Parse and create ECDH packets

src/crypto/crypto.js

@@ -21,6 +21,7 @@
  * @requires crypto/cipher
  * @requires crypto/public_key
  * @requires crypto/random
+ * @requires type/ecdh_symkey
  * @requires type/mpi
  * @module crypto/crypto
  */
@@ -30,8 +31,19 @@
 import random from './random.js';
 import cipher from './cipher';
 import publicKey from './public_key';
+import type_ecdh_symkey from '../type/ecdh_symkey.js';
 import type_mpi from '../type/mpi.js';
 
+function BigInteger2mpi(bn) {
+  var mpi = new type_mpi();
+  mpi.fromBigInteger(bn);
+  return mpi;
+}
+
+function mapResult(result) {
+  return result.map(BigInteger2mpi);
+}
+
 export default {
   /**
    * Encrypts data using the specified public key multiprecision integers
@@ -42,7 +54,7 @@ export default {
    * @return {Array<module:type/mpi>} if RSA an module:type/mpi;
    * if elgamal encryption an array of two module:type/mpi is returned; otherwise null
    */
-  publicKeyEncrypt: function(algo, publicMPIs, data) {
+  publicKeyEncrypt: function(algo, publicMPIs, data, fingerprint) {
     var result = (function() {
       var m;
       switch (algo) {
@@ -52,7 +64,7 @@ export default {
           var n = publicMPIs[0].toBigInteger();
           var e = publicMPIs[1].toBigInteger();
           m = data.toBigInteger();
-          return [rsa.encrypt(m, e, n)];
+          return mapResult([rsa.encrypt(m, e, n)]);
 
         case 'elgamal':
           var elgamal = new publicKey.elgamal();
@@ -60,18 +72,22 @@ export default {
           var g = publicMPIs[1].toBigInteger();
           var y = publicMPIs[2].toBigInteger();
           m = data.toBigInteger();
-          return elgamal.encrypt(m, g, p, y);
+          return mapResult(elgamal.encrypt(m, g, p, y));
+
+        case 'ecdh':
+          var ecdh = publicKey.elliptic.ecdh;
+          var curve = publicMPIs[0];
+          var kdf_params = publicMPIs[2];
+          var R = publicMPIs[1].toBigInteger();
+          var res = ecdh.encrypt(curve.oid, kdf_params.cipher, kdf_params.hash, data, R, fingerprint);
+          return [BigInteger2mpi(res.V), new type_ecdh_symkey(res.C)];
 
         default:
           return [];
       }
     })();
 
-    return result.map(function(bn) {
+    return result;
-      var mpi = new type_mpi();
-      mpi.fromBigInteger(bn);
-      return mpi;
-    });
   },
 
   /**
@@ -86,7 +102,7 @@ export default {
    * @return {module:type/mpi} returns a big integer containing the decrypted data; otherwise null
    */
 
-  publicKeyDecrypt: function(algo, keyIntegers, dataIntegers) {
+  publicKeyDecrypt: function(algo, keyIntegers, dataIntegers, fingerprint) {
     var p;
 
     var bn = (function() {
@@ -111,6 +127,16 @@ export default {
           var c2 = dataIntegers[1].toBigInteger();
           p = keyIntegers[0].toBigInteger();
           return elgamal.decrypt(c1, c2, p, x);
+
+        case 'ecdh':
+          var ecdh = publicKey.elliptic.ecdh;
+          var curve = keyIntegers[0];
+          var kdf_params = keyIntegers[2];
+          var V = dataIntegers[0].toBigInteger();
+          var C = dataIntegers[1].data;
+          var r = keyIntegers[3].toBigInteger();
+          return ecdh.decrypt(curve.oid, kdf_params.cipher, kdf_params.hash, V, C, r, fingerprint);
+
         default:
           return null;
       }
@@ -144,8 +170,9 @@ export default {
         // Algorithm-Specific Fields for DSA secret keys:
         //   - MPI of DSA secret exponent x.
         return 1;
+      case 'ecdh':
       case 'ecdsa':
-        // Algorithm-Specific Fields for ECDSA secret keys:
+        // Algorithm-Specific Fields for ECDSA or ECDH secret keys:
         //   - MPI of an integer representing the secret key.
         return 1;
       default:
@@ -185,6 +212,13 @@ export default {
       case 'ecdsa':
         return 2;
 
+        //   Algorithm-Specific Fields for ECDH public keys:
+        //       - OID of curve;
+        //       - MPI of EC point representing public key.
+        //       - variable-length field containing KDF parameters.
+      case 'ecdh':
+        return 3;
+
       default:
         throw new Error('Unknown algorithm.');
     }
@@ -210,14 +244,6 @@ export default {
       default:
         throw new Error('Unsupported algorithm for key generation.');
     }
-
-    function mapResult(result) {
-      return result.map(function(bn) {
-        var mpi = new type_mpi();
-        mpi.fromBigInteger(bn);
-        return mpi;
-      });
-    }
   },
 
