cecfd1832d
TEST=try bots R=mallinath@webrtc.org Review URL: https://webrtc-codereview.appspot.com/3139004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@5053 4adac7df-926f-26a2-2b94-8c16560cd09d
261 lines
7.7 KiB
C++
261 lines
7.7 KiB
C++
|
|
//*********************************************************************
|
|
//* Base64 - a simple base64 encoder and decoder.
|
|
//*
|
|
//* Copyright (c) 1999, Bob Withers - bwit@pobox.com
|
|
//*
|
|
//* This code may be freely used for any purpose, either personal
|
|
//* or commercial, provided the authors copyright notice remains
|
|
//* intact.
|
|
//*
|
|
//* Enhancements by Stanley Yamane:
|
|
//* o reverse lookup table for the decode function
|
|
//* o reserve string buffer space in advance
|
|
//*
|
|
//*********************************************************************
|
|
|
|
#include "talk/base/base64.h"
|
|
|
|
#include <string.h>
|
|
|
|
#include "talk/base/common.h"
|
|
|
|
using std::vector;
|
|
|
|
namespace talk_base {
|
|
|
|
static const char kPad = '=';
|
|
static const unsigned char pd = 0xFD; // Padding
|
|
static const unsigned char sp = 0xFE; // Whitespace
|
|
static const unsigned char il = 0xFF; // Illegal base64 character
|
|
|
|
const char Base64::Base64Table[] =
|
|
// 0000000000111111111122222222223333333333444444444455555555556666
|
|
// 0123456789012345678901234567890123456789012345678901234567890123
|
|
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
|
|
|
|
// Decode Table gives the index of any valid base64 character in the
|
|
// Base64 table
|
|
// 65 == A, 97 == a, 48 == 0, 43 == +, 47 == /
|
|
|
|
const unsigned char Base64::DecodeTable[] = {
|
|
// 0 1 2 3 4 5 6 7 8 9
|
|
il,il,il,il,il,il,il,il,il,sp, // 0 - 9
|
|
sp,sp,sp,sp,il,il,il,il,il,il, // 10 - 19
|
|
il,il,il,il,il,il,il,il,il,il, // 20 - 29
|
|
il,il,sp,il,il,il,il,il,il,il, // 30 - 39
|
|
il,il,il,62,il,il,il,63,52,53, // 40 - 49
|
|
54,55,56,57,58,59,60,61,il,il, // 50 - 59
|
|
il,pd,il,il,il, 0, 1, 2, 3, 4, // 60 - 69
|
|
5, 6, 7, 8, 9,10,11,12,13,14, // 70 - 79
|
|
15,16,17,18,19,20,21,22,23,24, // 80 - 89
|
|
25,il,il,il,il,il,il,26,27,28, // 90 - 99
|
|
29,30,31,32,33,34,35,36,37,38, // 100 - 109
|
|
39,40,41,42,43,44,45,46,47,48, // 110 - 119
|
|
49,50,51,il,il,il,il,il,il,il, // 120 - 129
|
|
il,il,il,il,il,il,il,il,il,il, // 130 - 139
|
|
il,il,il,il,il,il,il,il,il,il, // 140 - 149
|
|
il,il,il,il,il,il,il,il,il,il, // 150 - 159
|
|
il,il,il,il,il,il,il,il,il,il, // 160 - 169
|
|
il,il,il,il,il,il,il,il,il,il, // 170 - 179
|
|
il,il,il,il,il,il,il,il,il,il, // 180 - 189
|
|
il,il,il,il,il,il,il,il,il,il, // 190 - 199
|
|
il,il,il,il,il,il,il,il,il,il, // 200 - 209
