new file does skey_getpass() support

svn path=/head/; revision=3709

lib/libskey/skey_getpass.c

@@ -0,0 +1,40 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <skey.h>
+
+/* skey_getpass - read regular or s/key password */
+
+char   *skey_getpass(prompt, pwd, pwok)
+char   *prompt;
+struct passwd *pwd;
+int     pwok;
+{
+    static char buf[128];
+    struct skey skey;
+    char   *pass;
+    char   *username = pwd ? pwd->pw_name : "nope";
+    int     sflag;
+
+    /* Attempt an s/key challenge. */
+    sflag = skeychallenge(&skey, username, buf);
+    if (!sflag)
+	printf("%s\n", buf);
+
+    if (!pwok)
+	printf("(s/key required)\n");
+
+    pass = getpass(prompt);
+
+    /* Give S/Key users a chance to do it with echo on. */
+    if (!sflag && !feof(stdin) && *pass == '\0') {
+	fputs(" (turning echo on)\n", stdout);
+	fputs(prompt, stdout);
+	fflush(stdout);
+	fgets(buf, sizeof(buf), stdin);
+	rip(buf);
+	return (buf);
+    }
+
+    putchar('\n');
+    return (pass);
+}