Cancelling signing results in a hard crash

[vcsjones]

Performing a sign operation that requires user input, such as a smart card pin, then cancelling it, results in a hard crash.

Unhandled Exception: System.Security.Cryptography.CryptographicException: Access denied.

at System.Security.Cryptography.NCryptNative.SignHash[T](SafeNCryptKeyHandle key, Byte[] hash, T& paddingInfo, AsymmetricPaddingMode paddingMode, NCryptHashSigner`1 signer)
at System.Security.Cryptography.NCryptNative.SignHashPkcs1(SafeNCryptKeyHandle key, Byte[] hash, String hashAlgorithm)
at System.Security.Cryptography.RSACng.SignHash(Byte[] hash, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
at OpenVsixSignTool.Core.RSAPkcsSign.SignDigest(Byte[] digest, HashAlgorithmName pkcsAlgorithm)
at OpenVsixSignTool.Core.SigningContext.SignDigest(Byte[] digest)
at OpenVsixSignTool.Core.XmlSignatureBuilder.BuildSignatureValue(Byte[] signerInfoElementHash)
at OpenVsixSignTool.Core.XmlSignatureBuilder.Build()
at OpenVsixSignTool.Core.OpcPackageSignatureBuilder.Sign(HashAlgorithmName fileDigestAlgorithm, X509Certificate2 certificate)
at OpenVsixSignTool.SignCommand.PerformSignOnVsix(String vsixPath, Boolean force, Uri timestampUri, HashAlgorithmName fileDigestAlgorithm, HashAlgorithmName timestampDigestAlgorithm, X509Certificate2 certificate)
at OpenVsixSignTool.SignCommand.Sign(CommandOption sha1, CommandOption pfxPath, CommandOption password, CommandOption timestampUrl, CommandOption timestampAlgorithm, CommandOption fileDigest, CommandOption force, CommandArgument vsixPath)
at OpenVsixSignTool.Program.<>c__DisplayClass0_0.

b__1()
at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)