--- /dev/null
+/*
+ * 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_ALIAS("xtea");
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TEA & XTEA Cryptographic Algorithms");
git://git.onelab.eu / linux-2.6.git / blobdiff