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Diffstat (limited to 'tinySAK/src/tsk_base64.c')
| -rw-r--r-- | tinySAK/src/tsk_base64.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/tinySAK/src/tsk_base64.c b/tinySAK/src/tsk_base64.c new file mode 100644 index 0000000..d94ef5c --- /dev/null +++ b/tinySAK/src/tsk_base64.c @@ -0,0 +1,236 @@ +/*
+* Copyright (C) 2009-2010 Mamadou Diop.
+*
+* Contact: Mamadou Diop <diopmamadou(at)doubango.org>
+*
+* This file is part of Open Source Doubango Framework.
+*
+* DOUBANGO 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 3 of the License, or
+* (at your option) any later version.
+*
+* DOUBANGO is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with DOUBANGO.
+*
+*/
+
+/**@file tsk_base64.c
+ * @brief Base64 encoder and decoder as per RFC 4648.
+ *
+ * @author Mamadou Diop <diopmamadou(at)doubango.org>
+ *
+ * @date Created: Sat Nov 8 16:54:58 2009 mdiop
+ */
+#include "tsk_base64.h"
+
+#include "tsk_memory.h"
+
+/**@defgroup tsk_base64_group Base64 encoder/decoder as per RFC 4648.
+* @brief Provides base64 encoder and decoder functions.
+*/
+
+/** Pad char.*/
+#define TSK_BASE64_PAD '='
+
+/** Encoding block size. */
+#define TSK_BASE64_ENCODE_BLOCK_SIZE 3 /* 24-bit input group */
+/** Decoding block size. */
+#define TSK_BASE64_DECODE_BLOCK_SIZE 4
+
+/*==================================================================
+ Value Encoding Value Encoding Value Encoding Value Encoding
+ 0 A 17 R 34 i 51 z
+ 1 B 18 S 35 j 52 0
+ 2 C 19 T 36 k 53 1
+ 3 D 20 U 37 l 54 2
+ 4 E 21 V 38 m 55 3
+ 5 F 22 W 39 n 56 4
+ 6 G 23 X 40 o 57 5
+ 7 H 24 Y 41 p 58 6
+ 8 I 25 Z 42 q 59 7
+ 9 J 26 a 43 r 60 8
+ 10 K 27 b 44 s 61 9
+ 11 L 28 c 45 t 62 +
+ 12 M 29 d 46 u 63 /
+ 13 N 30 e 47 v
+ 14 O 31 f 48 w (pad) =
+ 15 P 32 g 49 x
+ 16 Q 33 h 50 y
+
+ RFC 4548 - Table 1: The Base 64 Alphabet
+*/
+
+/**@ingroup tsk_base64_group
+* Encodes arbitrary data into base64 format.
+* @param input The input data to encode in base64 format.
+* @param input_size The size of the @a input data.
+* @param output A pointer where to copy the encoded data.
+* If you don't know what will be the size of the output result then set the pointer value to NULL to let the function allocate it of you.
+* In all case it is up to you to free the @a ouput.
+* You can also use @ref TSK_BASE64_ENCODE_LEN to allocate the buffer before calling this method.
+*
+* @retval The size of the encoded data (sizeof(@a output))
+*/
+tsk_size_t tsk_base64_encode(const uint8_t* input, tsk_size_t input_size, char **output)
+{
+ static const char* TSK_BASE64_ENCODE_ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+ /*=================================================================================
+ content T S K
+ ASCII 0x54 0x53 0x4B
+ Binary 0101 0100 0101 0011 0100 1011
+ ------------------------------------------------------------------------------
+ ------------------------------------------------------------------------------
+ Packs of 6bits 010101 000101 001101 001011
+ Indexes 21 5 13 11
+ Base64 encoded V F N L <=== HERE IS THE RESULT OF tsk_base64_encode("TSK")
+ */
+
+ tsk_size_t i = 0;
+ tsk_size_t output_size = 0;
+
+ /* Caller provided his own buffer? */
+ if(!*output){
+ *output = tsk_calloc(1, (TSK_BASE64_ENCODE_LEN(input_size)+1));
+ }
+
+ /* Too short? */
+ if(input_size < TSK_BASE64_ENCODE_BLOCK_SIZE){
+ goto quantum;
+ }
+
+ do{
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ input[i]>> 2 ];
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ (input[i]<<4 | input[i+1]>>4) & 0x3F ];
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ (input[i+1]<<2 | input[i+2]>>6) & 0x3F ];
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ input[i+2] & 0x3F ];
+
+ i += TSK_BASE64_ENCODE_BLOCK_SIZE;
+ }
+ while(( i+ TSK_BASE64_ENCODE_BLOCK_SIZE) <= input_size);
+
+quantum:
+
+ if((input_size - i) == 1){
+ /* The final quantum of encoding input is exactly 8 bits; here, the
+ final unit of encoded output will be two characters followed by
+ two "=" padding characters.
