From dedad73e5e7a75d01a5f3d5a6702ab8ccd2ff40d Mon Sep 17 00:00:00 2001 From: mancha <mancha1@hush.com> Date: Thu, 11 Jul 2013 09:08:07 +0000 Subject: Handle NULL returns from glibc 2.17+ crypt() Starting with glibc 2.17 (eglibc 2.17), crypt() fails with EINVAL (w/ NULL return) if the salt violates specifications. Additionally, on FIPS-140 enabled Linux systems, DES/MD5-encrypted passwords passed to crypt() fail with EPERM (w/ NULL return). When using glibc's crypt(), check return value to avoid a possible NULL pointer dereference. Patch by mancha1@hush.com. --- diff --git a/pwcheck/pwcheck_getpwnam.c b/pwcheck/pwcheck_getpwnam.c index 4b34222..400289c 100644 --- a/pwcheck/pwcheck_getpwnam.c +++ b/pwcheck/pwcheck_getpwnam.c @@ -32,6 +32,7 @@ char *userid; char *password; { char* r; + char* crpt_passwd; struct passwd *pwd; pwd = getpwnam(userid); @@ -41,7 +42,7 @@ char *password; else if (pwd->pw_passwd[0] == '*') { r = "Account disabled"; } - else if (strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0) { + else if (!(crpt_passwd = crypt(password, pwd->pw_passwd)) || strcmp(pwd->pw_passwd, (const char *)crpt_passwd) != 0) { r = "Incorrect password"; } else { diff --git a/pwcheck/pwcheck_getspnam.c b/pwcheck/pwcheck_getspnam.c index 2b11286..6d607bb 100644 --- a/pwcheck/pwcheck_getspnam.c +++ b/pwcheck/pwcheck_getspnam.c @@ -32,13 +32,15 @@ char *userid; char *password; { struct spwd *pwd; + char *crpt_passwd; pwd = getspnam(userid); if (!pwd) { return "Userid not found"; } - if (strcmp(pwd->sp_pwdp, crypt(password, pwd->sp_pwdp)) != 0) { + crpt_passwd = crypt(password, pwd->sp_pwdp); + if (!crpt_passwd || strcmp(pwd->sp_pwdp, (const char *)crpt_passwd) != 0) { return "Incorrect password"; } else { diff --git a/saslauthd/auth_getpwent.c b/saslauthd/auth_getpwent.c index fc8029d..d4ebe54 100644 --- a/saslauthd/auth_getpwent.c +++ b/saslauthd/auth_getpwent.c @@ -77,6 +77,7 @@ auth_getpwent ( { /* VARIABLES */ struct passwd *pw; /* pointer to passwd file entry */ + char *crpt_passwd; /* encrypted password */ int errnum; /* END VARIABLES */ @@ -105,7 +106,8 @@ auth_getpwent ( } } - if (strcmp(pw->pw_passwd, (const char *)crypt(password, pw->pw_passwd))) { + crpt_passwd = crypt(password, pw->pw_passwd); + if (!crpt_passwd || strcmp(pw->pw_passwd, (const char *)crpt_passwd)) { if (flags & VERBOSE) { syslog(LOG_DEBUG, "DEBUG: auth_getpwent: %s: invalid password", login); } diff --git a/saslauthd/auth_shadow.c b/saslauthd/auth_shadow.c index 677131b..1988afd 100644 --- a/saslauthd/auth_shadow.c +++ b/saslauthd/auth_shadow.c @@ -210,8 +210,8 @@ auth_shadow ( RETURN("NO Insufficient permission to access NIS authentication database (saslauthd)"); } - cpw = strdup((const char *)crypt(password, sp->sp_pwdp)); - if (strcmp(sp->sp_pwdp, cpw)) { + cpw = crypt(password, sp->sp_pwdp); + if (!cpw || strcmp(sp->sp_pwdp, (const char *)cpw)) { if (flags & VERBOSE) { /* * This _should_ reveal the SHADOW_PW_LOCKED prefix to an @@ -221,10 +221,8 @@ auth_shadow ( syslog(LOG_DEBUG, "DEBUG: auth_shadow: pw mismatch: '%s' != '%s'", sp->sp_pwdp, cpw); } - free(cpw); RETURN("NO Incorrect password"); } - free(cpw); /* * The following fields will be set to -1 if: @@ -286,7 +284,7 @@ auth_shadow ( RETURN("NO Invalid username"); } - if (strcmp(upw->upw_passwd, crypt(password, upw->upw_passwd)) != 0) { + if (!(cpw = crypt(password, upw->upw_passwd)) || (strcmp(upw->upw_passwd, (const char *)cpw) != 0)) { if (flags & VERBOSE) { syslog(LOG_DEBUG, "auth_shadow: pw mismatch: %s != %s", password, upw->upw_passwd); -- cgit v0.9.2