1 /**
  2  *  ---------
  3  * |.##> <##.|  Open Smart Card Development Platform (www.openscdp.org)
  4  * |#       #|
  5  * |#       #|  Copyright (c) 1999-2018 CardContact Software & System Consulting
  6  * |'##> <##'|  Andreas Schwier, 32429 Minden, Germany (www.cardcontact.de)
  7  *  ---------
  8  *
  9  *  This file is part of OpenSCDP.
 10  *
 11  *  OpenSCDP is free software; you can redistribute it and/or modify
 12  *  it under the terms of the GNU General Public License version 2 as
 13  *  published by the Free Software Foundation.
 14  *
 15  *  OpenSCDP is distributed in the hope that it will be useful,
 16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18  *  GNU General Public License for more details.
 19  *
 20  *  You should have received a copy of the GNU General Public License
 21  *  along with OpenSCDP; if not, write to the Free Software
 22  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 23  *
 24  * @fileoverview Implementation of a secure messaging channel as defined in ISO 7814-4 and eSign-K
 25  */
 26 
 27 var APDU                                = require('scsh/cardsim/APDU').APDU;
 28 var SecureMessagingCommandAPDUDecoder   = require('scsh/cardsim/SecureMessagingCommandAPDUDecoder').SecureMessagingCommandAPDUDecoder;
 29 
 30 
 31 
 32 /**
 33  * Create a secure channel
 34  *
 35  * @class Class implementing a secure messaging channel
 36  * @constructor
 37  * @param {Crypto} crypto the crypto provider
 38  */
 39 function SecureChannelHandler(crypto) {
 40 	this.crypto = crypto;
 41 	this.policy = IsoSecureChannel.SSC_DEFAULT_POLICY;
 42 }
 43 
 44 exports.SecureChannelHandler = SecureChannelHandler;
 45 
 46 
 47 
 48 /**
 49  * Sets the policy for handling send sequence counters
 50  *
 51  * See IsoSecureChannel for details
 52  *
 53  * @param {Number} policy one of IsoSecureChannel.SSC_DEFAULT_POLICY, SSC_SYNC_POLICY or SSC_SYNC_ENC_POLICY
 54  */
 55 SecureChannelHandler.prototype.setSendSequenceCounterPolicy = function(policy) {
 56 	this.policy = policy;
 57 }
 58 
 59 
 60 
 61 /**
 62  * Sets the key used for encryption
 63  *
 64  * @param {Key} key the encryption key
 65  */
 66 SecureChannelHandler.prototype.setEncKey = function(key) {
 67 	this.encKey = key;
 68 
 69 	if (key.getComponent(Key.AES)) {
 70 		this.encBlockSize = 16;
 71 		this.encMechanism = Crypto.AES_CBC;
 72 		this.iv = new ByteString("00000000000000000000000000000000", HEX);
 73 	} else {
 74 		this.encBlockSize = 8;
 75 		this.encMechanism = Crypto.DES_CBC;
 76 		this.iv = new ByteString("0000000000000000", HEX);
 77 	}
 78 }
 79 
 80 
 81 
 82 /**
 83  * Sets the key used for message authentication
 84  *
 85  * @param {Key} key the message authentication key
 86  */
 87 SecureChannelHandler.prototype.setMacKey = function(key) {
 88 	this.macKey = key;
 89 
 90 	if (key.getComponent(Key.AES)) {
 91 		this.macBlockSize = 16;
 92 		this.macMechanism = Crypto.AES_CMAC;
 93 	} else {
 94 		this.macBlockSize = 8;
 95 		this.macMechanism = Crypto.DES_MAC_EMV;
 96 	}
 97 }
 98 
 99 
100 
101 /**
102  * Set the send sequence counter for MAC calculation
103  *
