/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.math;
import org.apache.harmony.math.internal.nls.Messages;
import org.openssl.NativeBN;
import java.util.Random;
/*
* In contrast to BigIntegers this class doesn't fake two's complement representation.
* Any Bit-Operations, including Shifting, solely regard the unsigned magnitude.
* Moreover BigInt objects are mutable and offer efficient in-place-operations.
*/
class BigInt
// extends Number
// implements Comparable<BigInt>,
// Serializable
{
class Context {
int bnctx;
Context() {
bnctx = NativeBN.BN_CTX_new();
}
}
static BigInt dummy;
static Context defaultContext;
static {
dummy = new BigInt();
defaultContext = dummy.new Context();
}
static int getCtx (Context t) {
return (t != null) ? t.bnctx : defaultContext.bnctx;
}
/** This is the serialVersionUID used by the sun implementation */
private static final long serialVersionUID = -8287574255936472291L;
/* Fields used for the internal representation. */
transient int bignum = 0;
public void dispose() {
if (this.bignum != 0) {
NativeBN.BN_free(this.bignum);
this.bignum = 0;
}
}
@Override
protected void finalize() {
dispose();
}
@Override
public String toString() {
return this.decString();
}
public int getNativeBIGNUM() {
return this.bignum;
}
public static int consumeErrors(StringBuilder sb) {
int cnt = 0;
int e, reason;
while ((e = NativeBN.ERR_get_error()) != 0) {
reason = e & 255;
if (reason == 103) {
// math.17=BigInteger divide by zero
throw new ArithmeticException(Messages.getString("math.17")); //$NON-NLS-1$
}
if (reason == 108) {
// math.19=BigInteger not invertible.
throw new ArithmeticException(Messages.getString("math.19")); //$NON-NLS-1$
}
if (reason == 65) {
throw new OutOfMemoryError();
}
sb.append(e).append(": ");
String s = NativeBN.ERR_error_string(e);
sb.append(s);
cnt++;
}
return cnt;
}
private static void Check(boolean success) {
if (!success) {
StringBuilder sb = new StringBuilder("(openssl)ERR: ");
int cnt = consumeErrors(sb);
if (cnt > 0)
throw new ArithmeticException(sb.toString());
}
}
private void makeValid() {
if (this.bignum == 0) {
this.bignum = NativeBN.BN_new();
Check(this.bignum != 0);
}
}
private static BigInt newBigInt() {
BigInt bi = new BigInt();
bi.bignum = NativeBN.BN_new();
Check(bi.bignum != 0);
return bi;
}
public static int cmp(BigInt a, BigInt b) {
return NativeBN.BN_cmp(a.bignum, b.bignum);
}
public void putCopy(BigInt from) {
this.makeValid();
Check(NativeBN.BN_copy(this.bignum, from.bignum));
}
public BigInt copy() {
BigInt bi = new BigInt();
bi.putCopy(this);
return bi;
}
public void putLongInt(long val) {
this.makeValid();
Check(NativeBN.putLongInt(this.bignum, val));
}
public void putULongInt(long val, boolean neg) {
this.makeValid();
Check(NativeBN.putULongInt(this.bignum, val, neg));
}
public void putDecString(String str) {
if (str == null) throw new NullPointerException();
if (str.length() == 0) {
// math.12=Zero length BigInteger
throw new NumberFormatException(Messages.getString("math.12")); //$NON-NLS-1$
}
this.makeValid();
int usedLen = NativeBN.BN_dec2bn(this.bignum, str);
Check((usedLen > 0));
if (usedLen < str.length()) {
throw new NumberFormatException(str);
}
}
public void putHexString(String str) {
if (str == null) throw new NullPointerException();
if (str.length() == 0) {
// math.12=Zero length BigInteger
throw new NumberFormatException(Messages.getString("math.12")); //$NON-NLS-1$
}
this.makeValid();
int usedLen = NativeBN.BN_hex2bn(this.bignum, str);
Check((usedLen > 0));
if (usedLen < str.length()) {
throw new NumberFormatException(str);
}
}
public void putBigEndian(byte[] a, boolean neg) {
this.makeValid();
Check(NativeBN.BN_bin2bn(a, a.length, neg, this.bignum));
}
public void putLittleEndianInts(int[] a, boolean neg) {
this.makeValid();
Check(NativeBN.litEndInts2bn(a, a.length, neg, this.bignum));
}
public void putBigEndianTwosComplement(byte[] a) {
this.makeValid();
Check(NativeBN.twosComp2bn(a, a.length, this.bignum));
}
public long longInt() {
return NativeBN.longInt(this.bignum);
}
public String decString() {
String str = NativeBN.BN_bn2dec(this.bignum);
return str;
}
public String hexString() {
String str = NativeBN.BN_bn2hex(this.bignum);
return str;
}
public byte[] bigEndianMagnitude() {
byte[] a = NativeBN.BN_bn2bin(this.bignum, null);
return a;
}
public int[] littleEndianIntsMagnitude() {
