ExternalSignature

Overview

ExternalSignature is a class in Aspose.PDF FOSS for .NET. Inherits from: Signature.

A detached PKCS#7 signature configuration built around an already-loaded platform certificate — typically from the OS certificate store, a smartcard or an HSM — rather than a PFX file.

This class provides 11 methods for working with ExternalSignature objects in .NET programs. Available methods include: ExternalSignature, GetSignatureAlgorithmInfo, Signature, Verify. All public members are accessible to any .NET application after installing the Aspose.PDF FOSS for .NET package. Properties: Authority, AvoidEstimatingSignatureLength, ByteRange, Certificate, ContactInfo, CustomAppearance, and 9 more.

Properties

Name	Type	Access	Description
`Certificate`	`System.Security.Cryptography.X509Certificates.X509Certificate2`	Read	The certificate this instance was constructed with.
`Authority`	`string`	Read/Write	Gets or sets the authority.
`ContactInfo`	`string`	Read/Write	Gets or sets the contact info.
`Location`	`string`	Read/Write	Gets or sets the location.
`Reason`	`string`	Read/Write	Gets or sets the reason.
`Date`	`DateTime`	Read/Write	Gets or sets the date.
`ByteRange`	`int[]`	Read	The signature’s /ByteRange entry.
`TimestampSettings`	`Aspose.Pdf.TimestampSettings`	Read/Write	RFC 3161 TSA settings; honoured by the signer when set.
`OcspSettings`	`Aspose.Pdf.OcspSettings`	Read/Write	OCSP / revocation-check settings; honoured by the signer when set.
`CustomAppearance`	`SignatureCustomAppearance?`	Read/Write	Visual-appearance knobs honoured by SignWithAppearance when the signature is signed via a visible-rect overload.
`CustomSignHash`	`SignHash?`	Read/Write	Optional external-signer callback.
`UseLtv`	`bool`	Read/Write	Gets or sets the use ltv.
`AvoidEstimatingSignatureLength`	`bool`	Read/Write	When true, the signer skips the byte-range estimation pass and uses DefaultSignatureLength directly when reserving space for the PKCS#7 /Contents hex string.
`DefaultSignatureLength`	`int`	Read/Write	Number of bytes reserved for the PKCS#7 /Contents hex string.
`ShowProperties`	`bool`	Read/Write	When true, the visible signature appearance includes the signer’s Reason/Location/ContactInfo as text.

Methods

Signature	Description
`ExternalSignature(certificate: System.Security.Cryptography.X509Certificates.X509Certificate2)`	Calls ExternalSignature(certificate) on this ExternalSignature instance.
`ExternalSignature(certificate: System.Security.Cryptography.X509Certificates.X509Certificate2, detached: bool)`	detached selects the handler, exactly as the PKCS7 / PKCS7Detached pair does: true emits an adbe.pkcs7.detached envelope over a SHA-256 digest, false the adbe.pkcs7.sha1 handler over a SHA-1 digest.
`ExternalSignature(certificate: System.Security.Cryptography.X509Certificates.X509Certificate2, digestHashAlgorithm: DigestHashAlgorithm)`	Calls ExternalSignature(certificate, digestHashAlgorithm) on this ExternalSignature instance.
`ExternalSignature(base64Certificate: string, detached: bool)`	Construct from a base64-encoded public certificate (no private key) for deferred/external signing via CustomSignHash.
`Signature()`	Calls Signature on this ExternalSignature instance.
`Signature(pfx: string, password: string)`	Calls Signature(pfx, password) on this ExternalSignature instance.
`Signature(pfx: Stream, password: string)`	Calls Signature(pfx, password) on this ExternalSignature instance.
`Verify()`	Verify the loaded signature’s PKCS#7 against the original PDF bytes — returns true when the signature decodes and validates.
`Verify(options: Security.ValidationOptions, validationResult: Security.ValidationResult)`	Verify with explicit options + a result DTO.
`Verify(publicKeyCertificate: System.Security.Cryptography.X509Certificates.X509Certificate2, options: Security.ValidationOptions, validationResult: Security.ValidationResult)`	Public-key-pinned verify.
`GetSignatureAlgorithmInfo()`	Parse the PKCS#7 envelope (when loaded from an existing signature) to report the signing-algorithm / digest-algorithm / cryptographic-standard triple.