add GENERATE KEY command

APPLICATION.MD

@@ -307,6 +307,19 @@ human-readable mnemonic. Each integer can have a value from 0 to 2047.
 Removes the key from the card, bringing it back to an uninitialized state. No signing operation is possible after this
 command until a new LOAD KEY command is performed.
 
+### GENERATE KEY
+
+* CLA = 0x80
+* INS = 0xD4
+* P1 = 0x00
+* P2 = 0x00
+* Response SW = 0x9000 on success.
+* Response Data = the key UID, defined as the SHA-256 of the public key
+* Preconditions: Secure Channel must be opened, user PIN must be verified
+
+Generates and stores keys completely on card. The state of the card after execution is the same as if a LOAD KEY command
+had been performed.
+
 ### SIGN
 
 * CLA = 0x80

build.gradle

@@ -27,7 +27,8 @@ javacard {
       aid = '0x53:0x74:0x61:0x74:0x75:0x73:0x57:0x61:0x6c:0x6c:0x65:0x74:0x4e:0x46:0x43'
       className = 'NDEFApplet'
     }
-    version = '1.2'
+    
+    version = '2.0'
   }
 }
 

src/main/java/im/status/wallet/WalletApplet.java

@@ -1000,7 +1000,9 @@ public class WalletApplet extends Applet {
       ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
     }
 
-    crypto.random.generateData(apduBuffer, (short) 0, BIP39_SEED_SIZE);
+    apduBuffer[ISO7816.OFFSET_LC] = BIP39_SEED_SIZE;
+    crypto.random.generateData(apduBuffer, ISO7816.OFFSET_CDATA, BIP39_SEED_SIZE);
+
     loadSeed(apduBuffer);
     generateKeyUIDAndRespond(apdu, apduBuffer);
   }

src/test/java/im/status/wallet/WalletAppletCommandSet.java

@@ -395,6 +395,17 @@ public class WalletAppletCommandSet {
     return secureChannel.transmit(apduChannel, removeKey);
   }
 
+  /**
+   * Sends a GENERATE KEY APDU.
+   *
+   * @return the raw card response
+   * @throws CardException communication error
+   */
+  public ResponseAPDU generateKey() throws CardException {
+    CommandAPDU generateKey = secureChannel.protectedCommand(0x80, WalletApplet.INS_GENERATE_KEY, 0, 0, new byte[0]);
+    return secureChannel.transmit(apduChannel, generateKey);
+  }
+
   /**
    * Sends a SIGN APDU. The dataType is P1 as defined in the applet. The isFirst and isLast arguments are used to form
    * the P2 parameter. The data is the data to sign, or part of it. Only when sending the last block a signature is

src/test/java/im/status/wallet/WalletAppletTest.java

@@ -685,6 +685,34 @@ public class WalletAppletTest {
     assertEquals(0, data[30 + data[21]]);
   }
 
+  @Test
+  @DisplayName("GENERATE KEY command")
+  void generateKeyTest() throws Exception {
+    // Security condition violation: SecureChannel not open
+    ResponseAPDU response = cmdSet.generateKey();
+    assertEquals(0x6985, response.getSW());
+
+    cmdSet.autoOpenSecureChannel();
+
+    // Security condition violation: PIN not verified
+    response = cmdSet.generateKey();
+    assertEquals(0x6985, response.getSW());
+
+    response = cmdSet.verifyPIN("000000");
+    assertEquals(0x9000, response.getSW());
+
+    // Good case
+    response = cmdSet.generateKey();
+    assertEquals(0x9000, response.getSW());
+    byte[] keyUID = response.getData();
+
+    response = cmdSet.exportKey(WalletApplet.EXPORT_KEY_P1_ANY, true);
+    assertEquals(0x9000, response.getSW());
+    byte[] pubKey = response.getData();
+
+    verifyKeyUID(keyUID, Arrays.copyOfRange(pubKey, 4, pubKey.length));
+  }
+
   @Test
   @DisplayName("DERIVE KEY command")
   void deriveKeyTest() throws Exception {