src/main/java/org/apache/milagro/amcl/RSA3072/RSA.java - incubator-milagro-java - Git at Google

 /*
 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements.  See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership.  The ASF licenses this file
 to you 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.
 */

 /* RSA API high-level functions  */

 package org.apache.milagro.amcl.RSA3072;

 import org.apache.milagro.amcl.RAND;
 import org.apache.milagro.amcl.HASH256;
 import org.apache.milagro.amcl.HASH384;
 import org.apache.milagro.amcl.HASH512;

 public final class RSA {

 	public static final int RFS=BIG.MODBYTES*FF.FFLEN;
 	public static final int SHA256=32;
 	public static final int SHA384=48;
 	public static final int SHA512=64;

 	public static final int HASH_TYPE=SHA256;

 /* Hash number (optional) and string to array size of Bigs */

 	public static byte[] hashit(int sha,byte[] A,int n)
 	{
 		byte[] R=null;

 		if (sha==SHA256)
 		{
 			HASH256 H=new HASH256();
 			if (A!=null) H.process_array(A);
 			if (n>=0) H.process_num(n);
 			R=H.hash();
 		}
 		if (sha==SHA384)
 		{
 			HASH384 H=new HASH384();
 			if (A!=null) H.process_array(A);
 			if (n>=0) H.process_num(n);
 			R=H.hash();
 		}
 		if (sha==SHA512)
 		{
 			HASH512 H=new HASH512();
 			if (A!=null) H.process_array(A);
 			if (n>=0) H.process_num(n);
 			R=H.hash();
 		}
 		return R;
 	}

 /* generate an RSA key pair */

 	public static void KEY_PAIR(RAND rng,int e,private_key PRIV,public_key PUB)
 	{ /* IEEE1363 A16.11/A16.12 more or less */

 		int n=PUB.n.getlen()/2;
 		FF t = new FF(n);
 		FF p1=new FF(n);
 		FF q1=new FF(n);

 		for (;;)
 		{
 			PRIV.p.random(rng);
 			while (PRIV.p.lastbits(2)!=3) PRIV.p.inc(1);
 			while (!FF.prime(PRIV.p,rng)) PRIV.p.inc(4);

 			p1.copy(PRIV.p);
 			p1.dec(1);

 			if (p1.cfactor(e)) continue;
 			break;
 		}

 		for (;;)
 		{
 			PRIV.q.random(rng);
 			while (PRIV.q.lastbits(2)!=3) PRIV.q.inc(1);
 			while (!FF.prime(PRIV.q,rng)) PRIV.q.inc(4);

 			q1.copy(PRIV.q);
 			q1.dec(1);

 			if (q1.cfactor(e)) continue;

 			break;
 		}

 		PUB.n=FF.mul(PRIV.p,PRIV.q);
 		PUB.e=e;

 		t.copy(p1);
 		t.shr();
 		PRIV.dp.set(e);
 		PRIV.dp.invmodp(t);
 		if (PRIV.dp.parity()==0) PRIV.dp.add(t);
 		PRIV.dp.norm();

 		t.copy(q1);
 		t.shr();
 		PRIV.dq.set(e);
 		PRIV.dq.invmodp(t);
 		if (PRIV.dq.parity()==0) PRIV.dq.add(t);
 		PRIV.dq.norm();

 		PRIV.c.copy(PRIV.p);
 		PRIV.c.invmodp(PRIV.q);

 		return;
 	}

 /* Mask Generation Function */

 	public static void MGF1(int sha,byte[] Z,int olen,byte[] K)
 	{
 		int hlen=sha;
 		byte[] B;

 		int counter,cthreshold,k=0;

 		for (int i=0;i<K.length;i++) K[i]=0;

 		cthreshold=olen/hlen; if (olen%hlen!=0) cthreshold++;
 		for (counter=0;counter<cthreshold;counter++)
 		{
 			B=hashit(sha,Z,counter);
 			if (k+hlen>olen) for (int i=0;i<olen%hlen;i++) K[k++]=B[i];
 			else for (int i=0;i<hlen;i++) K[k++]=B[i];
 		}
 	}

 	public static void printBinary(byte[] array)
 	{
 		int i;
 		for (i=0;i<array.length;i++)
 		{
 			System.out.printf("%02x", array[i]);
 		}
 		System.out.println();
 	}


