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authorStefan Metzmacher <metze@samba.org>2010-05-10 17:36:54 +0200
committerStefan Metzmacher <metze@samba.org>2010-05-10 18:06:54 +0200
commitfc8e3ffb5f261e7efdcbcef46b1f13c3b5599730 (patch)
treeb9650a38282b07404c56f0404688171aeeb4ca54
parent6a69ec2f5a046194c9f4dc108c0680ab263790c4 (diff)
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s4:password_hash - Implement password restrictions
Based on the Patch from Matthias Dieter Wallnöfer <mwallnoefer@yahoo.de>. metze
-rw-r--r--source4/dsdb/samdb/ldb_modules/password_hash.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/source4/dsdb/samdb/ldb_modules/password_hash.c b/source4/dsdb/samdb/ldb_modules/password_hash.c
index 3433fdbe17..08aa545937 100644
--- a/source4/dsdb/samdb/ldb_modules/password_hash.c
+++ b/source4/dsdb/samdb/ldb_modules/password_hash.c
@@ -116,6 +116,7 @@ struct setup_password_fields_io {
const char *sAMAccountName;
const char *user_principal_name;
bool is_computer;
+ uint32_t restrictions;
} u;
/* new credentials and old given credentials */
@@ -1462,6 +1463,179 @@ static int setup_password_fields(struct setup_password_fields_io *io)
return LDB_SUCCESS;
}
+static int check_password_restrictions(struct setup_password_fields_io *io)
+{
+ struct ldb_context *ldb;
+ int ret;
+ enum samr_ValidationStatus stat;
+
+ ldb = ldb_module_get_ctx(io->ac->module);
+
+ /* First check the old password is correct, for password changes */
+ if (!io->ac->pwd_reset && !io->ac->change_old_pw_checked) {
+ /* we need to old nt or lm hash given by the client */
+ if (!io->og.nt_hash && !io->og.lm_hash) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "You need to provide the old password "
+ "in order to change your password!");
+ return LDB_ERR_UNWILLING_TO_PERFORM;
+ }
+
+ if (io->og.nt_hash) {
+ if (!io->o.nt_hash) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "There's no old nt_hash, which is needed "
+ "in order to change your password!");
+ return LDB_ERR_UNWILLING_TO_PERFORM;
+ }
+
+ /* The password modify through the NT hash is encouraged
+ and has no problems at all */
+ if (memcmp(io->og.nt_hash->hash, io->o.nt_hash->hash, 16) != 0) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "The old password specified doesn't match!");
+ return LDB_ERR_UNWILLING_TO_PERFORM;
+ }
+ } else if (io->og.lm_hash) {
+ struct loadparm_context *lp_ctx =
+ (struct loadparm_context *)ldb_get_opaque(ldb, "loadparm");
+
+ if (!lp_lanman_auth(lp_ctx)) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "The password change through the LM hash is deactivated!");
+ return LDB_ERR_UNWILLING_TO_PERFORM;
+ }
+
+ if (!io->o.lm_hash) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "There's no old lm_hash, which is needed "
+ "in order to change your password!");
+ return LDB_ERR_UNWILLING_TO_PERFORM;
+ }
+
+ if (memcmp(io->og.lm_hash->hash, io->o.lm_hash->hash, 16) != 0) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "The old password specified doesn't match!");
+ return LDB_ERR_UNWILLING_TO_PERFORM;
+ }
+ }
+ }
+
+ if (io->u.restrictions == 0) {
+ /* FIXME: Is this right? */
+ return LDB_SUCCESS;
+ }
+
+ /*
+ * Fundamental password checks done by the call "samdb_check_password".
+ * It is also in use by "dcesrv_samr_ValidatePassword".
