From ecfc43292f68566c144afca966b46b371c26d56c Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 5 Dec 2007 21:08:36 +1100 Subject: [CRYPTO] skcipher: Add skcipher_geniv_alloc/skcipher_geniv_free This patch creates the infrastructure to help the construction of givcipher templates that wrap around existing blkcipher/ablkcipher algorithms by adding an IV generator to them. Signed-off-by: Herbert Xu --- crypto/ablkcipher.c | 10 +- crypto/blkcipher.c | 185 ++++++++++++++++++++++++++++++++++++- include/crypto/internal/skcipher.h | 18 ++++ include/linux/crypto.h | 18 +++- 4 files changed, 225 insertions(+), 6 deletions(-) diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c index 8f48b4d58fc..092d9659b86 100644 --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -80,6 +80,7 @@ static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type, crt->setkey = setkey; crt->encrypt = alg->encrypt; crt->decrypt = alg->decrypt; + crt->base = __crypto_ablkcipher_cast(tfm); crt->ivsize = alg->ivsize; return 0; @@ -122,11 +123,13 @@ static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type, if (alg->ivsize > PAGE_SIZE / 8) return -EINVAL; - crt->setkey = setkey; + crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ? + alg->setkey : setkey; crt->encrypt = alg->encrypt; crt->decrypt = alg->decrypt; crt->givencrypt = alg->givencrypt; crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt; + crt->base = __crypto_ablkcipher_cast(tfm); crt->ivsize = alg->ivsize; return 0; @@ -155,6 +158,11 @@ const struct crypto_type crypto_givcipher_type = { }; EXPORT_SYMBOL_GPL(crypto_givcipher_type); +const char *crypto_default_geniv(const struct crypto_alg *alg) +{ + return alg->cra_flags & CRYPTO_ALG_ASYNC ? "eseqiv" : "chainiv"; +} + int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name, u32 type, u32 mask) { diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index 7a3e1a30807..ca6ef065cde 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -14,8 +14,8 @@ * */ +#include #include -#include #include #include #include @@ -450,6 +450,7 @@ static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm) crt->setkey = async_setkey; crt->encrypt = async_encrypt; crt->decrypt = async_decrypt; + crt->base = __crypto_ablkcipher_cast(tfm); crt->ivsize = alg->ivsize; return 0; @@ -509,5 +510,187 @@ const struct crypto_type crypto_blkcipher_type = { }; EXPORT_SYMBOL_GPL(crypto_blkcipher_type); +static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn, + const char *name, u32 type, u32 mask) +{ + struct crypto_alg *alg; + int err; + + type = crypto_skcipher_type(type); + mask = crypto_skcipher_mask(mask) | CRYPTO_ALG_GENIV; + + alg = crypto_alg_mod_lookup(name, type, mask); + if (IS_ERR(alg)) + return PTR_ERR(alg); + + err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask); + crypto_mod_put(alg); + return err; +} + +struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl, + struct rtattr **tb, u32 type, + u32 mask) +{ + struct { + int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key, + unsigned int keylen); + int (*encrypt)(struct ablkcipher_request *req); + int (*decrypt)(struct ablkcipher_request *req); + + unsigned int min_keysize; + unsigned int max_keysize; + unsigned int ivsize; + + const char *geniv; + } balg; + const char *name; + struct crypto_skcipher_spawn *spawn; + struct crypto_attr_type *algt; + struct crypto_instance *inst; + struct crypto_alg *alg; + int err; + + algt = crypto_get_attr_type(tb); + err = PTR_ERR(algt); + if (IS_ERR(algt)) + return ERR_PTR(err); + + if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) & + algt->mask) + return ERR_PTR(-EINVAL); + + name = crypto_attr_alg_name(tb[1]); + err = PTR_ERR(name); + if (IS_ERR(name)) + return ERR_PTR(err); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + + spawn = crypto_instance_ctx(inst); + + /* Ignore async algorithms if necessary. */ + mask |= crypto_requires_sync(algt->type, algt->mask); + + crypto_set_skcipher_spawn(spawn, inst); + err = crypto_grab_nivcipher(spawn, name, type, mask); + if (err) + goto err_free_inst; + + alg = crypto_skcipher_spawn_alg(spawn); + + if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == + CRYPTO_ALG_TYPE_BLKCIPHER) { + balg.ivsize = alg->cra_blkcipher.ivsize; + balg.min_keysize = alg->cra_blkcipher.min_keysize; + balg.max_keysize = alg->cra_blkcipher.max_keysize; + + balg.setkey = async_setkey; + balg.encrypt = async_encrypt; + balg.decrypt = async_decrypt; + + balg.geniv = alg->cra_blkcipher.geniv; + } else { + balg.ivsize = alg->cra_ablkcipher.ivsize; + balg.min_keysize = alg->cra_ablkcipher.min_keysize; + balg.max_keysize = alg->cra_ablkcipher.max_keysize; + + balg.setkey = alg->cra_ablkcipher.setkey; + balg.encrypt = alg->cra_ablkcipher.encrypt; + balg.decrypt = alg->cra_ablkcipher.decrypt; + + balg.geniv = alg->cra_ablkcipher.geniv; + } + + err = -EINVAL; + if (!balg.ivsize) + goto err_drop_alg; + + /* + * This is only true if we're constructing an algorithm with its + * default IV generator. For the default generator we elide the + * template name and double-check the IV generator. + */ + if (algt->mask & CRYPTO_ALG_GENIV) { + if (!balg.geniv) + balg.geniv = crypto_default_geniv(alg); + err = -EAGAIN; + if (strcmp(tmpl->name, balg.geniv)) + goto err_drop_alg; + + memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); + memcpy(inst->alg.cra_driver_name, alg->cra_driver_name, + CRYPTO_MAX_ALG_NAME); + } else { + err = -ENAMETOOLONG; + if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, + "%s(%s)", tmpl->name, alg->cra_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_drop_alg; + if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "%s(%s)", tmpl->name, alg->cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_drop_alg; + } + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV; + inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; + inst->alg.cra_priority = alg->cra_priority; + inst->alg.cra_blocksize = alg->cra_blocksize; + inst->alg.cra_alignmask = alg->cra_alignmask; + inst->alg.cra_type = &crypto_givcipher_type; + + inst->alg.cra_ablkcipher.ivsize = balg.ivsize; + inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize; + inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize; + inst->alg.cra_ablkcipher.geniv = balg.geniv; + + inst->alg.cra_ablkcipher.setkey = balg.setkey; + inst->alg.cra_ablkcipher.encrypt = balg.encrypt; + inst->alg.cra_ablkcipher.decrypt = balg.decrypt; + +out: + return inst; + +err_drop_alg: + crypto_drop_skcipher(spawn); +err_free_inst: + kfree(inst); + inst = ERR_PTR(err); + goto out; +} +EXPORT_SYMBOL_GPL(skcipher_geniv_alloc); + +void skcipher_geniv_free(struct crypto_instance *inst) +{ + crypto_drop_skcipher(crypto_instance_ctx(inst)); + kfree(inst); +} +EXPORT_SYMBOL_GPL(skcipher_geniv_free); + +int skcipher_geniv_init(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_ablkcipher *cipher; + + cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst)); + if (IS_ERR(cipher)) + return PTR_ERR(cipher); + + tfm->crt_ablkcipher.base = cipher; + tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher); + + return 0; +} +EXPORT_SYMBOL_GPL(skcipher_geniv_init); + +void skcipher_geniv_exit(struct crypto_tfm *tfm) +{ + crypto_free_ablkcipher(tfm->crt_ablkcipher.base); +} +EXPORT_SYMBOL_GPL(skcipher_geniv_exit); + MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Generic block chaining cipher type"); diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h index c9402dd12d0..07e7c82324a 100644 --- a/include/crypto/internal/skcipher.h +++ b/include/crypto/internal/skcipher.h @@ -15,6 +15,9 @@ #include #include +#include + +struct rtattr; struct crypto_skcipher_spawn { struct crypto_spawn base; @@ -50,6 +53,21 @@ static inline struct crypto_ablkcipher *crypto_spawn_skcipher( crypto_skcipher_mask(0))); } +const char *crypto_default_geniv(const struct crypto_alg *alg); + +struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl, + struct rtattr **tb, u32 type, + u32 mask); +void skcipher_geniv_free(struct crypto_instance *inst); +int skcipher_geniv_init(struct crypto_tfm *tfm); +void skcipher_geniv_exit(struct crypto_tfm *tfm); + +static inline struct crypto_ablkcipher *skcipher_geniv_cipher( + struct crypto_ablkcipher *geniv) +{ + return crypto_ablkcipher_crt(geniv)->base; +} + static inline void *skcipher_givcrypt_reqctx( struct skcipher_givcrypt_request *req) { diff --git a/include/linux/crypto.h b/include/linux/crypto.h index facafa1bd8c..fa7afa9b9f4 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -52,6 +52,12 @@ */ #define CRYPTO_ALG_NEED_FALLBACK 0x00000100 +/* + * This bit is set for symmetric key ciphers that have already been wrapped + * with a generic IV generator to prevent them from being wrapped again. + */ +#define CRYPTO_ALG_GENIV 0x00000200 + /* * Transform masks and values (for crt_flags). */ @@ -331,6 +337,8 @@ struct ablkcipher_tfm { int (*givencrypt)(struct skcipher_givcrypt_request *req); int (*givdecrypt)(struct skcipher_givcrypt_request *req); + struct crypto_ablkcipher *base; + unsigned int ivsize; unsigned int reqsize; }; @@ -541,14 +549,14 @@ static inline struct crypto_ablkcipher *__crypto_ablkcipher_cast( static inline u32 crypto_skcipher_type(u32 type) { - type &= ~CRYPTO_ALG_TYPE_MASK; + type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); type |= CRYPTO_ALG_TYPE_BLKCIPHER; return type; } static inline u32 crypto_skcipher_mask(u32 mask) { - mask &= ~CRYPTO_ALG_TYPE_MASK; + mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); mask |= CRYPTO_ALG_TYPE_BLKCIPHER_MASK; return mask; } @@ -623,7 +631,9 @@ static inline void crypto_ablkcipher_clear_flags(struct crypto_ablkcipher *tfm, static inline int crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm, const u8 *key, unsigned int keylen) { - return crypto_ablkcipher_crt(tfm)->setkey(tfm, key, keylen); + struct ablkcipher_tfm *crt = crypto_ablkcipher_crt(tfm); + + return crt->setkey(crt->base, key, keylen); } static inline struct crypto_ablkcipher *crypto_ablkcipher_reqtfm( @@ -655,7 +665,7 @@ static inline unsigned int crypto_ablkcipher_reqsize( static inline void ablkcipher_request_set_tfm( struct ablkcipher_request *req, struct crypto_ablkcipher *tfm) { - req->base.tfm = crypto_ablkcipher_tfm(tfm); + req->base.tfm = crypto_ablkcipher_tfm(crypto_ablkcipher_crt(tfm)->base); } static inline struct ablkcipher_request *ablkcipher_request_cast( -- cgit v1.2.3