Fix bug with incorrect first responses

BryanJacobs · BryanJacobs · commit 3871640a44fa · 2023-09-17T12:13:13.000+10:00
We overwrote bufferMem when initializing the platform key, leading to
corrupted responses.
diff --git a/src/main/java/us/q3q/fido2/FIDO2Applet.java b/src/main/java/us/q3q/fido2/FIDO2Applet.java
@@ -3437,6 +3437,8 @@ public void process(APDU apdu) throws ISOException {
             }
         }
 
+        initKeyAgreementKeyIfNecessary();
+
         if (attestationData != null && filledAttestationData < attestationData.length &&
                 transientStorage.getChainIncomingReadOffset() > 0
                 && bufferMem[0] == FIDOConstants.CMD_INSTALL_CERTS
@@ -3542,8 +3544,6 @@ public void process(APDU apdu) throws ISOException {
             throwException(ISO7816.SW_DATA_INVALID);
         }
 
-        initKeyAgreementKeyIfNecessary();
-
         short lcEffective = (short)(lc + 1);
         byte cmdByte = apduBytes[apdu.getOffsetCdata()];
 

Original file line number	Diff line number	Diff line change
`@@ -3437,6 +3437,8 @@ public void process(APDU apdu) throws ISOException {`
`3437`	`3437`	`}`
`3438`	`3438`	`}`
`3439`	`3439`
	`3440`	`+ initKeyAgreementKeyIfNecessary();`
	`3441`	`+`
`3440`	`3442`	`if (attestationData != null && filledAttestationData < attestationData.length &&`
`3441`	`3443`	`transientStorage.getChainIncomingReadOffset() > 0`
`3442`	`3444`	`&& bufferMem[0] == FIDOConstants.CMD_INSTALL_CERTS`
`@@ -3542,8 +3544,6 @@ public void process(APDU apdu) throws ISOException {`
`3542`	`3544`	`throwException(ISO7816.SW_DATA_INVALID);`
`3543`	`3545`	`}`
`3544`	`3546`
`3545`		`- initKeyAgreementKeyIfNecessary();`
`3546`		`-`
`3547`	`3547`	`short lcEffective = (short)(lc + 1);`
`3548`	`3548`	`byte cmdByte = apduBytes[apdu.getOffsetCdata()];`
`3549`	`3549`