patch-2.4.22 linux-2.4.22/crypto/api.c

• Lines: 228
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/crypto/api.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/crypto/api.c linux-2.4.22/crypto/api.c
@@ -0,0 +1,227 @@
+/*
+ * 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_inc_mod_count(alg->cra_module);
+}
+
+static inline void crypto_alg_put(struct crypto_alg *alg)
+{
+	if (alg->cra_module)
+		__MOD_DEC_USE_COUNT(alg->cra_module);
+}
+
+struct crypto_alg *crypto_alg_lookup(const char *name)
+{
+	struct crypto_alg *q, *alg = 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)
+{
+	crypto_exit_ops(tfm);
+	crypto_alg_put(tfm->__crt_alg);
+	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);