLOCK_SIZE * 4 * blocks;
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}
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#endif
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if (likely(srclen >= POLY1305_BLOCK_SIZE * 2)) {
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if (unlikely(!sctx->uset)) {
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memcpy(sctx->u, dctx->r, sizeof(sctx->u));
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poly1305_simd_mult(sctx->u, dctx->r);
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sctx->uset = true;
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}
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blocks = srclen / (POLY1305_BLOCK_SIZE * 2);
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poly1305_2block_sse2(dctx->h, src, dctx->r, blocks, sctx->u);
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src += POLY1305_BLOCK_SIZE * 2 * blocks;
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srclen -= POLY1305_BLOCK_SIZE * 2 * blocks;
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}
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if (srclen >= POLY1305_BLOCK_SIZE) {
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poly1305_block_sse2(dctx->h, src, dctx->r, 1);
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srclen -= POLY1305_BLOCK_SIZE;
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}
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return srclen;
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}
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static int poly1305_simd_update(struct shash_desc *desc,
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const u8 *src, unsigned int srclen)
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{
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struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
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unsigned int bytes;
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/* kernel_fpu_begin/end is costly, use fallback for small updates */
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if (srclen <= 288 || !may_use_simd())
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return crypto_poly1305_update(desc, src, srclen);
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kernel_fpu_begin();
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if (unlikely(dctx->buflen)) {
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bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
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memcpy(dctx->buf + dctx->buflen, src, bytes);
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src += bytes;
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srclen -= bytes;
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dctx->buflen += bytes;
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if (dctx->buflen == POLY1305_BLOCK_SIZE) {
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poly1305_simd_blocks(dctx, dctx->buf,
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POLY1305_BLOCK_SIZE);
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dctx->buflen = 0;
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}
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}
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if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
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bytes = poly1305_simd_blocks(dctx, src, srclen);
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src += srclen - bytes;
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srclen = bytes;
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}
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kernel_fpu_end();
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if (unlikely(srclen)) {
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dctx->buflen = srclen;
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memcpy(dctx->buf, src, srclen);
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}
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return 0;
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}
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static struct shash_alg alg = {
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.digestsize = POLY1305_DIGEST_SIZE,
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.init = poly1305_simd_init,
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.update = poly1305_simd_update,
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.final = crypto_poly1305_final,
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.descsize = sizeof(struct poly1305_simd_desc_ctx),
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.base = {
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.cra_name = "poly1305",
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.cra_driver_name = "poly1305-simd",
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.cra_priority = 300,
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.cra_flags = CRYPTO_ALG_TYPE_SHASH,
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.cra_blocksize = POLY1305_BLOCK_SIZE,
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.cra_module = THIS_MODULE,
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},
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};
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static int __init poly1305_simd_mod_init(void)
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{
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if (!boot_cpu_has(X86_FEATURE_XMM2))
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return -ENODEV;
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#ifdef CONFIG_AS_AVX2
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poly1305_use_avx2 = boot_cpu_has(X86_FEATURE_AVX) &&
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boot_cpu_has(X86_FEATURE_AVX2) &&
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cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL);
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alg.descsize = sizeof(struct poly1305_simd_desc_ctx);
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if (poly1305_use_avx2)
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alg.descsize += 10 * sizeof(u32);
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#endif
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return crypto_register_shash(&alg);
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}
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static void __exit poly1305_simd_mod_exit(void)
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{
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crypto_unregister_shash(&alg);
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}
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module_init(poly1305_simd_mod_init);
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module_exit(poly1305_simd_mod_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
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MODULE_DESCRIPTION("Poly1305 authenticator");
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MODULE_ALIAS_CRYPTO("poly1305");
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MODULE_ALIAS_CRYPTO("poly1305-simd");
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