1 2 //********************************************************************* 3 //* C_Base64 - a simple base64 encoder and decoder. 4 //* 5 //* Copyright (c) 1999, Bob Withers - bwit@pobox.com 6 //* 7 //* This code may be freely used for any purpose, either personal 8 //* or commercial, provided the authors copyright notice remains 9 //* intact. 10 //********************************************************************* 11 12 #ifndef WEBRTC_BASE_BASE64_H__ 13 #define WEBRTC_BASE_BASE64_H__ 14 15 #include <string> 16 #include <vector> 17 18 namespace rtc { 19 20 class Base64 21 { 22 public: 23 enum DecodeOption { 24 DO_PARSE_STRICT = 1, // Parse only base64 characters 25 DO_PARSE_WHITE = 2, // Parse only base64 and whitespace characters 26 DO_PARSE_ANY = 3, // Parse all characters 27 DO_PARSE_MASK = 3, 28 29 DO_PAD_YES = 4, // Padding is required 30 DO_PAD_ANY = 8, // Padding is optional 31 DO_PAD_NO = 12, // Padding is disallowed 32 DO_PAD_MASK = 12, 33 34 DO_TERM_BUFFER = 16, // Must termiante at end of buffer 35 DO_TERM_CHAR = 32, // May terminate at any character boundary 36 DO_TERM_ANY = 48, // May terminate at a sub-character bit offset 37 DO_TERM_MASK = 48, 38 39 // Strictest interpretation 40 DO_STRICT = DO_PARSE_STRICT | DO_PAD_YES | DO_TERM_BUFFER, 41 42 DO_LAX = DO_PARSE_ANY | DO_PAD_ANY | DO_TERM_CHAR, 43 }; 44 typedef int DecodeFlags; 45 46 static bool IsBase64Char(char ch); 47 48 // Get the char next to the |ch| from the Base64Table. 49 // If the |ch| is the last one in the Base64Table then returns 50 // the first one from the table. 51 // Expects the |ch| be a base64 char. 52 // The result will be saved in |next_ch|. 53 // Returns true on success. 54 static bool GetNextBase64Char(char ch, char* next_ch); 55 56 // Determines whether the given string consists entirely of valid base64 57 // encoded characters. 58 static bool IsBase64Encoded(const std::string& str); 59 60 static void EncodeFromArray(const void* data, size_t len, 61 std::string* result); 62 static bool DecodeFromArray(const char* data, size_t len, DecodeFlags flags, 63 std::string* result, size_t* data_used); 64 static bool DecodeFromArray(const char* data, size_t len, DecodeFlags flags, 65 std::vector<char>* result, size_t* data_used); 66 67 // Convenience Methods Encode(const std::string & data)68 static inline std::string Encode(const std::string& data) { 69 std::string result; 70 EncodeFromArray(data.data(), data.size(), &result); 71 return result; 72 } Decode(const std::string & data,DecodeFlags flags)73 static inline std::string Decode(const std::string& data, DecodeFlags flags) { 74 std::string result; 75 DecodeFromArray(data.data(), data.size(), flags, &result, NULL); 76 return result; 77 } Decode(const std::string & data,DecodeFlags flags,std::string * result,size_t * data_used)78 static inline bool Decode(const std::string& data, DecodeFlags flags, 79 std::string* result, size_t* data_used) 80 { 81 return DecodeFromArray(data.data(), data.size(), flags, result, data_used); 82 } Decode(const std::string & data,DecodeFlags flags,std::vector<char> * result,size_t * data_used)83 static inline bool Decode(const std::string& data, DecodeFlags flags, 84 std::vector<char>* result, size_t* data_used) 85 { 86 return DecodeFromArray(data.data(), data.size(), flags, result, data_used); 87 } 88 89 private: 90 static const char Base64Table[]; 91 static const unsigned char DecodeTable[]; 92 93 static size_t GetNextQuantum(DecodeFlags parse_flags, bool illegal_pads, 94 const char* data, size_t len, size_t* dpos, 95 unsigned char qbuf[4], bool* padded); 96 template<typename T> 97 static bool DecodeFromArrayTemplate(const char* data, size_t len, 98 DecodeFlags flags, T* result, 99 size_t* data_used); 100 }; 101 102 } // namespace rtc 103 104 #endif // WEBRTC_BASE_BASE64_H__ 105