Support jcardsim and J3H081

jcardsim's PersistentSimulatorRuntime cannot persist Signature objects,
so make those temporary and not part of the class object. Additionally,
allow skipping checks for RSA4096 and for RSA PSS, as even just testing
them can prevent applet installation on certain cards (J3H081).

Author: Your Name

.gitignore

@@ -1,6 +1,6 @@
-ant-javacard.jar
 doc
 *.swp
 *.orig
 *.un~
 *.cap
+*.jar

README.md

@@ -37,5 +37,31 @@ After cloning the IsoApplet repository, all you have to do is:
 # Installation
 Install the CAP-file (IsoApplet.cap) to your Java Card smart card (e.g. with [GlobalPlatformPro](https://github.com/martinpaljak/GlobalPlatformPro)).
 
+# Using with jcardsim
+Make sure to install the appropriate vsmartcard package. On Debian/Ubuntu, this is called vsmartcard-vpcd. You may need to restart pcscd after installing it. Note: This is only appropriate for development machines; it creates an open listening socket with no authentication that pcscd exposes as the first reader so it is trivial to MitM for an attacker.
+
+Setup a jcardsim.cfg file like so:
+```
+com.licel.jcardsim.card.applet.0.AID=F276A288BCFBA69D34F31001
+com.licel.jcardsim.card.applet.0.Class=xyz.wendland.javacard.pki.isoapplet.IsoApplet
+com.licel.jcardsim.terminal.type=2
+com.licel.jcardsim.vsmartcard.host=127.0.0.1
+com.licel.jcardsim.vsmartcard.port=35963
+```
+
+Run jcardsim with the IsoApplet.jar file on the path:
+```java -cp IsoApplet.jar:jcardsim-3.0.5-SNAPSHOT.jar com.licel.jcardsim.remote.VSmartCard  jcardsim.cfg```
+
+Instantiate the applet in jcardsim (this example uses gpshell):
+```
+echo 'establish_context
+card_connect
+send_apdu -sc 0 -APDU 80b800000d0cF276A288BCFBA69D34F31001
+card_disconnect
+release_context' | gpshell
+```
+
+Now you should be able to use pkcs15-init and friends.
+
 **Have a look at the wiki for more information:** https://github.com/philipWendland/IsoApplet/wiki
 

build.xml

@@ -8,7 +8,7 @@
     <target name="dist" description="generate the distribution">
         <tstamp/>
         <javacard jckit="ext/sdks/jc310r20210706_kit">
-            <cap targetsdk="ext/sdks/jc304_kit" aid="f2:76:a2:88:bc:fb:a6:9d:34:f3:10" output="IsoApplet.cap" sources="src" version="1.0">
+            <cap targetsdk="ext/sdks/jc304_kit" aid="f2:76:a2:88:bc:fb:a6:9d:34:f3:10" output="IsoApplet.cap" sources="src" version="1.0" jar="IsoApplet.jar">
                 <applet class="xyz.wendland.javacard.pki.isoapplet.IsoApplet" aid="f2:76:a2:88:bc:fb:a6:9d:34:f3:10:01"/>
             </cap>
         </javacard>

src/xyz/wendland/javacard/pki/isoapplet/IsoApplet.java

@@ -23,6 +23,8 @@
 import javacard.framework.ISO7816;
 import javacard.framework.ISOException;
 import javacard.framework.APDU;
+import javacard.framework.SystemException;
+import javacard.framework.TransactionException;
 import javacard.framework.JCSystem;
 import javacard.framework.Util;
 import javacard.framework.OwnerPIN;
@@ -61,6 +63,11 @@ public class IsoApplet extends Applet implements ExtendedLength {
     /* Card-specific configuration */
     public static final boolean DEF_PRIVATE_KEY_IMPORT_ALLOWED = false;
 
+    /* Certain cards (J3H081) break in unexpected ways testing these at
+     * runtime. Allow them to be forced off so no test is run. */
+    public static final boolean DEF_TEST_RSA_4096 = true;
+    public static final boolean DEF_TEST_RSA_PSS = true;
+
     /* ISO constants not in the "ISO7816" interface */
     // File system related INS:
     public static final byte INS_CREATE_FILE = (byte) 0xE0;
@@ -138,12 +145,6 @@ public class IsoApplet extends Applet implements ExtendedLength {
     private Key[] keys = null;
     private byte[] ram_buf = null;
     private Cipher rsaPkcs1Cipher = null;
-    private Signature ecdsaSignature = null;
-    private Signature rsaSha1PssSignature = null;
-    private Signature rsaSha224PssSignature = null;
-    private Signature rsaSha256PssSignature = null;
-    private Signature rsaSha384PssSignature = null;
-    private Signature rsaSha512PssSignature = null;
     private RandomData randomData = null;
     private byte api_features;
 
