From 26051749bee3d7167636e3a65eadde471dd89d7d Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 8 Nov 2019 13:22:21 +0100 Subject: [PATCH] crypto: poly1305 - expose init/update/final library interface Expose the existing generic Poly1305 code via a init/update/final library interface so that callers are not required to go through the crypto API's shash abstraction to access it. At the same time, make some preparations so that the library implementation can be superseded by an accelerated arch-specific version in the future. Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- crypto/poly1305_generic.c | 22 +----------- include/crypto/poly1305.h | 38 +++++++++++++++++++- lib/crypto/Kconfig | 26 ++++++++++++++ lib/crypto/poly1305.c | 74 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 138 insertions(+), 22 deletions(-) diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c index f3fcd9578a47f..afe9a9e576dda 100644 --- a/crypto/poly1305_generic.c +++ b/crypto/poly1305_generic.c @@ -85,31 +85,11 @@ EXPORT_SYMBOL_GPL(crypto_poly1305_update); int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) { struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); - __le32 digest[4]; - u64 f = 0; if (unlikely(!dctx->sset)) return -ENOKEY; - if (unlikely(dctx->buflen)) { - dctx->buf[dctx->buflen++] = 1; - memset(dctx->buf + dctx->buflen, 0, - POLY1305_BLOCK_SIZE - dctx->buflen); - poly1305_core_blocks(&dctx->h, dctx->r, dctx->buf, 1, 0); - } - - poly1305_core_emit(&dctx->h, digest); - - /* mac = (h + s) % (2^128) */ - f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0]; - put_unaligned_le32(f, dst + 0); - f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1]; - put_unaligned_le32(f, dst + 4); - f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2]; - put_unaligned_le32(f, dst + 8); - f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3]; - put_unaligned_le32(f, dst + 12); - + poly1305_final_generic(dctx, dst); return 0; } EXPORT_SYMBOL_GPL(crypto_poly1305_final); diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h index 36b5886cb50ca..74c6e1cd73eee 100644 --- a/include/crypto/poly1305.h +++ b/include/crypto/poly1305.h @@ -35,7 +35,43 @@ struct poly1305_desc_ctx { /* accumulator */ struct poly1305_state h; /* key */ - struct poly1305_key r[1]; + struct poly1305_key r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE]; }; +void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key); +void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key); + +static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key) +{ + if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305)) + poly1305_init_arch(desc, key); + else + poly1305_init_generic(desc, key); +} + +void poly1305_update_arch(struct poly1305_desc_ctx *desc, const u8 *src, + unsigned int nbytes); +void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src, + unsigned int nbytes); + +static inline void poly1305_update(struct poly1305_desc_ctx *desc, + const u8 *src, unsigned int nbytes) +{ + if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305)) + poly1305_update_arch(desc, src, nbytes); + else + poly1305_update_generic(desc, src, nbytes); +} + +void poly1305_final_arch(struct poly1305_desc_ctx *desc, u8 *digest); +void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *digest); + +static inline void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest) +{ + if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305)) + poly1305_final_arch(desc, digest); + else + poly1305_final_generic(desc, digest); +} + #endif diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index c4882d29879e8..a731ea36bd5c7 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -37,8 +37,34 @@ config CRYPTO_LIB_CHACHA config CRYPTO_LIB_DES tristate +config CRYPTO_LIB_POLY1305_RSIZE + int + default 1 + +config CRYPTO_ARCH_HAVE_LIB_POLY1305 + tristate + help + Declares whether the architecture provides an arch-specific + accelerated implementation of the Poly1305 library interface, + either builtin or as a module. + config CRYPTO_LIB_POLY1305_GENERIC tristate + help + This symbol can be depended upon by arch implementations of the + Poly1305 library interface that require the generic code as a + fallback, e.g., for SIMD implementations. If no arch specific + implementation is enabled, this implementation serves the users + of CRYPTO_LIB_POLY1305. + +config CRYPTO_LIB_POLY1305 + tristate "Poly1305 library interface" + depends on CRYPTO_ARCH_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_HAVE_LIB_POLY1305 + select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n + help + Enable the Poly1305 library interface. This interface may be fulfilled + by either the generic implementation or an arch-specific one, if one + is available and enabled. config CRYPTO_LIB_SHA256 tristate diff --git a/lib/crypto/poly1305.c b/lib/crypto/poly1305.c index f019a57dbc1b9..32ec293c65ae7 100644 --- a/lib/crypto/poly1305.c +++ b/lib/crypto/poly1305.c @@ -154,5 +154,79 @@ void poly1305_core_emit(const struct poly1305_state *state, void *dst) } EXPORT_SYMBOL_GPL(poly1305_core_emit); +void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key) +{ + poly1305_core_setkey(desc->r, key); + desc->s[0] = get_unaligned_le32(key + 16); + desc->s[1] = get_unaligned_le32(key + 20); + desc->s[2] = get_unaligned_le32(key + 24); + desc->s[3] = get_unaligned_le32(key + 28); + poly1305_core_init(&desc->h); + desc->buflen = 0; + desc->sset = true; + desc->rset = 1; +} +EXPORT_SYMBOL_GPL(poly1305_init_generic); + +void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src, + unsigned int nbytes) +{ + unsigned int bytes; + + if (unlikely(desc->buflen)) { + bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen); + memcpy(desc->buf + desc->buflen, src, bytes); + src += bytes; + nbytes -= bytes; + desc->buflen += bytes; + + if (desc->buflen == POLY1305_BLOCK_SIZE) { + poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 1); + desc->buflen = 0; + } + } + + if (likely(nbytes >= POLY1305_BLOCK_SIZE)) { + poly1305_core_blocks(&desc->h, desc->r, src, + nbytes / POLY1305_BLOCK_SIZE, 1); + src += nbytes - (nbytes % POLY1305_BLOCK_SIZE); + nbytes %= POLY1305_BLOCK_SIZE; + } + + if (unlikely(nbytes)) { + desc->buflen = nbytes; + memcpy(desc->buf, src, nbytes); + } +} +EXPORT_SYMBOL_GPL(poly1305_update_generic); + +void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst) +{ + __le32 digest[4]; + u64 f = 0; + + if (unlikely(desc->buflen)) { + desc->buf[desc->buflen++] = 1; + memset(desc->buf + desc->buflen, 0, + POLY1305_BLOCK_SIZE - desc->buflen); + poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 0); + } + + poly1305_core_emit(&desc->h, digest); + + /* mac = (h + s) % (2^128) */ + f = (f >> 32) + le32_to_cpu(digest[0]) + desc->s[0]; + put_unaligned_le32(f, dst + 0); + f = (f >> 32) + le32_to_cpu(digest[1]) + desc->s[1]; + put_unaligned_le32(f, dst + 4); + f = (f >> 32) + le32_to_cpu(digest[2]) + desc->s[2]; + put_unaligned_le32(f, dst + 8); + f = (f >> 32) + le32_to_cpu(digest[3]) + desc->s[3]; + put_unaligned_le32(f, dst + 12); + + *desc = (struct poly1305_desc_ctx){}; +} +EXPORT_SYMBOL_GPL(poly1305_final_generic); + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Martin Willi "); -- 2.39.5