[PATCH] s3: Allow previous password to be stored and use it to check tickets
Matthieu Patou
mat at matws.net
Fri May 21 01:57:29 MDT 2010
This patch is to fix bug 7099. It stores the current password in the
previous password key when the password is changed. It also check the
user ticket against previous password.
---
source3/include/proto.h | 1 +
source3/include/secrets.h | 1 +
source3/libads/kerberos_verify.c | 93 ++++++++++++++++++-----------
source3/passdb/machine_account_secrets.c | 62 ++++++++++++++++++-
4 files changed, 118 insertions(+), 39 deletions(-)
diff --git a/source3/include/proto.h b/source3/include/proto.h
index f7d9f39..63d6129 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -4634,6 +4634,7 @@ bool secrets_delete_machine_password(const char *domain);
bool secrets_delete_machine_password_ex(const char *domain);
bool secrets_delete_domain_sid(const char *domain);
bool secrets_store_machine_password(const char *pass, const char *domain, enum netr_SchannelType sec_channel);
+char *secrets_fetch_prev_machine_password(const char *domain);
char *secrets_fetch_machine_password(const char *domain,
time_t *pass_last_set_time,
enum netr_SchannelType *channel);
diff --git a/source3/include/secrets.h b/source3/include/secrets.h
index b51fd22..624b146 100644
--- a/source3/include/secrets.h
+++ b/source3/include/secrets.h
@@ -25,6 +25,7 @@
*/
#define SECRETS_MACHINE_ACCT_PASS "SECRETS/$MACHINE.ACC"
#define SECRETS_MACHINE_PASSWORD "SECRETS/MACHINE_PASSWORD"
+#define SECRETS_MACHINE_PASSWORD_PREV "SECRETS/MACHINE_PASSWORD.PREV"
#define SECRETS_MACHINE_LAST_CHANGE_TIME "SECRETS/MACHINE_LAST_CHANGE_TIME"
#define SECRETS_MACHINE_SEC_CHANNEL_TYPE "SECRETS/MACHINE_SEC_CHANNEL_TYPE"
#define SECRETS_MACHINE_TRUST_ACCOUNT_NAME "SECRETS/SECRETS_MACHINE_TRUST_ACCOUNT_NAME"
diff --git a/source3/libads/kerberos_verify.c b/source3/libads/kerberos_verify.c
index 4d7bb8d..0afd84e 100644
--- a/source3/libads/kerberos_verify.c
+++ b/source3/libads/kerberos_verify.c
@@ -307,7 +307,10 @@ static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
{
krb5_error_code ret = 0;
bool auth_ok = False;
+ bool cont = True;
char *password_s = NULL;
+ /* Let's make some room for 2 password (old and new)*/
+ krb5_data passwords[2];
krb5_data password;
krb5_enctype enctypes[] = {
#if defined(ENCTYPE_ARCFOUR_HMAC)
@@ -318,12 +321,13 @@ static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
ENCTYPE_NULL
};
krb5_data packet;
- int i;
+ int i, j;
*pp_tkt = NULL;
*keyblock = NULL;
*perr = 0;
+ passwords[1].length = 0;
if (!secrets_init()) {
DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
@@ -338,8 +342,17 @@ static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
return False;
}
- password.data = password_s;
- password.length = strlen(password_s);
+
+ passwords[0].data = password_s;
+ passwords[0].length = strlen(password_s);
+
+ password_s = secrets_fetch_prev_machine_password(lp_workgroup());
+ if (password_s) {
+ DEBUG(10,("ads_secrets_verify_ticket: found previous password\n"));
+ password.data = password_s;
+ password.length = strlen(password_s);
+ passwords[1] = password;
+ }
/* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
@@ -347,46 +360,56 @@ static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
packet.data = (char *)ticket->data;
/* We need to setup a auth context with each possible encoding type in turn. */
- for (i=0;enctypes[i];i++) {
- krb5_keyblock *key = NULL;
+ for (j=0; j<2 && passwords[j].length; j++) {
- if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
- ret = ENOMEM;
- goto out;
- }
-
- if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i], false)) {
- SAFE_FREE(key);
- continue;
- }
+ for (i=0;enctypes[i];i++) {
+ krb5_keyblock *key = NULL;
- krb5_auth_con_setuseruserkey(context, auth_context, key);
+ if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
+ ret = ENOMEM;
+ goto out;
+ }
- if (!(ret = krb5_rd_req(context, &auth_context, &packet,
- NULL,
- NULL, NULL, pp_tkt))) {
- DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
- (unsigned int)enctypes[i] ));
- auth_ok = True;
- krb5_copy_keyblock(context, key, keyblock);
- krb5_free_keyblock(context, key);
- break;
- }
+ if (create_kerberos_key_from_string(context, host_princ, &passwords[j], key, enctypes[i], false)) {
+ SAFE_FREE(key);
+ continue;
+ }
+
+ krb5_auth_con_setuseruserkey(context, auth_context, key);
+
+ if (!(ret = krb5_rd_req(context, &auth_context, &packet,
+ NULL,
+ NULL, NULL, pp_tkt))) {
+ DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
+ (unsigned int)enctypes[i] ));
+ auth_ok = True;
+ cont = False;
+ krb5_copy_keyblock(context, key, keyblock);
+ krb5_free_keyblock(context, key);
+ break;
+ }
- DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
- ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
- (unsigned int)enctypes[i], error_message(ret)));
+ DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
+ ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
