int elgv3sign(const mpbarrett* p, const mpbarrett* n, const mpnumber* g, randomGeneratorContext* rgc, const mpnumber* hm, const mpnumber* x, mpnumber* r, mpnumber* s)
{
register size_t size = p->size;
register mpw* temp = (mpw*) malloc((6*size+2)*sizeof(mpw));
if (temp)
{
/* get a random k */
mpbrnd_w(p, rgc, temp, temp+2*size);
/* compute r = g^k mod p */
mpnfree(r);
mpnsize(r, size);
mpbpowmod_w(p, g->size, g->data, size, temp, r->data, temp+2*size);
/* compute u1 = x*r mod n */
mpbmulmod_w(n, x->size, x->data, size, r->data, temp+size, temp+2*size);
/* compute u2 = k*h(m) mod n */
mpbmulmod_w(n, size, temp, hm->size, hm->data, temp, temp+2*size);
/* compute s = u1+u2 mod n */
mpnfree(s);
mpnsize(s, n->size);
mpbaddmod_w(n, size, temp, size, temp+size, s->data, temp+2*size);
free(temp);
return 0;
}
return -1;
}
int dldp_pgoqGenerator_w(dldp_p* dp, randomGeneratorContext* rgc, mpw* wksp)
{
/*
* Randomly determine a generator over the subgroup with order q
*/
register size_t size = dp->p.size;
mpnfree(&dp->g);
mpnsize(&dp->g, size);
while (1)
{
/* get a random value h (stored into g) */
mpbrnd_w(&dp->p, rgc, dp->g.data, wksp);
/* first compute h^r mod p (stored in g) */
mpbpowmod_w(&dp->p, size, dp->g.data, dp->r.size, dp->r.data, dp->g.data, wksp);
if (mpisone(size, dp->g.data))
continue;
return 0;
}
return -1;
}
void mpbnrnd(const mpbarrett* b, randomGeneratorContext* rc, mpnumber* result)
{
register size_t size = b->size;
register mpw* temp = (mpw*) malloc(size * sizeof(mpw));
mpnfree(result);
mpnsize(result, size);
mpbrnd_w(b, rc, result->data, temp);
free(temp);
}
void mpbnpowmodsld(const mpbarrett* b, const mpw* slide, const mpnumber* pow, mpnumber* y)
{
register size_t size = b->size;
register mpw* temp = (mpw*) malloc((4*size+2) * sizeof(mpw));
mpnfree(y);
mpnsize(y, size);
mpbpowmodsld_w(b, slide, pow->size, pow->data, y->data, temp);
free(temp);
}
int elgv1sign(const mpbarrett* p, const mpbarrett* n, const mpnumber* g, randomGeneratorContext* rgc, const mpnumber* hm, const mpnumber* x, mpnumber* r, mpnumber* s)
{
register size_t size = p->size;
register mpw* temp = (mpw*) malloc((8*size+6)*sizeof(mpw));
if (temp)
{
/* get a random k, invertible modulo (p-1) */
mpbrndinv_w(n, rgc, temp, temp+size, temp+2*size);
/* compute r = g^k mod p */
mpnfree(r);
mpnsize(r, size);
mpbpowmod_w(p, g->size, g->data, size, temp, r->data, temp+2*size);
/* compute x*r mod n */
mpbmulmod_w(n, x->size, x->data, r->size, r->data, temp, temp+2*size);
/* compute -(x*r) mod n */
mpneg(size, temp);
mpadd(size, temp, n->modl);
/* compute h(m) - x*r mod n */
mpbaddmod_w(n, hm->size, hm->data, size, temp, temp, temp+2*size);
/* compute s = inv(k)*(h(m) - x*r) mod n */
mpnfree(s);
mpnsize(s, size);
mpbmulmod_w(n, size, temp, size, temp+size, s->data, temp+2*size);
free(temp);
return 0;
}
return -1;
}
void mpbnsqrmod(const mpbarrett* b, const mpnumber* x, mpnumber* result)
{
register size_t size = b->size;
register mpw* temp = (mpw*) malloc(size * sizeof(mpw));
/* xsize must be <= b->size */
register size_t fill = 2*(size-x->size);
register mpw* opnd = temp + size*2+2;
if (fill)
mpzero(fill, opnd);
mpsqr(opnd+fill, x->size, x->data);
mpnsize(result, size);
mpbmod_w(b, opnd, result->data, temp);
free(temp);
}
void mpbnmulmod(const mpbarrett* b, const mpnumber* x, const mpnumber* y, mpnumber* result)
{
register size_t size = b->size;
register mpw* temp = (mpw*) malloc((4*size+2) * sizeof(mpw));
/* xsize and ysize must be <= b->size */
register size_t fill = 2*size-x->size-y->size;
register mpw* opnd = temp+size*2+2;
mpnfree(result);
mpnsize(result, size);
if (fill)
mpzero(fill, opnd);
mpmul(opnd+fill, x->size, x->data, y->size, y->data);
mpbmod_w(b, opnd, result->data, temp);
free(temp);
}
int main( int argc, char **argv ) {
FILE *secblock;
unsigned char packetType;
unsigned short packetLen;
unsigned char buffer[4096];
unsigned char hexrep[8192];
// for CRT computation
mpbarrett psubone, qsubone;
// for testing
mpnumber m, cipher, decipher, holder;
rsakp keypair;
size_t bits = 2048;
size_t pbits = (bits+1) >> 1;
size_t qbits = (bits - pbits);
size_t psize = MP_BITS_TO_WORDS(pbits+MP_WBITS-1);
size_t qsize = MP_BITS_TO_WORDS(qbits+MP_WBITS-1);
size_t pqsize = psize+qsize;
mpw* temp = (mpw*) malloc((16*pqsize+6)*sizeof(mpw));
if( argc < 2 ) {
printf( "usage: %s <secblock>\n", argv[0] );
exit( 1 );
}
mpbzero(&psubone);
mpbzero(&qsubone);
secblock = fopen(argv[1], "rb");
if( secblock == NULL ) {
printf( "Can't open %s\n", argv[1] );
exit(0);
}
packetType = fgetc(secblock);
packetLen = 0;
//big endianness...
