/* * Copyright 2006 The Android Open Source Project * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "include/utils/SkBase64.h" #define DecodePad -2 #define EncodePad 64 static const char default_encode[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz" "0123456789+/="; static const signed char decodeData[] = { 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, DecodePad, -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 }; SkBase64::SkBase64() : fLength((size_t) -1), fData(nullptr) { } #if defined _WIN32 // disable 'two', etc. may be used without having been initialized #pragma warning ( push ) #pragma warning ( disable : 4701 ) #endif SkBase64::Error SkBase64::decode(const void* srcPtr, size_t size, bool writeDestination) { unsigned char* dst = (unsigned char*) fData; const unsigned char* dstStart = (const unsigned char*) fData; const unsigned char* src = (const unsigned char*) srcPtr; bool padTwo = false; bool padThree = false; const unsigned char* end = src + size; while (src < end) { unsigned char bytes[4]; int byte = 0; do { unsigned char srcByte = *src++; if (srcByte == 0) goto goHome; if (srcByte <= ' ') continue; // treat as white space if (srcByte < '+' || srcByte > 'z') return kBadCharError; signed char decoded = decodeData[srcByte - '+']; bytes[byte] = decoded; if (decoded < 0) { if (decoded == DecodePad) goto handlePad; return kBadCharError; } else byte++; if (*src) continue; if (byte == 0) goto goHome; if (byte == 4) break; handlePad: if (byte < 2) return kPadError; padThree = true; if (byte == 2) padTwo = true; break; } while (byte < 4); int two = 0; int three = 0; if (writeDestination) { int one = (uint8_t) (bytes[0] << 2); two = bytes[1]; one |= two >> 4; two = (uint8_t) ((two << 4) & 0xFF); three = bytes[2]; two |= three >> 2; three = (uint8_t) ((three << 6) & 0xFF); three |= bytes[3]; SkASSERT(one < 256 && two < 256 && three < 256); *dst = (unsigned char) one; } dst++; if (padTwo) break; if (writeDestination) *dst = (unsigned char) two; dst++; if (padThree) break; if (writeDestination) *dst = (unsigned char) three; dst++; } goHome: fLength = dst - dstStart; return kNoError; } #if defined _WIN32 #pragma warning ( pop ) #endif size_t SkBase64::Encode(const void* srcPtr, size_t length, void* dstPtr, const char* encodeMap) { const char* encode; if (nullptr == encodeMap) { encode = default_encode; } else { encode = encodeMap; } const unsigned char* src = (const unsigned char*) srcPtr; unsigned char* dst = (unsigned char*) dstPtr; if (dst) { size_t remainder = length % 3; const unsigned char* end = &src[length - remainder]; while (src < end) { unsigned a = *src++; unsigned b = *src++; unsigned c = *src++; int d = c & 0x3F; c = (c >> 6 | b << 2) & 0x3F; b = (b >> 4 | a << 4) & 0x3F; a = a >> 2; *dst++ = encode[a]; *dst++ = encode[b]; *dst++ = encode[c]; *dst++ = encode[d]; } if (remainder > 0) { int k1 = 0; int k2 = EncodePad; int a = (uint8_t) *src++; if (remainder == 2) { int b = *src++; k1 = b >> 4; k2 = (b << 2) & 0x3F; } *dst++ = encode[a >> 2]; *dst++ = encode[(k1 | a << 4) & 0x3F]; *dst++ = encode[k2]; *dst++ = encode[EncodePad]; } } return (length + 2) / 3 * 4; } SkBase64::Error SkBase64::decode(const char* src, size_t len) { Error err = decode(src, len, false); SkASSERT(err == kNoError); if (err != kNoError) return err; fData = new char[fLength]; // should use sk_malloc/sk_free decode(src, len, true); return kNoError; }