[linux-pam: 1/2] Fix matching of usernames in the pam_unix remember feature.

[Tomáš Mráz]

commit 0baf28fa03dfa46482e13390fd9a7545c30ccd7f
Author: Tomas Mraz <tmraz(a)fedoraproject.org&gt;
Date:   Tue Jan 3 12:30:43 2012 +0100

    Fix matching of usernames in the pam_unix remember feature.
    
    * modules/pam_unix/pam_unix_passwd.c (check_old_password): Make
    sure we match only the whole username in opasswd entry.
    * modules/pam_unix/passverify.c (save_old_password): Likewise make
    sure we match only the whole username in opasswd entry.

 modules/pam_unix/pam_unix_passwd.c |    4 +++-
 modules/pam_unix/passverify.c      |    3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/modules/pam_unix/pam_unix_passwd.c b/modules/pam_unix/pam_unix_passwd.c
index 6ba2c2e..498a81c 100644
--- a/modules/pam_unix/pam_unix_passwd.c
+++ b/modules/pam_unix/pam_unix_passwd.c
@@ -280,13 +280,15 @@ static int check_old_password(const char *forwho, const char
*newpass)
 	char *s_luser, *s_uid, *s_npas, *s_pas;
 	int retval = PAM_SUCCESS;
 	FILE *opwfile;
+	size_t len = strlen(forwho);
 
 	opwfile = fopen(OLD_PASSWORDS_FILE, "r");
 	if (opwfile == NULL)
 		return PAM_ABORT;
 
 	while (fgets(buf, 16380, opwfile)) {
-		if (!strncmp(buf, forwho, strlen(forwho))) {
+		if (!strncmp(buf, forwho, len) && (buf[len] == ':' ||
+			buf[len] == ',')) {
 			char *sptr;
 			buf[strlen(buf) - 1] = '\0';
 			s_luser = strtok_r(buf, ":,", &sptr);
diff --git a/modules/pam_unix/passverify.c b/modules/pam_unix/passverify.c
index 089f4b8..5289955 100644
--- a/modules/pam_unix/passverify.c
+++ b/modules/pam_unix/passverify.c
@@ -562,6 +562,7 @@ save_old_password(pam_handle_t *pamh, const char *forwho, const char
*oldpass,
     int found = 0;
     struct passwd *pwd = NULL;
     struct stat st;
+    size_t len = strlen(forwho);
 #ifdef WITH_SELINUX
     security_context_t prev_context=NULL;
 #endif
@@ -629,7 +630,7 @@ save_old_password(pam_handle_t *pamh, const char *forwho, const char
*oldpass,
     }
 
     while (fgets(buf, 16380, opwfile)) {
-	if (!strncmp(buf, forwho, strlen(forwho))) {
+	if (!strncmp(buf, forwho, len) && strchr(":,\n", buf[len]) != NULL) {
 	    char *sptr = NULL;
 	    found = 1;
 	    if (howmany == 0)