X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=crypto%2Ftea.c;h=a6a02b30e47072b76f41a695343709a82e21a4d3;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=03c23cbd3afa1f6373d964b308463701ab316458;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/crypto/tea.c b/crypto/tea.c index 03c23cbd3..a6a02b30e 100644 --- a/crypto/tea.c +++ b/crypto/tea.c @@ -1,11 +1,15 @@ /* * Cryptographic API. * - * TEA and Xtended TEA Algorithms + * 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 * * This program is free software; you can redistribute it and/or modify @@ -18,8 +22,10 @@ #include #include #include +#include #include #include +#include #define TEA_KEY_SIZE 16 #define TEA_BLOCK_SIZE 8 @@ -31,9 +37,6 @@ #define XTEA_ROUNDS 32 #define XTEA_DELTA 0x9e3779b9 -#define u32_in(x) le32_to_cpu(*(const __le32 *)(x)) -#define u32_out(to, from) (*(__le32 *)(to) = cpu_to_le32(from)) - struct tea_ctx { u32 KEY[4]; }; @@ -45,8 +48,8 @@ struct xtea_ctx { static int tea_setkey(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) { - struct tea_ctx *ctx = ctx_arg; + const __le32 *key = (const __le32 *)in_key; if (key_len != 16) { @@ -54,10 +57,10 @@ static int tea_setkey(void *ctx_arg, const u8 *in_key, 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); + 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; @@ -69,9 +72,11 @@ static void tea_encrypt(void *ctx_arg, u8 *dst, const u8 *src) u32 k0, k1, k2, k3; struct tea_ctx *ctx = ctx_arg; + const __le32 *in = (const __le32 *)src; + __le32 *out = (__le32 *)dst; - y = u32_in (src); - z = u32_in (src + 4); + y = le32_to_cpu(in[0]); + z = le32_to_cpu(in[1]); k0 = ctx->KEY[0]; k1 = ctx->KEY[1]; @@ -86,19 +91,20 @@ static void tea_encrypt(void *ctx_arg, u8 *dst, const u8 *src) z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); } - u32_out (dst, y); - u32_out (dst + 4, z); + out[0] = cpu_to_le32(y); + out[1] = cpu_to_le32(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; + const __le32 *in = (const __le32 *)src; + __le32 *out = (__le32 *)dst; - y = u32_in (src); - z = u32_in (src + 4); + y = le32_to_cpu(in[0]); + z = le32_to_cpu(in[1]); k0 = ctx->KEY[0]; k1 = ctx->KEY[1]; @@ -115,16 +121,15 @@ static void tea_decrypt(void *ctx_arg, u8 *dst, const u8 *src) sum -= TEA_DELTA; } - u32_out (dst, y); - u32_out (dst + 4, z); - + out[0] = cpu_to_le32(y); + out[1] = cpu_to_le32(z); } static int xtea_setkey(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) { - struct xtea_ctx *ctx = ctx_arg; + const __le32 *key = (const __le32 *)in_key; if (key_len != 16) { @@ -132,10 +137,10 @@ static int xtea_setkey(void *ctx_arg, const u8 *in_key, 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); + 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; @@ -143,34 +148,80 @@ static int xtea_setkey(void *ctx_arg, const u8 *in_key, 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; + const __le32 *in = (const __le32 *)src; + __le32 *out = (__le32 *)dst; - y = u32_in (src); - z = u32_in (src + 4); + 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]; + 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]; + z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]); } - u32_out (dst, y); - u32_out (dst + 4, z); - + out[0] = cpu_to_le32(y); + out[1] = cpu_to_le32(z); } static void xtea_decrypt(void *ctx_arg, u8 *dst, const u8 *src) { + u32 y, z, sum; + struct tea_ctx *ctx = ctx_arg; + 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(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; + 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(void *ctx_arg, u8 *dst, const u8 *src) +{ u32 y, z, sum; struct tea_ctx *ctx = ctx_arg; + const __le32 *in = (const __le32 *)src; + __le32 *out = (__le32 *)dst; - y = u32_in (src); - z = u32_in (src + 4); + y = le32_to_cpu(in[0]); + z = le32_to_cpu(in[1]); sum = XTEA_DELTA * XTEA_ROUNDS; @@ -180,9 +231,8 @@ static void xtea_decrypt(void *ctx_arg, u8 *dst, const u8 *src) y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3]; } - u32_out (dst, y); - u32_out (dst + 4, z); - + out[0] = cpu_to_le32(y); + out[1] = cpu_to_le32(z); } static struct crypto_alg tea_alg = { @@ -190,6 +240,7 @@ static struct crypto_alg tea_alg = { .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_list = LIST_HEAD_INIT(tea_alg.cra_list), .cra_u = { .cipher = { @@ -205,6 +256,7 @@ static struct crypto_alg xtea_alg = { .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_list = LIST_HEAD_INIT(xtea_alg.cra_list), .cra_u = { .cipher = { @@ -215,6 +267,22 @@ static struct crypto_alg xtea_alg = { .cia_decrypt = xtea_decrypt } } }; +static struct crypto_alg xeta_alg = { + .cra_name = "xeta", + .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_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 = xeta_encrypt, + .cia_decrypt = xeta_decrypt } } +}; + static int __init init(void) { int ret = 0; @@ -229,6 +297,13 @@ static int __init init(void) goto out; } + ret = crypto_register_alg(&xeta_alg); + if (ret < 0) { + crypto_unregister_alg(&tea_alg); + crypto_unregister_alg(&xtea_alg); + goto out; + } + out: return ret; } @@ -237,12 +312,14 @@ static void __exit fini(void) { crypto_unregister_alg(&tea_alg); crypto_unregister_alg(&xtea_alg); + crypto_unregister_alg(&xeta_alg); } MODULE_ALIAS("xtea"); +MODULE_ALIAS("xeta"); module_init(init); module_exit(fini); MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("TEA & XTEA Cryptographic Algorithms"); +MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms");