Diff: library/xtea.c

Revision:

0:cdf462088d13

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/library/xtea.c	Thu Jan 05 00:18:44 2017 +0000
@@ -0,0 +1,281 @@
+/*
+ *  An 32-bit implementation of the XTEA algorithm
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_XTEA_C)
+
+#include "mbedtls/xtea.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_SELF_TEST)
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdio.h>
+#define mbedtls_printf printf
+#endif /* MBEDTLS_PLATFORM_C */
+#endif /* MBEDTLS_SELF_TEST */
+
+#if !defined(MBEDTLS_XTEA_ALT)
+
+/* Implementation that should never be optimized out by the compiler */
+static void mbedtls_zeroize( void *v, size_t n ) {
+    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
+/*
+ * 32-bit integer manipulation macros (big endian)
+ */
+#ifndef GET_UINT32_BE
+#define GET_UINT32_BE(n,b,i)                            \
+{                                                       \
+    (n) = ( (uint32_t) (b)[(i)    ] << 24 )             \
+        | ( (uint32_t) (b)[(i) + 1] << 16 )             \
+        | ( (uint32_t) (b)[(i) + 2] <<  8 )             \
+        | ( (uint32_t) (b)[(i) + 3]       );            \
+}
+#endif
+
+#ifndef PUT_UINT32_BE
+#define PUT_UINT32_BE(n,b,i)                            \
+{                                                       \
+    (b)[(i)    ] = (unsigned char) ( (n) >> 24 );       \
+    (b)[(i) + 1] = (unsigned char) ( (n) >> 16 );       \
+    (b)[(i) + 2] = (unsigned char) ( (n) >>  8 );       \
+    (b)[(i) + 3] = (unsigned char) ( (n)       );       \
+}
+#endif
+
+void mbedtls_xtea_init( mbedtls_xtea_context *ctx )
+{
+    memset( ctx, 0, sizeof( mbedtls_xtea_context ) );
+}
+
+void mbedtls_xtea_free( mbedtls_xtea_context *ctx )
+{
+    if( ctx == NULL )
+        return;
+
+    mbedtls_zeroize( ctx, sizeof( mbedtls_xtea_context ) );
+}
+
+/*
+ * XTEA key schedule
+ */
+void mbedtls_xtea_setup( mbedtls_xtea_context *ctx, const unsigned char key[16] )
+{
+    int i;
+
+    memset( ctx, 0, sizeof(mbedtls_xtea_context) );
+
+    for( i = 0; i < 4; i++ )
+    {
+        GET_UINT32_BE( ctx->k[i], key, i << 2 );
+    }
+}
+
+/*
+ * XTEA encrypt function
+ */
+int mbedtls_xtea_crypt_ecb( mbedtls_xtea_context *ctx, int mode,
+                    const unsigned char input[8], unsigned char output[8])
+{
+    uint32_t *k, v0, v1, i;
+
+    k = ctx->k;
+
+    GET_UINT32_BE( v0, input, 0 );
+    GET_UINT32_BE( v1, input, 4 );
+
+    if( mode == MBEDTLS_XTEA_ENCRYPT )
+    {
+        uint32_t sum = 0, delta = 0x9E3779B9;
+
+        for( i = 0; i < 32; i++ )
+        {
+            v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
+            sum += delta;
+            v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
+        }
+    }
+    else /* MBEDTLS_XTEA_DECRYPT */
+    {
+        uint32_t delta = 0x9E3779B9, sum = delta * 32;
+
+        for( i = 0; i < 32; i++ )
+        {
+            v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum>>11) & 3]);
+            sum -= delta;
+            v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
+        }
+    }
+
+    PUT_UINT32_BE( v0, output, 0 );
+    PUT_UINT32_BE( v1, output, 4 );
+
+    return( 0 );
+}
+
+#if defined(MBEDTLS_CIPHER_MODE_CBC)
+/*
+ * XTEA-CBC buffer encryption/decryption
+ */
+int mbedtls_xtea_crypt_cbc( mbedtls_xtea_context *ctx, int mode, size_t length,
+                    unsigned char iv[8], const unsigned char *input,
+                    unsigned char *output)
+{
+    int i;
+    unsigned char temp[8];
+
+    if( length % 8 )
+        return( MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH );
+
+    if( mode == MBEDTLS_XTEA_DECRYPT )
+    {
+        while( length > 0 )
+        {
+            memcpy( temp, input, 8 );
+            mbedtls_xtea_crypt_ecb( ctx, mode, input, output );
+
+            for( i = 0; i < 8; i++ )
+                output[i] = (unsigned char)( output[i] ^ iv[i] );
+
+            memcpy( iv, temp, 8 );
+
+            input  += 8;
+            output += 8;
+            length -= 8;
+        }
+    }
+    else
+    {
+        while( length > 0 )
+        {
+            for( i = 0; i < 8; i++ )
+                output[i] = (unsigned char)( input[i] ^ iv[i] );
+
+            mbedtls_xtea_crypt_ecb( ctx, mode, output, output );
+            memcpy( iv, output, 8 );
+
+            input  += 8;
+            output += 8;
+            length -= 8;
+        }
+    }
+
+    return( 0 );
+}
+#endif /* MBEDTLS_CIPHER_MODE_CBC */
+#endif /* !MBEDTLS_XTEA_ALT */
+
+#if defined(MBEDTLS_SELF_TEST)
+
+/*
+ * XTEA tests vectors (non-official)
+ */
+
+static const unsigned char xtea_test_key[6][16] =
+{
+   { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
+     0x0c, 0x0d, 0x0e, 0x0f },
+   { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
+     0x0c, 0x0d, 0x0e, 0x0f },
+   { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
+     0x0c, 0x0d, 0x0e, 0x0f },
+   { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+     0x00, 0x00, 0x00, 0x00 },
+   { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+     0x00, 0x00, 0x00, 0x00 },
+   { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+     0x00, 0x00, 0x00, 0x00 }
+};
+
+static const unsigned char xtea_test_pt[6][8] =
+{
+    { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
+    { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
+    { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
+    { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
+    { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
+    { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }
+};
+
+static const unsigned char xtea_test_ct[6][8] =
+{
+    { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 },
+    { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 },
+    { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
+    { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 },
+    { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d },
+    { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
+};
+
+/*
+ * Checkup routine
+ */
+int mbedtls_xtea_self_test( int verbose )
+{
+    int i, ret = 0;
+    unsigned char buf[8];
+    mbedtls_xtea_context ctx;
+
+    mbedtls_xtea_init( &ctx );
+    for( i = 0; i < 6; i++ )
+    {
+        if( verbose != 0 )
+            mbedtls_printf( "  XTEA test #%d: ", i + 1 );
+
+        memcpy( buf, xtea_test_pt[i], 8 );
+
+        mbedtls_xtea_setup( &ctx, xtea_test_key[i] );
+        mbedtls_xtea_crypt_ecb( &ctx, MBEDTLS_XTEA_ENCRYPT, buf, buf );
+
+        if( memcmp( buf, xtea_test_ct[i], 8 ) != 0 )
+        {
+            if( verbose != 0 )
+                mbedtls_printf( "failed\n" );
+
+            ret = 1;
+            goto exit;
+        }
+
+        if( verbose != 0 )
+            mbedtls_printf( "passed\n" );
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "\n" );
+
+exit:
+    mbedtls_xtea_free( &ctx );
+
+    return( ret );
+}
+
+#endif /* MBEDTLS_SELF_TEST */
+
+#endif /* MBEDTLS_XTEA_C */