@@ -179,54 +180,60 @@ protected IsoApplet() {
 
         // API features: probe card support for ECDSA
         try {
-            ecdsaSignature = Signature.getInstance(MessageDigest.ALG_NULL, Signature.SIG_CIPHER_ECDSA, Cipher.PAD_NULL, false);
+            Signature.getInstance(MessageDigest.ALG_NULL, Signature.SIG_CIPHER_ECDSA, Cipher.PAD_NULL, false);
             api_features |= API_FEATURE_ECC;
         } catch (CryptoException e) {
             if(e.getReason() == CryptoException.NO_SUCH_ALGORITHM) {
                 /* Few Java Cards do not support ECDSA at all.
                  * We should not throw an exception in this cases
                  * as this would prevent installation. */
-                ecdsaSignature = null;
                 api_features &= ~API_FEATURE_ECC;
             } else {
                 throw e;
             }
         }
 
         // API features: probe card support for 4096 bit RSA keys
-        try {
-            RSAPrivateCrtKey testKey = (RSAPrivateCrtKey)KeyBuilder.buildKey(KeyBuilder.TYPE_RSA_CRT_PRIVATE, KeyBuilder.LENGTH_RSA_4096, false);
-            api_features |= API_FEATURE_RSA_4096;
-        } catch (CryptoException e) {
-            if(e.getReason() == CryptoException.NO_SUCH_ALGORITHM) {
-                api_features &= ~API_FEATURE_RSA_4096;
-            } else {
-                throw e;
+        if (DEF_TEST_RSA_4096) {
+            try {
+                RSAPrivateCrtKey testKey = (RSAPrivateCrtKey)KeyBuilder.buildKey(KeyBuilder.TYPE_RSA_CRT_PRIVATE, KeyBuilder.LENGTH_RSA_4096, false);
+                api_features |= API_FEATURE_RSA_4096;
+            } catch (CryptoException e) {
+                if(e.getReason() == CryptoException.NO_SUCH_ALGORITHM) {
+                    api_features &= ~API_FEATURE_RSA_4096;
+                } else {
+                    throw e;
+                }
+            } catch (TransactionException e) {
+                // J3H081 from javacardsdk.com (FUTAKO) raises this exception instead.
+                if(e.getReason() == TransactionException.INTERNAL_FAILURE) {
+                    api_features &= ~API_FEATURE_RSA_4096;
+                } else {
+                    throw e;
+                }
             }
         }
 
+
         /* API features: probe card support for RSA and PSS padding with SHA-1 and all SHA-2 algorithms
          * to be used with Signature.signPreComputedHash() */
-        try {
-            rsaSha1PssSignature = Signature.getInstance(Signature.ALG_RSA_SHA_PKCS1_PSS, false);
-            rsaSha224PssSignature = Signature.getInstance(Signature.ALG_RSA_SHA_224_PKCS1_PSS, false);
-            rsaSha256PssSignature = Signature.getInstance(Signature.ALG_RSA_SHA_256_PKCS1_PSS, false);
-            rsaSha384PssSignature = Signature.getInstance(Signature.ALG_RSA_SHA_384_PKCS1_PSS, false);
-            rsaSha512PssSignature = Signature.getInstance(Signature.ALG_RSA_SHA_512_PKCS1_PSS, false);
-            api_features |= API_FEATURE_RSA_PSS;
-        } catch (CryptoException e) {
-            if(e.getReason() == CryptoException.NO_SUCH_ALGORITHM) {
-                /* Certain Java Cards do not support this algorithm.
-                 * We should not throw an exception in this cases
-                 * as this would prevent installation. */
-                rsaSha1PssSignature = null;
-                rsaSha224PssSignature = null;
-                rsaSha384PssSignature = null;
-                rsaSha256PssSignature = null;
-                rsaSha512PssSignature = null;
-                api_features &= ~API_FEATURE_RSA_PSS;
-            } else {
-                throw e;
+        if (DEF_TEST_RSA_PSS) {
+            try {
+                Signature.getInstance(Signature.ALG_RSA_SHA_PKCS1_PSS, false);
+                Signature.getInstance(Signature.ALG_RSA_SHA_224_PKCS1_PSS, false);
+                Signature.getInstance(Signature.ALG_RSA_SHA_256_PKCS1_PSS, false);
+                Signature.getInstance(Signature.ALG_RSA_SHA_384_PKCS1_PSS, false);
+                Signature.getInstance(Signature.ALG_RSA_SHA_512_PKCS1_PSS, false);
+                api_features |= API_FEATURE_RSA_PSS;
+            } catch (CryptoException e) {
+                if(e.getReason() == CryptoException.NO_SUCH_ALGORITHM) {
+                    /* Certain Java Cards do not support this algorithm.
+                     * We should not throw an exception in this cases
+                     * as this would prevent installation. */
+                    api_features &= ~API_FEATURE_RSA_PSS;
+                } else {
+                    throw e;
+                }
             }
         }
 
