From: David Howells Subject: [PATCH 2/6] MODSIGN: In-kernel crypto extensions Date: Wed, 14 Feb 2007 19:09:49 +0000 Message-ID: <20070214190949.6438.28537.stgit@warthog.cambridge.redhat.com> References: <20070214190938.6438.15091.stgit@warthog.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, davej@redhat.com, arjan@infradead.org, linux-crypto@vger.kernel.org, dhowells@redhat.com To: torvalds@osdl.org, akpm@osdl.org, herbert.xu@redhat.com Return-path: In-Reply-To: <20070214190938.6438.15091.stgit@warthog.cambridge.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Two extensions are added: (1) Support for SHA1 digestion of in-kernel buffers directly without the use of scatter-gather lists. (2) Allocation of crypto algorithm instances without resort to fallback module loading. SHA1 is used by module signature checking, and so must not itself require loading as a module when the module signature checking is enabled. Signed-Off-By: David Howells --- crypto/api.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- crypto/digest.c | 9 +++++++++ include/linux/crypto.h | 11 +++++++++++ 3 files changed, 65 insertions(+), 1 deletions(-) diff --git a/crypto/api.c b/crypto/api.c index 55af8bb..3138d7c 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -341,6 +341,45 @@ out: EXPORT_SYMBOL_GPL(__crypto_alloc_tfm); /* + * crypto_alloc_tfm2 - Find or load crypto module + * @name: Name of algorithm + * @flags: Flags to control algorithm instance + * @nomodload: True to suppress resort to module loading + * + * Attempt to find or load a crypto algorithm module and create an + * instance of it. + */ +struct crypto_tfm *crypto_alloc_tfm2(const char *name, u32 flags, + int nomodload) +{ + struct crypto_tfm *tfm = NULL; + int err; + + do { + struct crypto_alg *alg; + + if (!nomodload) + alg = crypto_alg_mod_lookup(name, 0, CRYPTO_ALG_ASYNC); + else + alg = crypto_alg_lookup(name, 0, CRYPTO_ALG_ASYNC); + + err = PTR_ERR(alg); + if (IS_ERR(alg)) + continue; + + tfm = __crypto_alloc_tfm(alg, flags, 0); + err = 0; + if (IS_ERR(tfm)) { + crypto_mod_put(alg); + err = PTR_ERR(tfm); + tfm = NULL; + } + } while (err == -EAGAIN && !signal_pending(current)); + + return tfm; +} + +/* * crypto_alloc_base - Locate algorithm and allocate transform * @alg_name: Name of algorithm * @type: Type of algorithm @@ -392,7 +431,12 @@ err: return ERR_PTR(err); } EXPORT_SYMBOL_GPL(crypto_alloc_base); - + +struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags) +{ + return crypto_alloc_tfm2(name, flags, 0); +} + /* * crypto_free_tfm - Free crypto transform * @tfm: Transform to free diff --git a/crypto/digest.c b/crypto/digest.c index 1bf7414..d03a4e1 100644 --- a/crypto/digest.c +++ b/crypto/digest.c @@ -91,6 +91,14 @@ static int update(struct hash_desc *desc, return update2(desc, sg, nbytes); } +static void update_kernel(struct hash_desc *desc, + const void *data, size_t count) +{ + struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); + tfm->__crt_alg->cra_digest.dia_update(tfm, data, count); + crypto_yield(desc->flags); +} + static int final(struct hash_desc *desc, u8 *out) { struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); @@ -146,6 +154,7 @@ int crypto_init_digest_ops(struct crypto_tfm *tfm) ops->init = init; ops->update = update; + ops->update_kernel = update_kernel; ops->final = final; ops->digest = digest; ops->setkey = dalg->dia_setkey ? setkey : nosetkey; diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 779aa78..d960ec1 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -273,6 +273,8 @@ struct hash_tfm { int (*init)(struct hash_desc *desc); int (*update)(struct hash_desc *desc, struct scatterlist *sg, unsigned int nsg); + void (*update_kernel)(struct hash_desc *desc, + const void *data, size_t count); int (*final)(struct hash_desc *desc, u8 *out); int (*digest)(struct hash_desc *desc, struct scatterlist *sg, unsigned int nsg, u8 *out); @@ -341,6 +343,8 @@ struct crypto_attr_alg { */ struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags); +struct crypto_tfm *crypto_alloc_tfm2(const char *alg_name, u32 tfm_flags, + int nomodload); struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask); void crypto_free_tfm(struct crypto_tfm *tfm); @@ -739,6 +743,13 @@ static inline int crypto_hash_update(struct hash_desc *desc, return crypto_hash_crt(desc->tfm)->update(desc, sg, nbytes); } +static inline void crypto_hash_update_kernel(struct hash_desc *desc, + const void *data, + size_t count) +{ + return crypto_hash_crt(desc->tfm)->update_kernel(desc, data, count); +} + static inline int crypto_hash_final(struct hash_desc *desc, u8 *out) { return crypto_hash_crt(desc->tfm)->final(desc, out);