int[] a = NativeBN.bn2litEndInts(this.bignum, null);
return a;
}
public int sign() {
return NativeBN.sign(this.bignum);
}
public void setSign(int val) {
if (val > 0) NativeBN.BN_set_negative(this.bignum, 0);
else if (val < 0) NativeBN.BN_set_negative(this.bignum, 1);
}
public boolean twosCompFitsIntoBytes(int desiredByteCount) {
int actualByteCount = (NativeBN.bitLength(this.bignum) + 7) / 8;
return actualByteCount <= desiredByteCount;
}
public int bitLength() {
return NativeBN.bitLength(this.bignum);
}
public boolean isBitSet(int n) {
return NativeBN.BN_is_bit_set(this.bignum, n);
}
public void modifyBit(int n, int op) {
// op: 0 = reset; 1 = set; -1 = flip
Check(NativeBN.modifyBit(this.bignum, n, op));
}
// n > 0: shift left (multiply)
public static BigInt shift(BigInt a, int n) {
BigInt r = newBigInt();
Check(NativeBN.BN_lshift(r.bignum, a.bignum, n));
return r;
}
public void shift(int n) {
Check(NativeBN.BN_lshift(this.bignum, this.bignum, n));
}
public void addPositiveInt(int w) {
Check(NativeBN.BN_add_word(this.bignum, w));
}
public void subtractPositiveInt(int w) {
Check(NativeBN.BN_sub_word(this.bignum, w));
}
public void multiplyByPositiveInt(int w) {
Check(NativeBN.BN_mul_word(this.bignum, w));
}
public int divideByPositiveInt(int w) {
int rem = NativeBN.BN_div_word(this.bignum, w);
Check(rem != -1);
return rem;
}
public static int remainderByPositiveInt(BigInt a, int w) {
int rem = NativeBN.BN_mod_word(a.bignum, w);
Check(rem != -1);
return rem;
}
public static BigInt addition(BigInt a, BigInt b) {
BigInt r = newBigInt();
Check(NativeBN.BN_add(r.bignum, a.bignum, b.bignum));
return r;
}
public void add(BigInt a) {
Check(NativeBN.BN_add(this.bignum, this.bignum, a.bignum));
}
public static BigInt subtraction(BigInt a, BigInt b) {
BigInt r = newBigInt();
Check(NativeBN.BN_sub(r.bignum, a.bignum, b.bignum));
return r;
}
public static BigInt gcd(BigInt a, BigInt b, Context t) {
BigInt r = newBigInt();
Check(NativeBN.BN_gcd(r.bignum, a.bignum, b.bignum, getCtx(t)));
return r;
}
public static BigInt product(BigInt a, BigInt b, Context t) {
BigInt r = newBigInt();
Check(NativeBN.BN_mul(r.bignum, a.bignum, b.bignum, getCtx(t)));
return r;
}
public void multiplyBy(BigInt a, Context t) {
Check(NativeBN.BN_mul(this.bignum, this.bignum, a.bignum, getCtx(t)));
}
public static BigInt bigExp(BigInt a, BigInt p, Context t) {
// Sign of p is ignored!
BigInt r = newBigInt();
Check(NativeBN.BN_exp(r.bignum, a.bignum, p.bignum, getCtx(t)));
return r;
}
public static BigInt exp(BigInt a, int p, Context t) {
// Sign of p is ignored!
BigInt power = new BigInt();
power.putLongInt(p);
return bigExp(a, power, t);
// OPTIONAL:
// public int BN_sqr(BigInteger r, BigInteger a, BN_CTX ctx);
// int BN_sqr(BIGNUM *r, const BIGNUM *a,BN_CTX *ctx);
}
public static void division(BigInt dividend, BigInt divisor, Context t,
BigInt quotient, BigInt remainder) {
int quot, rem;
if (quotient != null) {
quotient.makeValid();
quot = quotient.bignum;
}
else quot = 0;
if (remainder != null) {
remainder.makeValid();
rem = remainder.bignum;
}
else rem = 0;
Check(NativeBN.BN_div(quot, rem, dividend.bignum, divisor.bignum, getCtx(t)));
}
public static BigInt modulus(BigInt a, BigInt m, Context t) {
// Sign of p is ignored! ?
BigInt r = newBigInt();
Check(NativeBN.BN_nnmod(r.bignum, a.bignum, m.bignum, getCtx(t)));
return r;
}
public static BigInt modExp(BigInt a, BigInt p, BigInt m, Context t) {
// Sign of p is ignored!
BigInt r = newBigInt();
Check(NativeBN.BN_mod_exp(r.bignum, a.bignum, p.bignum, m.bignum, getCtx(t)));
// OPTIONAL:
// int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);
return r;
}
public static BigInt modInverse(BigInt a, BigInt m, Context t) {
BigInt r = newBigInt();
Check(NativeBN.BN_mod_inverse(r.bignum, a.bignum, m.bignum, getCtx(t)));
return r;
}
public static BigInt generatePrimeDefault(int bitLength, Random rnd, Context t) {
BigInt r = newBigInt();
Check(NativeBN.BN_generate_prime_ex(r.bignum, bitLength, false, 0, 0, 0));
return r;
}
public static BigInt generatePrimeSafe(int bitLength, Random rnd, Context t) {
BigInt r = newBigInt();
Check(NativeBN.BN_generate_prime_ex(r.bignum, bitLength, true, 0, 0, 0));
return r;
}
public boolean isPrime(int certainty, Random rnd, Context t) {
return NativeBN.BN_is_prime_ex(bignum, certainty, getCtx(t), 0);
}
}