/// Always correct
public IPaddingScheme GetPaddingScheme(SignatureSchemes sigMode, ISha sha, PssMaskTypes maskType = PssMaskTypes.None, IEntropyProvider entropyProvider = null, int saltLength = 0)
{
switch (sigMode)
{
case SignatureSchemes.Ansx931:
return(new AnsxPadder(sha));
case SignatureSchemes.Pkcs1v15:
return(new PkcsPadder(sha));
case SignatureSchemes.Pss:
var mask = _maskFactory.GetMaskInstance(maskType, sha.HashFunction);
return(new PssPadder(sha, mask, entropyProvider, saltLength));
default:
throw new ArgumentException("Invalid signature scheme");
}
}
public IMaskFunction GetMaskInstance(PssMaskTypes maskType, HashFunction hashFunction = null)
{
switch (maskType)
{
case PssMaskTypes.MGF1:
var shaMgf = _shaFactory.GetShaInstance(hashFunction);
return(new Mgf1Mask(shaMgf));
case PssMaskTypes.SHAKE128:
var shake128 = _shaFactory.GetShaInstance(new HashFunction(ModeValues.SHAKE, DigestSizes.d128));
return(new ShakeMask(shake128));
case PssMaskTypes.SHAKE256:
var shake256 = _shaFactory.GetShaInstance(new HashFunction(ModeValues.SHAKE, DigestSizes.d256));
return(new ShakeMask(shake256));
default:
throw new ArgumentException($"Invalid {nameof(maskType)} provided");
}
}
/// Could introduce errors
public IPaddingScheme GetSigningPaddingScheme(SignatureSchemes sigMode, ISha sha, SignatureModifications errors, PssMaskTypes maskType = PssMaskTypes.None, IEntropyProvider entropyProvider = null, int saltLength = 0)
{
if (sigMode == SignatureSchemes.Ansx931)
{
switch (errors)
{
case SignatureModifications.None:
return(new AnsxPadder(sha));
case SignatureModifications.E:
return(new AnsxPadderWithModifiedPublicExponent(sha));
case SignatureModifications.Message:
return(new AnsxPadderWithModifiedMessage(sha));
case SignatureModifications.ModifyTrailer:
return(new AnsxPadderWithModifiedTrailer(sha));
case SignatureModifications.MoveIr:
return(new AnsxPadderWithMovedIr(sha));
case SignatureModifications.Signature:
return(new AnsxPadderWithModifiedSignature(sha));
default:
throw new ArgumentException("Signature modification does not exist for selected scheme");
}
}
else if (sigMode == SignatureSchemes.Pkcs1v15)
{
switch (errors)
{
case SignatureModifications.None:
return(new PkcsPadder(sha));
case SignatureModifications.E:
return(new PkcsPadderWithModifiedPublicExponent(sha));
case SignatureModifications.Message:
return(new PkcsPadderWithModifiedMessage(sha));
case SignatureModifications.ModifyTrailer:
return(new PkcsPadderWithModifiedTrailer(sha));
case SignatureModifications.MoveIr:
return(new PkcsPadderWithMovedIr(sha));
case SignatureModifications.Signature:
return(new PkcsPadderWithModifiedSignature(sha));
default:
throw new ArgumentException("Signature modification does not exist for selected scheme");
}
}
else if (sigMode == SignatureSchemes.Pss)
{
var mask = _maskFactory.GetMaskInstance(maskType, sha.HashFunction);
switch (errors)
{
case SignatureModifications.None:
return(new PssPadder(sha, mask, entropyProvider, saltLength));
case SignatureModifications.E:
return(new PssPadderWithModifiedPublicExponent(sha, mask, entropyProvider, saltLength));
case SignatureModifications.Message:
return(new PssPadderWithModifiedMessage(sha, mask, entropyProvider, saltLength));
case SignatureModifications.ModifyTrailer:
return(new PssPadderWithModifiedTrailer(sha, mask, entropyProvider, saltLength));
case SignatureModifications.MoveIr:
return(new PssPadderWithMovedIr(sha, mask, entropyProvider, saltLength));
case SignatureModifications.Signature:
return(new PssPadderWithModifiedSignature(sha, mask, entropyProvider, saltLength));
default:
throw new ArgumentException("Signature modification does not exist for selected scheme");
}
}
throw new ArgumentException("Invalid signature scheme");
}
