diff options
Diffstat (limited to 'crypto/api.c')
-rw-r--r-- | crypto/api.c | 428 |
1 files changed, 299 insertions, 129 deletions
diff --git a/crypto/api.c b/crypto/api.c index c11ec1fd4f1..2e84d4b5479 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -15,70 +15,202 @@ * */ -#include <linux/compiler.h> -#include <linux/init.h> -#include <linux/crypto.h> +#include <linux/err.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/kmod.h> -#include <linux/rwsem.h> +#include <linux/module.h> +#include <linux/param.h> +#include <linux/sched.h> #include <linux/slab.h> #include <linux/string.h> #include "internal.h" LIST_HEAD(crypto_alg_list); +EXPORT_SYMBOL_GPL(crypto_alg_list); DECLARE_RWSEM(crypto_alg_sem); +EXPORT_SYMBOL_GPL(crypto_alg_sem); -static inline int crypto_alg_get(struct crypto_alg *alg) +BLOCKING_NOTIFIER_HEAD(crypto_chain); +EXPORT_SYMBOL_GPL(crypto_chain); + +static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) +{ + atomic_inc(&alg->cra_refcnt); + return alg; +} + +struct crypto_alg *crypto_mod_get(struct crypto_alg *alg) { - return try_module_get(alg->cra_module); + return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL; } +EXPORT_SYMBOL_GPL(crypto_mod_get); -static inline void crypto_alg_put(struct crypto_alg *alg) +void crypto_mod_put(struct crypto_alg *alg) { + crypto_alg_put(alg); module_put(alg->cra_module); } +EXPORT_SYMBOL_GPL(crypto_mod_put); -static struct crypto_alg *crypto_alg_lookup(const char *name) +struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, u32 mask) { struct crypto_alg *q, *alg = NULL; - int best = -1; + int best = -2; - if (!name) - return NULL; - - down_read(&crypto_alg_sem); - list_for_each_entry(q, &crypto_alg_list, cra_list) { int exact, fuzzy; + if (crypto_is_moribund(q)) + continue; + + if ((q->cra_flags ^ type) & mask) + continue; + + if (crypto_is_larval(q) && + ((struct crypto_larval *)q)->mask != mask) + continue; + exact = !strcmp(q->cra_driver_name, name); fuzzy = !strcmp(q->cra_name, name); if (!exact && !(fuzzy && q->cra_priority > best)) continue; - if (unlikely(!crypto_alg_get(q))) + if (unlikely(!crypto_mod_get(q))) continue; best = q->cra_priority; if (alg) - crypto_alg_put(alg); + crypto_mod_put(alg); alg = q; if (exact) break; } - + + return alg; +} +EXPORT_SYMBOL_GPL(__crypto_alg_lookup); + +static void crypto_larval_destroy(struct crypto_alg *alg) +{ + struct crypto_larval *larval = (void *)alg; + + BUG_ON(!crypto_is_larval(alg)); + if (larval->adult) + crypto_mod_put(larval->adult); + kfree(larval); +} + +static struct crypto_alg *crypto_larval_alloc(const char *name, u32 type, + u32 mask) +{ + struct crypto_alg *alg; + struct crypto_larval *larval; + + larval = kzalloc(sizeof(*larval), GFP_KERNEL); + if (!larval) + return ERR_PTR(-ENOMEM); + + larval->mask = mask; + larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type; + larval->alg.cra_priority = -1; + larval->alg.cra_destroy = crypto_larval_destroy; + + atomic_set(&larval->alg.cra_refcnt, 2); + strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME); + init_completion(&larval->completion); + + down_write(&crypto_alg_sem); + alg = __crypto_alg_lookup(name, type, mask); + if (!alg) { + alg = &larval->alg; + list_add(&alg->cra_list, &crypto_alg_list); + } + up_write(&crypto_alg_sem); + + if (alg != &larval->alg) + kfree(larval); + + return alg; +} + +static void crypto_larval_kill(struct crypto_alg *alg) +{ + struct crypto_larval *larval = (void *)alg; + + down_write(&crypto_alg_sem); + list_del(&alg->cra_list); + up_write(&crypto_alg_sem); + complete(&larval->completion); + crypto_alg_put(alg); +} + +static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg) +{ + struct crypto_larval *larval = (void *)alg; + + wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ); + alg = larval->adult; + if (alg) { + if (!crypto_mod_get(alg)) + alg = ERR_PTR(-EAGAIN); + } else + alg = ERR_PTR(-ENOENT); + crypto_mod_put(&larval->alg); + + return alg; +} + +static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, + u32 mask) +{ + struct crypto_alg *alg; + + down_read(&crypto_alg_sem); + alg = __crypto_alg_lookup(name, type, mask); up_read(&crypto_alg_sem); + return alg; } -/* A far more intelligent version of this is planned. For now, just - * try an exact match on the name of the algorithm. */ -static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name) +struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) { - return try_then_request_module(crypto_alg_lookup(name), name); + struct crypto_alg *alg; + struct crypto_alg *larval; + int ok; + + if (!name) + return ERR_PTR(-ENOENT); + + mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); + type &= mask; + + alg = try_then_request_module(crypto_alg_lookup(name, type, mask), + name); + if (alg) + return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg; + + larval = crypto_larval_alloc(name, type, mask); + if (IS_ERR(larval) || !crypto_is_larval(larval)) + return larval; + + ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval); + if (ok == NOTIFY_DONE) { + request_module("cryptomgr"); + ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval); + } + + if (ok == NOTIFY_STOP) + alg = crypto_larval_wait(larval); + else { + crypto_mod_put(larval); + alg = ERR_PTR(-ENOENT); + } + crypto_larval_kill(larval); + return alg; } +EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup); static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags) { @@ -94,17 +226,18 @@ static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags) case CRYPTO_ALG_TYPE_COMPRESS: return crypto_init_compress_flags(tfm, flags); - - default: - break; } - BUG(); - return -EINVAL; + return 0; } static int crypto_init_ops(struct crypto_tfm *tfm) { + const struct crypto_type *type = tfm->__crt_alg->cra_type; + + if (type) + return type->init(tfm); + switch (crypto_tfm_alg_type(tfm)) { case CRYPTO_ALG_TYPE_CIPHER: return crypto_init_cipher_ops(tfm); @@ -125,6 +258,14 @@ static int crypto_init_ops(struct crypto_tfm *tfm) static void crypto_exit_ops(struct crypto_tfm *tfm) { + const struct crypto_type *type = tfm->__crt_alg->cra_type; + + if (type) { + if (type->exit) + type->exit(tfm); + return; + } + switch (crypto_tfm_alg_type(tfm)) { case CRYPTO_ALG_TYPE_CIPHER: crypto_exit_cipher_ops(tfm); @@ -146,53 +287,67 @@ static void crypto_exit_ops(struct crypto_tfm *tfm) static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags) { + const struct crypto_type *type = alg->cra_type; unsigned int len; + len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1); + if (type) + return len + type->ctxsize(alg); + switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) { default: BUG(); case CRYPTO_ALG_TYPE_CIPHER: - len = crypto_cipher_ctxsize(alg, flags); + len += crypto_cipher_ctxsize(alg, flags); break; case CRYPTO_ALG_TYPE_DIGEST: - len = crypto_digest_ctxsize(alg, flags); + len += crypto_digest_ctxsize(alg, flags); break; case CRYPTO_ALG_TYPE_COMPRESS: - len = crypto_compress_ctxsize(alg, flags); + len += crypto_compress_ctxsize(alg, flags); break; } - return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1)); + return len; } -struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags) +void crypto_shoot_alg(struct crypto_alg *alg) +{ + down_write(&crypto_alg_sem); + alg->cra_flags |= CRYPTO_ALG_DYING; + up_write(&crypto_alg_sem); +} +EXPORT_SYMBOL_GPL(crypto_shoot_alg); + +struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 flags) { struct crypto_tfm *tfm = NULL; - struct crypto_alg *alg; unsigned int tfm_size; - - alg = crypto_alg_mod_lookup(name); - if (alg == NULL) - goto out; + int err = -ENOMEM; tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags); tfm = kzalloc(tfm_size, GFP_KERNEL); if (tfm == NULL) - goto out_put; + goto out; tfm->__crt_alg = alg; - - if (crypto_init_flags(tfm, flags)) + + err = crypto_init_flags(tfm, flags); + if (err) goto out_free_tfm; - if (crypto_init_ops(tfm)) + err = crypto_init_ops(tfm); + if (err) goto out_free_tfm; - if (alg->cra_init && alg->cra_init(tfm)) + if (alg->cra_init && (err = alg->cra_init(tfm))) { + if (err == -EAGAIN) + crypto_shoot_alg(alg); goto cra_init_failed; + } goto out; @@ -200,13 +355,97 @@ cra_init_failed: crypto_exit_ops(tfm); out_free_tfm: kfree(tfm); - tfm = NULL; -out_put: - crypto_alg_put(alg); + tfm = ERR_PTR(err); out: return tfm; } +EXPORT_SYMBOL_GPL(__crypto_alloc_tfm); + +struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags) +{ + struct crypto_tfm *tfm = NULL; + int err; + + do { + struct crypto_alg *alg; + + alg = crypto_alg_mod_lookup(name, 0, CRYPTO_ALG_ASYNC); + err = PTR_ERR(alg); + if (IS_ERR(alg)) + continue; + + tfm = __crypto_alloc_tfm(alg, flags); + 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 + * @mask: Mask for type comparison + * + * crypto_alloc_base() will first attempt to locate an already loaded + * algorithm. If that fails and the kernel supports dynamically loadable + * modules, it will then attempt to load a module of the same name or + * alias. If that fails it will send a query to any loaded crypto manager + * to construct an algorithm on the fly. A refcount is grabbed on the + * algorithm which is then associated with the new transform. + * + * The returned transform is of a non-determinate type. Most people + * should use one of the more specific allocation functions such as + * crypto_alloc_blkcipher. + * + * In case of error the return value is an error pointer. + */ +struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask) +{ + struct crypto_tfm *tfm; + int err; + + for (;;) { + struct crypto_alg *alg; + + alg = crypto_alg_mod_lookup(alg_name, type, mask); + err = PTR_ERR(alg); + tfm = ERR_PTR(err); + if (IS_ERR(alg)) + goto err; + + tfm = __crypto_alloc_tfm(alg, 0); + if (!IS_ERR(tfm)) + break; + + crypto_mod_put(alg); + err = PTR_ERR(tfm); +err: + if (err != -EAGAIN) + break; + if (signal_pending(current)) { + err = -EINTR; + break; + } + }; + + return tfm; +} +EXPORT_SYMBOL_GPL(crypto_alloc_base); + +/* + * crypto_free_tfm - Free crypto transform + * @tfm: Transform to free + * + * crypto_free_tfm() frees up the transform and any associated resources, + * then drops the refcount on the associated algorithm. + */ void crypto_free_tfm(struct crypto_tfm *tfm) { struct crypto_alg *alg; @@ -221,108 +460,39 @@ void crypto_free_tfm(struct crypto_tfm *tfm) if (alg->cra_exit) alg->cra_exit(tfm); crypto_exit_ops(tfm); - crypto_alg_put(alg); + crypto_mod_put(alg); memset(tfm, 0, size); kfree(tfm); } -static inline int crypto_set_driver_name(struct crypto_alg *alg) -{ - static const char suffix[] = "-generic"; - char *driver_name = alg->cra_driver_name; - int len; - - if (*driver_name) - return 0; - - len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); - if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME) - return -ENAMETOOLONG; - - memcpy(driver_name + len, suffix, sizeof(suffix)); - return 0; -} - -int crypto_register_alg(struct crypto_alg *alg) +int crypto_alg_available(const char *name, u32 flags) { - int ret; - struct crypto_alg *q; - - if (alg->cra_alignmask & (alg->cra_alignmask + 1)) - return -EINVAL; - - if (alg->cra_alignmask & alg->cra_blocksize) - return -EINVAL; - - if (alg->cra_blocksize > PAGE_SIZE / 8) - return -EINVAL; - - if (alg->cra_priority < 0) - return -EINVAL; - - ret = crypto_set_driver_name(alg); - if (unlikely(ret)) - return ret; - - down_write(&crypto_alg_sem); + int ret = 0; + struct crypto_alg *alg = crypto_alg_mod_lookup(name, 0, + CRYPTO_ALG_ASYNC); - list_for_each_entry(q, &crypto_alg_list, cra_list) { - if (q == alg) { - ret = -EEXIST; - goto out; - } + if (!IS_ERR(alg)) { + crypto_mod_put(alg); + ret = 1; } - list_add(&alg->cra_list, &crypto_alg_list); -out: - up_write(&crypto_alg_sem); return ret; } -int crypto_unregister_alg(struct crypto_alg *alg) -{ - int ret = -ENOENT; - struct crypto_alg *q; - - BUG_ON(!alg->cra_module); - - down_write(&crypto_alg_sem); - list_for_each_entry(q, &crypto_alg_list, cra_list) { - if (alg == q) { - list_del(&alg->cra_list); - ret = 0; - goto out; - } - } -out: - up_write(&crypto_alg_sem); - return ret; -} +EXPORT_SYMBOL_GPL(crypto_alloc_tfm); +EXPORT_SYMBOL_GPL(crypto_free_tfm); +EXPORT_SYMBOL_GPL(crypto_alg_available); -int crypto_alg_available(const char *name, u32 flags) +int crypto_has_alg(const char *name, u32 type, u32 mask) { int ret = 0; - struct crypto_alg *alg = crypto_alg_mod_lookup(name); + struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask); - if (alg) { - crypto_alg_put(alg); + if (!IS_ERR(alg)) { + crypto_mod_put(alg); ret = 1; } return ret; } - -static int __init init_crypto(void) -{ - printk(KERN_INFO "Initializing Cryptographic API\n"); - crypto_init_proc(); - return 0; -} - -__initcall(init_crypto); - -EXPORT_SYMBOL_GPL(crypto_register_alg); -EXPORT_SYMBOL_GPL(crypto_unregister_alg); -EXPORT_SYMBOL_GPL(crypto_alloc_tfm); -EXPORT_SYMBOL_GPL(crypto_free_tfm); -EXPORT_SYMBOL_GPL(crypto_alg_available); +EXPORT_SYMBOL_GPL(crypto_has_alg); |