patch-2.4.27 linux-2.4.27/crypto/tea.c

• Lines: 247
• Date: 2004-08-07 16:26:04.644346367 -0700
• Orig file: linux-2.4.26/crypto/tea.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.26/crypto/tea.c linux-2.4.27/crypto/tea.c
@@ -0,0 +1,246 @@
+/* 
+ * Cryptographic API.
+ *
+ * TEA and Xtended TEA Algorithms
+ *
+ * The TEA and Xtended TEA algorithms were developed by David Wheeler 
+ * and Roger Needham at the Computer Laboratory of Cambridge University.
+ *
+ * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
+ *
+ * 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/module.h>
+#include <linux/mm.h>
+#include <asm/scatterlist.h>
+#include <linux/crypto.h>
+
+#define TEA_KEY_SIZE		16
+#define TEA_BLOCK_SIZE		8
+#define TEA_ROUNDS		32
+#define TEA_DELTA		0x9e3779b9
+
+#define XTEA_KEY_SIZE		16
+#define XTEA_BLOCK_SIZE		8
+#define XTEA_ROUNDS		32
+#define XTEA_DELTA		0x9e3779b9
+
+#define u32_in(x) le32_to_cpu(*(const u32 *)(x))
+#define u32_out(to, from) (*(u32 *)(to) = cpu_to_le32(from))
+
+struct tea_ctx {
+	u32 KEY[4];
+};
+
+struct xtea_ctx {
+	u32 KEY[4];
+};
+
+static int tea_setkey(void *ctx_arg, const u8 *in_key,
+                       unsigned int key_len, u32 *flags)
+{ 
+
+	struct tea_ctx *ctx = ctx_arg;
+	
+	if (key_len != 16)
+	{
+		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+		return -EINVAL;
+	}
+
+	ctx->KEY[0] = u32_in (in_key);
+	ctx->KEY[1] = u32_in (in_key + 4);
+	ctx->KEY[2] = u32_in (in_key + 8);
+	ctx->KEY[3] = u32_in (in_key + 12);
+
+	return 0; 
+
+}
+
+static void tea_encrypt(void *ctx_arg, u8 *dst, const u8 *src)
+{ 
+	u32 y, z, n, sum = 0;
+	u32 k0, k1, k2, k3;
+
+	struct tea_ctx *ctx = ctx_arg;
+
+	y = u32_in (src);
+	z = u32_in (src + 4);
+
+	k0 = ctx->KEY[0];
+	k1 = ctx->KEY[1];
+	k2 = ctx->KEY[2];
+	k3 = ctx->KEY[3];
+
+	n = TEA_ROUNDS;
+
+	while (n-- > 0) {
+		sum += TEA_DELTA;
+		y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
+		z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
+	}
+	
+	u32_out (dst, y);
+	u32_out (dst + 4, z);
+}
+
+static void tea_decrypt(void *ctx_arg, u8 *dst, const u8 *src)
+{ 
+	u32 y, z, n, sum;
+	u32 k0, k1, k2, k3;
+
+	struct tea_ctx *ctx = ctx_arg;
+
+	y = u32_in (src);
+	z = u32_in (src + 4);
+
+	k0 = ctx->KEY[0];
+	k1 = ctx->KEY[1];
+	k2 = ctx->KEY[2];
+	k3 = ctx->KEY[3];
+
+	sum = TEA_DELTA << 5;
+
+	n = TEA_ROUNDS;
+
+	while (n-- > 0) {
+		z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3);
+		y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1);
+		sum -= TEA_DELTA;
+	}
+	
+	u32_out (dst, y);
+	u32_out (dst + 4, z);
+
+}
+
+static int xtea_setkey(void *ctx_arg, const u8 *in_key,
+                       unsigned int key_len, u32 *flags)
+{ 
+
+	struct xtea_ctx *ctx = ctx_arg;
+	
+	if (key_len != 16)
+	{
+		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+		return -EINVAL;
+	}
+
+	ctx->KEY[0] = u32_in (in_key);
+	ctx->KEY[1] = u32_in (in_key + 4);
+	ctx->KEY[2] = u32_in (in_key + 8);
+	ctx->KEY[3] = u32_in (in_key + 12);
+
+	return 0; 
+
+}
+
+static void xtea_encrypt(void *ctx_arg, u8 *dst, const u8 *src)
+{ 
+
+	u32 y, z, sum = 0;
+	u32 limit = XTEA_DELTA * XTEA_ROUNDS;
+
+	struct xtea_ctx *ctx = ctx_arg;
+
+	y = u32_in (src);
+	z = u32_in (src + 4);
+
+	while (sum != limit) {
+		y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3]; 
+		sum += TEA_DELTA;
+		z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3]; 
+	}
+	
+	u32_out (dst, y);
+	u32_out (dst + 4, z);
+
+}
+
+static void xtea_decrypt(void *ctx_arg, u8 *dst, const u8 *src)
+{ 
+
+	u32 y, z, sum;
+	struct tea_ctx *ctx = ctx_arg;
+
+	y = u32_in (src);
+	z = u32_in (src + 4);
+
+	sum = XTEA_DELTA * XTEA_ROUNDS;
+
+	while (sum) {
+		z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3];
+		sum -= XTEA_DELTA;
+		y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3];
+	}
+	
+	u32_out (dst, y);
+	u32_out (dst + 4, z);
+
+}
+
+static struct crypto_alg tea_alg = {
+	.cra_name		=	"tea",
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	TEA_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof (struct tea_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_list		=	LIST_HEAD_INIT(tea_alg.cra_list),
+	.cra_u			=	{ .cipher = {
+	.cia_min_keysize	=	TEA_KEY_SIZE,
+	.cia_max_keysize	=	TEA_KEY_SIZE,
+	.cia_setkey		= 	tea_setkey,
+	.cia_encrypt		=	tea_encrypt,
+	.cia_decrypt		=	tea_decrypt } }
+};
+
+static struct crypto_alg xtea_alg = {
+	.cra_name		=	"xtea",
+	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
+	.cra_blocksize		=	XTEA_BLOCK_SIZE,
+	.cra_ctxsize		=	sizeof (struct xtea_ctx),
+	.cra_module		=	THIS_MODULE,
+	.cra_list		=	LIST_HEAD_INIT(xtea_alg.cra_list),
+	.cra_u			=	{ .cipher = {
+	.cia_min_keysize	=	XTEA_KEY_SIZE,
+	.cia_max_keysize	=	XTEA_KEY_SIZE,
+	.cia_setkey		= 	xtea_setkey,
+	.cia_encrypt		=	xtea_encrypt,
+	.cia_decrypt		=	xtea_decrypt } }
+};
+
+static int __init init(void)
+{
+	int ret = 0;
+	
+	ret = crypto_register_alg(&tea_alg);
+	if (ret < 0)
+		goto out;
+
+	ret = crypto_register_alg(&xtea_alg);
+	if (ret < 0) {
+		crypto_unregister_alg(&tea_alg);
+		goto out;
+	}
+
+out:	
+	return ret;
+}
+
+static void __exit fini(void)
+{
+	crypto_unregister_alg(&tea_alg);
+	crypto_unregister_alg(&xtea_alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TEA & XTEA Cryptographic Algorithms");