104  * @param {ByteString} ssc the send sequence counter
105  */
106 SecureChannelHandler.prototype.setMACSendSequenceCounter = function(ssc) {
107 	this.macSendSequenceCounter = ssc;
108 }
109 
110 
111 
112 /**
113  * Set the send sequence counter for encryption calculation
114  *
115  * @param {ByteString} ssc the send sequence counter
116  */
117 SecureChannelHandler.prototype.setEncSendSequenceCounter = function(ssc) {
118 	this.encSendSequenceCounter = ssc;
119 }
120 
121 
122 
123 /**
124  * Return an initialisation vector based on the defined policy
125  *
126  * @type ByteString
127  * @return the IV
128  */
129 SecureChannelHandler.prototype.getIV = function() {
130 	var iv = this.iv;
131 	if (this.policy == IsoSecureChannel.SSC_SYNC_ENC_POLICY) {
132 		iv = this.crypto.encrypt(this.encKey, this.encMechanism, this.macSendSequenceCounter, iv);
133 	} else if (this.policy == IsoSecureChannel.SSC_SYNC_POLICY) {
134 		iv = this.macSendSequenceCounter;
135 	} else {
136 		if (typeof(this.encSendSequenceCounter) != "undefined") {
137 			iv = this.encSendSequenceCounter
138 		}
139 	}
140 	return iv;
141 }
142 
143 
144 
145 /**
146  * Unwrap a secure messaging APDU recovering the content
147  *
148  * @param {APDU} apdu the APDU to unwrap
149  */
150 SecureChannelHandler.prototype.unwrap = function(apdu) {
151 	var decoder = new SecureMessagingCommandAPDUDecoder(this, apdu);
152 	if (!decoder.verifyMAC(this.macKey)) {
153 		throw new GPError("SecureChannelHandler", GPError.CRYPTO_FAILED, APDU.SW_INCSMDATAOBJECT, "MAC verification failed");
154 	}
155 
156 	var le = decoder.getLe();
157 	if (le >= 0) {
158 		apdu.ne = le;
159 	} else {
160 		apdu.ne = undefined;
161 	}
162 
163 	var plain = decoder.decryptBody(this.encKey);
164 	apdu.setCData(plain);
165 }
166 
167 
168 
169 /**
170  * Wrap an APDU for secure messaging
171  *
172  * @param {APDU} apdu the APDU to wrap
173  */
174 SecureChannelHandler.prototype.wrap = function(apdu) {
175 	var rdata = new ByteBuffer();
176 
177 	var macinp = new ByteBuffer();
178 
179 	if (typeof(this.macSendSequenceCounter) != "undefined") {
180 		var ssc = this.macSendSequenceCounter.add(1);
181 		this.macSendSequenceCounter = ssc;
182 		macinp.append(ssc);
183 	}
184 
185 	if (apdu.hasRData()) {
186 		var padbuff = new ByteBuffer(apdu.getRData());
187 		SecureMessagingCommandAPDUDecoder.pad(padbuff, this.encBlockSize);
188 		var iv = this.getIV();
189 		var cryptogram = this.crypto.encrypt(this.encKey, this.encMechanism, padbuff.toByteString(), iv);
190 		var padind = new ByteString("01", HEX);
191 
192 		var do87 = new TLV(0x87, padind.concat(cryptogram), TLV.EMV);
193 		rdata.append(do87.getTLV());
194 	}
195 
196 	rdata.append(0x99);
197 	rdata.append(2);
198 	rdata.append(apdu.getSW() >> 8);
199 	rdata.append(apdu.getSW() & 0xFF);
200 
201 	macinp.append(rdata);
202 
203 	SecureMessagingCommandAPDUDecoder.pad(macinp, this.macBlockSize);
204 	var mac = this.crypto.sign(this.macKey, this.macMechanism, macinp.toByteString());
205 
206 	rdata.append(0x8E);
207 	rdata.append(0x08);
208 	rdata.append(mac.left(8));
209 
210 	apdu.setRData(rdata.toByteString());
211 }
212