+ */
+ stat = samdb_check_password(io->n.cleartext_utf8,
+ io->ac->status->domain_data.pwdProperties,
+ io->ac->status->domain_data.minPwdLength);
+ switch (stat) {
+ case SAMR_VALIDATION_STATUS_SUCCESS:
+ /* perfect -> proceed! */
+ break;
+
+ case SAMR_VALIDATION_STATUS_PWD_TOO_SHORT:
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "the password is too short. It should be equal or longer than %i characters!",
+ io->ac->status->domain_data.minPwdLength);
+
+ io->ac->status->reject_reason = SAM_PWD_CHANGE_PASSWORD_TOO_SHORT;
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+
+ case SAMR_VALIDATION_STATUS_NOT_COMPLEX_ENOUGH:
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "the password does not meet the complexity criterias!");
+ io->ac->status->reject_reason = SAM_PWD_CHANGE_NOT_COMPLEX;
+
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+
+ default:
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "the password doesn't fit by a certain reason!");
+
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+ }
+
+ if (io->ac->pwd_reset) {
+ return LDB_SUCCESS;
+ }
+
+ if (io->n.nt_hash) {
+ uint32_t i;
+
+ /* checks the NT hash password history */
+ for (i = 0; i < io->o.nt_history_len; i++) {
+ ret = memcmp(io->n.nt_hash, io->o.nt_history[i].hash, 16);
+ if (ret == 0) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "the password was already used (in history)!");
+
+ io->ac->status->reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY;
+
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+ }
+ }
+ }
+
+ if (io->n.lm_hash) {
+ uint32_t i;
+
+ /* checks the LM hash password history */
+ for (i = 0; i < io->o.lm_history_len; i++) {
+ ret = memcmp(io->n.nt_hash, io->o.lm_history[i].hash, 16);
+ if (ret == 0) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "the password was already used (in history)!");
+
+ io->ac->status->reject_reason = SAM_PWD_CHANGE_PWD_IN_HISTORY;
+
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+ }
+ }
+ }
+
+ /* are all password changes disallowed? */
+ if (io->ac->status->domain_data.pwdProperties & DOMAIN_REFUSE_PASSWORD_CHANGE) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "password changes disabled!");
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+ }
+
+ /* can this user change the password? */
+ if (io->u.userAccountControl & UF_PASSWD_CANT_CHANGE) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "password can't be changed on this account!");
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+ }
+
+ /* Password minimum age: yes, this is a minus. The ages are in negative 100nsec units! */
+ if (io->u.pwdLastSet - io->ac->status->domain_data.minPwdAge > io->g.last_set) {
+ ldb_asprintf_errstring(ldb,
+ "check_password_restrictions: "
+ "password is too young to change!");
+ return LDB_ERR_CONSTRAINT_VIOLATION;
+ }
+
+ return LDB_SUCCESS;
+}
+
static int setup_io(struct ph_context *ac,
const struct ldb_message *orig_msg,
const struct ldb_message *searched_msg,
@@ -1498,6 +1672,17 @@ static int setup_io(struct ph_context *ac,
return LDB_ERR_CONSTRAINT_VIOLATION;
}
+ /* Only non-trust accounts have restrictions (possibly this test is the
+ * wrong way around, but we like to be restrictive if possible */
+ io->u.restrictions = !(io->u.userAccountControl
+ & (UF_INTERDOMAIN_TRUST_ACCOUNT | UF_WORKSTATION_TRUST_ACCOUNT
+ | UF_SERVER_TRUST_ACCOUNT));
+
+ if ((io->u.userAccountControl & UF_PASSWD_NOTREQD) != 0) {
+ /* see [MS-ADTS] 2.2.15 */
+ io->u.restrictions = 0;
+ }
+
ret = samdb_msg_find_old_and_new_ldb_val(orig_msg, "userPassword",
&io->n.cleartext_utf8, &io->og.cleartext_utf8);
if (ret != LDB_SUCCESS) {
@@ -2113,6 +2298,11 @@ static int password_hash_add_do_add(struct ph_context *ac)
return ret;
}
+ ret = check_password_restrictions(&io);
+ if (ret != LDB_SUCCESS) {
+ return ret;
+ }
+
if (io.g.nt_hash) {
ret = samdb_msg_add_hash(ldb, ac, msg,
"unicodePwd", io.g.nt_hash);
@@ -2508,6 +2698,11 @@ static int password_hash_mod_do_mod(struct ph_context *ac)
return ret;
}
+ ret = check_password_restrictions(&io);
+ if (ret != LDB_SUCCESS) {
+ return ret;
+ }
+
/* make sure we replace all the old attributes */
ret = ldb_msg_add_empty(msg, "unicodePwd", LDB_FLAG_MOD_REPLACE, NULL);
ret = ldb_msg_add_empty(msg, "dBCSPwd", LDB_FLAG_MOD_REPLACE, NULL);