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#include <qpdf/Pl_Base64.hh>
#include <qpdf/QIntC.hh>
#include <qpdf/QUtil.hh>
#include <cstring>
#include <stdexcept>
static char
to_c(unsigned int ch)
{
return static_cast<char>(ch);
}
static unsigned char
to_uc(int ch)
{
return static_cast<unsigned char>(ch);
}
static int
to_i(int i)
{
return static_cast<int>(i);
}
Pl_Base64::Pl_Base64(char const* identifier, Pipeline* next, action_e action) :
Pipeline(identifier, next),
action(action),
pos(0),
end_of_data(false),
finished(false)
{
reset();
}
void
Pl_Base64::write(unsigned char const* data, size_t len)
{
if (finished) {
throw std::logic_error("Pl_Base64 used after finished");
}
if (this->action == a_decode) {
decode(data, len);
} else {
encode(data, len);
}
}
void
Pl_Base64::decode(unsigned char const* data, size_t len)
{
unsigned char const* p = data;
while (len > 0) {
if (!QUtil::is_space(to_c(*p))) {
this->buf[this->pos++] = *p;
if (this->pos == 4) {
flush();
}
}
++p;
--len;
}
}
void
Pl_Base64::encode(unsigned char const* data, size_t len)
{
unsigned char const* p = data;
while (len > 0) {
this->buf[this->pos++] = *p;
if (this->pos == 3) {
flush();
}
++p;
--len;
}
}
void
Pl_Base64::flush()
{
if (this->action == a_decode) {
flush_decode();
} else {
flush_encode();
}
reset();
}
void
Pl_Base64::flush_decode()
{
if (this->end_of_data) {
throw std::runtime_error(getIdentifier() + ": base64 decode: data follows pad characters");
}
int pad = 0;
int shift = 18;
int outval = 0;
for (size_t i = 0; i < 4; ++i) {
int v = 0;
char ch = to_c(this->buf[i]);
if ((ch >= 'A') && (ch <= 'Z')) {
v = ch - 'A';
} else if ((ch >= 'a') && (ch <= 'z')) {
v = ch - 'a' + 26;
} else if ((ch >= '0') && (ch <= '9')) {
v = ch - '0' + 52;
} else if ((ch == '+') || (ch == '-')) {
v = 62;
} else if ((ch == '/') || (ch == '_')) {
v = 63;
} else if ((ch == '=') && ((i == 3) || ((i == 2) && (this->buf[3] == '=')))) {
++pad;
this->end_of_data = true;
v = 0;
} else {
throw std::runtime_error(getIdentifier() + ": base64 decode: invalid input");
}
outval |= v << shift;
shift -= 6;
}
unsigned char out[3] = {
to_uc(outval >> 16),
to_uc(0xff & (outval >> 8)),
to_uc(0xff & outval),
};
getNext()->write(out, QIntC::to_size(3 - pad));
}
void
Pl_Base64::flush_encode()
{
int outval = ((this->buf[0] << 16) | (this->buf[1] << 8) | (this->buf[2]));
unsigned char out[4] = {
to_uc(outval >> 18),
to_uc(0x3f & (outval >> 12)),
to_uc(0x3f & (outval >> 6)),
to_uc(0x3f & outval),
};
for (size_t i = 0; i < 4; ++i) {
int ch = to_i(out[i]);
if (ch < 26) {
ch += 'A';
} else if (ch < 52) {
ch -= 26;
ch += 'a';
} else if (ch < 62) {
ch -= 52;
ch += '0';
} else if (ch == 62) {
ch = '+';
} else if (ch == 63) {
ch = '/';
}
out[i] = to_uc(ch);
}
for (size_t i = 0; i < 3 - this->pos; ++i) {
out[3 - i] = '=';
}
getNext()->write(out, 4);
}
void
Pl_Base64::finish()
{
if (this->pos > 0) {
if (finished) {
throw std::logic_error("Pl_Base64 used after finished");
}
if (this->action == a_decode) {
for (size_t i = this->pos; i < 4; ++i) {
this->buf[i] = '=';
}
}
flush();
}
this->finished = true;
getNext()->finish();
}
void
Pl_Base64::reset()
{
this->pos = 0;
memset(buf, 0, 4);
}
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