/* * Copyright (c) 2013-2023, The PurpleI2P Project * * This file is part of Purple i2pd project and licensed under BSD3 * * See full license text in LICENSE file at top of project tree */ #include <stdlib.h> #include <string.h> #include "Base.h" namespace i2p { namespace data { static const char T32[32] = { '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', '2', '3', '4', '5', '6', '7', }; const char * GetBase32SubstitutionTable () { return T32; } bool IsBase32 (char ch) { return (ch >= 'a' && ch <= 'z') || (ch >= '2' && ch <= '7'); } static void iT64Build(void); /* * * BASE64 Substitution Table * ------------------------- * * Direct Substitution Table */ static const char T64[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', '-', '~' }; const char * GetBase64SubstitutionTable () { return T64; } bool IsBase64 (char ch) { return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9') || ch == '-' || ch == '~'; } /* * Reverse Substitution Table (built in run time) */ static char iT64[256]; static int isFirstTime = 1; /* * Padding */ static char P64 = '='; /* * * ByteStreamToBase64 * ------------------ * * Converts binary encoded data to BASE64 format. * */ size_t ByteStreamToBase64 ( /* Number of bytes in the encoded buffer */ const uint8_t * InBuffer, /* Input buffer, binary data */ size_t InCount, /* Number of bytes in the input buffer */ char * OutBuffer, /* output buffer */ size_t len /* length of output buffer */ ) { unsigned char * ps; unsigned char * pd; unsigned char acc_1; unsigned char acc_2; int i; int n; int m; size_t outCount; ps = (unsigned char *)InBuffer; n = InCount / 3; m = InCount % 3; if (!m) outCount = 4 * n; else outCount = 4 * (n + 1); if (outCount > len) return 0; pd = (unsigned char *)OutBuffer; for ( i = 0; i < n; i++ ) { acc_1 = *ps++; acc_2 = (acc_1 << 4) & 0x30; acc_1 >>= 2; /* base64 digit #1 */ *pd++ = T64[acc_1]; acc_1 = *ps++; acc_2 |= acc_1 >> 4; /* base64 digit #2 */ *pd++ = T64[acc_2]; acc_1 &= 0x0f; acc_1 <<= 2; acc_2 = *ps++; acc_1 |= acc_2 >> 6; /* base64 digit #3 */ *pd++ = T64[acc_1]; acc_2 &= 0x3f; /* base64 digit #4 */ *pd++ = T64[acc_2]; } if ( m == 1 ) { acc_1 = *ps++; acc_2 = (acc_1 << 4) & 0x3f; /* base64 digit #2 */ acc_1 >>= 2; /* base64 digit #1 */ *pd++ = T64[acc_1]; *pd++ = T64[acc_2]; *pd++ = P64; *pd++ = P64; } else if ( m == 2 ) { acc_1 = *ps++; acc_2 = (acc_1 << 4) & 0x3f; acc_1 >>= 2; /* base64 digit #1 */ *pd++ = T64[acc_1]; acc_1 = *ps++; acc_2 |= acc_1 >> 4; /* base64 digit #2 */ *pd++ = T64[acc_2]; acc_1 &= 0x0f; acc_1 <<= 2; /* base64 digit #3 */ *pd++ = T64[acc_1]; *pd++ = P64; } return outCount; } /* * * Base64ToByteStream * ------------------ * * Converts BASE64 encoded data to binary format. If input buffer is * not properly padded, buffer of negative length is returned * */ size_t Base64ToByteStream ( /* Number of output bytes */ const char * InBuffer, /* BASE64 encoded buffer */ size_t InCount, /* Number of input bytes */ uint8_t * OutBuffer, /* output buffer length */ size_t len /* length of output buffer */ ) { unsigned char * ps; unsigned char * pd; unsigned char acc_1; unsigned char acc_2; int i; int n; int m; size_t outCount; if (isFirstTime) iT64Build(); n = InCount / 4; m = InCount % 4; if (InCount && !m) outCount = 3 * n; else return 0; if(*InBuffer == P64) return 0; ps = (unsigned char *)(InBuffer + InCount - 1); while ( *ps-- == P64 ) outCount--; ps = (unsigned char *)InBuffer; if (outCount > len) return 0; pd = OutBuffer; auto endOfOutBuffer = OutBuffer + outCount; for ( i = 0; i < n; i++ ) { acc_1 = iT64[*ps++]; acc_2 = iT64[*ps++]; acc_1 <<= 2; acc_1 |= acc_2 >> 4; *pd++ = acc_1; if (pd >= endOfOutBuffer) break; acc_2 <<= 4; acc_1 = iT64[*ps++]; acc_2 |= acc_1 >> 2; *pd++ = acc_2; if (pd >= endOfOutBuffer) break; acc_2 = iT64[*ps++]; acc_2 |= acc_1 << 6; *pd++ = acc_2; } return outCount; } size_t Base64EncodingBufferSize (const size_t input_size) { auto d = div (input_size, 3); if (d.rem) d.quot++; return 4 * d.quot; } std::string ToBase64Standard (const std::string& in) { auto len = Base64EncodingBufferSize (in.length ()); char * str = new char[len + 1]; auto l = ByteStreamToBase64 ((const uint8_t *)in.c_str (), in.length (), str, len); str[l] = 0; // replace '-' by '+' and '~' by '/' for (size_t i = 0; i < l; i++) if (str[i] == '-') str[i] = '+'; else if (str[i] == '~') str[i] = '/'; std::string s(str); delete[] str; return s; } /* * * iT64 * ---- * Reverse table builder. P64 character is replaced with 0 * * */ static void iT64Build() { int i; isFirstTime = 0; for ( i = 0; i < 256; i++ ) iT64[i] = -1; for ( i = 0; i < 64; i++ ) iT64[(int)T64[i]] = i; iT64[(int)P64] = 0; } size_t Base32ToByteStream (const char * inBuf, size_t len, uint8_t * outBuf, size_t outLen) { unsigned int tmp = 0, bits = 0; size_t ret = 0; for (size_t i = 0; i < len; i++) { char ch = inBuf[i]; if (ch >= '2' && ch <= '7') // digit ch = (ch - '2') + 26; // 26 means a-z else if (ch >= 'a' && ch <= 'z') ch = ch - 'a'; // a = 0 else return 0; // unexpected character tmp |= ch; bits += 5; if (bits >= 8) { if (ret >= outLen) return ret; outBuf[ret] = tmp >> (bits - 8); bits -= 8; ret++; } tmp <<= 5; } return ret; } size_t ByteStreamToBase32 (const uint8_t * inBuf, size_t len, char * outBuf, size_t outLen) { size_t ret = 0, pos = 1; unsigned int bits = 8, tmp = inBuf[0]; while (ret < outLen && (bits > 0 || pos < len)) { if (bits < 5) { if (pos < len) { tmp <<= 8; tmp |= inBuf[pos] & 0xFF; pos++; bits += 8; } else // last byte { tmp <<= (5 - bits); bits = 5; } } bits -= 5; int ind = (tmp >> bits) & 0x1F; outBuf[ret] = (ind < 26) ? (ind + 'a') : ((ind - 26) + '2'); ret++; } return ret; } } }