Diff: library/base64.c

Revision:

0:cdf462088d13

Child:

1:9ebc941037d5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/library/base64.c	Thu Jan 05 00:18:44 2017 +0000
@@ -0,0 +1,289 @@
+/*
+ *  RFC 1521 base64 encoding/decoding
+ *
+ *  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_BASE64_C)
+
+#include "mbedtls/base64.h"
+
+#include <stdint.h>
+
+#if defined(MBEDTLS_SELF_TEST)
+#include <string.h>
+#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 */
+
+static const unsigned char base64_enc_map[64] =
+{
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
+    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
+    'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
+    'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+    'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
+    'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
+    '8', '9', '+', '/'
+};
+
+static const unsigned char base64_dec_map[128] =
+{
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127,  62, 127, 127, 127,  63,  52,  53,
+     54,  55,  56,  57,  58,  59,  60,  61, 127, 127,
+    127,  64, 127, 127, 127,   0,   1,   2,   3,   4,
+      5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+     15,  16,  17,  18,  19,  20,  21,  22,  23,  24,
+     25, 127, 127, 127, 127, 127, 127,  26,  27,  28,
+     29,  30,  31,  32,  33,  34,  35,  36,  37,  38,
+     39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
+     49,  50,  51, 127, 127, 127, 127, 127
+};
+
+#define BASE64_SIZE_T_MAX   ( (size_t) -1 ) /* SIZE_T_MAX is not standard */
+
+/*
+ * Encode a buffer into base64 format
+ */
+int mbedtls_base64_encode( unsigned char *dst, size_t dlen, size_t *olen,
+                   const unsigned char *src, size_t slen )
+{
+    size_t i, n;
+    int C1, C2, C3;
+    unsigned char *p;
+
+    if( slen == 0 )
+    {
+        *olen = 0;
+        return( 0 );
+    }
+
+    n = slen / 3 + ( slen % 3 != 0 );
+
+    if( n > ( BASE64_SIZE_T_MAX - 1 ) / 4 )
+    {
+        *olen = BASE64_SIZE_T_MAX;
+        return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
+    }
+
+    n *= 4;
+
+    if( ( dlen < n + 1 ) || ( NULL == dst ) )
+    {
+        *olen = n + 1;
+        return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
+    }
+
+    n = ( slen / 3 ) * 3;
+
+    for( i = 0, p = dst; i < n; i += 3 )
+    {
+        C1 = *src++;
+        C2 = *src++;
+        C3 = *src++;
+
+        *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
+        *p++ = base64_enc_map[(((C1 &  3) << 4) + (C2 >> 4)) & 0x3F];
+        *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F];
+        *p++ = base64_enc_map[C3 & 0x3F];
+    }
+
+    if( i < slen )
+    {
+        C1 = *src++;
+        C2 = ( ( i + 1 ) < slen ) ? *src++ : 0;
+
+        *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
+        *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
+
+        if( ( i + 1 ) < slen )
+             *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F];
+        else *p++ = '=';
+
+        *p++ = '=';
+    }
+
+    *olen = p - dst;
+    *p = 0;
+
+    return( 0 );
+}
+
+/*
+ * Decode a base64-formatted buffer
+ */
+int mbedtls_base64_decode( unsigned char *dst, size_t dlen, size_t *olen,
+                   const unsigned char *src, size_t slen )
+{
+    size_t i, n;
+    uint32_t j, x;
+    unsigned char *p;
+
+    /* First pass: check for validity and get output length */
+    for( i = n = j = 0; i < slen; i++ )
+    {
+        /* Skip spaces before checking for EOL */
+        x = 0;
+        while( i < slen && src[i] == ' ' )
+        {
+            ++i;
+            ++x;
+        }
+
+        /* Spaces at end of buffer are OK */
+        if( i == slen )
+            break;
+
+        if( ( slen - i ) >= 2 &&
+            src[i] == '\r' && src[i + 1] == '\n' )
+            continue;
+
+        if( src[i] == '\n' )
+            continue;
+
+        /* Space inside a line is an error */
+        if( x != 0 )
+            return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
+
+        if( src[i] == '=' && ++j > 2 )
+            return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
+
+        if( src[i] > 127 || base64_dec_map[src[i]] == 127 )
+            return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
+
+        if( base64_dec_map[src[i]] < 64 && j != 0 )
+            return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
+
+        n++;
+    }
+
+    if( n == 0 )
+    {
+        *olen = 0;
+        return( 0 );
+    }
+
+    n = ( ( n * 6 ) + 7 ) >> 3;
+    n -= j;
+
+    if( dst == NULL || dlen < n )
+    {
+        *olen = n;
+        return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
+    }
+
+   for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ )
+   {
+        if( *src == '\r' || *src == '\n' || *src == ' ' )
+            continue;
+
+        j -= ( base64_dec_map[*src] == 64 );
+        x  = ( x << 6 ) | ( base64_dec_map[*src] & 0x3F );
+
+        if( ++n == 4 )
+        {
+            n = 0;
+            if( j > 0 ) *p++ = (unsigned char)( x >> 16 );
+            if( j > 1 ) *p++ = (unsigned char)( x >>  8 );
+            if( j > 2 ) *p++ = (unsigned char)( x       );
+        }
+    }
+
+    *olen = p - dst;
+
+    return( 0 );
+}
+
+#if defined(MBEDTLS_SELF_TEST)
+
+static const unsigned char base64_test_dec[64] =
+{
+    0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD,
+    0xBF, 0x17, 0xD9, 0xA2, 0xC4, 0x17, 0x1A, 0x01,
+    0x94, 0xED, 0x8F, 0x1E, 0x11, 0xB3, 0xD7, 0x09,
+    0x0C, 0xB6, 0xE9, 0x10, 0x6F, 0x22, 0xEE, 0x13,
+    0xCA, 0xB3, 0x07, 0x05, 0x76, 0xC9, 0xFA, 0x31,
+    0x6C, 0x08, 0x34, 0xFF, 0x8D, 0xC2, 0x6C, 0x38,
+    0x00, 0x43, 0xE9, 0x54, 0x97, 0xAF, 0x50, 0x4B,
+    0xD1, 0x41, 0xBA, 0x95, 0x31, 0x5A, 0x0B, 0x97
+};
+
+static const unsigned char base64_test_enc[] =
+    "JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i7hPK"
+    "swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw==";
+
+/*
+ * Checkup routine
+ */
+int mbedtls_base64_self_test( int verbose )
+{
+    size_t len;
+    const unsigned char *src;
+    unsigned char buffer[128];
+
+    if( verbose != 0 )
+        mbedtls_printf( "  Base64 encoding test: " );
+
+    src = base64_test_dec;
+
+    if( mbedtls_base64_encode( buffer, sizeof( buffer ), &len, src, 64 ) != 0 ||
+         memcmp( base64_test_enc, buffer, 88 ) != 0 )
+    {
+        if( verbose != 0 )
+            mbedtls_printf( "failed\n" );
+
+        return( 1 );
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\n  Base64 decoding test: " );
+
+    src = base64_test_enc;
+
+    if( mbedtls_base64_decode( buffer, sizeof( buffer ), &len, src, 88 ) != 0 ||
+         memcmp( base64_test_dec, buffer, 64 ) != 0 )
+    {
+        if( verbose != 0 )
+            mbedtls_printf( "failed\n" );
+
+        return( 1 );
+    }
+
+    if( verbose != 0 )
+        mbedtls_printf( "passed\n\n" );
+
+    return( 0 );
+}
+
+#endif /* MBEDTLS_SELF_TEST */
+
+#endif /* MBEDTLS_BASE64_C */