Files
guacamole-client/guacamole/proxy/base64.c
2010-09-05 13:02:57 -07:00

124 lines
2.8 KiB
C

#include <unistd.h>
#include <stdio.h>
char characters[64] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/',
};
int ready_buf[3];
int ready = 0;
int written = 0;
char out_buf[8192];
ssize_t __write_base64_triplet(int fd, int a, int b, int c) {
int retval;
/* Byte 1 */
out_buf[written++] = characters[(a & 0xFC) >> 2]; /* [AAAAAA]AABBBB BBBBCC CCCCCC */
if (b >= 0) {
out_buf[written++] = characters[((a & 0x03) << 4) | ((b & 0xF0) >> 4)]; /* AAAAAA[AABBBB]BBBBCC CCCCCC */
if (c >= 0) {
out_buf[written++] = characters[((b & 0x0F) << 2) | ((c & 0xC0) >> 6)]; /* AAAAAA AABBBB[BBBBCC]CCCCCC */
out_buf[written++] = characters[c & 0x3F]; /* AAAAAA AABBBB BBBBCC[CCCCCC] */
}
else {
out_buf[written++] = characters[((b & 0x0F) << 2)]; /* AAAAAA AABBBB[BBBB--]------ */
out_buf[written++] = '='; /* AAAAAA AABBBB BBBB--[------] */
}
}
else {
out_buf[written++] = characters[((a & 0x03) << 4)]; /* AAAAAA[AA----]------ ------ */
out_buf[written++] = '='; /* AAAAAA AA----[------]------ */
out_buf[written++] = '='; /* AAAAAA AA---- ------[------] */
}
/* At this point, 4 bytes have been written */
/* Flush when necessary, return on error */
if (written > 8188 /* sizeof(out_buf) - 4 */) {
retval = write(fd, out_buf, written);
if (retval < 0)
return retval;
written = 0;
}
if (b < 0)
return 1;
if (c < 0)
return 2;
return 3;
}
ssize_t __write_base64_byte(int fd, char buf) {
int retval;
ready_buf[ready++] = buf & 0xFF;
/* Flush triplet */
if (ready == 3) {
retval = __write_base64_triplet(fd, ready_buf[0], ready_buf[1], ready_buf[2]);
if (retval < 0)
return retval;
ready = 0;
}
return 1;
}
ssize_t write_base64(int fd, const char* buf, size_t count) {
int retval;
const char* end = buf + count;
while (buf < end) {
retval = __write_base64_byte(fd, *(buf++));
if (retval < 0)
return retval;
}
return count;
}
ssize_t flush_base64(int fd) {
int retval;
/* Flush triplet to output buffer */
while (ready > 0) {
retval = __write_base64_byte(fd, -1);
if (retval < 0)
return retval;
}
/* Flush remaining bytes in buffer */
if (written > 0) {
retval = write(fd, out_buf, written);
if (retval < 0)
return retval;
written = 0;
}
return 0;
}