diff options
| author | Todd C. Miller <millert@cvs.openbsd.org> | 2006-03-09 19:14:11 +0000 |
|---|---|---|
| committer | Todd C. Miller <millert@cvs.openbsd.org> | 2006-03-09 19:14:11 +0000 |
| commit | 3a6c6b26f4f6a8488243ac8edd6d2a7cd710ae86 (patch) | |
| tree | 7a662e4e6494e0deed33b32d493731108d5059f3 /libexec/login_chpass/login_chpass.c | |
| parent | 36b32be082b3a821442bae3180bb6f9a98d4a6e3 (diff) | |
Foil potential timing attacks by using the correct password hash
instead of "xx". In practice this means bcrypt() will be used for
non-existent users instead of DES crypt().
Adapted from a patch by Peter Philipp. OK deraadt@
Diffstat (limited to 'libexec/login_chpass/login_chpass.c')
| -rw-r--r-- | libexec/login_chpass/login_chpass.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/libexec/login_chpass/login_chpass.c b/libexec/login_chpass/login_chpass.c index 605070a2d4a..2d665d5fa14 100644 --- a/libexec/login_chpass/login_chpass.c +++ b/libexec/login_chpass/login_chpass.c @@ -1,4 +1,4 @@ -/* $OpenBSD: login_chpass.c,v 1.14 2005/04/14 18:33:42 biorn Exp $ */ +/* $OpenBSD: login_chpass.c,v 1.15 2006/03/09 19:14:09 millert Exp $ */ /*- * Copyright (c) 1995,1996 Berkeley Software Design, Inc. All rights reserved. @@ -73,6 +73,7 @@ int _yp_check(char **); char *ypgetnewpasswd(struct passwd *, char **); struct passwd *ypgetpwnam(char *); void kbintr(int); +int pwd_gensalt(char *, int, login_cap_t *, char); #endif void local_chpass(char **); @@ -199,9 +200,15 @@ yp_chpass(char *username) } } if (pw == NULL) { - char *p = getpass("Old password:"); - if (p != NULL) { - crypt(p, "xx"); + char *p, salt[_PASSWORD_LEN + 1]; + login_cap_t *lc; + + /* no such user, get appropriate salt to thwart timing attack */ + if ((p = getpass("Old password:")) != NULL) { + if ((lc = login_getclass(NULL)) == NULL || + pwd_gensalt(salt, sizeof(salt), lc, 'y') == 0) + strlcpy(salt, "xx", sizeof(salt)); + crypt(p, salt); memset(p, 0, strlen(p)); } warnx("YP passwd database unchanged."); |