/* Return sign (-1, 0, +1) of a-b. a <=> b --> bnCmpQ(a, b) <=> 0 */
PGPInt32
PGPBigNumCompareQ(
PGPBigNumRef bn,
PGPUInt16 sm )
{
PGPUInt32 result = 0;
if ( pgpBigNumIsValid( bn ) )
{
result = bnCmpQ( &bn->bn, sm );
}
return( result );
}
int32_t ZrtpDH::checkPubKey(uint8_t *pubKeyBytes) const
{
/* ECC validation (partial), NIST SP800-56A, section 5.6.2.6 */
if (pkType == EC25 || pkType == EC38 || pkType == E414) {
dhCtx* tmpCtx = static_cast<dhCtx*>(ctx);
EcPoint pub;
INIT_EC_POINT(&pub);
int32_t len = getPubKeySize() / 2;
bnInsertBigBytes(pub.x, pubKeyBytes, 0, len);
bnInsertBigBytes(pub.y, pubKeyBytes+len, 0, len);
return ecCheckPubKey(&tmpCtx->curve, &pub);
}
if (pkType == E255) {
return 1;
}
BigNum pubKeyOther;
bnBegin(&pubKeyOther);
bnInsertBigBytes(&pubKeyOther, pubKeyBytes, 0, getDhSize());
if (pkType == DH2K) {
if (bnCmp(&bnP2048MinusOne, &pubKeyOther) == 0) {
return 0;
}
}
else if (pkType == DH3K) {
if (bnCmp(&bnP3072MinusOne, &pubKeyOther) == 0) {
return 0;
}
}
else {
return 0;
}
if (bnCmpQ(&pubKeyOther, 1) == 0) {
return 0;
}
bnEnd(&pubKeyOther);
return 1;
}