peass-ng/PEASS-ng · error · InvalidOperationException

invalid encoding value:

Error message

invalid encoding value: 

What it means

The Encoding property setter enforces the same constraint as the constructor: the External encoding value must be 0 (single-ASN1-type), 1 (octet-aligned), or 2 (arbitrary). Assigning any other value throws InvalidOperationException with the offending value appended to the message.

Source

Thrown at winPEAS/winPEASexe/winPEAS/3rdParty/BouncyCastle/asn1/DerExternal.cs:166

		/**
		* The encoding of the content. Valid values are
		* <ul>
		* <li><code>0</code> single-ASN1-type</li>
		* <li><code>1</code> OCTET STRING</li>
		* <li><code>2</code> BIT STRING</li>
		* </ul>
		*/
		public int Encoding
		{
			get
			{
				return encoding;
			}
			set
			{
				if (encoding < 0 || encoding > 2)
					throw new InvalidOperationException("invalid encoding value: " + encoding);

				this.encoding = value;
			}
		}

		public Asn1Object ExternalContent
		{
			get { return externalContent; }
			set { this.externalContent = value; }
		}

		public DerInteger IndirectReference
		{
			get { return indirectReference; }
			set { this.indirectReference = value; }
		}

		private static Asn1Object GetObjFromVector(Asn1EncodableVector v, int index)

View on GitHub (pinned to 53fb989abc)

Solutions

1. Clamp or validate the value before assignment: only 0, 1, or 2 are legal
2. Map your application's encoding enum to the correct 0-2 range before setting
3. If the encoding is unknown, don't assign a sentinel — construct a new DerExternal once the real value is known

Example fix

// before
external.Encoding = encodingId; // may be -1 or 3
// after
if (encodingId < 0 || encodingId > 2)
    throw new ArgumentOutOfRangeException(nameof(encodingId));
external.Encoding = encodingId;

if (encodingValue < 0 || encodingValue > 2)
    throw new ArgumentOutOfRangeException(nameof(encodingValue), "External encoding must be 0, 1 or 2");
external.Encoding = encodingValue;

static bool IsValidExternalEncoding(int v) => v == 0 || v == 1 || v == 2;

try { external.Encoding = value; }
catch (InvalidOperationException ex) when (ex.Message.StartsWith("invalid encoding value")) {
    // clamp or map the value before retrying
}

When it happens

Trigger: Assigning external.Encoding = n where n < 0 or n > 2 in C# code that builds or mutates a DerExternal instance.

Common situations: Application code mapping its own protocol enum onto the Encoding property with out-of-range values; copy/paste code using a sentinel like -1 for 'unknown'; off-by-one constants (e.g. 3) for encodings.

Related errors

• invalid encoding value
• unknown object encountered in constructed OCTET STRING:
• unknown tag {tagNo} encountered
• unexpected end-of-contents marker
• indefinite-length primitive encoding encountered

AI-assisted analysis of peass-ng/PEASS-ng@53fb989abc (2026-09-02). Data as JSON: /api/errors/c29328384b159984. Report an issue: GitHub.