version22/go/RSA.go - incubator-milagro-crypto - 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 main

 //import "fmt"

 const RSA_RFS int=int(MODBYTES)*FFLEN
 const RSA_SHA256 int=32
 const RSA_SHA384 int=48
 const RSA_SHA512 int=64

 const RSA_HASH_TYPE int=RSA_SHA256


 type rsa_private_key struct {
 	p,q,dp,dq,c *FF
 }

 func New_rsa_private_key(n int) *rsa_private_key {
 	SK:=new(rsa_private_key)
 	SK.p=NewFFint(n)
 	SK.q=NewFFint(n)
 	SK.dp=NewFFint(n)
 	SK.dq=NewFFint(n)
 	SK.c=NewFFint(n)
 	return SK
 }

 type rsa_public_key struct {
 	e int
 	n *FF
 }

 func New_rsa_public_key(m int) *rsa_public_key{
 	PK:=new(rsa_public_key)
 	PK.e=0
 	PK.n=NewFFint(m)
 	return PK
 }

 func hashit(sha int,A []byte,n int) []byte {
 	var R []byte
 	if sha==RSA_SHA256 {
 		H:=NewHASH256()
 		if A!=nil {H.Process_array(A)}
 		if n>=0 {H.Process_num(int32(n))}
 		R=H.Hash()
 	}
 	if sha==RSA_SHA384 {
 		H:=NewHASH384()
 		if A!=nil {H.Process_array(A)}
 		if n>=0 {H.Process_num(int32(n))}
 		R=H.Hash()
 	}
 	if sha==RSA_SHA512 {
 		H:=NewHASH512()
 		if A!=nil {H.Process_array(A)}
 		if n>=0 {H.Process_num(int32(n))}
 		R=H.Hash()
 	}
 	return R
 }

 func RSA_KEY_PAIR(rng *RAND,e int,PRIV *rsa_private_key,PUB *rsa_public_key) { /* IEEE1363 A16.11/A16.12 more or less */
 	n:=PUB.n.getlen()/2
 	t:=NewFFint(n)
 	p1:=NewFFint(n)
 	q1:=NewFFint(n)

 	for true {
 		PRIV.p.random(rng)
 		for PRIV.p.lastbits(2)!=3 {PRIV.p.inc(1)}
 		for !prime(PRIV.p,rng) {
 			PRIV.p.inc(4)
 		}

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

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

 	for true {
 		PRIV.q.random(rng);
 		for PRIV.q.lastbits(2)!=3 {PRIV.q.inc(1)}
 		for !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)

 }

 /* Mask Generation Function */

 func RSA_MGF1(sha int,Z []byte,olen int,K []byte) {
 	hlen:=sha

 	var k int=0
 	for i:=0;i<len(K);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 i:=0;i<olen%hlen;i++ {K[k]=B[i]; k++}
 		} else {
 			for i:=0;i<hlen;i++ {K[k]=B[i]; k++}
 		}
 	}
 }

 /* SHAXXX identifier strings */
 var SHA256ID= [...]byte {0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,0x20}
 var SHA384ID= [...]byte {0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,0x30};
 var SHA512ID= [...]byte {0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,0x00,0x04,0x40};

 func PKCS15(sha int,m []byte,w []byte) bool {
 	olen:=FF_BITS/8
 	hlen:=sha
 	idlen:=19

 	if olen<idlen+hlen+10 {return false}
 	H:=hashit(sha,m,-1)

 	for i:=0;i<len(w);i++ {w[i]=0}
 	i:=0
 	w[i]=0; i++
 	w[i]=1; i++
 	for j:=0;j<olen-idlen-hlen-3;j++ {w[i]=0xff; i++}
 	w[i]=0; i++

 	if hlen==RSA_SHA256 {
 		for j:=0;j<idlen;j++ {w[i]=SHA256ID[j]; i++}
 	}
 	if hlen==RSA_SHA384 {
 		for j:=0;j<idlen;j++ {w[i]=SHA384ID[j]; i++}
 	}
 	if hlen==RSA_SHA512 {
 		for j:=0;j<idlen;j++ {w[i]=SHA512ID[j]; i++}
 	}
 	for j:=0;j<hlen;j++ {w[i]=H[j]; i++}

 	return true
 }


 /* OAEP Message Encoding for Encryption */
 func RSA_OAEP_ENCODE(sha int,m []byte,rng *RAND,p []byte) []byte {
 	olen:=RSA_RFS-1
 	mlen:=len(m)
 	var f [RSA_RFS]byte

 	hlen:=sha

 	SEED:=make([]byte,hlen);

 	seedlen:=hlen
 	if (mlen>olen-hlen-seedlen-1) {return nil}

 	DBMASK:=make([]byte,olen-seedlen)