|
|
il,il,il,il,il,il,il,il,il,il, // 210 - 219
|
|
il,il,il,il,il,il,il,il,il,il, // 220 - 229
|
|
il,il,il,il,il,il,il,il,il,il, // 230 - 239
|
|
il,il,il,il,il,il,il,il,il,il, // 240 - 249
|
|
il,il,il,il,il,il // 250 - 255
|
|
};
|
|
|
|
bool Base64::IsBase64Char(char ch) {
|
|
return (('A' <= ch) && (ch <= 'Z')) ||
|
|
(('a' <= ch) && (ch <= 'z')) ||
|
|
(('0' <= ch) && (ch <= '9')) ||
|
|
(ch == '+') || (ch == '/');
|
|
}
|
|
|
|
bool Base64::GetNextBase64Char(char ch, char* next_ch) {
|
|
if (next_ch == NULL) {
|
|
return false;
|
|
}
|
|
const char* p = strchr(Base64Table, ch);
|
|
if (!p)
|
|
return false;
|
|
++p;
|
|
*next_ch = (*p) ? *p : Base64Table[0];
|
|
return true;
|
|
}
|
|
|
|
bool Base64::IsBase64Encoded(const std::string& str) {
|
|
for (size_t i = 0; i < str.size(); ++i) {
|
|
if (!IsBase64Char(str.at(i)))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void Base64::EncodeFromArray(const void* data, size_t len,
|
|
std::string* result) {
|
|
ASSERT(NULL != result);
|
|
result->clear();
|
|
result->resize(((len + 2) / 3) * 4);
|
|
const unsigned char* byte_data = static_cast<const unsigned char*>(data);
|
|
|
|
unsigned char c;
|
|
size_t i = 0;
|
|
size_t dest_ix = 0;
|
|
while (i < len) {
|
|
c = (byte_data[i] >> 2) & 0x3f;
|
|
(*result)[dest_ix++] = Base64Table[c];
|
|
|
|
c = (byte_data[i] << 4) & 0x3f;
|
|
if (++i < len) {
|
|
c |= (byte_data[i] >> 4) & 0x0f;
|
|
}
|
|
(*result)[dest_ix++] = Base64Table[c];
|
|
|
|
if (i < len) {
|
|
c = (byte_data[i] << 2) & 0x3f;
|
|
if (++i < len) {
|
|
c |= (byte_data[i] >> 6) & 0x03;
|
|
}
|
|
(*result)[dest_ix++] = Base64Table[c];
|
|
} else {
|
|
(*result)[dest_ix++] = kPad;
|
|
}
|
|
|
|
if (i < len) {
|
|
c = byte_data[i] & 0x3f;
|
|
(*result)[dest_ix++] = Base64Table[c];
|
|
++i;
|
|
} else {
|
|
(*result)[dest_ix++] = kPad;
|
|
}
|
|
}
|
|
}
|
|
|
|
size_t Base64::GetNextQuantum(DecodeFlags parse_flags, bool illegal_pads,
|
|
const char* data, size_t len, size_t* dpos,
|
|
unsigned char qbuf[4], bool* padded)
|
|
{
|
|
size_t byte_len = 0, pad_len = 0, pad_start = 0;
|
|
for (; (byte_len < 4) && (*dpos < len); ++*dpos) {
|
|
qbuf[byte_len] = DecodeTable[static_cast<unsigned char>(data[*dpos])];
|
|
if ((il == qbuf[byte_len]) || (illegal_pads && (pd == qbuf[byte_len]))) {
|
|
if (parse_flags != DO_PARSE_ANY)
|
|
break;
|
|
// Ignore illegal characters
|
|
} else if (sp == qbuf[byte_len]) {
|
|
if (parse_flags == DO_PARSE_STRICT)
|
|
break;
|
|
// Ignore spaces
|
|
} else if (pd == qbuf[byte_len]) {
|
|
if (byte_len < 2) {
|
|
if (parse_flags != DO_PARSE_ANY)
|
|
break;
|
|
// Ignore unexpected padding
|
|
