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-rw-r--r--crypto/tea.c279
1 files changed, 279 insertions, 0 deletions
diff --git a/crypto/tea.c b/crypto/tea.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cryptographic API.
+ *
+ * TEA, XTEA, and XETA crypto alogrithms
+ *
+ * The TEA and Xtended TEA algorithms were developed by David Wheeler
+ * and Roger Needham at the Computer Laboratory of Cambridge University.
+ *
+ * Due to the order of evaluation in XTEA many people have incorrectly
+ * implemented it. XETA (XTEA in the wrong order), exists for
+ * compatibility with these implementations.
+ *
+ * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com
+ */
+
+#include <crypto/algapi.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <asm/byteorder.h>
+#include <linux/types.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
+
+struct tea_ctx {
+ u32 KEY[4];
+};
+
+struct xtea_ctx {
+ u32 KEY[4];
+};
+
+static int tea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *key = (const __le32 *)in_key;
+
+ ctx->KEY[0] = le32_to_cpu(key[0]);
+ ctx->KEY[1] = le32_to_cpu(key[1]);
+ ctx->KEY[2] = le32_to_cpu(key[2]);
+ ctx->KEY[3] = le32_to_cpu(key[3]);
+
+ return 0;
+
+}
+
+static void tea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+ u32 y, z, n, sum = 0;
+ u32 k0, k1, k2, k3;
+ struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *in = (const __le32 *)src;
+ __le32 *out = (__le32 *)dst;
+
+ y = le32_to_cpu(in[0]);
+ z = le32_to_cpu(in[1]);
+
+ 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);
+ }
+
+ out[0] = cpu_to_le32(y);
+ out[1] = cpu_to_le32(z);
+}
+
+static void tea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+ u32 y, z, n, sum;
+ u32 k0, k1, k2, k3;
+ struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *in = (const __le32 *)src;
+ __le32 *out = (__le32 *)dst;
+
+ y = le32_to_cpu(in[0]);
+ z = le32_to_cpu(in[1]);
+
+ 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;
+ }
+
+ out[0] = cpu_to_le32(y);
+ out[1] = cpu_to_le32(z);
+}
+
+static int xtea_setkey(struct crypto_tfm *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *key = (const __le32 *)in_key;
+
+ ctx->KEY[0] = le32_to_cpu(key[0]);
+ ctx->KEY[1] = le32_to_cpu(key[1]);
+ ctx->KEY[2] = le32_to_cpu(key[2]);
+ ctx->KEY[3] = le32_to_cpu(key[3]);
+
+ return 0;
+
+}
+
+static void xtea_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+ u32 y, z, sum = 0;
+ u32 limit = XTEA_DELTA * XTEA_ROUNDS;
+ struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *in = (const __le32 *)src;
+ __le32 *out = (__le32 *)dst;
+
+ y = le32_to_cpu(in[0]);
+ z = le32_to_cpu(in[1]);
+
+ while (sum != limit) {
+ y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]);
+ sum += XTEA_DELTA;
+ z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]);
+ }
+
+ out[0] = cpu_to_le32(y);
+ out[1] = cpu_to_le32(z);
+}
+
+static void xtea_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+ u32 y, z, sum;
+ struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *in = (const __le32 *)src;
+ __le32 *out = (__le32 *)dst;
+
+ y = le32_to_cpu(in[0]);
+ z = le32_to_cpu(in[1]);
+
+ 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]);
+ }
+
+ out[0] = cpu_to_le32(y);
+ out[1] = cpu_to_le32(z);
+}
+
+
+static void xeta_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+ u32 y, z, sum = 0;
+ u32 limit = XTEA_DELTA * XTEA_ROUNDS;
+ struct xtea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *in = (const __le32 *)src;
+ __le32 *out = (__le32 *)dst;
+
+ y = le32_to_cpu(in[0]);
+ z = le32_to_cpu(in[1]);
+
+ while (sum != limit) {
+ y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3];
+ sum += XTEA_DELTA;
+ z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3];
+ }
+
+ out[0] = cpu_to_le32(y);
+ out[1] = cpu_to_le32(z);
+}
+
+static void xeta_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
+{
+ u32 y, z, sum;
+ struct tea_ctx *ctx = crypto_tfm_ctx(tfm);
+ const __le32 *in = (const __le32 *)src;
+ __le32 *out = (__le32 *)dst;
+
+ y = le32_to_cpu(in[0]);
+ z = le32_to_cpu(in[1]);
+
+ 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];
+ }
+
+ out[0] = cpu_to_le32(y);
+ out[1] = cpu_to_le32(z);
+}
+
+static struct crypto_alg tea_algs[3] = { {
+ .cra_name = "tea",
+ .cra_driver_name = "tea-generic",
+ .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
+ .cra_blocksize = TEA_BLOCK_SIZE,
+ .cra_ctxsize = sizeof (struct tea_ctx),
+ .cra_alignmask = 3,
+ .cra_module = THIS_MODULE,
+ .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 } }
+}, {
+ .cra_name = "xtea",
+ .cra_driver_name = "xtea-generic",
+ .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
+ .cra_blocksize = XTEA_BLOCK_SIZE,
+ .cra_ctxsize = sizeof (struct xtea_ctx),
+ .cra_alignmask = 3,
+ .cra_module = THIS_MODULE,
+ .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 } }
+}, {
+ .cra_name = "xeta",
+ .cra_driver_name = "xeta-generic",
+ .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
+ .cra_blocksize = XTEA_BLOCK_SIZE,
+ .cra_ctxsize = sizeof (struct xtea_ctx),
+ .cra_alignmask = 3,
+ .cra_module = THIS_MODULE,
+ .cra_u = { .cipher = {
+ .cia_min_keysize = XTEA_KEY_SIZE,
+ .cia_max_keysize = XTEA_KEY_SIZE,
+ .cia_setkey = xtea_setkey,
+ .cia_encrypt = xeta_encrypt,
+ .cia_decrypt = xeta_decrypt } }
+} };
+
+static int __init tea_mod_init(void)
+{
+ return crypto_register_algs(tea_algs, ARRAY_SIZE(tea_algs));
+}
+
+static void __exit tea_mod_fini(void)
+{
+ crypto_unregister_algs(tea_algs, ARRAY_SIZE(tea_algs));
+}
+
+MODULE_ALIAS_CRYPTO("tea");
+MODULE_ALIAS_CRYPTO("xtea");
+MODULE_ALIAS_CRYPTO("xeta");
+
+subsys_initcall(tea_mod_init);
+module_exit(tea_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");