ipa-kdb: Add OTP support

If OTP is enabled for a user, then:
  1. Long-term keys are not provided to KDB
  2. The user string 'otp' is defined to KDB

Since it is not secure to send radius configuration information
over krb5 user strings, we simply set the string to a known default
('[]') which enables the default configuration in the KDC.

https://fedorahosted.org/freeipa/ticket/3561
http://freeipa.org/page/V3/OTP

daemons/ipa-kdb/ipa_kdb.c

@@ -173,9 +173,42 @@ done:
     return base;
 }
 
+static const struct {
+    const char *name;
+    enum ipadb_user_auth flag;
+} userauth_table[] = {
+    { "disabled", IPADB_USER_AUTH_DISABLED },
+    { "password", IPADB_USER_AUTH_PASSWORD },
+    { "radius", IPADB_USER_AUTH_RADIUS },
+    { "otp", IPADB_USER_AUTH_OTP },
+    { }
+};
+
+void ipadb_get_user_auth(LDAP *lcontext, LDAPMessage *le,
+                         enum ipadb_user_auth *userauth)
+{
+    struct berval **vals;
+    int i, j;
+
+    *userauth = IPADB_USER_AUTH_EMPTY;
+    vals = ldap_get_values_len(lcontext, le, IPA_USER_AUTH_TYPE);
+    if (!vals)
+        return;
+
+    for (i = 0; vals[i]; i++) {
+        for (j = 0; userauth_table[j].name; j++) {
+            if (strcasecmp(vals[i]->bv_val, userauth_table[j].name) == 0) {
+                *userauth |= userauth_table[j].flag;
+                break;
+            }
+        }
+    }
+}
+
 int ipadb_get_global_configs(struct ipadb_context *ipactx)
 {
-    char *attrs[] = { "ipaConfigString", IPA_KRB_AUTHZ_DATA_ATTR, NULL };
+    char *attrs[] = { "ipaConfigString", IPA_KRB_AUTHZ_DATA_ATTR,
+                      IPA_USER_AUTH_TYPE, NULL };
     struct berval **vals = NULL;
     LDAPMessage *res = NULL;
     LDAPMessage *first;
@@ -203,6 +236,9 @@ int ipadb_get_global_configs(struct ipadb_context *ipactx)
         goto done;
     }
 
+    /* Check for permitted authentication types. */
+    ipadb_get_user_auth(ipactx->lcontext, res, &ipactx->user_auth);
+
     vals = ldap_get_values_len(ipactx->lcontext, first,
                                "ipaConfigString");
     if (!vals || !vals[0]) {

daemons/ipa-kdb/ipa_kdb.h

@@ -75,9 +75,18 @@
 #define IPA_SETUP "ipa-setup-override-restrictions"
 
 #define IPA_KRB_AUTHZ_DATA_ATTR "ipaKrbAuthzData"
+#define IPA_USER_AUTH_TYPE "ipaUserAuthType"
 
 struct ipadb_mspac;
 
+enum ipadb_user_auth {
+  IPADB_USER_AUTH_EMPTY    = 0,
+  IPADB_USER_AUTH_DISABLED = 1 << 0,
+  IPADB_USER_AUTH_PASSWORD = 1 << 1,
+  IPADB_USER_AUTH_RADIUS   = 1 << 2,
+  IPADB_USER_AUTH_OTP      = 1 << 3,
+};
+
 struct ipadb_context {
     char *uri;
     char *base;
@@ -92,6 +101,7 @@ struct ipadb_context {
     bool disable_last_success;
     bool disable_lockout;
     char **authz_data;
+    enum ipadb_user_auth user_auth;
 };
 
 #define IPA_E_DATA_MAGIC 0x0eda7a
@@ -259,3 +269,6 @@ void ipadb_audit_as_req(krb5_context kcontext,
                         krb5_timestamp authtime,
                         krb5_error_code error_code);
 
+/* AUTH METHODS */
+void ipadb_get_user_auth(LDAP *lcontext, LDAPMessage *le,
+                         enum ipadb_user_auth *user_auth);

daemons/ipa-kdb/ipa_kdb_principals.c

@@ -64,6 +64,7 @@ static char *std_principal_attrs[] = {
     "nsaccountlock",
     "passwordHistory",
     IPA_KRB_AUTHZ_DATA_ATTR,
+    IPA_USER_AUTH_TYPE,
 
     "objectClass",
     NULL
@@ -228,6 +229,9 @@ static krb5_error_code ipadb_parse_ldap_entry(krb5_context kcontext,
                                               krb5_db_entry **kentry,
                                               uint32_t *polmask)
 {
+    krb5_octet otp_string[] = {'o', 't', 'p', 0, '[', ']', 0 };
+    enum ipadb_user_auth user_ua = IPADB_USER_AUTH_EMPTY;
+    enum ipadb_user_auth *active_ua = &user_ua;
     struct ipadb_context *ipactx;
     LDAP *lcontext;
     krb5_db_entry *entry;
@@ -262,6 +266,17 @@ static krb5_error_code ipadb_parse_ldap_entry(krb5_context kcontext,
     entry->magic = KRB5_KDB_MAGIC_NUMBER;
     entry->len = KRB5_KDB_V1_BASE_LENGTH;
 
+    /* Get the user's user_auth settings. */
+    ipadb_get_user_auth(ipactx->lcontext, lentry, &user_ua);
+
+    /* TODO: Should we confirm the existence of ipatokenRadiusConfigLink in
+     *       the case of RADIUS? Existence of a token for OTP? */
+
+    /* Determine which user_auth policy is active: user or global. */
+    if ((ipactx->user_auth & IPADB_USER_AUTH_DISABLED)
+        || user_ua == IPADB_USER_AUTH_EMPTY)
+        active_ua = &ipactx->user_auth;
+
     /* ignore mask for now */
 
     ret = ipadb_ldap_attr_to_int(lcontext, lentry,
@@ -393,6 +408,13 @@ static krb5_error_code ipadb_parse_ldap_entry(krb5_context kcontext,
                                       &res_key_data, &result, &mkvno);
     switch (ret) {
     case 0:
+        /* Only set a principal's key if password auth should be used. */
+        if ((*active_ua & ~IPADB_USER_AUTH_DISABLED) != IPADB_USER_AUTH_EMPTY
+            && !(*active_ua & IPADB_USER_AUTH_PASSWORD)) {
+            /* This is the same behavior as ENOENT below. */
+            break;
+        }
+
         entry->key_data = res_key_data;
         entry->n_key_data = result;
         if (mkvno) {
@@ -515,6 +537,12 @@ static krb5_error_code ipadb_parse_ldap_entry(krb5_context kcontext,
         ied->authz_data = authz_data_list;
     }
 
+    /* If enabled, set the otp user string, enabling otp. */
+    if ((*active_ua & (IPADB_USER_AUTH_RADIUS | IPADB_USER_AUTH_OTP)) &&
+        !(*active_ua & IPADB_USER_AUTH_DISABLED)) {
+        ret = ipadb_set_tl_data(entry, KRB5_TL_STRING_ATTRS,
+                                sizeof(otp_string), otp_string);
+    }
 
     kerr = 0;