copy bcrypt autotune from encrypt(1) and expose via crypt_newhash

ok deraadt miod

1 files changed, 10 insertions, 4 deletions

diff --git a/src/lib/libc/crypt/cryptutil.c b/src/lib/libc/crypt/cryptutil.c
index f101240524..7e93dad3c8 100644
--- a/src/lib/libc/crypt/cryptutil.c
+++ b/src/lib/libc/crypt/cryptutil.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cryptutil.c,v 1.6 2014/12/24 22:10:34 tedu Exp $ */
+/* $OpenBSD: cryptutil.c,v 1.7 2014/12/30 10:27:24 tedu Exp $ */
 /*
  * Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
  *
@@ -21,6 +21,8 @@
 #include <login_cap.h>
 #include <errno.h>
 
+int bcrypt_autorounds(void);
+
 int
 crypt_checkpass(const char *pass, const char *goodhash)
 {
@@ -64,9 +66,13 @@ crypt_newhash(const char *pass, const char *pref, char *hash, size_t hashlen)
                 errno = EINVAL;
                 goto err;
         }
-        rounds = strtonum(pref + 9, 4, 31, &errstr);
-        if (errstr)
-                goto err;
+        if (strcmp(pref + 9, "a") == 0) {
+                rounds = bcrypt_autorounds();
+        } else {
+                rounds = strtonum(pref + 9, 4, 31, &errstr);
+                if (errstr)
+                        goto err;
+        }
         rv = bcrypt_newhash(pass, rounds, hash, hashlen);
 
 err: