src/bls192.c.in - incubator-milagro-crypto-c - 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.
 */

 /* Boneh-Lynn-Shacham signature 192-bit API */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include "bls192_ZZZ.h"

 // Polynomial interpolation coefficients
 static void recover_coefficients(int k, octet* X, BIG_XXX* coefs)
 {
     BIG_XXX r;
     BIG_XXX_rcopy(r,CURVE_Order_ZZZ);

     BIG_XXX x2[k];

     for(int i=0; i<k; i++)
     {
         BIG_XXX_fromBytes(x2[i],X[i].val);
     }

     // Compute numerators in place using partial products
     // to achieve it in O(n)
     // c_i = x_0 * ... * x_(i-1) * x_(i+1) * ... * x_(k-1)

     // Compute partial left products
     // leave c_0 alone since it only has a right partial product
     BIG_XXX_copy(coefs[1], x2[0]);

     for(int i=2; i < k; i++)
     {
         // lp_i = x_0 * ... * x_(i-1) = lp_(i-1) * x_(i-1)
         BIG_XXX_modmul(coefs[i], coefs[i-1], x2[i-1], r);
     }

     // Compute partial right products and combine

     // Store partial right products in c_0 so at the end
     // of the procedure c_0 = x_1 * ... x_(k-1)
     BIG_XXX_copy(coefs[0], x2[k-1]);

     for(int i=k-2; i > 0; i--)
     {
         // c_i = lp_i * rp_i
         BIG_XXX_modmul(coefs[i], coefs[i], coefs[0], r);

         // rp_(i-1) = x_i * ... * x_k = x_i * rp_i
         BIG_XXX_modmul(coefs[0], coefs[0], x2[i], r);
     }

     BIG_XXX cneg;
     BIG_XXX denominator;
     BIG_XXX s;

     for(int i=0; i<k; i++)
     {
         BIG_XXX_one(denominator);

         // cneg = -x_i mod r
         BIG_XXX_sub(cneg, r, x2[i]);

         for(int j=0; j<k; j++)
         {
             if (i != j)
             {
                 // denominator = denominator * (x_j - x_i)
                 BIG_XXX_add(s,x2[j],cneg);
                 BIG_XXX_modmul(denominator,denominator,s,r);
             }
         }

         BIG_XXX_moddiv(coefs[i], coefs[i], denominator, r);
     }
 }

 /* hash a message, M, to an ECP point, using SHA3 */
 static void BLS_HASHIT(ECP_ZZZ *P,octet *M)
 {
     int i;
     int j;
     sha3 hs;
     char h[MODBYTES_XXX];
     octet HM= {0,sizeof(h),h};
     SHA3_init(&hs,SHAKE256);
     for (i=0; i<M->len; i++)
     {
         j = (unsigned char) M->val[i];
         SHA3_process(&hs,j);
     }
     SHA3_shake(&hs,HM.val,MODBYTES_XXX);
     HM.len=MODBYTES_XXX;
     ECP_ZZZ_mapit(P,&HM);
 }

 /* generate key pair, private key S, public key W */
 int BLS_ZZZ_KEY_PAIR_GENERATE(csprng *RNG,octet* S,octet *W)
 {
     ECP4_ZZZ G;
     BIG_XXX s,q;
     BIG_XXX_rcopy(q,CURVE_Order_ZZZ);
     ECP4_ZZZ_generator(&G);

     if (RNG!=NULL)
     {
         BIG_XXX_randomnum(s,q,RNG);
         BIG_XXX_toBytes(S->val,s);
         S->len=MODBYTES_XXX;
     }
     else
     {
         S->len=MODBYTES_XXX;
         BIG_XXX_fromBytes(s,S->val);
     }

     PAIR_ZZZ_G2mul(&G,s);
     ECP4_ZZZ_toOctet(W,&G);

     return BLS_OK;
 }

 /* Sign message M using private key S to produce signature SIG */
 int BLS_ZZZ_SIGN(octet *SIG,octet *M,octet *S)
 {
     BIG_XXX s;
     ECP_ZZZ D;
     BLS_HASHIT(&D,M);
     BIG_XXX_fromBytes(s,S->val);
     PAIR_ZZZ_G1mul(&D,s);
     ECP_ZZZ_toOctet(SIG,&D,true); /* compress output */

     return BLS_OK;
 }

 /* Verify signature given message M, the signature SIG, and the public key W */
 int BLS_ZZZ_VERIFY(octet *SIG,octet *M,octet *W)
 {
     FP24_YYY v;
     ECP4_ZZZ G,PK;
     ECP_ZZZ D,HM;
     BLS_HASHIT(&HM,M);

     if (!ECP_ZZZ_fromOctet(&D,SIG))
     {
         return BLS_INVALID_G1;
     }

     ECP4_ZZZ_generator(&G);

     if (!ECP4_ZZZ_fromOctet(&PK,W))
     {
         return BLS_INVALID_G2;
     }
     ECP_ZZZ_neg(&D);

     PAIR_ZZZ_double_ate(&v,&G,&D,&PK,&HM);
     PAIR_ZZZ_fexp(&v);

     if (!FP24_YYY_isunity(&v))
     {
         return BLS_FAIL;
     }

     return BLS_OK;
 }


 /* R=R1+R2 in group G1 */
 int BLS_ZZZ_ADD_G1(octet *R1,octet *R2,octet *R)
 {
     ECP_ZZZ P;
     ECP_ZZZ T;

     if (!ECP_ZZZ_fromOctet(&P,R1))
     {
         return BLS_INVALID_G1;
     }

     if (!ECP_ZZZ_fromOctet(&T,R2))
     {
         return BLS_INVALID_G1;
     }

     ECP_ZZZ_add(&P,&T);
     ECP_ZZZ_toOctet(R,&P,true);

     return BLS_OK;
 }

 /* W=W1+W2 in group G2 */
 int BLS_ZZZ_ADD_G2(octet *W1,octet *W2,octet *W)
 {
     ECP4_ZZZ Q;
     ECP4_ZZZ T;

     if (!ECP4_ZZZ_fromOctet(&Q,W1))
     {
         return BLS_INVALID_G2;
     }

     if (!ECP4_ZZZ_fromOctet(&T,W2))
     {
         return BLS_INVALID_G2;
     }

     ECP4_ZZZ_add(&Q,&T);
     ECP4_ZZZ_toOctet(W,&Q);

     return BLS_OK;
 }

 int BLS_ZZZ_MAKE_SHARES(int k, int n, csprng *RNG, octet* X, octet* Y, octet* SKI, octet* SKO)
 {
     BIG_XXX r;
     BIG_XXX_rcopy(r,CURVE_Order_ZZZ);

     // Generate polynomial: f(x) = a_0 + a_1x + a_2x^2 ... a_{k-1}x^{k-1}
     BIG_XXX poly[k];
     for(int i=0; i<k; i++)
     {
         BIG_XXX_randomnum(poly[i],r,RNG);
     }

     // Use predefined secret
     if (SKI != NULL)
     {
         BIG_XXX_fromBytes(poly[0],SKI->val);
     }

     /* Calculate f(x) = a_0 + a_1x + a_2x^2 ... a_{k-1}x^{k-1}
        a0 is the secret */
     BIG_XXX x;
     BIG_XXX_zero(x);

     BIG_XXX y;

     for(int j=0; j<n; j++)
     {
         BIG_XXX_inc(x,1);

         // Output X shares
         BIG_XXX_toBytes(X[j].val,x);
         X[j].len = MODBYTES_XXX;

         // y is the accumulator
         BIG_XXX_zero(y);

         for(int i=k-1; i>=0; i--)
         {
             BIG_XXX_modmul(y,y,x,r);
             BIG_XXX_add(y,y,poly[i]);
         }

         // Normalise input for comp
         BIG_XXX_norm(y);
         if(BIG_XXX_comp(y,r) == 1)
         {
             BIG_XXX_sub(y,y,r);
         }

         // Output Y shares
         BIG_XXX_toBytes(Y[j].val,y);
         Y[j].len = MODBYTES_XXX;
     }

     // Output secret
     BIG_XXX_toBytes(SKO->val,poly[0]);
     SKO->len = MODBYTES_XXX;

     return BLS_OK;
 }

 int BLS_ZZZ_RECOVER_SECRET(int k, octet* X, octet* Y, octet* SK)
 {
     BIG_XXX r;
     BIG_XXX_rcopy(r,CURVE_Order_ZZZ);

     BIG_XXX y;
     BIG_XXX coefs[k];

     BIG_XXX secret;
     BIG_XXX prod;
     BIG_XXX_zero(secret);

     recover_coefficients(k, X, coefs);

     for(int i=0; i<k; i++)
     {
         BIG_XXX_fromBytes(y,Y[i].val);

         BIG_XXX_modmul(prod,y,coefs[i],r);
         BIG_XXX_add(secret, secret, prod);

         // Normalise input for comp
         BIG_XXX_norm(secret);
         if (BIG_XXX_comp(secret,r) == 1)
         {
             BIG_XXX_sub(secret,secret,r);
         }
     }

     // Output secret
     BIG_XXX_toBytes(SK->val,secret);
     SK->len = MODBYTES_XXX;

     return BLS_OK;
 }

 int BLS_ZZZ_RECOVER_SIGNATURE(int k, octet* X, octet* Y, octet* SIG)
 {
     BIG_XXX coefs[k];
     ECP_ZZZ y;

     ECP_ZZZ sig;
     ECP_ZZZ_inf(&sig);

     recover_coefficients(k, X, coefs);

     for(int i=0; i<k; i++)
     {
         if (!ECP_ZZZ_fromOctet(&y,&Y[i]))
         {
             return BLS_INVALID_G1;
         }

         PAIR_ZZZ_G1mul(&y,coefs[i]);
         ECP_ZZZ_add(&sig,&y);
     }

     ECP_ZZZ_toOctet(SIG, &sig, true);

     return BLS_OK;
 }
	/*
	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.
	*/

	/* Boneh-Lynn-Shacham signature 192-bit API */

	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <time.h>
	#include "bls192_ZZZ.h"

	// Polynomial interpolation coefficients
	static void recover_coefficients(int k, octet* X, BIG_XXX* coefs)
	{
	BIG_XXX r;
	BIG_XXX_rcopy(r,CURVE_Order_ZZZ);

	BIG_XXX x2[k];

	for(int i=0; i<k; i++)
	{
	BIG_XXX_fromBytes(x2[i],X[i].val);
	}

	// Compute numerators in place using partial products
	// to achieve it in O(n)
	// c_i = x_0 * ... * x_(i-1) * x_(i+1) * ... * x_(k-1)

	// Compute partial left products
	// leave c_0 alone since it only has a right partial product
	BIG_XXX_copy(coefs[1], x2[0]);

	for(int i=2; i < k; i++)
	{
	// lp_i = x_0 * ... * x_(i-1) = lp_(i-1) * x_(i-1)
	BIG_XXX_modmul(coefs[i], coefs[i-1], x2[i-1], r);
	}

	// Compute partial right products and combine

	// Store partial right products in c_0 so at the end
	// of the procedure c_0 = x_1 * ... x_(k-1)
	BIG_XXX_copy(coefs[0], x2[k-1]);

	for(int i=k-2; i > 0; i--)
	{
	// c_i = lp_i * rp_i
	BIG_XXX_modmul(coefs[i], coefs[i], coefs[0], r);

	// rp_(i-1) = x_i * ... * x_k = x_i * rp_i
	BIG_XXX_modmul(coefs[0], coefs[0], x2[i], r);
	}

	BIG_XXX cneg;
	BIG_XXX denominator;
	BIG_XXX s;

	for(int i=0; i<k; i++)
	{
	BIG_XXX_one(denominator);

