Add +d (detect password prompt) flag

Also, rename -P flag to +p.

2 files changed, 63 insertions, 32 deletions

diff --git a/rtty.1 b/rtty.1
index c6ee571..7fc2fee 100644
--- a/rtty.1
+++ b/rtty.1
@@ -6,7 +6,7 @@
 .Nd limited but responsive remote shell
 .Sh SYNOPSIS
 .Nm
-.Op Fl P
+.Op Sy +dp
 .Op Ar ...
 .Sh DESCRIPTION
 .Pp
@@ -15,7 +15,7 @@ is a wrapper around
 .Xr ssh 1
 that provides a remote shell as responsive as
 .Xr mosh 1
-and as limited as a traditional teletypewriter.
+and as limited as a hard-copy teletypewriter.
 It is a very useful tool on slow connections.
 As
 .Nm
@@ -23,21 +23,31 @@ uses the default line-editing capabilities of the terminal,
 user input is only sent to the remote server
 once a full line has been input.
 .Pp
+Flags specific to
+.Nm
+are prefixed with a plus sign.
 If the
-.Fl P
+.Sy +d
 flag is provided,
 .Nm
-will manually ask the user for a password and run
-.Xr ssh 1
-using
-.Xr sshpass 1 .
-Otherwise,
+tries to detect password prompts from the remote server
+and hide the user's input.
+If the
+.Sy +p
+flag is provided,
+.Nm
+manually asks the user for a password
+before connecting to the server.
+This requires
+.Xr sshpass 1
+to be installed.
+Without the
+.Sy +p
+flag,
 .Xr ssh 1
-is launched in batch mode,
-without the possibility of interactive password entry.
+is launched in batch mode.
 .Pp
-All arguments except
-.Fl P
+All other arguments
 are passed to
 .Xr ssh 1 .
 .Sh AUTHORS
diff --git a/rtty.c b/rtty.c
index 6a69e56..18eeae6 100644
--- a/rtty.c
+++ b/rtty.c
@@ -13,16 +13,17 @@
 #define INIT "export TERM=tty43 EDITOR=ed PAGER='pr -ptl23'\n"
 #define MAXBUF 2048
 
-char *getpw(void);
+char *getpw(char *);
 void sigchld();
 
 int
 main(int argc, char *argv[])
 {
-	char bufin[MAXBUF], bufout[MAXBUF], *bi, *bo, in[30], **nargv, out[30];
-	fd_set rfds0, rfds1;
-	int fdin, fdout, i, n, offset, sshpass;
-	struct timeval tv;
+	char	bufin[MAXBUF], bufout[MAXBUF], *bi, *bo, in[30], **nargv,
+		out[30], pw[255];
+	fd_set	rfds0, rfds1;
+	int	detect, fdin, fdout, i, n, offset, sshpass;
+	struct timeval	tv;
 
 	signal(SIGCHLD, sigchld);
 
@@ -33,17 +34,25 @@ main(int argc, char *argv[])
 		if(errno != EEXIST)
 			err(1, "mkfifo");
 
-	/* Ask for password on -P. */
-	sshpass = 0;
-	if(strcmp(argv[1], "-P") == 0){
-		sshpass = 1;
-		setenv("SSHPASS", getpw(), 1);
+	/* Process rtty-specific flags. */
+	detect = sshpass = 0;
+	for(;argv[1][0] == '+';){
+		if(strchr(argv[1], 'd')) detect = 1;
+		if(strchr(argv[1], 'p')) sshpass = 1;
 
-		/* Remove -P from argv. */
+		/* Remove flag argument from argv. */
 		argv[1] = argv[0];
 		argv++; argc--;
 	}
 
+	/* Ask for password on +p. */
+	if(sshpass){
+		printf("password: ");
+		getpw(pw);
+		setenv("SSHPASS", pw, 1);
+		sshpass = 1;
+	}
+
 	if(fork() == 0){
 		/* Redirect standard in, out. */
 		if(!(fdin = open(in, O_RDONLY)))
@@ -143,29 +152,41 @@ main(int argc, char *argv[])
 			printf("%s", bo);
 			fflush(stdout);
 			bufin[0] = 0;
+
+			if(!detect)
+				continue;
+
+			/*
+			 * As the +d flag is given, rtty tries to detect
+			 * password prompts and hide the user's input.
+			 */
+			if(bo[strlen(bo)-1] == ':'
+			|| strcmp(bo+strlen(bo)-2, ": ") == 0){
+				if(!(bo = strrchr(bufout, '\n')))
+					bo = bufout;
+				if(strstr(bo, "password")
+				|| strstr(bo, "Password")
+				|| strstr(bo, "passphrase")
+				|| strstr(bo, "Passphrase")){
+					getpw(pw);
+					dprintf(fdin, "%s\n", pw);
+				}
+			}
 		}
 	}
 
 }
 
 char *
-getpw()
+getpw(char *pw)
 {
-	char *pw;
 	struct termios orig, term;
 
-	/*
-	 * This pointer will never be freed, but eh... whatever.
-	 */
-	if(!(pw = malloc(255)))
-		err(1, "malloc");
-
 	tcgetattr(0, &orig);
 	tcgetattr(0, &term);
 	term.c_lflag &= ~ECHO;
 	tcsetattr(0, TCSANOW, &term);
 
-	printf("password: ");
 	fgets(pw, 255, stdin);
 	pw[strcspn(pw, "\n")] = 0;