]> nv-tegra.nvidia Code Review - linux-3.10.git/blobdiff - crypto/api.c
[CRYPTO] api: Added crypto_type support
[linux-3.10.git] / crypto / api.c
index e26156f718395393bc50883bc61edc7b2a7e2d22..edaa843d8e83b04beece1f5b51ffb8efbb1a6299 100644 (file)
  *
  */
 
-#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);
@@ -146,180 +287,198 @@ 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;
+       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 = kmalloc(tfm_size, GFP_KERNEL);
+       tfm = kzalloc(tfm_size, GFP_KERNEL);
        if (tfm == NULL)
-               goto out_put;
+               goto out;
 
-       memset(tfm, 0, tfm_size);
-       
        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)) {
-               crypto_exit_ops(tfm);
+       err = crypto_init_ops(tfm);
+       if (err)
                goto out_free_tfm;
+
+       if (alg->cra_init && (err = alg->cra_init(tfm))) {
+               if (err == -EAGAIN)
+                       crypto_shoot_alg(alg);
+               goto cra_init_failed;
        }
 
        goto out;
 
+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);
 
-void crypto_free_tfm(struct crypto_tfm *tfm)
+struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
 {
-       struct crypto_alg *alg;
-       int size;
-
-       if (unlikely(!tfm))
-               return;
-
-       alg = tfm->__crt_alg;
-       size = sizeof(*tfm) + alg->cra_ctxsize;
-
-       crypto_exit_ops(tfm);
-       crypto_alg_put(alg);
-       memset(tfm, 0, size);
-       kfree(tfm);
-}
+       struct crypto_tfm *tfm = NULL;
+       int err;
 
-static inline int crypto_set_driver_name(struct crypto_alg *alg)
-{
-       static const char suffix[] = "-generic";
-       char *driver_name = (char *)alg->cra_driver_name;
-       int len;
+       do {
+               struct crypto_alg *alg;
 
-       if (*driver_name)
-               return 0;
+               alg = crypto_alg_mod_lookup(name, 0, CRYPTO_ALG_ASYNC);
+               err = PTR_ERR(alg);
+               if (IS_ERR(alg))
+                       continue;
 
-       len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
-       if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
-               return -ENAMETOOLONG;
+               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));
 
-       memcpy(driver_name + len, suffix, sizeof(suffix));
-       return 0;
+       return tfm;
 }
 
-int crypto_register_alg(struct crypto_alg *alg)
+/*
+ *     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)
 {
-       int ret;
-       struct crypto_alg *q;
+       struct crypto_tfm *tfm;
+       int err;
 
-       if (alg->cra_alignmask & (alg->cra_alignmask + 1))
-               return -EINVAL;
+       for (;;) {
+               struct crypto_alg *alg;
 
-       if (alg->cra_alignmask & alg->cra_blocksize)
-               return -EINVAL;
+               alg = crypto_alg_mod_lookup(alg_name, type, mask);
+               err = PTR_ERR(alg);
+               tfm = ERR_PTR(err);
+               if (IS_ERR(alg))
+                       goto err;
 
-       if (alg->cra_blocksize > PAGE_SIZE / 8)
-               return -EINVAL;
+               tfm = __crypto_alloc_tfm(alg, 0);
+               if (!IS_ERR(tfm))
+                       break;
 
-       if (alg->cra_priority < 0)
-               return -EINVAL;
-       
-       ret = crypto_set_driver_name(alg);
-       if (unlikely(ret))
-               return ret;
+               crypto_mod_put(alg);
+               err = PTR_ERR(tfm);
 
-       down_write(&crypto_alg_sem);
-       
-       list_for_each_entry(q, &crypto_alg_list, cra_list) {
-               if (!strcmp(q->cra_driver_name, alg->cra_driver_name)) {
-                       ret = -EEXIST;
-                       goto out;
+err:
+               if (err != -EAGAIN)
+                       break;
+               if (signal_pending(current)) {
+                       err = -EINTR;
+                       break;
                }
-       }
-       
-       list_add_tail(&alg->cra_list, &crypto_alg_list);
-out:   
-       up_write(&crypto_alg_sem);
-       return ret;
-}
+       };
 
-int crypto_unregister_alg(struct crypto_alg *alg)
+       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)
 {
-       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;
+       struct crypto_alg *alg;
+       int size;
+
+       if (unlikely(!tfm))
+               return;
+
+       alg = tfm->__crt_alg;
+       size = sizeof(*tfm) + alg->cra_ctxsize;
+
+       if (alg->cra_exit)
+               alg->cra_exit(tfm);
+       crypto_exit_ops(tfm);
+       crypto_mod_put(alg);
+       memset(tfm, 0, size);
+       kfree(tfm);
 }
 
 int crypto_alg_available(const char *name, u32 flags)
 {
        int ret = 0;
-       struct crypto_alg *alg = crypto_alg_mod_lookup(name);
+       struct crypto_alg *alg = crypto_alg_mod_lookup(name, 0,
+                                                      CRYPTO_ALG_ASYNC);
        
-       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);