mirror of
https://github.com/PurpleI2P/i2pd.git
synced 2024-11-04 06:00:37 +00:00
342 lines
6.8 KiB
C++
342 lines
6.8 KiB
C++
/*
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* Copyright (c) 2013-2023, The PurpleI2P Project
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*
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* This file is part of Purple i2pd project and licensed under BSD3
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*
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* See full license text in LICENSE file at top of project tree
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*/
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#include <stdlib.h>
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#include <string.h>
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#include "Base.h"
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namespace i2p
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{
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namespace data
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{
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static const char T32[32] =
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{
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'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
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'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
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'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
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'y', 'z', '2', '3', '4', '5', '6', '7',
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};
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const char * GetBase32SubstitutionTable ()
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{
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return T32;
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}
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bool IsBase32 (char ch)
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{
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return (ch >= 'a' && ch <= 'z') || (ch >= '2' && ch <= '7');
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}
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static void iT64Build(void);
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/*
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*
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* BASE64 Substitution Table
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* -------------------------
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*
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* Direct Substitution Table
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*/
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static const char T64[64] =
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{
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
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'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
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'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
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'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
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'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
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'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
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'w', 'x', 'y', 'z', '0', '1', '2', '3',
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'4', '5', '6', '7', '8', '9', '-', '~'
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};
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const char * GetBase64SubstitutionTable ()
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{
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return T64;
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}
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bool IsBase64 (char ch)
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{
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return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9') || ch == '-' || ch == '~';
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}
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/*
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* Reverse Substitution Table (built in run time)
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*/
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static char iT64[256];
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static int isFirstTime = 1;
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/*
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* Padding
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*/
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static char P64 = '=';
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/*
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*
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* ByteStreamToBase64
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* ------------------
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*
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* Converts binary encoded data to BASE64 format.
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*
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*/
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size_t ByteStreamToBase64 ( /* Number of bytes in the encoded buffer */
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const uint8_t * InBuffer, /* Input buffer, binary data */
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size_t InCount, /* Number of bytes in the input buffer */
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char * OutBuffer, /* output buffer */
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size_t len /* length of output buffer */
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)
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{
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unsigned char * ps;
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unsigned char * pd;
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unsigned char acc_1;
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unsigned char acc_2;
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int i;
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int n;
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int m;
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size_t outCount;
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ps = (unsigned char *)InBuffer;
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n = InCount / 3;
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m = InCount % 3;
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if (!m)
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outCount = 4 * n;
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else
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outCount = 4 * (n + 1);
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if (outCount > len) return 0;
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pd = (unsigned char *)OutBuffer;
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for ( i = 0; i < n; i++ )
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{
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acc_1 = *ps++;
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acc_2 = (acc_1 << 4) & 0x30;
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acc_1 >>= 2; /* base64 digit #1 */
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*pd++ = T64[acc_1];
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acc_1 = *ps++;
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acc_2 |= acc_1 >> 4; /* base64 digit #2 */
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*pd++ = T64[acc_2];
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acc_1 &= 0x0f;
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acc_1 <<= 2;
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acc_2 = *ps++;
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acc_1 |= acc_2 >> 6; /* base64 digit #3 */
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*pd++ = T64[acc_1];
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acc_2 &= 0x3f; /* base64 digit #4 */
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*pd++ = T64[acc_2];
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}
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if ( m == 1 )
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{
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acc_1 = *ps++;
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acc_2 = (acc_1 << 4) & 0x3f; /* base64 digit #2 */
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acc_1 >>= 2; /* base64 digit #1 */
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*pd++ = T64[acc_1];
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*pd++ = T64[acc_2];
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*pd++ = P64;
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*pd++ = P64;
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}
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else if ( m == 2 )
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{
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acc_1 = *ps++;
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acc_2 = (acc_1 << 4) & 0x3f;
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acc_1 >>= 2; /* base64 digit #1 */
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*pd++ = T64[acc_1];
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acc_1 = *ps++;
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acc_2 |= acc_1 >> 4; /* base64 digit #2 */
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*pd++ = T64[acc_2];
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acc_1 &= 0x0f;
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acc_1 <<= 2; /* base64 digit #3 */
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*pd++ = T64[acc_1];
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*pd++ = P64;
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}
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return outCount;
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}
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/*
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*
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* Base64ToByteStream
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* ------------------
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*
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* Converts BASE64 encoded data to binary format. If input buffer is
