Merge pull request #637 from mmso/feat/compression

Feat/compression

README.md

@@ -154,6 +154,35 @@ openpgp.decrypt(options).then(function(plaintext) {
 });
 ```
 
+#### Encrypt with compression
+
+By default, `encrypt` will not use any compression. It's possible to override that behavior in two ways:
+
+Either set the `compression` parameter in the options object when calling `encrypt`.
+
+```js
+var options, encrypted;
+
+options = {
+    data: new Uint8Array([0x01, 0x02, 0x03]),    // input as Uint8Array (or String)
+    passwords: ['secret stuff'],                 // multiple passwords possible
+    compression: openpgp.enums.compression.zip   // compress the data with zip
+};
+
+openpgp.encrypt(options).then(function(ciphertext) {
+    // use ciphertext
+});
+```
+
+Or, override the config to enable compression:
+
+```js
+openpgp.config.compression = openpgp.enums.compression.zip
+```
+
+Where `compression` can take the value of `openpgp.enums.compression.zlib` or `openpgp.enums.compression.zip`.
+
+
 #### Generate new key pair
 
 RSA keys:

src/config/config.js

@@ -31,7 +31,7 @@ export default {
   /** @property {Integer} encryption_cipher Default encryption cipher {@link module:enums.symmetric} */
   encryption_cipher: enums.symmetric.aes256,
   /** @property {Integer} compression Default compression algorithm {@link module:enums.compression} */
-  compression: enums.compression.zip,
+  compression: enums.compression.uncompressed,
 
   /**
    * Use Authenticated Encryption with Additional Data (AEAD) protection for symmetric encryption.

src/message.js

@@ -451,6 +451,26 @@ Message.prototype.sign = async function(privateKeys=[], signature=null) {
   return new Message(packetlist);
 };
 
+/**
+ * Compresses the message (the literal and -if signed- signature data packets of the message)
+ * @param  {module:enums.compression}   compression     compression algorithm to be used
+ * @return {module:message~Message}       new message with compressed content
+ */
+Message.prototype.compress = function(compression) {
+  if (compression === enums.compression.uncompressed) {
+    return this;
+  }
+
+  const compressed = new packet.Compressed();
+  compressed.packets = this.packets;
+  compressed.algorithm = enums.read(enums.compression, compression);
+
+  const packetList = new packet.List();
+  packetList.push(compressed);
+
+  return new Message(packetList);
+};
+
 /**
  * Create a detached signature for the message (the literal data packet of the message)
  * @param  {Array<module:key~Key>}           privateKey private keys with decrypted secret key data for signing

src/openpgp.js

@@ -186,23 +186,24 @@ export function decryptKey({ privateKey, passphrase }) {
 /**
  * Encrypts message text/data with public keys, passwords or both at once. At least either public keys or passwords
  *   must be specified. If private keys are specified, those will be used to sign the message.
- * @param  {String|Uint8Array} data           text/data to be encrypted as JavaScript binary string or Uint8Array
- * @param  {Key|Array<Key>} publicKeys        (optional) array of keys or single key, used to encrypt the message
- * @param  {Key|Array<Key>} privateKeys       (optional) private keys for signing. If omitted message will not be signed
- * @param  {String|Array<String>} passwords   (optional) array of passwords or a single password to encrypt the message
- * @param  {Object} sessionKey                (optional) session key in the form: { data:Uint8Array, algorithm:String }
- * @param  {String} filename                  (optional) a filename for the literal data packet
- * @param  {Boolean} armor                    (optional) if the return values should be ascii armored or the message/signature objects
- * @param  {Boolean} detached                 (optional) if the signature should be detached (if true, signature will be added to returned object)
- * @param  {Signature} signature              (optional) a detached signature to add to the encrypted message
- * @param  {Boolean} returnSessionKey         (optional) if the unencrypted session key should be added to returned object
- * @param  {Boolean} wildcard                 (optional) use a key ID of 0 instead of the public key IDs
- * @return {Promise<Object>}                  encrypted (and optionally signed message) in the form:
- *                                              {data: ASCII armored message if 'armor' is true,
- *                                                message: full Message object if 'armor' is false, signature: detached signature if 'detached' is true}
+ * @param  {String|Uint8Array} data               text/data to be encrypted as JavaScript binary string or Uint8Array
+ * @param  {Key|Array<Key>} publicKeys            (optional) array of keys or single key, used to encrypt the message
+ * @param  {Key|Array<Key>} privateKeys           (optional) private keys for signing. If omitted message will not be signed
+ * @param  {String|Array<String>} passwords       (optional) array of passwords or a single password to encrypt the message
+ * @param  {Object} sessionKey                    (optional) session key in the form: { data:Uint8Array, algorithm:String }
+ * @param  {String} filename                      (optional) a filename for the literal data packet
+ * @param  {module:enums.compression} compression (optional) which compression algorithm to compress the message with, defaults to what is specified in config
+ * @param  {Boolean} armor                        (optional) if the return values should be ascii armored or the message/signature objects
+ * @param  {Boolean} detached                     (optional) if the signature should be detached (if true, signature will be added to returned object)
+ * @param  {Signature} signature                  (optional) a detached signature to add to the encrypted message
+ * @param  {Boolean} returnSessionKey             (optional) if the unencrypted session key should be added to returned object
+ * @param  {Boolean} wildcard                     (optional) use a key ID of 0 instead of the public key IDs
+ * @return {Promise<Object>}                      encrypted (and optionally signed message) in the form:
+ *                                                  {data: ASCII armored message if 'armor' is true,
+ *                                                  message: full Message object if 'armor' is false, signature: detached signature if 'detached' is true}
  * @static
  */
-export function encrypt({ data, publicKeys, privateKeys, passwords, sessionKey, filename, armor=true, detached=false, signature=null, returnSessionKey=false, wildcard=false}) {
+export function encrypt({ data, publicKeys, privateKeys, passwords, sessionKey, filename, compression=config.compression, armor=true, detached=false, signature=null, returnSessionKey=false, wildcard=false}) {
   checkData(data); publicKeys = toArray(publicKeys); privateKeys = toArray(privateKeys); passwords = toArray(passwords);
 
   if (!nativeAEAD() && asyncProxy) { // use web worker if web crypto apis are not supported
@@ -223,6 +224,7 @@ export function encrypt({ data, publicKeys, privateKeys, passwords, sessionKey,
         message = await message.sign(privateKeys, signature);
       }
     }
+    message = message.compress(compression);
     return message.encrypt(publicKeys, passwords, sessionKey, wildcard);
 
   }).then(encrypted => {

src/packet/compressed.js

@@ -88,7 +88,7 @@ Compressed.prototype.write = function () {
     this.compress();
   }
 
-  return util.concatUint8Array(new Uint8Array([enums.write(enums.compression, this.algorithm)]), this.compressed);
+  return util.concatUint8Array([new Uint8Array([enums.write(enums.compression, this.algorithm)]), this.compressed]);
 };