From 48ea8c6ebc96bc0990e12ee1c43d0832c23576bb Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 8 Nov 2019 13:22:19 +0100 Subject: crypto: poly1305 - move core routines into a separate library Move the core Poly1305 routines shared between the generic Poly1305 shash driver and the Adiantum and NHPoly1305 drivers into a separate library so that using just this pieces does not pull in the crypto API pieces of the generic Poly1305 routine. In a subsequent patch, we will augment this generic library with init/update/final routines so that Poyl1305 algorithm can be used directly without the need for using the crypto API's shash abstraction. Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- include/crypto/internal/poly1305.h | 67 ++++++++++++++++++++++++++++++++++++++ include/crypto/poly1305.h | 23 ------------- 2 files changed, 67 insertions(+), 23 deletions(-) create mode 100644 include/crypto/internal/poly1305.h (limited to 'include/crypto') diff --git a/include/crypto/internal/poly1305.h b/include/crypto/internal/poly1305.h new file mode 100644 index 000000000000..cb58e61f73a7 --- /dev/null +++ b/include/crypto/internal/poly1305.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values for the Poly1305 algorithm + */ + +#ifndef _CRYPTO_INTERNAL_POLY1305_H +#define _CRYPTO_INTERNAL_POLY1305_H + +#include +#include +#include + +struct shash_desc; + +/* + * Poly1305 core functions. These implement the ε-almost-∆-universal hash + * function underlying the Poly1305 MAC, i.e. they don't add an encrypted nonce + * ("s key") at the end. They also only support block-aligned inputs. + */ +void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key); +static inline void poly1305_core_init(struct poly1305_state *state) +{ + *state = (struct poly1305_state){}; +} + +void poly1305_core_blocks(struct poly1305_state *state, + const struct poly1305_key *key, const void *src, + unsigned int nblocks, u32 hibit); +void poly1305_core_emit(const struct poly1305_state *state, void *dst); + +/* Crypto API helper functions for the Poly1305 MAC */ +int crypto_poly1305_init(struct shash_desc *desc); + +int crypto_poly1305_update(struct shash_desc *desc, + const u8 *src, unsigned int srclen); +int crypto_poly1305_final(struct shash_desc *desc, u8 *dst); + +/* + * Poly1305 requires a unique key for each tag, which implies that we can't set + * it on the tfm that gets accessed by multiple users simultaneously. Instead we + * expect the key as the first 32 bytes in the update() call. + */ +static inline +unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx, + const u8 *src, unsigned int srclen) +{ + if (!dctx->sset) { + if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) { + poly1305_core_setkey(&dctx->r, src); + src += POLY1305_BLOCK_SIZE; + srclen -= POLY1305_BLOCK_SIZE; + dctx->rset = true; + } + if (srclen >= POLY1305_BLOCK_SIZE) { + dctx->s[0] = get_unaligned_le32(src + 0); + dctx->s[1] = get_unaligned_le32(src + 4); + dctx->s[2] = get_unaligned_le32(src + 8); + dctx->s[3] = get_unaligned_le32(src + 12); + src += POLY1305_BLOCK_SIZE; + srclen -= POLY1305_BLOCK_SIZE; + dctx->sset = true; + } + } + return srclen; +} + +#endif diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h index 34317ed2071e..f5a4319c2a1f 100644 --- a/include/crypto/poly1305.h +++ b/include/crypto/poly1305.h @@ -38,27 +38,4 @@ struct poly1305_desc_ctx { bool sset; }; -/* - * Poly1305 core functions. These implement the ε-almost-∆-universal hash - * function underlying the Poly1305 MAC, i.e. they don't add an encrypted nonce - * ("s key") at the end. They also only support block-aligned inputs. - */ -void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key); -static inline void poly1305_core_init(struct poly1305_state *state) -{ - memset(state->h, 0, sizeof(state->h)); -} -void poly1305_core_blocks(struct poly1305_state *state, - const struct poly1305_key *key, - const void *src, unsigned int nblocks); -void poly1305_core_emit(const struct poly1305_state *state, void *dst); - -/* Crypto API helper functions for the Poly1305 MAC */ -int crypto_poly1305_init(struct shash_desc *desc); -unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx, - const u8 *src, unsigned int srclen); -int crypto_poly1305_update(struct shash_desc *desc, - const u8 *src, unsigned int srclen); -int crypto_poly1305_final(struct shash_desc *desc, u8 *dst); - #endif -- cgit