Refactor pairing to allow implementations to fully handle pairing

Implementations can now supply a full pair record and thus use their
own preferred method of managing pairing records if needed.

1 files changed, 108 insertions, 56 deletions

diff --git a/src/lockdown.c b/src/lockdown.c
index ea161bc..a85f8ae 100644
--- a/src/lockdown.c
+++ b/src/lockdown.c
@@ -656,10 +656,10 @@ lockdownd_error_t lockdownd_client_new_with_handshake(iphone_device_t device, lo
         }
 
         if (LOCKDOWN_E_SUCCESS == ret && !userpref_has_device_public_key(client_loc->uuid))
-                ret = lockdownd_pair(client_loc, host_id);
+                ret = lockdownd_pair(client_loc, NULL);
 
         /* in any case, we need to validate pairing to receive trusted host status */
-        ret = lockdownd_validate_pair(client_loc, host_id);
+        ret = lockdownd_validate_pair(client_loc, NULL);
 
         if (LOCKDOWN_E_SUCCESS == ret) {
                 ret = lockdownd_start_session(client_loc, host_id, NULL, NULL);
@@ -682,57 +682,109 @@ lockdownd_error_t lockdownd_client_new_with_handshake(iphone_device_t device, lo
         return ret;
 }
 
+static plist_t lockdownd_pair_record_to_plist(lockdownd_pair_record_t pair_record)
+{
+        if (!pair_record)
+                return NULL;
+
+        char *host_id_loc = pair_record->host_id;
+
+        /* setup request plist */
+        plist_t dict = plist_new_dict();
+        plist_dict_insert_item(dict, "DeviceCertificate", plist_new_data(pair_record->device_certificate, strlen(pair_record->device_certificate)));
+        plist_dict_insert_item(dict, "HostCertificate", plist_new_data(pair_record->host_certificate, strlen(pair_record->host_certificate)));
+        if (!pair_record->host_id)
+                userpref_get_host_id(&host_id_loc);
+        plist_dict_insert_item(dict, "HostID", plist_new_string(host_id_loc));
+        plist_dict_insert_item(dict, "RootCertificate", plist_new_data(pair_record->root_certificate, strlen(pair_record->root_certificate)));
+
+        if (!pair_record->host_id)
+                free(host_id_loc);
+
+        return dict;
+}
+
+static lockdownd_error_t generate_pair_record_plist(gnutls_datum_t public_key, char *host_id, plist_t *pair_record_plist)
+{
+        lockdownd_error_t ret = LOCKDOWN_E_UNKNOWN_ERROR;
+
+        gnutls_datum_t device_cert = { NULL, 0 };
+        gnutls_datum_t host_cert = { NULL, 0 };
+        gnutls_datum_t root_cert = { NULL, 0 };
+
+        ret = lockdownd_gen_pair_cert(public_key, &device_cert, &host_cert, &root_cert);
+        if (ret != LOCKDOWN_E_SUCCESS) {
+                return ret;
+        }
+
+        char *host_id_loc = host_id;
+
+        if (!host_id)
+                userpref_get_host_id(&host_id_loc);
+
+        /* setup request plist */
+        *pair_record_plist = plist_new_dict();
+        plist_dict_insert_item(*pair_record_plist, "DeviceCertificate", plist_new_data((const char*)device_cert.data, device_cert.size));
+        plist_dict_insert_item(*pair_record_plist, "HostCertificate", plist_new_data((const char*)host_cert.data, host_cert.size));
+        plist_dict_insert_item(*pair_record_plist, "HostID", plist_new_string(host_id_loc));
+        plist_dict_insert_item(*pair_record_plist, "RootCertificate", plist_new_data((const char*)root_cert.data, root_cert.size));
+
+        if (!host_id)
+                free(host_id_loc);
+
+        return ret;
+}
+
 /** Function used internally by lockdownd_pair() and lockdownd_validate_pair()
  *
  * @param client The lockdown client to pair with.
- * @param host_id The HostID to use for pairing. If NULL is passed, then
- *    the HostID of the current machine is used. A new HostID will be
+ * @param pair_record The pair record to use for pairing. If NULL is passed, then
+ *    the pair records from the current machine are used. New records will be
  *    generated automatically when pairing is done for the first time.
- * @param verb This is either "Pair" or "ValidatePair".
+ * @param verb This is either "Pair", "ValidatePair" or "Unpair".
  *
  * @return an error code (LOCKDOWN_E_SUCCESS on success)
  */
-static lockdownd_error_t lockdownd_do_pair(lockdownd_client_t client, char *host_id, const char *verb)
+static lockdownd_error_t lockdownd_do_pair(lockdownd_client_t client, lockdownd_pair_record_t pair_record, const char *verb)
 {
         lockdownd_error_t ret = LOCKDOWN_E_UNKNOWN_ERROR;
         plist_t dict = NULL;
         plist_t dict_record = NULL;
-
-        gnutls_datum_t device_cert = { NULL, 0 };
-        gnutls_datum_t host_cert = { NULL, 0 };
-        gnutls_datum_t root_cert = { NULL, 0 };
         gnutls_datum_t public_key = { NULL, 0 };
+        int pairing_mode = 0; /* 0 = libiphone, 1 = external */
 