 

src/packet/public_key.js

@@ -24,6 +24,7 @@
  * major versions.  Consequently, this section is complex.
  * @requires crypto
  * @requires enums
+ * @requires type/kdf_params
  * @requires type/keyid
  * @requires type/mpi
  * @requires type/oid
@@ -35,6 +36,7 @@
 
 import util from '../util.js';
 import type_mpi from '../type/mpi.js';
+import type_kdf_params from '../type/kdf_params.js';
 import type_keyid from '../type/keyid.js';
 import type_oid from '../type/oid.js';
 import enums from '../enums.js';
@@ -102,8 +104,10 @@ PublicKey.prototype.read = function (bytes) {
     var p = 0;
 
     for (var i = 0; i < mpicount && p < bmpi.length; i++) {
-      if (this.algorithm === 'ecdsa' && i === 0) {
+      if ((this.algorithm === 'ecdsa' || this.algorithm === 'ecdh') && i === 0) {
         this.mpi[i] = new type_oid();
+      } else if (this.algorithm === 'ecdh' && i === 2) {
+        this.mpi[i] = new type_kdf_params();
       } else {
         this.mpi[i] = new type_mpi();
       }

src/packet/public_key_encrypted_session_key.js

@@ -31,6 +31,7 @@
  * decrypt the message.
  * @requires crypto
  * @requires enums
+ * @requires type/ecdh_symkey
  * @requires type/keyid
  * @requires type/mpi
  * @requires util
@@ -41,6 +42,7 @@
 
 import type_keyid from '../type/keyid.js';
 import util from '../util.js';
+import type_ecdh_symkey from '../type/ecdh_symkey.js';
 import type_mpi from '../type/mpi.js';
 import enums from '../enums.js';
 import crypto from '../crypto';
@@ -88,6 +90,9 @@ PublicKeyEncryptedSessionKey.prototype.read = function (bytes) {
       case 'elgamal':
         return 2;
 
+      case 'ecdh':
+        return 2;
+
       default:
         throw new Error("Invalid algorithm.");
     }
@@ -96,7 +101,12 @@ PublicKeyEncryptedSessionKey.prototype.read = function (bytes) {
   this.encrypted = [];
 
   for (var j = 0; j < integerCount; j++) {
-    var mpi = new type_mpi();
+    var mpi;
+    if (this.publicKeyAlgorithm === 'ecdh' && j === 1) {
+      mpi = new type_ecdh_symkey();
+    } else {
+      mpi = new type_mpi();
+    }
     i += mpi.read(bytes.subarray(i, bytes.length));
     this.encrypted.push(mpi);
   }
@@ -126,15 +136,21 @@ PublicKeyEncryptedSessionKey.prototype.encrypt = function (key) {
   var checksum = util.calc_checksum(this.sessionKey);
   data += util.Uint8Array2str(util.writeNumber(checksum, 2));
 
-  var mpi = new type_mpi();
+  var mpi;
+  if (this.publicKeyAlgorithm === 'ecdh') {
+    mpi = util.str2Uint8Array(crypto.pkcs5.addPadding(data));
+  } else {
+    mpi = new type_mpi();
     mpi.fromBytes(crypto.pkcs1.eme.encode(
       data,
       key.mpi[0].byteLength()));
+  }
 
   this.encrypted = crypto.publicKeyEncrypt(
     this.publicKeyAlgorithm,
     key.mpi,
-    mpi);
+    mpi,
+    key.fingerprint);
 };
 
 /**
@@ -149,11 +165,18 @@ PublicKeyEncryptedSessionKey.prototype.decrypt = function (key) {
   var result = crypto.publicKeyDecrypt(
     this.publicKeyAlgorithm,
     key.mpi,
-    this.encrypted).toBytes();
+    this.encrypted,
+    key.fingerprint).toBytes();
 
-  var checksum = util.readNumber(util.str2Uint8Array(result.substr(result.length - 2)));
+  var checksum;
-
+  var decoded;
-  var decoded = crypto.pkcs1.eme.decode(result);
+  if (this.publicKeyAlgorithm === 'ecdh') {
+    decoded = crypto.pkcs5.removePadding(result);
+    checksum = util.readNumber(util.str2Uint8Array(decoded.substr(decoded.length - 2)));
+  } else {
+    decoded = crypto.pkcs1.eme.decode(result);
+    checksum = util.readNumber(util.str2Uint8Array(result.substr(result.length - 2)));
+  }
 
   key = util.str2Uint8Array(decoded.substring(1, decoded.length - 2));