rdo/readpassphrase.h
sw1tchbl4d3 d09a59a77e Add own readpassphrase function
This removes the libbsd dependency.
Fixed #10.
2022-05-05 08:21:48 +02:00

61 lines
1.2 KiB
C

#include <stdio.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
char* readpassphrase(const char* prompt, char* buf, size_t bufsz) {
char stdin_path[256];
char tty_link_path[256];
int n;
int ttyfd = -1;
struct termios term;
for (int i = 0; i < 3; i++) {
if (tcgetattr(i, &term) == 0) {
ttyfd = i;
break;
}
}
if (ttyfd < 0)
return NULL;
snprintf(tty_link_path, sizeof(tty_link_path), "/proc/self/fd/%d", ttyfd);
n = readlink(tty_link_path, stdin_path, sizeof(stdin_path));
if (n < 0)
return NULL;
stdin_path[n] = '\0';
int fd = open(stdin_path, O_RDWR);
if (fd < 0)
return NULL;
term.c_lflag &= ~ECHO;
tcsetattr(ttyfd, 0, &term);
term.c_lflag |= ECHO;
if (write(fd, prompt, strlen(prompt)) < 0) {
tcsetattr(ttyfd, 0, &term);
return NULL;
}
n = read(fd, buf, bufsz);
if (n < 0) {
tcsetattr(ttyfd, 0, &term);
printf("\n");
return NULL;
}
buf[n-1] = '\0';
close(fd);
tcsetattr(ttyfd, 0, &term);
// NOTE: As we disabled echo, the enter sent by the user isn't displayed.
printf("\n");
return buf;
}