 /* SHARSA3072 identifier strings */
 	private static final byte[] SHA256ID={0x30,0x31,0x30,0x0d,0x06,0x09,0x60,(byte)0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,0x20};
 	private static final byte[] SHA384ID={0x30,0x41,0x30,0x0d,0x06,0x09,0x60,(byte)0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,0x30};
 	private static final byte[] SHA512ID={0x30,0x51,0x30,0x0d,0x06,0x09,0x60,(byte)0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,0x00,0x04,0x40};

 /* PKCS 1.5 padding of a message to be signed */

 	public static boolean PKCS15(int sha,byte[] m,byte[] w)
 	{
 		int olen=FF.FF_BITS/8;
 		int i,hlen=sha;
 		int idlen=19;

 		if (olen<idlen+hlen+10) return false;
 		byte[] H=hashit(sha,m,-1);

 		for (i=0;i<w.length;i++) w[i]=0;
 		i=0;
 		w[i++]=0;
 		w[i++]=1;
 		for (int j=0;j<olen-idlen-hlen-3;j++)
 			w[i++]=(byte)0xff;
 		w[i++]=0;


 		if (hlen==SHA256) for (int j=0;j<idlen;j++) w[i++]=SHA256ID[j];
 		if (hlen==SHA384) for (int j=0;j<idlen;j++) w[i++]=SHA384ID[j];
 		if (hlen==SHA512) for (int j=0;j<idlen;j++) w[i++]=SHA512ID[j];

 		for (int j=0;j<hlen;j++)
 			w[i++]=H[j];

 		return true;
 	}


 	/* OAEP Message Encoding for Encryption */
 	public static byte[] OAEP_ENCODE(int sha,byte[] m,RAND rng,byte[] p)
 	{
 		int i,slen,olen=RFS-1;
 		int mlen=m.length;
 		int hlen,seedlen;
 		byte[] f=new byte[RFS];

 		hlen=sha;
 		byte[] SEED=new byte[hlen];
 		seedlen=hlen;

 		if (mlen>olen-hlen-seedlen-1) return new byte[0];

 		byte[] DBMASK=new byte[olen-seedlen];

 		byte[] h=hashit(sha,p,-1);

 		for (i=0;i<hlen;i++) f[i]=h[i];

 		slen=olen-mlen-hlen-seedlen-1;

 		for (i=0;i<slen;i++) f[hlen+i]=0;
 		f[hlen+slen]=1;
 		for (i=0;i<mlen;i++) f[hlen+slen+1+i]=m[i];

 		for (i=0;i<seedlen;i++) SEED[i]=(byte)rng.getByte();

 		MGF1(sha,SEED,olen-seedlen,DBMASK);

 		for (i=0;i<olen-seedlen;i++) DBMASK[i]^=f[i];

 		MGF1(sha,DBMASK,seedlen,f);

 		for (i=0;i<seedlen;i++) f[i]^=SEED[i];

 		for (i=0;i<olen-seedlen;i++) f[i+seedlen]=DBMASK[i];

 		/* pad to length RFS */
 		int d=1;
 		for (i=RFS-1;i>=d;i--)
 			f[i]=f[i-d];
 		for (i=d-1;i>=0;i--)
 			f[i]=0;

 		return f;
 	}

 	/* OAEP Message Decoding for Decryption */
 	public static byte[] OAEP_DECODE(int sha,byte[] p,byte[] f)
 	{
 		int x,t;
 		boolean comp;
 		int i,k,olen=RFS-1;
 		int hlen,seedlen;

 		hlen=sha;
 		byte[] SEED=new byte[hlen];
 		seedlen=hlen;
 		byte[] CHASH=new byte[hlen];

 		if (olen<seedlen+hlen+1) return new byte[0];
 		byte[] DBMASK=new byte[olen-seedlen];
 		for (i=0;i<olen-seedlen;i++) DBMASK[i]=0;

 		if (f.length<RFS)
 		{
 			int d=RFS-f.length;
 			for (i=RFS-1;i>=d;i--)
 				f[i]=f[i-d];
 			for (i=d-1;i>=0;i--)
 				f[i]=0;

 		}

 		byte[] h=hashit(sha,p,-1);

 		for (i=0;i<hlen;i++) CHASH[i]=h[i];

 		x=f[0];

 		for (i=seedlen;i<olen;i++)
 			DBMASK[i-seedlen]=f[i+1];

