Lookup ssh(1) password in factotum(4)

gistfile1.diff

diff --git a/misc.c b/misc.c
index a7a23dc..73a1741 100644
--- a/misc.c
+++ b/misc.c
@@ -712,6 +712,59 @@ tun_open(int tun, int mode)
 #endif
 }
 
+/*
+ * Query factotum(4) for the password.  Return NULL if not found.
+ * Reuses SSH_ASKPASS code.
+ */
+char *
+factotum_rpc(const char *user, const char *server) {
+	char *odisplay, *oaskpass;
+	char *args, *password;
+	char *glue;
+
+	glue = getenv("SSH_FACTOTUM");
+	if (glue == NULL)
+		return NULL;
+
+	debug("Querying factotum: %s@%s", user, server);
+
+	/* preserve original environment */
+	oaskpass = getenv(SSH_ASKPASS_ENV);
+	odisplay = getenv("DISPLAY");
+
+	/* override */
+	if (setenv(SSH_ASKPASS_ENV, glue, 1) < 0) {
+		error("factotum_rpc: setenv: %s", strerror(errno));
+		exit(1);
+	}
+	if (setenv("DISPLAY", "factotum", 1) < 0) {
+		error("factotum_rpc: setenv: %s", strerror(errno));
+		exit(1);
+	}
+
+	/* make the call */
+	if (asprintf(&args, "%s@%s", user, server) < 0) {
+		error("factotum_rpc: asprintf: %s", strerror(errno));
+		exit(1);
+	}
+	password = read_passphrase(args, RP_USE_ASKPASS);
+	if (strcmp(password, "") == 0)
+		password = NULL;
+
+	/* restore original environment */
+	if (oaskpass)
+		setenv(SSH_ASKPASS_ENV, oaskpass, 1);
+	else
+		unsetenv(SSH_ASKPASS_ENV);
+	if (odisplay)
+		setenv(SSH_ASKPASS_ENV, odisplay, 1);
+	else
+		unsetenv("DISPLAY");
+
+	return password;
+}
+
+
 void
 sanitise_stdfd(void)
 {
diff --git a/misc.h b/misc.h
index f3142a9..836a6a1 100644
--- a/misc.h
+++ b/misc.h
@@ -53,6 +53,7 @@ void	 replacearg(arglist *, u_int, char *, ...)
 void	 freeargs(arglist *);
 
 int	 tun_open(int, int);
+char	*factotum_rpc(const char *, const char *);
 
 /* Common definitions for ssh tunnel device forwarding */
 #define SSH_TUNMODE_NO		0x00
diff --git a/sshconnect1.c b/sshconnect1.c
index fd07bbf..e2dcf8f 100644
--- a/sshconnect1.c
+++ b/sshconnect1.c
@@ -444,7 +444,7 @@ try_challenge_response_authentication(void)
  * Tries to authenticate with plain passwd authentication.
  */
 static int
-try_password_authentication(char *prompt)
+try_password_authentication(char *prompt, const char *user, const char *server)
 {
 	int type, i;
 	char *password;
@@ -455,7 +455,9 @@ try_password_authentication(char *prompt)
 	for (i = 0; i < options.number_of_password_prompts; i++) {
 		if (i != 0)
 			error("Permission denied, please try again.");
-		password = read_passphrase(prompt, 0);
+		password = factotum_rpc(user, server);
+		if (password == NULL)
+			password = read_passphrase(prompt, 0);
 		packet_start(SSH_CMSG_AUTH_PASSWORD);
 		ssh_put_password(password);
 		memset(password, 0, strlen(password));
@@ -741,7 +743,7 @@ ssh_userauth1(const char *local_user, const char *server_user, char *host,
 
 		snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
 		    server_user, host);
-		if (try_password_authentication(prompt))
+		if (try_password_authentication(prompt, server_user, host))
 			goto success;
 	}
 	/* All authentication methods have failed.  Exit with an error message. */
diff --git a/sshconnect2.c b/sshconnect2.c
index c24b202..ea2b920 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -875,9 +875,12 @@ userauth_passwd(Authctxt *authctxt)
 	if (attempt != 1)
 		error("Permission denied, please try again.");
 
-	snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
-	    authctxt->server_user, host);
-	password = read_passphrase(prompt, 0);
+	password = factotum_rpc(authctxt->server_user, host);
+	if (password == NULL) {
+		snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
+		    authctxt->server_user, host);
+		password = read_passphrase(prompt, 0);
+	}
 	packet_start(SSH2_MSG_USERAUTH_REQUEST);
 	packet_put_cstring(authctxt->server_user);
 	packet_put_cstring(authctxt->service);
@@ -989,9 +992,12 @@ jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
 	u_int secret_len;
 	BIGNUM *ret;
 
-	snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
-	    authctxt->server_user, authctxt->host);
-	password = read_passphrase(prompt, 0);
+	password = factotum_rpc(authctxt->server_user, authctxt->host);
+	if (password == NULL) {
+		snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
+		    authctxt->server_user, authctxt->host);
+		password = read_passphrase(prompt, 0);
+	}
 
 	if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
 		logit("Disabling %s authentication", authctxt->method->name);