 	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]=rng.GetByte()}
 	RSA_MGF1(sha,SEED,olen-seedlen,DBMASK)

 	for i:=0;i<olen-seedlen;i++ {DBMASK[i]^=f[i]}

 	RSA_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 */
 	d:=1
 	for i:=RSA_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 */
 func RSA_OAEP_DECODE(sha int,p []byte,f []byte) [] byte {
 	olen:=RSA_RFS-1

 	hlen:=sha
 	SEED:=make([]byte,hlen)
 	seedlen:=hlen;
 	CHASH:=make([]byte,hlen)

 	if olen<seedlen+hlen+1 {return nil}
 	DBMASK:=make([]byte,olen-seedlen)
 	for i:=0;i<olen-seedlen;i++ {DBMASK[i]=0}

 	if len(f)<RSA_RFS {
 		d:=RSA_RFS-len(f)
 		for i:=RSA_RFS-1;i>=d;i-- {
 			f[i]=f[i-d]
 		}
 		for i:=d-1;i>=0;i-- {
 			f[i]=0
 		}
 	}

 	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]
 	}

 	RSA_MGF1(sha,DBMASK,seedlen,SEED)
 	for i:=0;i<seedlen;i++ {SEED[i]^=f[i+1]}
 	RSA_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]=0; CHASH[i]=0
 	}

 	var k int
 	for k=0;;k++ {
 		if k>=olen-seedlen-hlen {return nil}
 		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 nil
 	}

 	var r = make([]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 */
 func RSA_PRIVATE_KEY_KILL(PRIV *rsa_private_key) {
 	PRIV.p.zero();
 	PRIV.q.zero();
 	PRIV.dp.zero();
 	PRIV.dq.zero();
 	PRIV.c.zero();
 }

 /* RSA encryption with the public key */
 func RSA_ENCRYPT(PUB *rsa_public_key,F []byte,G []byte) {
 	n:=PUB.n.getlen()
 	f:=NewFFint(n)

 	ff_fromBytes(f,F)
 	f.power(PUB.e,PUB.n)
 	f.toBytes(G)
 }

 /* RSA decryption with the private key */
 func RSA_DECRYPT(PRIV *rsa_private_key,G []byte,F []byte) {
 	n:=PRIV.p.getlen()
 	g:=NewFFint(2*n)

 	ff_fromBytes(g,G);
 	jp:=g.dmod(PRIV.p)
 	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()

 	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 main

	//import "fmt"

	const RSA_RFS int=int(MODBYTES)*FFLEN
	const RSA_SHA256 int=32
	const RSA_SHA384 int=48
	const RSA_SHA512 int=64

	const RSA_HASH_TYPE int=RSA_SHA256


	type rsa_private_key struct {
	p,q,dp,dq,c *FF
	}

	func New_rsa_private_key(n int) *rsa_private_key {
	SK:=new(rsa_private_key)
	SK.p=NewFFint(n)
	SK.q=NewFFint(n)
	SK.dp=NewFFint(n)
	SK.dq=NewFFint(n)
	SK.c=NewFFint(n)
	return SK
	}

	type rsa_public_key struct {
	e int
	n *FF
	}

	func New_rsa_public_key(m int) *rsa_public_key{
	PK:=new(rsa_public_key)
	PK.e=0
	PK.n=NewFFint(m)
	return PK
	}

	func hashit(sha int,A []byte,n int) []byte {
	var R []byte
	if sha==RSA_SHA256 {
	H:=NewHASH256()
	if A!=nil {H.Process_array(A)}
	if n>=0 {H.Process_num(int32(n))}
	R=H.Hash()
	}
	if sha==RSA_SHA384 {
	H:=NewHASH384()
	if A!=nil {H.Process_array(A)}
	if n>=0 {H.Process_num(int32(n))}
	R=H.Hash()
	}
	if sha==RSA_SHA512 {
	H:=NewHASH512()
	if A!=nil {H.Process_array(A)}
	if n>=0 {H.Process_num(int32(n))}
	R=H.Hash()
	}
	return R
	}

	func RSA_KEY_PAIR(rng RAND,e int,PRIV rsa_private_key,PUB rsa_public_key) { / IEEE1363 A16.11/A16.12 more or less */
	n:=PUB.n.getlen()/2
	t:=NewFFint(n)
	p1:=NewFFint(n)
	q1:=NewFFint(n)

	for true {
	PRIV.p.random(rng)
	for PRIV.p.lastbits(2)!=3 {PRIV.p.inc(1)}
	for !prime(PRIV.p,rng) {
	PRIV.p.inc(4)
	}

