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-rw-r--r--crypto/api.c233
1 files changed, 233 insertions, 0 deletions
diff --git a/crypto/api.c b/crypto/api.c
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index 0000000..394169a
--- /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);
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