	// cneg = -x_i mod r
	BIG_XXX_sub(cneg, r, x2[i]);

	for(int j=0; j<k; j++)
	{
	if (i != j)
	{
	// denominator = denominator * (x_j - x_i)
	BIG_XXX_add(s,x2[j],cneg);
	BIG_XXX_modmul(denominator,denominator,s,r);
	}
	}

	BIG_XXX_moddiv(coefs[i], coefs[i], denominator, r);
	}
	}

	/* hash a message, M, to an ECP point, using SHA3 */
	static void BLS_HASHIT(ECP_ZZZ P,octet M)
	{
	int i;
	int j;
	sha3 hs;
	char h[MODBYTES_XXX];
	octet HM= {0,sizeof(h),h};
	SHA3_init(&hs,SHAKE256);
	for (i=0; i<M->len; i++)
	{
	j = (unsigned char) M->val[i];
	SHA3_process(&hs,j);
	}
	SHA3_shake(&hs,HM.val,MODBYTES_XXX);
	HM.len=MODBYTES_XXX;
	ECP_ZZZ_mapit(P,&HM);
	}

	/* generate key pair, private key S, public key W */
	int BLS_ZZZ_KEY_PAIR_GENERATE(csprng RNG,octet S,octet *W)
	{
	ECP4_ZZZ G;
	BIG_XXX s,q;
	BIG_XXX_rcopy(q,CURVE_Order_ZZZ);
	ECP4_ZZZ_generator(&G);

	if (RNG!=NULL)
	{
	BIG_XXX_randomnum(s,q,RNG);
	BIG_XXX_toBytes(S->val,s);
	S->len=MODBYTES_XXX;
	}
	else
	{
	S->len=MODBYTES_XXX;
	BIG_XXX_fromBytes(s,S->val);
	}

	PAIR_ZZZ_G2mul(&G,s);
	ECP4_ZZZ_toOctet(W,&G);

	return BLS_OK;
	}

	/* Sign message M using private key S to produce signature SIG */
	int BLS_ZZZ_SIGN(octet SIG,octet M,octet *S)
	{
	BIG_XXX s;
	ECP_ZZZ D;
	BLS_HASHIT(&D,M);
	BIG_XXX_fromBytes(s,S->val);
	PAIR_ZZZ_G1mul(&D,s);
	ECP_ZZZ_toOctet(SIG,&D,true); /* compress output */

	return BLS_OK;
	}

	/* Verify signature given message M, the signature SIG, and the public key W */
	int BLS_ZZZ_VERIFY(octet SIG,octet M,octet *W)
	{
	FP24_YYY v;
	ECP4_ZZZ G,PK;
	ECP_ZZZ D,HM;
	BLS_HASHIT(&HM,M);

	if (!ECP_ZZZ_fromOctet(&D,SIG))
	{
	return BLS_INVALID_G1;
	}

	ECP4_ZZZ_generator(&G);

	if (!ECP4_ZZZ_fromOctet(&PK,W))
	{
	return BLS_INVALID_G2;
	}
	ECP_ZZZ_neg(&D);

	PAIR_ZZZ_double_ate(&v,&G,&D,&PK,&HM);
	PAIR_ZZZ_fexp(&v);

	if (!FP24_YYY_isunity(&v))
	{
	return BLS_FAIL;
	}

	return BLS_OK;
	}


	/* R=R1+R2 in group G1 */
	int BLS_ZZZ_ADD_G1(octet R1,octet R2,octet *R)
	{
	ECP_ZZZ P;
	ECP_ZZZ T;

	if (!ECP_ZZZ_fromOctet(&P,R1))
	{
	return BLS_INVALID_G1;
	}

	if (!ECP_ZZZ_fromOctet(&T,R2))
	{
	return BLS_INVALID_G1;
	}

	ECP_ZZZ_add(&P,&T);
	ECP_ZZZ_toOctet(R,&P,true);

	return BLS_OK;
	}

	/* W=W1+W2 in group G2 */
	int BLS_ZZZ_ADD_G2(octet W1,octet W2,octet *W)
	{
	ECP4_ZZZ Q;
	ECP4_ZZZ T;

