fix: keep compatibility with GD60 cards (revert c9892ff) and change ECCurve bitlength computation

Author: dufkan

applet/src/main/java/opencrypto/jcmathlib/ECCurve.java

@@ -38,8 +38,8 @@ public ECCurve(byte[] p, byte[] a, byte[] b, byte[] G, byte[] r, short k, Resour
  for (short i = 0; i < (short) p.length; ++i) {
  bits -= 8;
  if (p[i] != (byte) 0x00) {
- byte tmp = p[i];
- while (tmp != (byte) 0x00) {
+ short tmp = (short) (p[i] & 0xff);
+ while (tmp != (short) 0x00) {
  tmp >>= (short) 1;
  ++bits;
  }

applet/src/main/java/opencrypto/jcmathlib/Example.java

@@ -59,7 +59,7 @@ public void initialize() {
  // Allocate resources for a required elliptic curve size (in bits)
  rm = new ResourceManager((short) 256);
  // Allocate SecP256r1 curve and two EC points on this curve
- curve = new SecP256k1(rm);
+ curve = new ECCurve(SecP256r1.p, SecP256r1.a, SecP256r1.b, SecP256r1.G, SecP256r1.r, SecP256r1.k, rm);
  point1 = new ECPoint(curve);
  point2 = new ECPoint(curve);
  // Allocate two BigNats large enough to hold scalars of the elliptic curve

applet/src/main/java/opencrypto/jcmathlib/UnitTests.java

@@ -117,7 +117,7 @@ public void initialize() {
 
 
  // Pre-allocate test objects (no new allocation for every tested operation)
- curve = new SecP256r1(rm);
+ curve = new ECCurve(SecP256r1.p, SecP256r1.a, SecP256r1.b, SecP256r1.G, SecP256r1.r, SecP256r1.k, rm);
  memoryInfoOffset = snapshotAvailableMemory((short) 3, memoryInfo, memoryInfoOffset);
 
  memoryInfoOffset = snapshotAvailableMemory((short) 5, memoryInfo, memoryInfoOffset);

applet/src/main/java/opencrypto/jcmathlib/curves/SecP256k1.java

@@ -1,10 +1,6 @@
 package opencrypto.jcmathlib;
 
-public class SecP256k1 extends ECCurve {
- public SecP256k1(ResourceManager rm) {
- super(p, a, b, G, r, k, rm);
- }
-
+public class SecP256k1 {
  public final static short k = 1;
 
  public final static byte[] p = {

applet/src/main/java/opencrypto/jcmathlib/curves/SecP256r1.java

@@ -1,10 +1,6 @@
 package opencrypto.jcmathlib;
 
-public class SecP256r1 extends ECCurve {
- public SecP256r1(ResourceManager rm) {
- super(p, a, b, G, r, k, rm);
- }
-
+public class SecP256r1 {
  public final static short k = 1;
 
  public final static byte[] p = {

applet/src/main/java/opencrypto/jcmathlib/curves/SecP512r1.java

@@ -1,10 +1,6 @@
 package opencrypto.jcmathlib;
 
-public class SecP512r1 extends ECCurve {
- public SecP512r1(ResourceManager rm) {
- super(p, a, b, G, r, k, rm);
- }
-
+public class SecP512r1 {
  public final static short k = 1;
 
  public final static byte[] p = {

applet/src/main/java/opencrypto/jcmathlib/curves/Wei25519.java

@@ -1,10 +1,6 @@
 package opencrypto.jcmathlib;
 
-public class Wei25519 extends ECCurve {
- public Wei25519(ResourceManager rm) {
- super(p, a, b, G, r, k, rm);
- }
-
+public class Wei25519 {
  public final static short k = 8;
 
  public final static byte[] p = {