+ (unsigned int)enctypes[i], error_message(ret)));
+
+ /* successfully decrypted but ticket is just not valid at the moment */
+ if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
+ ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
+ ret == KRB5KRB_AP_ERR_SKEW) {
+ krb5_free_keyblock(context, key);
+ cont = False;
+ break;
+ }
- /* successfully decrypted but ticket is just not valid at the moment */
- if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
- ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
- ret == KRB5KRB_AP_ERR_SKEW) {
krb5_free_keyblock(context, key);
+ }
+ if (!cont) {
+ /* If we found a valid pass then no need to try
+ * the next one or we have invalid ticket so no need
+ * to try next password*/
break;
}
-
- krb5_free_keyblock(context, key);
-
}
out:
diff --git a/source3/passdb/machine_account_secrets.c b/source3/passdb/machine_account_secrets.c
index 4a1c3fa..1ee764e 100644
--- a/source3/passdb/machine_account_secrets.c
+++ b/source3/passdb/machine_account_secrets.c
@@ -161,6 +161,23 @@ static const char *machine_last_change_time_keystr(const char *domain)
/**
+ * Form a key for fetching the machine previous trust account password
+ *
+ * @param domain domain name
+ *
+ * @return keystring
+ **/
+static const char *machine_prev_password_keystr(const char *domain)
+{
+ char *keystr;
+
+ keystr = talloc_asprintf_strupper_m(talloc_tos(), "%s/%s",
+ SECRETS_MACHINE_PASSWORD_PREV, domain);
+ SMB_ASSERT(keystr != NULL);
+ return keystr;
+}
+
+/**
* Form a key for fetching the machine trust account password
*
* @param domain domain name
@@ -300,21 +317,38 @@ bool secrets_fetch_trust_account_password(const char *domain, uint8 ret_pwd[16],
}
/************************************************************************
- Routine to delete the plaintext machine account password
+ Routine to delete the plaintext machine account password and old
+ password if any
************************************************************************/
bool secrets_delete_machine_password(const char *domain)
{
+ const char *ret = (char *)secrets_fetch(machine_prev_password_keystr(domain), NULL);
+ if (ret != NULL) {
+ if (!secrets_delete(machine_prev_password_keystr(domain))) {
+ SAFE_FREE(ret);
+ return false;
+ }
+ }
+ SAFE_FREE(ret);
return secrets_delete(machine_password_keystr(domain));
}
/************************************************************************
- Routine to delete the plaintext machine account password, sec channel type and
- last change time from secrets database
+ Routine to delete the plaintext machine account password, old password,
+ sec channel type and last change time from secrets database
************************************************************************/
bool secrets_delete_machine_password_ex(const char *domain)
{
+ const char *ret = (char *)secrets_fetch(machine_prev_password_keystr(domain), NULL);
+ if (ret != NULL) {
+ if (!secrets_delete(machine_prev_password_keystr(domain))) {
+ SAFE_FREE(ret);
+ return false;
+ }
+ }
+ SAFE_FREE(ret);
if (!secrets_delete(machine_password_keystr(domain))) {
return false;
}
@@ -335,7 +369,8 @@ bool secrets_delete_domain_sid(const char *domain)
/************************************************************************
Routine to set the plaintext machine account password for a realm
-the password is assumed to be a null terminated ascii string
+ the password is assumed to be a null terminated ascii string.
+ Before storing
************************************************************************/
bool secrets_store_machine_password(const char *pass, const char *domain,
@@ -344,7 +379,14 @@ bool secrets_store_machine_password(const char *pass, const char *domain,
bool ret;
uint32 last_change_time;
uint32 sec_channel_type;
+ const char *oldpass;
+ oldpass = (char *)secrets_fetch(machine_password_keystr(domain), NULL);
+ if (oldpass!=NULL && strlen(oldpass) > 0) {
+ if (!secrets_store(machine_prev_password_keystr(domain), oldpass, strlen(oldpass)+1))
+ return ret;
+ SAFE_FREE(oldpass);
+ }
ret = secrets_store(machine_password_keystr(domain), pass, strlen(pass)+1);
if (!ret)
return ret;
@@ -358,6 +400,18 @@ bool secrets_store_machine_password(const char *pass, const char *domain,
return ret;
}
+
+/************************************************************************
+ Routine to fetch the previous plaintext machine account password for a realm
+ the password is assumed to be a null terminated ascii string.
+************************************************************************/
+
+char *secrets_fetch_prev_machine_password(const char *domain)
+{
+ char *ret;
+ ret = (char *)secrets_fetch(machine_prev_password_keystr(domain), NULL);
+}
+
/************************************************************************
Routine to fetch the plaintext machine account password for a realm
the password is assumed to be a null terminated ascii string.
--
1.7.0.4
--------------010903070607040808070107--
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