} else if (byte_len + pad_len >= 4) {
|
|
if (parse_flags != DO_PARSE_ANY)
|
|
break;
|
|
// Ignore extra pads
|
|
} else {
|
|
if (1 == ++pad_len) {
|
|
pad_start = *dpos;
|
|
}
|
|
}
|
|
} else {
|
|
if (pad_len > 0) {
|
|
if (parse_flags != DO_PARSE_ANY)
|
|
break;
|
|
// Ignore pads which are followed by data
|
|
pad_len = 0;
|
|
}
|
|
++byte_len;
|
|
}
|
|
}
|
|
for (size_t i = byte_len; i < 4; ++i) {
|
|
qbuf[i] = 0;
|
|
}
|
|
if (4 == byte_len + pad_len) {
|
|
*padded = true;
|
|
} else {
|
|
*padded = false;
|
|
if (pad_len) {
|
|
// Roll back illegal padding
|
|
*dpos = pad_start;
|
|
}
|
|
}
|
|
return byte_len;
|
|
}
|
|
|
|
bool Base64::DecodeFromArray(const char* data, size_t len, DecodeFlags flags,
|
|
std::string* result, size_t* data_used) {
|
|
return DecodeFromArrayTemplate<std::string>(
|
|
data, len, flags, result, data_used);
|
|
}
|
|
|
|
bool Base64::DecodeFromArray(const char* data, size_t len, DecodeFlags flags,
|
|
vector<char>* result, size_t* data_used) {
|
|
return DecodeFromArrayTemplate<vector<char> >(data, len, flags, result,
|
|
data_used);
|
|
}
|
|
|
|
template<typename T>
|
|
bool Base64::DecodeFromArrayTemplate(const char* data, size_t len,
|
|
DecodeFlags flags, T* result,
|
|
size_t* data_used)
|
|
{
|
|
ASSERT(NULL != result);
|
|
ASSERT(flags <= (DO_PARSE_MASK | DO_PAD_MASK | DO_TERM_MASK));
|
|
|
|
const DecodeFlags parse_flags = flags & DO_PARSE_MASK;
|
|
const DecodeFlags pad_flags = flags & DO_PAD_MASK;
|
|
const DecodeFlags term_flags = flags & DO_TERM_MASK;
|
|
ASSERT(0 != parse_flags);
|
|
ASSERT(0 != pad_flags);
|
|
ASSERT(0 != term_flags);
|
|
|
|
result->clear();
|
|
result->reserve(len);
|
|
|
|
size_t dpos = 0;
|
|
bool success = true, padded;
|
|
unsigned char c, qbuf[4];
|
|
while (dpos < len) {
|
|
size_t qlen = GetNextQuantum(parse_flags, (DO_PAD_NO == pad_flags),
|
|
data, len, &dpos, qbuf, &padded);
|
|
c = (qbuf[0] << 2) | ((qbuf[1] >> 4) & 0x3);
|
|
if (qlen >= 2) {
|
|
result->push_back(c);
|
|
c = ((qbuf[1] << 4) & 0xf0) | ((qbuf[2] >> 2) & 0xf);
|
|
if (qlen >= 3) {
|
|
result->push_back(c);
|
|
c = ((qbuf[2] << 6) & 0xc0) | qbuf[3];
|
|
if (qlen >= 4) {
|
|
result->push_back(c);
|
|
c = 0;
|
|
}
|
|
}
|
|
}
|
|
if (qlen < 4) {
|
|
if ((DO_TERM_ANY != term_flags) && (0 != c)) {
|
|
success = false; // unused bits
|
|
}
|
|
if ((DO_PAD_YES == pad_flags) && !padded) {
|
|
success = false; // expected padding
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if ((DO_TERM_BUFFER == term_flags) && (dpos != len)) {
|
|
success = false; // unused chars
|
|
}
|
|
if (data_used) {
|
|
*data_used = dpos;
|
|
}
|
|
return success;
|
|
}
|
|
|
|
} // namespace talk_base
|