| /* |
| * 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 |
| }; |
| |
| #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* srcv, size_t srcLength, void* dstv, size_t* dstLength){ |
| const unsigned char* src = static_cast<const unsigned char*>(srcv); |
| unsigned char* dst = static_cast<unsigned char*>(dstv); |
| |
| int i = 0; |
| bool padTwo = false; |
| bool padThree = false; |
| char unsigned const * const end = src + srcLength; |
| 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 (dst) { |
| 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[i] = (unsigned char) one; |
| } |
| i++; |
| if (padTwo) |
| break; |
| if (dst) |
| dst[i] = (unsigned char) two; |
| i++; |
| if (padThree) |
| break; |
| if (dst) |
| dst[i] = (unsigned char) three; |
| i++; |
| } |
| goHome: |
| *dstLength = i; |
| return kNoError; |
| } |
| |
| #if defined _WIN32 |
| #pragma warning ( pop ) |
| #endif |
| |
| size_t SkBase64::Encode(const void* srcv, size_t length, void* dstv, const char* encodeMap) { |
| const unsigned char* src = static_cast<const unsigned char*>(srcv); |
| unsigned char* dst = static_cast<unsigned char*>(dstv); |
| |
| const char* encode; |
| if (nullptr == encodeMap) { |
| encode = default_encode; |
| } else { |
| encode = encodeMap; |
| } |
| if (dst) { |
| size_t remainder = length % 3; |
| char unsigned const * const 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; |
| } |