big16read(&packetLen, secblock);
printf( "Packet type: 0x%02X\n", packetType );
printf( "Packet length: %04d\n", (int) packetLen );
// skip ahead six bytes, this includes key generation time and other attributes
fread( buffer, 6, 1, secblock);
rsakpInit(&keypair);
big16read(&packetLen, secblock);
printf( "n Packet length: %02d bits, %02d bytes\n", (int) packetLen, (int) bytesFromMpn(packetLen) );
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
mpbsetbin(&keypair.n, buffer, bytesFromMpn(packetLen));
mpprintln(packetLen/32, keypair.n.modl);
big16read(&packetLen, secblock);
printf( "e Packet length: %02d bits, %02d bytes\n", (int) packetLen, (int) bytesFromMpn(packetLen) );
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
mpnsetbin(&keypair.e, buffer, bytesFromMpn(packetLen));
mpprintln(keypair.e.size, keypair.e.data);
packetType = fgetc(secblock);
if( packetType == 0 ) {
printf( "secret data is plaintext\n" );
} else {
printf( "secret data is encrypted\n" );
}
big16read(&packetLen, secblock);
printf( "d Packet length: %02d bits, %02d bytes\n", (int) packetLen, (int) bytesFromMpn(packetLen) );
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
mpnsetbin(&keypair.d, buffer, bytesFromMpn(packetLen));
mpprintln(keypair.d.size, keypair.d.data);
big16read(&packetLen, secblock);
printf( "p Packet length: %02d bits, %02d bytes\n", (int) packetLen, (int) bytesFromMpn(packetLen) );
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
mpbsetbin(&keypair.p, buffer, bytesFromMpn(packetLen));
mpprintln(packetLen/32, keypair.p.modl);
big16read(&packetLen, secblock);
printf( "q Packet length: %02d bits, %02d bytes\n", (int) packetLen, (int) bytesFromMpn(packetLen) );
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
mpbsetbin(&keypair.q, buffer, bytesFromMpn(packetLen));
mpprintln(packetLen/32, keypair.q.modl);
big16read(&packetLen, secblock);
printf( "mystery packet length: %02d bits, %02d bytes\n", (int) packetLen, (int) bytesFromMpn(packetLen) );
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
mpnzero(&holder);
mpnsetbin(&holder, buffer, bytesFromMpn(packetLen));
mpprintln(holder.size, holder.data);
fread( buffer, 4, 1, secblock ); // advance by two bytes
printf( "offset: %x\n", ftell( secblock ) );
fread( buffer, bytesFromMpn(packetLen), 1, secblock );
printf( "%s\n", buffer );
#ifdef USE_CRT
// compute CRT elements
/* compute p-1 */
mpbsubone(&keypair.p, temp);
mpbset(&psubone, psize, temp);
/* compute q-1 */
mpbsubone(&keypair.q, temp);
mpbset(&qsubone, qsize, temp);
/* compute dp = d mod (p-1) */
mpnsize(&keypair.dp, psize);
mpbmod_w(&psubone, keypair.d.data, keypair.dp.data, temp);
/* compute dq = d mod (q-1) */
mpnsize(&keypair.dq, qsize);
mpbmod_w(&qsubone, keypair.d.data, keypair.dq.data, temp);
/* compute qi = inv(q) mod p */
mpninv(&keypair.qi, (mpnumber*) &keypair.q, (mpnumber*) &keypair.p);
#endif
// now test
mpnzero(&m);
mpnzero(&cipher);
mpnzero(&decipher);
mpnsethex(&m, "d436e99569fd32a7c8a05bbc90d32c49");
printf( "Original: " );
mpprintln(m.size, m.data);
rsapub(&keypair.n, &keypair.e, &m, &cipher);
printf( "Encrypted: " );
mpprintln(cipher.size, cipher.data);
#ifdef USE_CRT
rsapricrt(&keypair.n, &keypair.p, &keypair.q, &keypair.dp, &keypair.dq, &keypair.qi, &cipher, &decipher);
#else
rsapri(&keypair.n, &keypair.d, &cipher, &decipher);
#endif
printf( "Recovered: " );
mpprintln(decipher.size, decipher.data);
if (mpnex(m.size, m.data, decipher.size, decipher.data))
printf ( "results don't match\n" );
