System.Formats.Asn1.AsnContentException: 'The encoded length exceeds the maximum supported by this library (Int32.MaxValue).'

System.Formats.Asn1.AsnContentException occurs when loading a private key file generated by PuTTY key generator.

PrivateKeyFile[] keyFiles = new[] { new PrivateKeyFile(PrivateKeyFilePath, PrivateKeyFilePassword) };

System.Formats.Asn1.AsnContentException
  HResult=0x80131500
  Message=The encoded length exceeds the maximum supported by this library (Int32.MaxValue).
  Source=System.Formats.Asn1
  StackTrace:
   at System.Formats.Asn1.AsnDecoder.ReadLength(ReadOnlySpan`1 source, AsnEncodingRules ruleSet, Int32& bytesConsumed)
   at System.Formats.Asn1.AsnDecoder.ReadTagAndLength(ReadOnlySpan`1 source, AsnEncodingRules ruleSet, Nullable`1& contentsLength, Int32& bytesRead)
   at System.Formats.Asn1.AsnDecoder.ReadSequence(ReadOnlySpan`1 source, AsnEncodingRules ruleSet, Int32& contentOffset, Int32& contentLength, Int32& bytesConsumed, Nullable`1 expectedTag)
   at System.Formats.Asn1.AsnReader.ReadSequence(Nullable`1 expectedTag)
   at Renci.SshNet.Security.RsaKey..ctor(Byte[] privateKeyData)
   at Renci.SshNet.PrivateKeyFile.Open(Stream privateKey, String passPhrase)
   at Renci.SshNet.PrivateKeyFile..ctor(String fileName, String passPhrase, String certificateFileName)
   at Renci.SshNet.PrivateKeyFile..ctor(String fileName, String passPhrase)

Changing the key produces a new error:

System.Formats.Asn1.AsnContentException: 'The provided data is tagged with 'ContextSpecific' class value '14', but it should have been 'Universal' class value '16'.'

   at System.Formats.Asn1.AsnDecoder.CheckExpectedTag(Asn1Tag tag, Asn1Tag expectedTag, UniversalTagNumber tagNumber)
   at System.Formats.Asn1.AsnDecoder.ReadSequence(ReadOnlySpan`1 source, AsnEncodingRules ruleSet, Int32& contentOffset, Int32& contentLength, Int32& bytesConsumed, Nullable`1 expectedTag)
   at System.Formats.Asn1.AsnReader.ReadSequence(Nullable`1 expectedTag)
   at Renci.SshNet.Security.RsaKey..ctor(Byte[] privateKeyData)
   at Renci.SshNet.PrivateKeyFile.Open(Stream privateKey, String passPhrase)
   at Renci.SshNet.PrivateKeyFile..ctor(String fileName, String passPhrase, String certificateFileName)
   at Renci.SshNet.PrivateKeyFile..ctor(String fileName, String passPhrase)
   

Start at Renci.SshNet.Security.RsaKey..ctor and the PrivateKeyFile.Open path shown in the stack trace. Reproduce the failure with the PuTTY-generated private key and compare its encoding with the formats these entry points expect. Done means the supported key format loads successfully, or its unsupported status is clearly established and covered by an appropriate regression test.