@@ -1101,7 +1108,7 @@ public void processManageSecurityEnvironment(APDU apdu) throws ISOException {
             if(privKeyRef < 0) {
                 ISOException.throwIt(ISO7816.SW_DATA_INVALID);
             }
-            if(algRef == ALG_GEN_EC && ecdsaSignature == null) {
+            if(algRef == ALG_GEN_EC && (api_features & API_FEATURE_ECC) == 0) {
                 // There are cards that do not support ECDSA at all.
                 ISOException.throwIt(ISO7816.SW_FUNC_NOT_SUPPORTED);
             }
@@ -1129,7 +1136,7 @@ public void processManageSecurityEnvironment(APDU apdu) throws ISOException {
                 if(keys[privKeyRef].getType() != KeyBuilder.TYPE_EC_FP_PRIVATE) {
                     ISOException.throwIt(ISO7816.SW_DATA_INVALID);
                 }
-                if(ecdsaSignature == null) {
+                if((api_features & API_FEATURE_ECC) == 0) {
                     ISOException.throwIt(ISO7816.SW_FUNC_NOT_SUPPORTED);
                 }
 
@@ -1297,24 +1304,27 @@ private void computeDigitalSignature(APDU apdu) throws ISOException {
             } else if (currentAlgorithmRef[0] == ALG_RSA_PAD_PSS) {
                 // ALG_RSA_PAD_PSS with pre-computed hash.
                 // Determine Signature object by hash length.
+                Signature obj = null;
                 if(lc == (short) 20) {
-                    rsaSha1PssSignature.init(rsaKey, Signature.MODE_SIGN);
-                    sigLen = rsaSha1PssSignature.signPreComputedHash(ram_buf, (short)0, lc, ram_buf, lc);
+                    obj = Signature.getInstance(Signature.ALG_RSA_SHA_PKCS1_PSS, false);
                 } else if (lc == (short) 28) {
-                    rsaSha224PssSignature.init(rsaKey, Signature.MODE_SIGN);
-                    sigLen = rsaSha224PssSignature.signPreComputedHash(ram_buf, (short)0, lc, ram_buf, lc);
+                    obj = Signature.getInstance(Signature.ALG_RSA_SHA_224_PKCS1_PSS, false);
                 } else if (lc == (short) 32) {
-                    rsaSha256PssSignature.init(rsaKey, Signature.MODE_SIGN);
-                    sigLen = rsaSha256PssSignature.signPreComputedHash(ram_buf, (short)0, lc, ram_buf, lc);
+                    obj = Signature.getInstance(Signature.ALG_RSA_SHA_256_PKCS1_PSS, false);
                 } else if (lc == (short) 48) {
-                    rsaSha384PssSignature.init(rsaKey, Signature.MODE_SIGN);
-                    sigLen = rsaSha384PssSignature.signPreComputedHash(ram_buf, (short)0, lc, ram_buf, lc);
+                    obj = Signature.getInstance(Signature.ALG_RSA_SHA_384_PKCS1_PSS, false);
                 } else if (lc == (short) 64) {
-                    rsaSha512PssSignature.init(rsaKey, Signature.MODE_SIGN);
-                    sigLen = rsaSha512PssSignature.signPreComputedHash(ram_buf, (short)0, lc, ram_buf, lc);
+                    obj = Signature.getInstance(Signature.ALG_RSA_SHA_512_PKCS1_PSS, false);
                 } else {
                     ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
                 }
+
+                obj.init(rsaKey, Signature.MODE_SIGN);
+                sigLen = obj.signPreComputedHash(ram_buf, (short)0, lc, ram_buf, lc);
+
+                if(JCSystem.isObjectDeletionSupported()) {
+                    JCSystem.requestObjectDeletion();
+                }
             } else {
                 ISOException.throwIt(ISO7816.SW_FUNC_NOT_SUPPORTED);
             }
@@ -1331,8 +1341,12 @@ private void computeDigitalSignature(APDU apdu) throws ISOException {
             // Get the key - it must be a EC private key,
             // checks have been done in MANAGE SECURITY ENVIRONMENT.
             ECPrivateKey ecKey = (ECPrivateKey) keys[currentPrivateKeyRef[0]];
+            Signature ecdsaSignature = Signature.getInstance(MessageDigest.ALG_NULL, Signature.SIG_CIPHER_ECDSA, Cipher.PAD_NULL, false);
             ecdsaSignature.init(ecKey, Signature.MODE_SIGN);
             sigLen = ecdsaSignature.sign(ram_buf, (short)0, lc, apdu.getBuffer(), (short)0);
+            if(JCSystem.isObjectDeletionSupported()) {
+                JCSystem.requestObjectDeletion();
+            }
             apdu.setOutgoingAndSend((short) 0, sigLen);
             break;