 		MGF1(sha,DBMASK,seedlen,SEED);
 		for (i=0;i<seedlen;i++) SEED[i]^=f[i+1];
 		MGF1(sha,SEED,olen-seedlen,f);
 		for (i=0;i<olen-seedlen;i++) DBMASK[i]^=f[i];

 		comp=true;
 		for (i=0;i<hlen;i++)
 		{
 			if (CHASH[i]!=DBMASK[i]) comp=false;
 		}

 		for (i=0;i<olen-seedlen-hlen;i++)
 			DBMASK[i]=DBMASK[i+hlen];

 		for (i=0;i<hlen;i++)
 			SEED[i]=CHASH[i]=0;

 		for (k=0;;k++)
 		{
 			if (k>=olen-seedlen-hlen) return new byte[0];
 			if (DBMASK[k]!=0) break;
 		}

 		t=DBMASK[k];
 		if (!comp || x!=0 || t!=0x01)
 		{
 			for (i=0;i<olen-seedlen;i++) DBMASK[i]=0;
 			return new byte[0];
 		}

 		byte[] r=new byte[olen-seedlen-hlen-k-1];

 		for (i=0;i<olen-seedlen-hlen-k-1;i++)
 			r[i]=DBMASK[i+k+1];

 		for (i=0;i<olen-seedlen;i++) DBMASK[i]=0;

 		return r;
 	}

 	/* destroy the Private Key structure */
 	public static void PRIVATE_KEY_KILL(private_key PRIV)
 	{
 		PRIV.p.zero();
 		PRIV.q.zero();
 		PRIV.dp.zero();
 		PRIV.dq.zero();
 		PRIV.c.zero();
 	}

 	/* RSA encryption with the public key */
 	public static void ENCRYPT(public_key PUB,byte[] F,byte[] G)
 	{
 		int n=PUB.n.getlen();
 		FF f=new FF(n);
 		FF.fromBytes(f,F);
 		f.power(PUB.e,PUB.n);
 		f.toBytes(G);
 	}

 	/* RSA decryption with the private key */
 	public static void DECRYPT(private_key PRIV,byte[] G,byte[] F)
 	{
 		int n=PRIV.p.getlen();
 		FF g=new FF(2*n);

 		FF.fromBytes(g,G);
 		FF jp=g.dmod(PRIV.p);
 		FF jq=g.dmod(PRIV.q);

 		jp.skpow(PRIV.dp,PRIV.p);
 		jq.skpow(PRIV.dq,PRIV.q);

 		g.zero();
 		g.dscopy(jp);
 		jp.mod(PRIV.q);
 		if (FF.comp(jp,jq)>0) jq.add(PRIV.q);
 		jq.sub(jp);
 		jq.norm();

 		FF t=FF.mul(PRIV.c,jq);
 		jq=t.dmod(PRIV.q);

 		t=FF.mul(jq,PRIV.p);
 		g.add(t);
 		g.norm();

 		g.toBytes(F);
 	}
 }
	/*
	Licensed to the Apache Software Foundation (ASF) under one
	or more contributor license agreements. See the NOTICE file
	distributed with this work for additional information
	regarding copyright ownership. The ASF licenses this file
	to you 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.
	*/

	/* RSA API high-level functions */

	package org.apache.milagro.amcl.RSA3072;

	import org.apache.milagro.amcl.RAND;
	import org.apache.milagro.amcl.HASH256;
	import org.apache.milagro.amcl.HASH384;
	import org.apache.milagro.amcl.HASH512;

	public final class RSA {

	public static final int RFS=BIG.MODBYTES*FF.FFLEN;
	public static final int SHA256=32;
	public static final int SHA384=48;
	public static final int SHA512=64;

	public static final int HASH_TYPE=SHA256;

	/* Hash number (optional) and string to array size of Bigs */

	public static byte[] hashit(int sha,byte[] A,int n)
	{
	byte[] R=null;

	if (sha==SHA256)
	{
	HASH256 H=new HASH256();
	if (A!=null) H.process_array(A);
	if (n>=0) H.process_num(n);
	R=H.hash();
	}
	if (sha==SHA384)
	{
	HASH384 H=new HASH384();
	if (A!=null) H.process_array(A);
	if (n>=0) H.process_num(n);
	R=H.hash();
	}
	if (sha==SHA512)
	{
	HASH512 H=new HASH512();
	if (A!=null) H.process_array(A);
	if (n>=0) H.process_num(n);
	R=H.hash();
	}
	return R;
	}