else
printf ( "before and after encyrption sizes match\n" );
printf( "special test routine for STM32 validation\n" );
mpnzero(&cipher);
mpnzero(&decipher);
mpnsethex(&cipher, "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" );
printf( "Decrypting: " );
mpprintln(cipher.size, cipher.data);
rsapub(&keypair.n, &keypair.e, &cipher, &decipher);
printf( "Recovered: " );
mpprintln(decipher.size, decipher.data);
free(temp);
return 0;
}
int dsasign(const mpbarrett* p, const mpbarrett* q, const mpnumber* g, randomGeneratorContext* rgc, const mpnumber* hm, const mpnumber* x, mpnumber* r, mpnumber* s)
{
register size_t psize = p->size;
register size_t qsize = q->size;
register mpw* ptemp;
register mpw* qtemp;
register mpw* pwksp;
register mpw* qwksp;
register int rc = -1;
ptemp = (mpw*) malloc((5*psize+2)*sizeof(mpw));
if (ptemp == (mpw*) 0)
return rc;
qtemp = (mpw*) malloc((9*qsize+6)*sizeof(mpw));
if (qtemp == (mpw*) 0)
{
free(ptemp);
return rc;
}
pwksp = ptemp+psize;
qwksp = qtemp+3*qsize;
/* allocate r */
mpnfree(r);
mpnsize(r, qsize);
/* get a random k, invertible modulo q; store k @ qtemp, inv(k) @ qtemp+qsize */
mpbrndinv_w(q, rgc, qtemp, qtemp+qsize, qwksp);
/* g^k mod p */
mpbpowmod_w(p, g->size, g->data, qsize, qtemp, ptemp, pwksp);
/* (g^k mod p) mod q - simple modulo */
mpmod(qtemp+2*qsize, psize, ptemp, qsize, q->modl, pwksp);
mpcopy(qsize, r->data, qtemp+psize+qsize);
/* allocate s */
mpnfree(s);
mpnsize(s, qsize);
/* x*r mod q */
mpbmulmod_w(q, x->size, x->data, r->size, r->data, qtemp, qwksp);
/* add h(m) mod q */
mpbaddmod_w(q, qsize, qtemp, hm->size, hm->data, qtemp+2*qsize, qwksp);
/* multiply inv(k) mod q */
mpbmulmod_w(q, qsize, qtemp+qsize, qsize, qtemp+2*qsize, s->data, qwksp);
rc = 0;
free(qtemp);
free(ptemp);
return rc;
}
int dldp_pgonGenerator_w(dldp_p* dp, randomGeneratorContext* rgc, mpw* wksp)
{
register size_t size = dp->p.size;
mpnfree(&dp->g);
mpnsize(&dp->g, size);
while (1)
{
mpbrnd_w(&dp->p, rgc, dp->g.data, wksp);
if (mpistwo(dp->r.size, dp->r.data))
{
/*
* A little math here: the only element in the group which has order 2 is (p-1);
* the two group elements raised to power two which result in 1 (mod p) are thus (p-1) and 1
*
* mpbrnd_w doesn't return 1 or (p-1), so the test where g^2 mod p = 1 can be safely skipped
*/
/* check g^q mod p*/
mpbpowmod_w(&dp->p, size, dp->g.data, dp->q.size, dp->q.modl, wksp, wksp+size);
if (mpisone(size, wksp))
continue;
}
else
{
/* we can either compute g^r, g^2q and g^(qr/2) or
* we first compute s = r/2, and then compute g^2s, g^2q and g^qs
*
* hence we first compute t = g^s
* then compute t^2 mod p, and test if one
* then compute t^q mod p, and test if one
* then compute (g^q mod p)^2 mod p, and test if one
*/
/* compute s = r/2 */
mpsetx(size, wksp, dp->r.size, dp->r.data);
mpdivtwo(size, wksp);
/* compute t = g^s mod p */
mpbpowmod_w(&dp->p, size, dp->g.data, size, wksp, wksp+size, wksp+2*size);
/* compute t^2 mod p = g^2s mod p = g^r mod p*/
mpbsqrmod_w(&dp->p, size, wksp+size, wksp+size, wksp+2*size);
if (mpisone(size, wksp+size))
continue;
/* compute t^q mod p = g^qs mod p */
mpbpowmod_w(&dp->p, size, wksp, dp->q.size, dp->q.modl, wksp+size, wksp+2*size);
if (mpisone(size, wksp+size))
continue;
/* compute g^2q mod p */
mpbpowmod_w(&dp->p, size, dp->g.data, dp->q.size, dp->q.modl, wksp, wksp+size);
mpbsqrmod_w(&dp->p, size, wksp, wksp+size, wksp+2*size);
if (mpisone(size, wksp+size))
continue;
}
return 0;
}
return -1;
}