-        char *host_id_loc = host_id;
-
-        ret = lockdownd_get_device_public_key(client, &public_key);
-        if (ret != LOCKDOWN_E_SUCCESS) {
-                debug_info("device refused to send public key.");
-                return ret;
-        }
-        debug_info("device public key follows:\n%s", public_key.data);
+        if (pair_record && pair_record->host_id) {
+                /* valid pair_record passed? */
+                if (!pair_record->device_certificate || !pair_record->host_certificate || !pair_record->root_certificate) {
+                        return LOCKDOWN_E_PLIST_ERROR;
+                }
 
-        ret = lockdownd_gen_pair_cert(public_key, &device_cert, &host_cert, &root_cert);
-        if (ret != LOCKDOWN_E_SUCCESS) {
-                free(public_key.data);
-                return ret;
-        }
+                /* use passed pair_record */
+                dict_record = lockdownd_pair_record_to_plist(pair_record);
 
-        if (!host_id) {
-                userpref_get_host_id(&host_id_loc);
+                pairing_mode = 1;
+        } else {
+                ret = lockdownd_get_device_public_key(client, &public_key);
+                if (ret != LOCKDOWN_E_SUCCESS) {
+                        if (public_key.data)
+                                free(public_key.data);
+                        debug_info("device refused to send public key.");
+                        return ret;
+                }
+                debug_info("device public key follows:\n%s", public_key.data);
+                /* get libiphone pair_record */
+                ret = generate_pair_record_plist(public_key, NULL, &dict_record);
+                if (ret != LOCKDOWN_E_SUCCESS) {
+                        if (dict_record)
+                                plist_free(dict_record);
+                        return ret;
+                }
         }
 
         /* Setup Pair request plist */
         dict = plist_new_dict();
-        dict_record = plist_new_dict();
         plist_dict_add_label(dict, client->label);
         plist_dict_insert_item(dict,"PairRecord", dict_record);
-
-        plist_dict_insert_item(dict_record, "DeviceCertificate", plist_new_data((const char*)device_cert.data, device_cert.size));
-        plist_dict_insert_item(dict_record, "HostCertificate", plist_new_data((const char*)host_cert.data, host_cert.size));
-        plist_dict_insert_item(dict_record, "HostID", plist_new_string(host_id_loc));
-        plist_dict_insert_item(dict_record, "RootCertificate", plist_new_data((const char*)root_cert.data, root_cert.size));
-
         plist_dict_insert_item(dict, "Request", plist_new_string(verb));
 
         /* send to iPhone */
@@ -740,10 +792,6 @@ static lockdownd_error_t lockdownd_do_pair(lockdownd_client_t client, char *host
         plist_free(dict);
         dict = NULL;
 
-        if (!host_id) {
-                free(host_id_loc);
-        }
-
         if (ret != LOCKDOWN_E_SUCCESS)
                 return ret;
 