	/* generate an RSA key pair */

	public static void KEY_PAIR(RAND rng,int e,private_key PRIV,public_key PUB)
	{ /* IEEE1363 A16.11/A16.12 more or less */

	int n=PUB.n.getlen()/2;
	FF t = new FF(n);
	FF p1=new FF(n);
	FF q1=new FF(n);

	for (;;)
	{
	PRIV.p.random(rng);
	while (PRIV.p.lastbits(2)!=3) PRIV.p.inc(1);
	while (!FF.prime(PRIV.p,rng)) PRIV.p.inc(4);

	p1.copy(PRIV.p);
	p1.dec(1);

	if (p1.cfactor(e)) continue;
	break;
	}

	for (;;)
	{
	PRIV.q.random(rng);
	while (PRIV.q.lastbits(2)!=3) PRIV.q.inc(1);
	while (!FF.prime(PRIV.q,rng)) PRIV.q.inc(4);

	q1.copy(PRIV.q);
	q1.dec(1);

	if (q1.cfactor(e)) continue;

	break;
	}

	PUB.n=FF.mul(PRIV.p,PRIV.q);
	PUB.e=e;

	t.copy(p1);
	t.shr();
	PRIV.dp.set(e);
	PRIV.dp.invmodp(t);
	if (PRIV.dp.parity()==0) PRIV.dp.add(t);
	PRIV.dp.norm();

	t.copy(q1);
	t.shr();
	PRIV.dq.set(e);
	PRIV.dq.invmodp(t);
	if (PRIV.dq.parity()==0) PRIV.dq.add(t);
	PRIV.dq.norm();

	PRIV.c.copy(PRIV.p);
	PRIV.c.invmodp(PRIV.q);

	return;
	}

	/* Mask Generation Function */

	public static void MGF1(int sha,byte[] Z,int olen,byte[] K)
	{
	int hlen=sha;
	byte[] B;

	int counter,cthreshold,k=0;

	for (int i=0;i<K.length;i++) K[i]=0;

	cthreshold=olen/hlen; if (olen%hlen!=0) cthreshold++;
	for (counter=0;counter<cthreshold;counter++)
	{
	B=hashit(sha,Z,counter);
	if (k+hlen>olen) for (int i=0;i<olen%hlen;i++) K[k++]=B[i];
	else for (int i=0;i<hlen;i++) K[k++]=B[i];
	}
	}

	public static void printBinary(byte[] array)
	{
	int i;
	for (i=0;i<array.length;i++)
	{
	System.out.printf("%02x", array[i]);
	}
	System.out.println();
	}



	/* SHARSA3072 identifier strings */
	private static final byte[] SHA256ID={0x30,0x31,0x30,0x0d,0x06,0x09,0x60,(byte)0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,0x20};
	private static final byte[] SHA384ID={0x30,0x41,0x30,0x0d,0x06,0x09,0x60,(byte)0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,0x30};
	private static final byte[] SHA512ID={0x30,0x51,0x30,0x0d,0x06,0x09,0x60,(byte)0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,0x00,0x04,0x40};

	/* PKCS 1.5 padding of a message to be signed */

	public static boolean PKCS15(int sha,byte[] m,byte[] w)
	{
	int olen=FF.FF_BITS/8;
	int i,hlen=sha;
	int idlen=19;

	if (olen<idlen+hlen+10) return false;
	byte[] H=hashit(sha,m,-1);

	for (i=0;i<w.length;i++) w[i]=0;
	i=0;
	w[i++]=0;
	w[i++]=1;
	for (int j=0;j<olen-idlen-hlen-3;j++)
	w[i++]=(byte)0xff;
	w[i++]=0;


	if (hlen==SHA256) for (int j=0;j<idlen;j++) w[i++]=SHA256ID[j];
	if (hlen==SHA384) for (int j=0;j<idlen;j++) w[i++]=SHA384ID[j];
	if (hlen==SHA512) for (int j=0;j<idlen;j++) w[i++]=SHA512ID[j];

	for (int j=0;j<hlen;j++)
	w[i++]=H[j];

	return true;
	}


	/* OAEP Message Encoding for Encryption */
	public static byte[] OAEP_ENCODE(int sha,byte[] m,RAND rng,byte[] p)
	{
	int i,slen,olen=RFS-1;
	int mlen=m.length;
	int hlen,seedlen;
	byte[] f=new byte[RFS];

	hlen=sha;
	byte[] SEED=new byte[hlen];
	seedlen=hlen;

	if (mlen>olen-hlen-seedlen-1) return new byte[0];

	byte[] DBMASK=new byte[olen-seedlen];

	byte[] h=hashit(sha,p,-1);

	for (i=0;i<hlen;i++) f[i]=h[i];

	slen=olen-mlen-hlen-seedlen-1;

	for (i=0;i<slen;i++) f[hlen+i]=0;
	f[hlen+slen]=1;
	for (i=0;i<mlen;i++) f[hlen+slen+1+i]=m[i];

	for (i=0;i<seedlen;i++) SEED[i]=(byte)rng.getByte();