+ */
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ input[i]>> 2 ];
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ input[i]<<4 & 0x3F ];
+ *(*output + output_size++) = TSK_BASE64_PAD, *(*output + output_size++) = TSK_BASE64_PAD;
+ }
+ else if((input_size-i) == 2){
+ /* The final quantum of encoding input is exactly 16 bits; here, the
+ final unit of encoded output will be three characters followed by
+ one "=" padding character.
+ */
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ input[i]>> 2 ];
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ (input[i]<<4 | input[i+1]>>4) & 0x3F ];
+ *(*output + output_size++) = TSK_BASE64_ENCODE_ALPHABET [ (input[i+1]<<2 | input[i+2]>>6) & 0x3F ];
+ *(*output + output_size++) = TSK_BASE64_PAD;
+ }
+
+ return output_size;
+}
+
+/**@ingroup tsk_base64_group
+* Decodes arbitrary base64 data.
+* @param input The input base64 data to decode.
+* @param input_size The size of the @a input data.
+* @param output A pointer where to copy the decoded data.
+* If you don't know what will be the size of the output result then set the pointer value to NULL to let the function allocate it of you.
+* In all case it is up to you to free the @a ouput.
+* You can also use @ref TSK_BASE64_DECODE_LEN to allocate the buffer before calling this method.
+*
+* @retval The size of the decoded data (sizeof(@a output))
+*/
+tsk_size_t tsk_base64_decode(const uint8_t* input, tsk_size_t input_size, char **output)
+{
+ static const uint8_t TSK_BASE64_DECODE_ALPHABET[256] =
+ {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1,
+ 62,
+ -1, -1, -1,
+ 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
+ -1, -1, -1, -1, -1, -1, -1,
+ 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,
+ -1, -1, -1, -1, -1, -1,
+ 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,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1,
+ };
+
+ tsk_size_t i, pay_size;
+ tsk_size_t output_size = 0;
+
+ /* Caller provided his own buffer? */
+ if(!*output){
+ *output = tsk_calloc(1, (TSK_BASE64_DECODE_LEN(input_size)+1));
+ }
+
+ /* Count pads and remove them from the base64 string */
+ for(i = input_size, pay_size = input_size; i > 0; i--){
+ if(input[i-1] == TSK_BASE64_PAD) {
+ pay_size--;
+ }
+ else{
+ break;
+ }
+ }
+
+ /* Reset i */
+ i = 0;
+
+ if(pay_size < TSK_BASE64_DECODE_BLOCK_SIZE){
+ goto quantum;
+ }
+
+ do{
+ *(*output + output_size++) = (TSK_BASE64_DECODE_ALPHABET [ input[i] ]<< 2
+ | TSK_BASE64_DECODE_ALPHABET [ input[i+1] ]>>4);
+ *(*output + output_size++) = (TSK_BASE64_DECODE_ALPHABET [ input[i+1] ]<< 4
+ | TSK_BASE64_DECODE_ALPHABET [ input[i+2] ]>>2);
+ *(*output + output_size++) = (TSK_BASE64_DECODE_ALPHABET [ input[i+2] ]<<6
+ | TSK_BASE64_DECODE_ALPHABET [ input[i+3] ]);
+
+ i += TSK_BASE64_DECODE_BLOCK_SIZE;
+ }
+ while(( i+ TSK_BASE64_DECODE_BLOCK_SIZE) <= pay_size);
+
+quantum:
+
+ if((input_size - pay_size) == 1){
+ *(*output + output_size++) = (TSK_BASE64_DECODE_ALPHABET [ input[i] ]<< 2
+ | TSK_BASE64_DECODE_ALPHABET [ input[i+1] ]>>4);
+ *(*output + output_size++) = (TSK_BASE64_DECODE_ALPHABET [ input[i+1] ]<< 4
+ | TSK_BASE64_DECODE_ALPHABET [ input[i+2] ]>>2);
+ }
+ else if((input_size-pay_size) == 2){
+ *(*output + output_size++) = (TSK_BASE64_DECODE_ALPHABET [ input[i] ]<< 2
+ | TSK_BASE64_DECODE_ALPHABET [ input[i+1] ]>>4);
+ }
+
+ return output_size;
+}
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