1 files changed, 233 insertions, 0 deletions

diff --git a/crypto/api.c b/crypto/api.c
new file mode 100644
index 000000000000..394169a8577d
--- /dev/null
+++ b/crypto/api.c
@@ -0,0 +1,233 @@
+/*
+ * Scatterlist Cryptographic API.
+ *
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2002 David S. Miller (davem@redhat.com)
+ *
+ * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
+ * and Nettle, by Niels Möller.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option) 
+ * any later version.
+ *
+ */
+#include <linux/init.h>
+#include <linux/crypto.h>
+#include <linux/errno.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+LIST_HEAD(crypto_alg_list);
+DECLARE_RWSEM(crypto_alg_sem);
+
+static inline int crypto_alg_get(struct crypto_alg *alg)
+{
+        return try_module_get(alg->cra_module);
+}
+
+static inline void crypto_alg_put(struct crypto_alg *alg)
+{
+        module_put(alg->cra_module);
+}
+
+struct crypto_alg *crypto_alg_lookup(const char *name)
+{
+        struct crypto_alg *q, *alg = NULL;
+
+        if (!name)
+                return NULL;
+        
+        down_read(&crypto_alg_sem);
+        
+        list_for_each_entry(q, &crypto_alg_list, cra_list) {
+                if (!(strcmp(q->cra_name, name))) {
+                        if (crypto_alg_get(q))
+                                alg = q;
+                        break;
+                }
+        }
+        
+        up_read(&crypto_alg_sem);
+        return alg;
+}
+
+static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
+{
+        tfm->crt_flags = 0;
+        
+        switch (crypto_tfm_alg_type(tfm)) {
+        case CRYPTO_ALG_TYPE_CIPHER:
+                return crypto_init_cipher_flags(tfm, flags);
+                
+        case CRYPTO_ALG_TYPE_DIGEST:
+                return crypto_init_digest_flags(tfm, flags);
+                
+        case CRYPTO_ALG_TYPE_COMPRESS:
+                return crypto_init_compress_flags(tfm, flags);
+        
+        default:
+                break;
+        }
+        
+        BUG();
+        return -EINVAL;
+}
+
+static int crypto_init_ops(struct crypto_tfm *tfm)
+{
+        switch (crypto_tfm_alg_type(tfm)) {
+        case CRYPTO_ALG_TYPE_CIPHER:
+                return crypto_init_cipher_ops(tfm);
+                
+        case CRYPTO_ALG_TYPE_DIGEST:
+                return crypto_init_digest_ops(tfm);
+                
+        case CRYPTO_ALG_TYPE_COMPRESS:
+                return crypto_init_compress_ops(tfm);
+        
+        default:
+                break;
+        }
+        
+        BUG();
+        return -EINVAL;
+}
+
+static void crypto_exit_ops(struct crypto_tfm *tfm)
+{
+        switch (crypto_tfm_alg_type(tfm)) {
+        case CRYPTO_ALG_TYPE_CIPHER:
+                crypto_exit_cipher_ops(tfm);
+                break;
+                
+        case CRYPTO_ALG_TYPE_DIGEST:
+                crypto_exit_digest_ops(tfm);
+                break;
+                
+        case CRYPTO_ALG_TYPE_COMPRESS:
+                crypto_exit_compress_ops(tfm);
+                break;
+        
+        default:
+                BUG();
+                
+        }
+}
+
+struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
+{
+        struct crypto_tfm *tfm = NULL;
+        struct crypto_alg *alg;
+
+        alg = crypto_alg_mod_lookup(name);
+        if (alg == NULL)
+                goto out;
+        
+        tfm = kmalloc(sizeof(*tfm) + alg->cra_ctxsize, GFP_KERNEL);
+        if (tfm == NULL)
+                goto out_put;
+
+        memset(tfm, 0, sizeof(*tfm) + alg->cra_ctxsize);
+        
+        tfm->__crt_alg = alg;
+        
+        if (crypto_init_flags(tfm, flags))
+                goto out_free_tfm;
+                
+        if (crypto_init_ops(tfm)) {
+                crypto_exit_ops(tfm);
+                goto out_free_tfm;
+        }
+
+        goto out;
+
+out_free_tfm:
+        kfree(tfm);
+        tfm = NULL;
+out_put:
+        crypto_alg_put(alg);
+out:
+        return tfm;
+}
+
+void crypto_free_tfm(struct crypto_tfm *tfm)
+{
+        struct crypto_alg *alg = tfm->__crt_alg;
+        int size = sizeof(*tfm) + alg->cra_ctxsize;
+
+        crypto_exit_ops(tfm);
+        crypto_alg_put(alg);
+        memset(tfm, 0, size);
+        kfree(tfm);
+}
+
+int crypto_register_alg(struct crypto_alg *alg)
+{
+        int ret = 0;
+        struct crypto_alg *q;
+        
+        down_write(&crypto_alg_sem);
+        
+        list_for_each_entry(q, &crypto_alg_list, cra_list) {
+                if (!(strcmp(q->cra_name, alg->cra_name))) {
+                        ret = -EEXIST;
+                        goto out;
+                }
+        }
+        
+        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)
+{
+        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;
+}
+
+int crypto_alg_available(const char *name, u32 flags)
+{
+        int ret = 0;
+        struct crypto_alg *alg = crypto_alg_mod_lookup(name);
+        
+        if (alg) {
+                crypto_alg_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);