+#if HAVE_CRYPT_H
+# include <crypt.h>
+#endif
+#include <err.h>
+#include <errno.h>
+#include <limits.h>
+#include <pwd.h>
+#ifdef HAVE_READPASSPHRASE_H
+# include <readpassphrase.h>
+#else
+# include "readpassphrase.h"
+#endif
+#include <shadow.h>
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+
+#include "openbsd.h"
+
+void
+shadowauth(const char *myname, int persist)
+{
+ const char *hash;
+ char *encrypted;
+ struct passwd *pw;
+ char *challenge, *response, rbuf[1024], cbuf[128];
+
+#ifdef USE_TIMESTAMP
+ int fd = -1;
+ int valid = 0;
+
+ if (persist)
+ fd = timestamp_open(&valid, 5 * 60);
+ if (fd != -1 && valid == 1)
+ goto good;
+#else
+ (void) persist;
+#endif
+
+ if ((pw = getpwnam(myname)) == NULL)
+ err(1, "getpwnam");
+
+ hash = pw->pw_passwd;
+ if (hash[0] == 'x' && hash[1] == '\0') {
+ struct spwd *sp;
+ if ((sp = getspnam(myname)) == NULL)
+ errx(1, "Authorization failed");
+ hash = sp->sp_pwdp;
+ } else if (hash[0] != '*') {
+ errx(1, "Authorization failed");
+ }
+
+ char host[HOST_NAME_MAX + 1];
+ if (gethostname(host, sizeof(host)))
+ snprintf(host, sizeof(host), "?");
+ snprintf(cbuf, sizeof(cbuf),
+ "\rdoas (%.32s@%.32s) password: ", myname, host);
+ challenge = cbuf;
+
+ response = readpassphrase(challenge, rbuf, sizeof(rbuf), RPP_REQUIRE_TTY);
+ if (response == NULL && errno == ENOTTY) {
+ syslog(LOG_AUTHPRIV | LOG_NOTICE,
+ "tty required for %s", myname);
+ errx(1, "a tty is required");
+ }
+ if ((encrypted = crypt(response, hash)) == NULL)
+ err(1, "crypt");
+ if (strcmp(encrypted, hash) != 0) {
+ syslog(LOG_AUTHPRIV | LOG_NOTICE, "failed auth for %s", myname);
+ errx(1, "Authorization failed");
+ }
+
+ explicit_bzero(rbuf, sizeof(rbuf));
+
+#ifdef USE_TIMESTAMP
+good:
+ if (fd != -1) {
+ timestamp_set(fd, 5 * 60);
+ close(fd);
+ }
+#endif
+}