From bec943d06db41e1ba2a4832fe10924a10ea91166 Mon Sep 17 00:00:00 2001
From: Lucas <lucas@domain.invalid>
Date: Mon, 15 Jun 2020 23:57:28 +0000
Subject: [PATCH] Read key from standard input if there are no arguments

---
 cli.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/cli.c b/cli.c
index 5d060f4..3be0610 100644
--- a/cli.c
+++ b/cli.c
@@ -26,6 +26,8 @@
 #include "mystrtonum.h"
 #include "otp.h"
 
+#define LINE_SIZE 16384
+
 extern const char *__progname;
 
 static void
@@ -42,6 +44,8 @@ int
 main(int argc, char *argv[])
 {
 	const char *errstr;
+	char *key;
+	size_t key_len;
 	uint64_t counter;
 	unsigned int step;
 	int32_t r;
@@ -99,16 +103,32 @@ main(int argc, char *argv[])
 		usage();
 	}
 
-	if (argc != 1)
+	if (argc > 1)
 		usage();
 
+	if (argc == 1) {
+		key = argv[0];
+		key_len = strlen(key);
+	} else {
+		key = malloc(sizeof(uint8_t) * (LINE_SIZE + 1));
+		if (key == NULL)
+			err(1, "malloc");
+		if (fgets(key, LINE_SIZE + 1, stdin) == NULL)
+			err(1, "fgets");
+		key_len = strlen(key);
+		if (key[key_len - 1] == '\n') {
+			key[key_len - 1] = '\0';
+			key_len--;
+		}
+	}
+
 	if (do_hotp) {
-		r = hotp(hmac, argv[0], strlen(argv[0]), counter, digits);
+		r = hotp(hmac, key, key_len, counter, digits);
 		if (r == -1)
 			errx(1, "couldn't calculate HOTP");
 		printf("%0*" PRId32 "\n", digits, r);
 	} else {
-		r = totp(hmac, argv[0], strlen(argv[0]), counter, step, digits);
+		r = totp(hmac, key, key_len, counter, step, digits);
 		if (r == -1)
 			errx(1, "couldn't calculate TOTP");
 		printf("%0*" PRId32 "\n", digits, r);