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

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

	for true {
	PRIV.q.random(rng);
	for PRIV.q.lastbits(2)!=3 {PRIV.q.inc(1)}
	for !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)

	}

	/* Mask Generation Function */

	func RSA_MGF1(sha int,Z []byte,olen int,K []byte) {
	hlen:=sha

	var k int=0
	for i:=0;i<len(K);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 i:=0;i<olen%hlen;i++ {K[k]=B[i]; k++}
	} else {
	for i:=0;i<hlen;i++ {K[k]=B[i]; k++}
	}
	}
	}

	/* SHAXXX identifier strings */
	var SHA256ID= [...]byte {0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,0x20}
	var SHA384ID= [...]byte {0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,0x30};
	var SHA512ID= [...]byte {0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x03,0x05,0x00,0x04,0x40};

	func PKCS15(sha int,m []byte,w []byte) bool {
	olen:=FF_BITS/8
	hlen:=sha
	idlen:=19

	if olen<idlen+hlen+10 {return false}
	H:=hashit(sha,m,-1)

	for i:=0;i<len(w);i++ {w[i]=0}
	i:=0
	w[i]=0; i++
	w[i]=1; i++
	for j:=0;j<olen-idlen-hlen-3;j++ {w[i]=0xff; i++}
	w[i]=0; i++

	if hlen==RSA_SHA256 {
	for j:=0;j<idlen;j++ {w[i]=SHA256ID[j]; i++}
	}
	if hlen==RSA_SHA384 {
	for j:=0;j<idlen;j++ {w[i]=SHA384ID[j]; i++}
	}
	if hlen==RSA_SHA512 {
	for j:=0;j<idlen;j++ {w[i]=SHA512ID[j]; i++}
	}
	for j:=0;j<hlen;j++ {w[i]=H[j]; i++}

	return true
	}


	/* OAEP Message Encoding for Encryption */
	func RSA_OAEP_ENCODE(sha int,m []byte,rng *RAND,p []byte) []byte {
	olen:=RSA_RFS-1
	mlen:=len(m)
	var f [RSA_RFS]byte

	hlen:=sha

	SEED:=make([]byte,hlen);

	seedlen:=hlen
	if (mlen>olen-hlen-seedlen-1) {return nil}

	DBMASK:=make([]byte,olen-seedlen)

	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]=rng.GetByte()}
	RSA_MGF1(sha,SEED,olen-seedlen,DBMASK)

	for i:=0;i<olen-seedlen;i++ {DBMASK[i]^=f[i]}

	RSA_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 */
	d:=1
	for i:=RSA_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 */
	func RSA_OAEP_DECODE(sha int,p []byte,f []byte) [] byte {
	olen:=RSA_RFS-1

	hlen:=sha
	SEED:=make([]byte,hlen)
	seedlen:=hlen;
	CHASH:=make([]byte,hlen)

	if olen<seedlen+hlen+1 {return nil}
	DBMASK:=make([]byte,olen-seedlen)
	for i:=0;i<olen-seedlen;i++ {DBMASK[i]=0}

	if len(f)<RSA_RFS {
	d:=RSA_RFS-len(f)
	for i:=RSA_RFS-1;i>=d;i-- {
	f[i]=f[i-d]
	}
	for i:=d-1;i>=0;i-- {
	f[i]=0
	}
	}

	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]
	}

	RSA_MGF1(sha,DBMASK,seedlen,SEED)
	for i:=0;i<seedlen;i++ {SEED[i]^=f[i+1]}
	RSA_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]=0; CHASH[i]=0
	}

	var k int
	for k=0;;k++ {
	if k>=olen-seedlen-hlen {return nil}
	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 nil
	}

	var r = make([]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 */
	func RSA_PRIVATE_KEY_KILL(PRIV *rsa_private_key) {
	PRIV.p.zero();
	PRIV.q.zero();
	PRIV.dp.zero();
	PRIV.dq.zero();
	PRIV.c.zero();
	}

	/* RSA encryption with the public key */
	func RSA_ENCRYPT(PUB *rsa_public_key,F []byte,G []byte) {
	n:=PUB.n.getlen()
	f:=NewFFint(n)

	ff_fromBytes(f,F)
	f.power(PUB.e,PUB.n)
	f.toBytes(G)
	}

	/* RSA decryption with the private key */
	func RSA_DECRYPT(PRIV *rsa_private_key,G []byte,F []byte) {
	n:=PRIV.p.getlen()
	g:=NewFFint(2*n)

	ff_fromBytes(g,G);
	jp:=g.dmod(PRIV.p)
	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()

	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)
	}