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Diffstat (limited to 'libdevcore/Base64.cpp')
| -rw-r--r-- | libdevcore/Base64.cpp | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/libdevcore/Base64.cpp b/libdevcore/Base64.cpp new file mode 100644 index 00000000..8ee2b29f --- /dev/null +++ b/libdevcore/Base64.cpp @@ -0,0 +1,146 @@ +/* + base64.cpp and base64.h + + Copyright (C) 2004-2008 René Nyffenegger + + This source code is provided 'as-is', without any express or implied + warranty. In no event will the author be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this source code must not be misrepresented; you must not + claim that you wrote the original source code. If you use this source code + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original source code. + + 3. This notice may not be removed or altered from any source distribution. + + René Nyffenegger rene.nyffenegger@adp-gmbh.ch +*/ +/// Adapted from code found on http://stackoverflow.com/questions/180947/base64-decode-snippet-in-c +/// Originally by René Nyffenegger, modified by some other guy and then devified by Gav Wood. + +#include "Base64.h" + +using namespace std; +using namespace dev; + +static inline bool is_base64(byte c) +{ + return (isalnum(c) || (c == '+') || (c == '/')); +} + +static inline byte find_base64_char_index(byte c) +{ + if ('A' <= c && c <= 'Z') return c - 'A'; + else if ('a' <= c && c <= 'z') return c - 'a' + 1 + find_base64_char_index('Z'); + else if ('0' <= c && c <= '9') return c - '0' + 1 + find_base64_char_index('z'); + else if (c == '+') return 1 + find_base64_char_index('9'); + else if (c == '/') return 1 + find_base64_char_index('+'); + else return 1 + find_base64_char_index('/'); +} + +string dev::toBase64(bytesConstRef _in) +{ + static const char base64_chars[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789+/"; + + string ret; + int i = 0; + int j = 0; + byte char_array_3[3]; + byte char_array_4[4]; + + auto buf = _in.data(); + auto bufLen = _in.size(); + + while (bufLen--) + { + char_array_3[i++] = *(buf++); + if (i == 3) + { + char_array_4[0] = (char_array_3[0] & 0xfc) >> 2; + char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4); + char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6); + char_array_4[3] = char_array_3[2] & 0x3f; + + for (i = 0; i < 4; i++) + ret += base64_chars[char_array_4[i]]; + i = 0; + } + } + + if (i) + { + for (j = i; j < 3; j++) + char_array_3[j] = '\0'; + + char_array_4[0] = (char_array_3[0] & 0xfc) >> 2; + char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4); + char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6); + char_array_4[3] = char_array_3[2] & 0x3f; + + for (j = 0; j < i + 1; j++) + ret += base64_chars[char_array_4[j]]; + + while (i++ < 3) + ret += '='; + } + + return ret; +} + +bytes dev::fromBase64(string const& encoded_string) +{ + auto in_len = encoded_string.size(); + int i = 0; + int j = 0; + int in_ = 0; + byte char_array_3[3]; + byte char_array_4[4]; + bytes ret; + + while (in_len-- && encoded_string[in_] != '=' && is_base64(encoded_string[in_])) + { + char_array_4[i++] = encoded_string[in_]; in_++; + if (i == 4) + { + for (i = 0; i < 4; i++) + char_array_4[i] = find_base64_char_index(char_array_4[i]); + + char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4); + char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2); + char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; + + for (i = 0; (i < 3); i++) + ret.push_back(char_array_3[i]); + i = 0; + } + } + + if (i) + { + for (j = i; j < 4; j++) + char_array_4[j] = 0; + + for (j = 0; j < 4; j++) + char_array_4[j] = find_base64_char_index(char_array_4[j]); + + char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4); + char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2); + char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; + + for (j = 0; j < i - 1; j++) + ret.push_back(char_array_3[j]); + } + + return ret; +} |