diff --git a/contrib/libexec/encrypt/encrypt.c b/contrib/libexec/encrypt/encrypt.c
index e525fd27..f0d2b9e5 100644
--- a/contrib/libexec/encrypt/encrypt.c
+++ b/contrib/libexec/encrypt/encrypt.c
@@ -52,23 +52,24 @@ static struct hashing_method ids[] = {
 };
 
 static void to64(char *, long int, int);
+static void check_passwd(const char *, const char *);
 static void print_passwd(const char *);
 
 int
 main(int argc, char *argv[])
 {
 	char *line;
+	char *hash="";
 	size_t linesz;
 	ssize_t linelen;
 
 	if (argc > 2) {
-		fprintf(stderr, "usage: encrypt <string>\n");
+		fprintf(stderr, "usage: encrypt [<hash>]\n<hash>: exactly as received from a previous encrypt invocation\n");
 		return (1);
 	}
 
 	if (argc == 2) {
-		print_passwd(argv[1]);
-		return (0);
+		hash=argv[1];
 	}
 
 	line = NULL;
@@ -76,13 +77,20 @@ main(int argc, char *argv[])
 	while ((linelen = getline(&line, &linesz, stdin)) != -1) {
 		if (line[linelen - 1] == '\n')
 			line[linelen - 1] = '\0';
-		print_passwd(line);
+		check_passwd(line,hash);
 	}
 	free(line);
 
 	return (0);
 }
 
+
+void check_passwd(const char *string, const char *salt)
+{
+	if (!salt || !*salt) {print_passwd(string); return;}
+	printf("%s\n", crypt(string, salt));
+}
+
 void
 print_passwd(const char *string)
 {