js: add verify and signature parsing

--

* src/gpgmejs.js:
  - Added verify method
  - Added verification results in decrypt (if signatures are present
    in the message)
  - Added a base64 option to decrypt

* src/Signature.js: Convenience class for verification results. Used
   for e.g. converting timestamps to javascript time, quick overall
   validity checks

* src/Keyring.js: removed debug code

* src/Errors.js add two new Signature errors

1 files changed, 193 insertions, 0 deletions

diff --git a/lang/js/src/Signature.js b/lang/js/src/Signature.js
new file mode 100644
index 00000000..d7d05983
--- /dev/null
+++ b/lang/js/src/Signature.js
@@ -0,0 +1,193 @@
+/* gpgme.js - Javascript integration for gpgme
+ * Copyright (C) 2018 Bundesamt für Sicherheit in der Informationstechnik
+ *
+ * This file is part of GPGME.
+ *
+ * GPGME is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * GPGME is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
+ * Author(s):
+ *     Maximilian Krambach <[email protected]>
+ */
+
+/**
+ * Validates a signature object and returns
+ * @param {Object} sigObject Object as returned by gpgme-json. The definition
+ * of the expected values are to be found in the constants 'expKeys', 'expSum',
+ * 'expNote' in this file.
+ * @returns {GPGME_Signature} Signature Object
+ */
+
+import { gpgme_error } from './Errors';
+
+export function createSignature(sigObject){
+    if (
+        typeof(sigObject) !=='object' ||
+        !sigObject.hasOwnProperty('summary') ||
+        !sigObject.hasOwnProperty('fingerpprint') ||
+        !sigObject.hasOwnProperty('timestamp')
+        //TODO check if timestamp is mandatory in specification
+    ){
+        return gpgme_error('SIG_WRONG');
+    }
+    let keys = Object.keys(sigObject);
+    for (let i=0; i< keys.length; i++){
+        if ( typeof(sigObject[keys[i]]) !== expKeys[keys[i]] ){
+            return gpgme_error('SIG_WRONG');
+        }
+    }
+    let sumkeys = Object.keys(sigObject.summary);
+    for (let i=0; i< sumkeys.length; i++){
+        if ( typeof(sigObject.summary[sumkeys[i]]) !== expSum[sumkeys[i]] ){
+            return gpgme_error('SIG_WRONG');
+        }
+    }
+    if (sigObject.hasOwnProperty('notations')){
+        if (!Array.isArray(sigObject.notations)){
+            return gpgme_error('SIG_WRONG');
+        }
+        for (let i=0; i < sigObject.notations.length; i++){
+            let notation = sigObject.notations[i];
+            let notekeys = Object.keys(notation);
+            for (let j=0; j < notekeys.length; j++){
+                if ( typeof(notation[notekeys[j]]) !== expNote[notekeys[j]] ){
+                    return gpgme_error('SIG_WRONG');
+                }
+            }
+        }
+    }
+    return new GPGME_Signature(sigObject);
+}
+
+
+/**
+ * Representing the details of a signature. It is supposed to be read-only. The
+ * full details as given by gpgme-json can be accessed from the _rawSigObject.
+ * )
+ */
+class GPGME_Signature {
+    constructor(sigObject){
+        this._rawSigObject = sigObject;
+    }
+
+    /**
+     * The signatures' fingerprint
+     */
+    get fingerprint(){
+        return this._rawSigObject.fingerprint;
+    }
+
+    /**
+     * The expiration of this Signature as Javascript date, or null if
+     * signature does not expire
+     * @returns {Date | null}
+     */
+    get expiration(){
+        if (!this._rawSigObject.exp_timestamp){
+            return null;
+        }
+        return new Date(this._rawSigObject.exp_timestamp* 1000);
+    }
+
+    /**
+     * The creation date of this Signature in Javascript Date
+     * @returns {Date}
+     */
+    get timestamp(){
+        return new Date(this._rawSigObject.timestamp* 1000);
+    }
+
+    /**
+     * The overall validity of the key. If false, errorDetails may contain
+     * additional information
+     */
+    get valid() {
+        if (this._rawSigObject.valid === true){
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * gives more information on non-valid signatures. Refer to the gpgme docs
+     * https://www.gnupg.org/documentation/manuals/gpgme/Verify.html for
+     * details on the values
+     * @returns {Object} Object with boolean properties
+     */
+    get errorDetails(){
+        let properties = ['revoked', 'key-expired', 'sig-expired',
+            'key-missing', 'crl-missing', 'crl-too-old', 'bad-policy',
+            'sys-error'];
+        let result = {};
+        for (let i=0; i< properties.length; i++){
+            if ( this._rawSigObject.hasOwnProperty(properties[i]) ){
+                result[properties[i]] = this._rawSigObject[properties[i]];
+            }
+        }
+        return result;
+    }
+
+}
+
+/**
+ * Keys and their value's type for the signature Object
+ */
+const expKeys = {
+    'wrong_key_usage': 'boolean',
+    'chain_model': 'boolean',
+    'summary': 'object',
+    'is_de_vs': 'boolean',
+    'status_string':'string',
+    'fingerprint':'string',
+    'validity_string': 'string',
+    'pubkey_algo_name':'string',
+    'hash_algo_name':'string',
+    'pka_address':'string',
+    'status_code':'number',
+    'timestamp':'number',
+    'exp_timestamp':'number',
+    'pka_trust':'number',
+    'validity':'number',
+    'validity_reason':'number',
+    'notations': 'object'
+};
+
+/**
+ * Keys and their value's type for the summary
+ */
+const expSum = {
+    'valid': 'boolean',
+    'green': 'boolean',
+    'red': 'boolean',
+    'revoked': 'boolean',
+    'key-expired': 'boolean',
+    'sig-expired': 'boolean',
+    'key-missing': 'boolean',
+    'crl-missing': 'boolean',
+    'crl-too-old': 'boolean',
+    'bad-policy': 'boolean',
+    'sys-error': 'boolean'
+};
+
+/**
+ * Keys and their value's type for notations objects
+ */
+const expNote = {
+    'human_readable': 'boolean',
+    'critical':'boolean',
+    'name': 'string',
+    'value': 'string',
+    'flags': 'number'
+};