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| author | Stefan Boberg <[email protected]> | 2023-05-02 10:01:47 +0200 |
|---|---|---|
| committer | GitHub <[email protected]> | 2023-05-02 10:01:47 +0200 |
| commit | 075d17f8ada47e990fe94606c3d21df409223465 (patch) | |
| tree | e50549b766a2f3c354798a54ff73404217b4c9af /src/zencore/base64.cpp | |
| parent | fix: bundle shouldn't append content zip to zen (diff) | |
| download | zen-075d17f8ada47e990fe94606c3d21df409223465.tar.xz zen-075d17f8ada47e990fe94606c3d21df409223465.zip | |
moved source directories into `/src` (#264)
* moved source directories into `/src`
* updated bundle.lua for new `src` path
* moved some docs, icon
* removed old test trees
Diffstat (limited to 'src/zencore/base64.cpp')
| -rw-r--r-- | src/zencore/base64.cpp | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/zencore/base64.cpp b/src/zencore/base64.cpp new file mode 100644 index 000000000..b97dfebbf --- /dev/null +++ b/src/zencore/base64.cpp @@ -0,0 +1,107 @@ +// Copyright Epic Games, Inc. All Rights Reserved. + +#include <zencore/base64.h> + +namespace zen { + +/** The table used to encode a 6 bit value as an ascii character */ +static const uint8_t EncodingAlphabet[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', '+', '/'}; + +/** The table used to convert an ascii character into a 6 bit value */ +#if 0 +static const uint8_t DecodingAlphabet[256] = { + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x00-0x0f + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x10-0x1f + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xFF, 0xFF, 0x3F, // 0x20-0x2f + 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x30-0x3f + 0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, // 0x40-0x4f + 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x50-0x5f + 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, // 0x60-0x6f + 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x70-0x7f + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x80-0x8f + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0x90-0x9f + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0xa0-0xaf + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0xb0-0xbf + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0xc0-0xcf + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0xd0-0xdf + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 0xe0-0xef + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF // 0xf0-0xff +}; +#endif // 0 + +template<typename CharType> +uint32_t +Base64::Encode(const uint8_t* Source, uint32_t Length, CharType* Dest) +{ + CharType* EncodedBytes = Dest; + + // Loop through the buffer converting 3 bytes of binary data at a time + while (Length >= 3) + { + uint8_t A = *Source++; + uint8_t B = *Source++; + uint8_t C = *Source++; + Length -= 3; + + // The algorithm takes 24 bits of data (3 bytes) and breaks it into 4 6bit chunks represented as ascii + uint32_t ByteTriplet = A << 16 | B << 8 | C; + + // Use the 6bit block to find the representation ascii character for it + EncodedBytes[3] = EncodingAlphabet[ByteTriplet & 0x3F]; + ByteTriplet >>= 6; + EncodedBytes[2] = EncodingAlphabet[ByteTriplet & 0x3F]; + ByteTriplet >>= 6; + EncodedBytes[1] = EncodingAlphabet[ByteTriplet & 0x3F]; + ByteTriplet >>= 6; + EncodedBytes[0] = EncodingAlphabet[ByteTriplet & 0x3F]; + + // Now we can append this buffer to our destination string + EncodedBytes += 4; + } + + // Since this algorithm operates on blocks, we may need to pad the last chunks + if (Length > 0) + { + uint8_t A = *Source++; + uint8_t B = 0; + uint8_t C = 0; + // Grab the second character if it is a 2 uint8_t finish + if (Length == 2) + { + B = *Source; + } + uint32_t ByteTriplet = A << 16 | B << 8 | C; + // Pad with = to make a 4 uint8_t chunk + EncodedBytes[3] = '='; + ByteTriplet >>= 6; + // If there's only one 1 uint8_t left in the source, then you need 2 pad chars + if (Length == 1) + { + EncodedBytes[2] = '='; + } + else + { + EncodedBytes[2] = EncodingAlphabet[ByteTriplet & 0x3F]; + } + // Now encode the remaining bits the same way + ByteTriplet >>= 6; + EncodedBytes[1] = EncodingAlphabet[ByteTriplet & 0x3F]; + ByteTriplet >>= 6; + EncodedBytes[0] = EncodingAlphabet[ByteTriplet & 0x3F]; + + EncodedBytes += 4; + } + + // Add a null terminator + *EncodedBytes = 0; + + return uint32_t(EncodedBytes - Dest); +} + +template ZENCORE_API uint32_t Base64::Encode<char>(const uint8_t* Source, uint32_t Length, char* Dest); +template ZENCORE_API uint32_t Base64::Encode<wchar_t>(const uint8_t* Source, uint32_t Length, wchar_t* Dest); + +} // namespace zen |