	MGF1(sha,SEED,olen-seedlen,DBMASK);

	for (i=0;i<olen-seedlen;i++) DBMASK[i]^=f[i];

	MGF1(sha,DBMASK,seedlen,f);

	for (i=0;i<seedlen;i++) f[i]^=SEED[i];

	for (i=0;i<olen-seedlen;i++) f[i+seedlen]=DBMASK[i];

	/* pad to length RFS */
	int d=1;
	for (i=RFS-1;i>=d;i--)
	f[i]=f[i-d];
	for (i=d-1;i>=0;i--)
	f[i]=0;

	return f;
	}

	/* OAEP Message Decoding for Decryption */
	public static byte[] OAEP_DECODE(int sha,byte[] p,byte[] f)
	{
	int x,t;
	boolean comp;
	int i,k,olen=RFS-1;
	int hlen,seedlen;

	hlen=sha;
	byte[] SEED=new byte[hlen];
	seedlen=hlen;
	byte[] CHASH=new byte[hlen];

	if (olen<seedlen+hlen+1) return new byte[0];
	byte[] DBMASK=new byte[olen-seedlen];
	for (i=0;i<olen-seedlen;i++) DBMASK[i]=0;

	if (f.length<RFS)
	{
	int d=RFS-f.length;
	for (i=RFS-1;i>=d;i--)
	f[i]=f[i-d];
	for (i=d-1;i>=0;i--)
	f[i]=0;

	}

	byte[] h=hashit(sha,p,-1);

	for (i=0;i<hlen;i++) CHASH[i]=h[i];

	x=f[0];

	for (i=seedlen;i<olen;i++)
	DBMASK[i-seedlen]=f[i+1];

	MGF1(sha,DBMASK,seedlen,SEED);
	for (i=0;i<seedlen;i++) SEED[i]^=f[i+1];
	MGF1(sha,SEED,olen-seedlen,f);
	for (i=0;i<olen-seedlen;i++) DBMASK[i]^=f[i];

	comp=true;
	for (i=0;i<hlen;i++)
	{
	if (CHASH[i]!=DBMASK[i]) comp=false;
	}

	for (i=0;i<olen-seedlen-hlen;i++)
	DBMASK[i]=DBMASK[i+hlen];

	for (i=0;i<hlen;i++)
	SEED[i]=CHASH[i]=0;

	for (k=0;;k++)
	{
	if (k>=olen-seedlen-hlen) return new byte[0];
	if (DBMASK[k]!=0) break;
	}

	t=DBMASK[k];
	if (!comp \|\| x!=0 \|\| t!=0x01)
	{
	for (i=0;i<olen-seedlen;i++) DBMASK[i]=0;
	return new byte[0];
	}

	byte[] r=new byte[olen-seedlen-hlen-k-1];

	for (i=0;i<olen-seedlen-hlen-k-1;i++)
	r[i]=DBMASK[i+k+1];

	for (i=0;i<olen-seedlen;i++) DBMASK[i]=0;

	return r;
	}

	/* destroy the Private Key structure */
	public static void PRIVATE_KEY_KILL(private_key PRIV)
	{
	PRIV.p.zero();
	PRIV.q.zero();
	PRIV.dp.zero();
	PRIV.dq.zero();
	PRIV.c.zero();
	}

	/* RSA encryption with the public key */
	public static void ENCRYPT(public_key PUB,byte[] F,byte[] G)
	{
	int n=PUB.n.getlen();
	FF f=new FF(n);
	FF.fromBytes(f,F);
	f.power(PUB.e,PUB.n);
	f.toBytes(G);
	}

	/* RSA decryption with the private key */
	public static void DECRYPT(private_key PRIV,byte[] G,byte[] F)
	{
	int n=PRIV.p.getlen();
	FF g=new FF(2*n);

	FF.fromBytes(g,G);
	FF jp=g.dmod(PRIV.p);
	FF jq=g.dmod(PRIV.q);

	jp.skpow(PRIV.dp,PRIV.p);
	jq.skpow(PRIV.dq,PRIV.q);

	g.zero();
	g.dscopy(jp);
	jp.mod(PRIV.q);
	if (FF.comp(jp,jq)>0) jq.add(PRIV.q);
	jq.sub(jp);
	jq.norm();

	FF t=FF.mul(PRIV.c,jq);
	jq=t.dmod(PRIV.q);

	t=FF.mul(jq,PRIV.p);
	g.add(t);
	g.norm();

	g.toBytes(F);
	}
	}