mirror of
https://github.com/qpdf/qpdf.git
synced 2024-11-16 17:45:09 +00:00
12f1eb15ca
Run this: for i in **/*.cc **/*.c **/*.h **/*.hh; do clang-format < $i >| $i.new && mv $i.new $i done
55 lines
1.2 KiB
C++
55 lines
1.2 KiB
C++
#include <qpdf/RC4_native.hh>
|
|
|
|
#include <qpdf/QIntC.hh>
|
|
|
|
#include <string.h>
|
|
|
|
static void
|
|
swap_byte(unsigned char& a, unsigned char& b)
|
|
{
|
|
unsigned char t;
|
|
|
|
t = a;
|
|
a = b;
|
|
b = t;
|
|
}
|
|
|
|
RC4_native::RC4_native(unsigned char const* key_data, int key_len)
|
|
{
|
|
if (key_len == -1) {
|
|
key_len =
|
|
QIntC::to_int(strlen(reinterpret_cast<char const*>(key_data)));
|
|
}
|
|
|
|
for (int i = 0; i < 256; ++i) {
|
|
key.state[i] = static_cast<unsigned char>(i);
|
|
}
|
|
key.x = 0;
|
|
key.y = 0;
|
|
|
|
int i1 = 0;
|
|
int i2 = 0;
|
|
for (int i = 0; i < 256; ++i) {
|
|
i2 = (key_data[i1] + key.state[i] + i2) % 256;
|
|
swap_byte(key.state[i], key.state[i2]);
|
|
i1 = (i1 + 1) % key_len;
|
|
}
|
|
}
|
|
|
|
void
|
|
RC4_native::process(unsigned char* in_data, size_t len, unsigned char* out_data)
|
|
{
|
|
if (out_data == 0) {
|
|
// Convert in place
|
|
out_data = in_data;
|
|
}
|
|
|
|
for (size_t i = 0; i < len; ++i) {
|
|
key.x = static_cast<unsigned char>((key.x + 1) % 256);
|
|
key.y = static_cast<unsigned char>((key.state[key.x] + key.y) % 256);
|
|
swap_byte(key.state[key.x], key.state[key.y]);
|
|
int xor_index = (key.state[key.x] + key.state[key.y]) % 256;
|
|
out_data[i] = in_data[i] ^ key.state[xor_index];
|
|
}
|
|
}
|