mirror of https://github.com/PurpleI2P/i2pd.git
I2P: End-to-End encrypted and anonymous Internet
https://i2pd.website/
290 lines
6.2 KiB
290 lines
6.2 KiB
#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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'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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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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'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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/* |
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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 /* Number of bytes in the encoded buffer */ |
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ByteStreamToBase64 ( |
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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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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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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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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 /* Number of output bytes */ |
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Base64ToByteStream ( |
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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) 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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outCount = 0; |
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return 0; |
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} |
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ps = (unsigned char *)(InBuffer + InCount - 1); |
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while ( *ps-- == P64 ) outCount--; |
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ps = (unsigned char *)InBuffer; |
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if (outCount > len) return -1; |
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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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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) 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) 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) d.quot++; |
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return 4*d.quot; |
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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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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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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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