	if (!ECP4_ZZZ_fromOctet(&Q,W1))
	{
	return BLS_INVALID_G2;
	}

	if (!ECP4_ZZZ_fromOctet(&T,W2))
	{
	return BLS_INVALID_G2;
	}

	ECP4_ZZZ_add(&Q,&T);
	ECP4_ZZZ_toOctet(W,&Q);

	return BLS_OK;
	}

	int BLS_ZZZ_MAKE_SHARES(int k, int n, csprng RNG, octet X, octet* Y, octet* SKI, octet* SKO)
	{
	BIG_XXX r;
	BIG_XXX_rcopy(r,CURVE_Order_ZZZ);

	// Generate polynomial: f(x) = a_0 + a_1x + a_2x^2 ... a_{k-1}x^{k-1}
	BIG_XXX poly[k];
	for(int i=0; i<k; i++)
	{
	BIG_XXX_randomnum(poly[i],r,RNG);
	}

	// Use predefined secret
	if (SKI != NULL)
	{
	BIG_XXX_fromBytes(poly[0],SKI->val);
	}

	/* Calculate f(x) = a_0 + a_1x + a_2x^2 ... a_{k-1}x^{k-1}
	a0 is the secret */
	BIG_XXX x;
	BIG_XXX_zero(x);

	BIG_XXX y;

	for(int j=0; j<n; j++)
	{
	BIG_XXX_inc(x,1);

	// Output X shares
	BIG_XXX_toBytes(X[j].val,x);
	X[j].len = MODBYTES_XXX;

	// y is the accumulator
	BIG_XXX_zero(y);

	for(int i=k-1; i>=0; i--)
	{
	BIG_XXX_modmul(y,y,x,r);
	BIG_XXX_add(y,y,poly[i]);
	}

	// Normalise input for comp
	BIG_XXX_norm(y);
	if(BIG_XXX_comp(y,r) == 1)
	{
	BIG_XXX_sub(y,y,r);
	}

	// Output Y shares
	BIG_XXX_toBytes(Y[j].val,y);
	Y[j].len = MODBYTES_XXX;
	}

	// Output secret
	BIG_XXX_toBytes(SKO->val,poly[0]);
	SKO->len = MODBYTES_XXX;

	return BLS_OK;
	}

	int BLS_ZZZ_RECOVER_SECRET(int k, octet* X, octet* Y, octet* SK)
	{
	BIG_XXX r;
	BIG_XXX_rcopy(r,CURVE_Order_ZZZ);

	BIG_XXX y;
	BIG_XXX coefs[k];

	BIG_XXX secret;
	BIG_XXX prod;
	BIG_XXX_zero(secret);

	recover_coefficients(k, X, coefs);

	for(int i=0; i<k; i++)
	{
	BIG_XXX_fromBytes(y,Y[i].val);

	BIG_XXX_modmul(prod,y,coefs[i],r);
	BIG_XXX_add(secret, secret, prod);

	// Normalise input for comp
	BIG_XXX_norm(secret);
	if (BIG_XXX_comp(secret,r) == 1)
	{
	BIG_XXX_sub(secret,secret,r);
	}
	}

	// Output secret
	BIG_XXX_toBytes(SK->val,secret);
	SK->len = MODBYTES_XXX;

	return BLS_OK;
	}

	int BLS_ZZZ_RECOVER_SIGNATURE(int k, octet* X, octet* Y, octet* SIG)
	{
	BIG_XXX coefs[k];
	ECP_ZZZ y;

	ECP_ZZZ sig;
	ECP_ZZZ_inf(&sig);

	recover_coefficients(k, X, coefs);

	for(int i=0; i<k; i++)
	{
	if (!ECP_ZZZ_fromOctet(&y,&Y[i]))
	{
	return BLS_INVALID_G1;
	}

	PAIR_ZZZ_G1mul(&y,coefs[i]);
	ECP_ZZZ_add(&sig,&y);
	}

	ECP_ZZZ_toOctet(SIG, &sig, true);

	return BLS_OK;
	}