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* not properly padded, buffer of negative length is returned
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*
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*/
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size_t Base64ToByteStream ( /* Number of output bytes */
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const char * InBuffer, /* BASE64 encoded buffer */
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size_t InCount, /* Number of input bytes */
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uint8_t * OutBuffer, /* output buffer length */
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size_t len /* length of output buffer */
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)
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{
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unsigned char * ps;
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unsigned char * pd;
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unsigned char acc_1;
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unsigned char acc_2;
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int i;
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int n;
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int m;
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size_t outCount;
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if (isFirstTime)
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iT64Build();
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n = InCount / 4;
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m = InCount % 4;
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if (InCount && !m)
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outCount = 3 * n;
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else
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return 0;
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if(*InBuffer == P64)
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return 0;
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ps = (unsigned char *)(InBuffer + InCount - 1);
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while ( *ps-- == P64 )
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outCount--;
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ps = (unsigned char *)InBuffer;
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if (outCount > len)
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return 0;
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pd = OutBuffer;
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auto endOfOutBuffer = OutBuffer + outCount;
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for ( i = 0; i < n; i++ )
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{
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acc_1 = iT64[*ps++];
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acc_2 = iT64[*ps++];
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acc_1 <<= 2;
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acc_1 |= acc_2 >> 4;
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*pd++ = acc_1;
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if (pd >= endOfOutBuffer)
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break;
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acc_2 <<= 4;
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acc_1 = iT64[*ps++];
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acc_2 |= acc_1 >> 2;
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*pd++ = acc_2;
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if (pd >= endOfOutBuffer)
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break;
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acc_2 = iT64[*ps++];
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acc_2 |= acc_1 << 6;
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*pd++ = acc_2;
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}
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return outCount;
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}
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size_t Base64EncodingBufferSize (const size_t input_size)
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{
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auto d = div (input_size, 3);
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if (d.rem)
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d.quot++;
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return 4 * d.quot;
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}
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std::string ToBase64Standard (const std::string& in)
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{
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auto len = Base64EncodingBufferSize (in.length ());
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char * str = new char[len + 1];
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auto l = ByteStreamToBase64 ((const uint8_t *)in.c_str (), in.length (), str, len);
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str[l] = 0;
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// replace '-' by '+' and '~' by '/'
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for (size_t i = 0; i < l; i++)
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if (str[i] == '-')
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str[i] = '+';
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else if (str[i] == '~')
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str[i] = '/';
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std::string s(str);
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delete[] str;
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return s;
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}
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/*
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*
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* iT64
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* ----
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* Reverse table builder. P64 character is replaced with 0
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*
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*
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*/
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static void iT64Build()
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{
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int i;
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isFirstTime = 0;
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for ( i = 0; i < 256; i++ ) iT64[i] = -1;
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for ( i = 0; i < 64; i++ ) iT64[(int)T64[i]] = i;
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iT64[(int)P64] = 0;
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}
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size_t Base32ToByteStream (const char * inBuf, size_t len, uint8_t * outBuf, size_t outLen)
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{
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unsigned int tmp = 0, bits = 0;
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size_t ret = 0;
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for (size_t i = 0; i < len; i++)
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{
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char ch = inBuf[i];
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if (ch >= '2' && ch <= '7') // digit
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ch = (ch - '2') + 26; // 26 means a-z
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else if (ch >= 'a' && ch <= 'z')
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ch = ch - 'a'; // a = 0
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else
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return 0; // unexpected character
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tmp |= ch;
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bits += 5;
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if (bits >= 8)
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{
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if (ret >= outLen) return ret;
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outBuf[ret] = tmp >> (bits - 8);
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bits -= 8;
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ret++;
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}
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tmp <<= 5;
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}
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return ret;
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}
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size_t ByteStreamToBase32 (const uint8_t * inBuf, size_t len, char * outBuf, size_t outLen)
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{
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size_t ret = 0, pos = 1;
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unsigned int bits = 8, tmp = inBuf[0];
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while (ret < outLen && (bits > 0 || pos < len))
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{
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if (bits < 5)
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{
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if (pos < len)
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{
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tmp <<= 8;
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tmp |= inBuf[pos] & 0xFF;
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pos++;
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bits += 8;
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}
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else // last byte
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{
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tmp <<= (5 - bits);
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bits = 5;
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}
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}
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bits -= 5;
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int ind = (tmp >> bits) & 0x1F;
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outBuf[ret] = (ind < 26) ? (ind + 'a') : ((ind - 26) + '2');
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ret++;
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}
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return ret;
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}
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}
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}
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