Class TimestampHashAlgorithmExtensions
Helpers for TimestampHashAlgorithms.
Inheritance
Namespace: IronPdf.Signing
Assembly: IronPdf.dll
Syntax
public static class TimestampHashAlgorithmExtensions : ObjectConverting a TimestampHashAlgorithms enum value into its corresponding OID string is the job TimestampHashAlgorithmExtensions handles. The single extension method it exposes, ToDigestAlgorithmOid, translates a hash algorithm selection into the dotted-decimal Object Identifier that RFC 3161 timestamp authorities expect when a PDF signature is being countersigned with a trusted timestamp.
When IronPDF applies a digital signature that includes a timestamp, the timestamp request must specify the digest algorithm as an OID rather than a human-readable name. ToDigestAlgorithmOid performs that translation cleanly, so calling code never has to hard-code strings like "2.16.840.1.101.3.4.2.1" for SHA-256. Instead, the algorithm is expressed as a TimestampHashAlgorithms enum value, and the extension method resolves the correct OID at the point of use.
Because ToDigestAlgorithmOid is a static extension method on TimestampHashAlgorithms, it reads as a natural call on the enum value itself:
using IronPdf.Signing;
string oid = TimestampHashAlgorithms.SHA256.ToDigestAlgorithmOid();
// oid now holds the OID string passed to the timestamp authorityThis pattern keeps signing configuration readable and avoids magic strings scattered across a codebase. The class lives entirely in the IronPdf.Signing namespace alongside the signing and certificate types it supports, so no additional import is needed when working with PDF signature workflows.
For a broader look at PDF signing with timestamps, see the digital signature how-to and the PDF signing examples on the IronPDF site.
Methods
ToDigestAlgorithmOid(TimestampHashAlgorithms)
Returns the digest algorithm OID for the given timestamp hash algorithm. Unknown values default to
SHA-1 (1.3.14.3.2.26). This is the single source of truth for the enum to OID mapping used by
both the certificate based and HSM signing paths.
Declaration
public static string ToDigestAlgorithmOid(this TimestampHashAlgorithms algorithm)Parameters
| Type | Name | Description |
|---|---|---|
| TimestampHashAlgorithms | algorithm | The timestamp hash algorithm. |
Returns
| Type | Description |
|---|---|
| System.String | The digest algorithm OID string. |