@@ -760,12 +808,14 @@ static lockdownd_error_t lockdownd_do_pair(lockdownd_client_t client, char *host
         /* if pairing succeeded */
         if (ret == LOCKDOWN_E_SUCCESS) {
                 debug_info("%s success", verb);
-                if (!strcmp("Unpair", verb)) {
-                        /* remove public key from config */
-                        userpref_remove_device_public_key(client->uuid);
-                } else {
-                        /* store public key in config */
-                        userpref_set_device_public_key(client->uuid, public_key);
+                if (!pairing_mode) {
+                        if (!strcmp("Unpair", verb)) {
+                                /* remove public key from config */
+                                userpref_remove_device_public_key(client->uuid);
+                        } else {
+                                /* store public key in config */
+                                userpref_set_device_public_key(client->uuid, public_key);
+                        }
                 }
         } else {
                 debug_info("%s failure", verb);
@@ -786,7 +836,8 @@ static lockdownd_error_t lockdownd_do_pair(lockdownd_client_t client, char *host
         }
         plist_free(dict);
         dict = NULL;
-        free(public_key.data);
+        if (public_key.data)
+                free(public_key.data);
         return ret;
 }
 
@@ -795,15 +846,15 @@ static lockdownd_error_t lockdownd_do_pair(lockdownd_client_t client, char *host
  * It's part of the lockdownd handshake.
  *
  * @param client The lockdown client to pair with.
- * @param host_id The HostID to use for pairing. If NULL is passed, then
- *    the HostID of the current machine is used. A new HostID will be
+ * @param pair_record The pair record to use for pairing. If NULL is passed, then
+ *    the pair records from the current machine are used. New records will be
  *    generated automatically when pairing is done for the first time.
  *
  * @return an error code (LOCKDOWN_E_SUCCESS on success)
  */
-lockdownd_error_t lockdownd_pair(lockdownd_client_t client, char *host_id)
+lockdownd_error_t lockdownd_pair(lockdownd_client_t client, lockdownd_pair_record_t pair_record)
 {
-        return lockdownd_do_pair(client, host_id, "Pair");
+        return lockdownd_do_pair(client, pair_record, "Pair");
 }
 
 /** 
@@ -812,15 +863,16 @@ lockdownd_error_t lockdownd_pair(lockdownd_client_t client, char *host_id)
  * It's part of the lockdownd handshake.
  *
  * @param client The lockdown client to pair with.
- * @param host_id The HostID to use for pairing. If NULL is passed, then
- *    the HostID of the current machine is used. A new HostID will be
- *    generated automatically when pairing is done for the first time.
+ * @param pair_record The pair record to validate pairing with. If NULL is
+ *    passed, then the pair records from the current machine are used.
+ *    New records will be generated automatically when pairing is done
+ *    for the first time.
  *
  * @return an error code (LOCKDOWN_E_SUCCESS on success)
  */
-lockdownd_error_t lockdownd_validate_pair(lockdownd_client_t client, char *host_id)
+lockdownd_error_t lockdownd_validate_pair(lockdownd_client_t client, lockdownd_pair_record_t pair_record)
 {
-        return lockdownd_do_pair(client, host_id, "ValidatePair");
+        return lockdownd_do_pair(client, pair_record, "ValidatePair");
 }
 
 /** 
@@ -828,14 +880,14 @@ lockdownd_error_t lockdownd_validate_pair(lockdownd_client_t client, char *host_
  * from the device and host.
  *
  * @param client The lockdown client to pair with.
- * @param host_id The HostID to use for unpairing. If NULL is passed, then
- *    the HostID of the current machine is used.
+ * @param pair_record The pair record to use for unpair. If NULL is passed, then
+ *    the pair records from the current machine are used.
  *
  * @return an error code (LOCKDOWN_E_SUCCESS on success)
  */
-lockdownd_error_t lockdownd_unpair(lockdownd_client_t client, char *host_id)
+lockdownd_error_t lockdownd_unpair(lockdownd_client_t client, lockdownd_pair_record_t pair_record)
 {
-        return lockdownd_do_pair(client, host_id, "Unpair");
+        return lockdownd_do_pair(client, pair_record, "Unpair");
 }
 
 /**