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Make passphrase_prompt() return -1 on failure so that caller can clean up

This commit is contained in:
Juhani Krekelä 2021-04-09 20:52:04 +03:00
parent 0cb02aaf14
commit f445783a44
1 changed files with 30 additions and 14 deletions
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44
puer.c
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@ -452,31 +452,34 @@ bool ccm_decrypt(unsigned char key[16], uint32_t messageindex, unsigned char mes
return true;
}
size_t passphrase_prompt(unsigned char *passphrase, size_t size, const char *prompt) {
// Read from controlling TTY, even if stdion has been redirected
ssize_t passphrase_prompt(unsigned char *passphrase, size_t size, const char *prompt) {
// Read from controlling TTY, even if stdio has been redirected
int tty = open("/dev/tty", O_RDWR);
if (tty == -1) {
perror("Failed to open controlling tty");
exit(1);
return -1;
}
if (write(tty, prompt, strlen(prompt)) == -1) {
perror("Failed to write to terminal");
exit(1);
close(tty);
return -1;
}
// Turn off echo
struct termios saved;
if (tcgetattr(tty, &saved) != 0) {
perror("tcgetattr");
exit(1);
perror("Failed to get terminal attributes");
close(tty);
return -1;
}
struct termios altered;
altered = saved;
altered.c_lflag &= ~ECHO;
if (tcsetattr(tty, TCSANOW, &altered) != 0) {
perror("tcsetattr");
exit(1);
perror("Failed to turn echoing off");
close(tty);
return -1;
}
// Read until newline
@ -495,18 +498,21 @@ size_t passphrase_prompt(unsigned char *passphrase, size_t size, const char *pro
}
}
tcsetattr(tty, TCSANOW, &saved);
exit(1);
close(tty);
return -1;
}
ssize_t bytes_read = read(tty, &passphrase[index], size - index);
if (bytes_read == -1) {
perror("Failed to read passphrase");
tcsetattr(tty, TCSANOW, &saved);
exit(1);
close(tty);
return -1;
} else if (bytes_read == 0) {
fprintf(stderr, "Unexpected EOF\n");
tcsetattr(tty, TCSANOW, &saved);
exit(1);
close(tty);
return -1;
}
index += bytes_read;
@ -520,9 +526,15 @@ size_t passphrase_prompt(unsigned char *passphrase, size_t size, const char *pro
// terminal settings
if (write(tty, "\n", 1) == -1) {
perror("Failed to write to terminal");
exit(1);
tcsetattr(tty, TCSANOW, &saved);
close(tty);
return -1;
}
if (tcsetattr(tty, TCSANOW, &saved) != 0) {
perror("Failed to restore terminal state");
close(tty);
return -1;
}
tcsetattr(tty, TCSANOW, &saved);
close(tty);
return index - 1;
@ -535,7 +547,11 @@ int main(void) {
}
unsigned char passphrase[128] = {0};
size_t passphrase_len = passphrase_prompt(passphrase, sizeof(passphrase), "passphrase: ");
ssize_t passphrase_len = passphrase_prompt(passphrase, sizeof(passphrase), "passphrase: ");
if (passphrase_len == -1) {
explicit_bzero(passphrase, sizeof(passphrase));
exit(1);
}
unsigned char key[16];
kdf(key, salt, passphrase, passphrase_len);