IOpcSigningOptions::GetSignatureMethod method (msopc.h)

Article
10/13/2021

Gets the signature method to use to calculate and encrypt the hash value of the SignedInfo element, which will be serialized as the SignatureValue element of the signature.

Syntax

HRESULT GetSignatureMethod(
  [out, retval] LPWSTR *signatureMethod
);

Parameters

[out, retval] signatureMethod

A pointer to the signature method to use, or the empty string "" if no method has been set using the SetSignatureMethod method.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code	Description
S_OK	The method succeeded.
E_POINTER	The signatureMethod parameter is NULL.

Remarks

This method allocates memory used by the string returned in signatureMethod. If the method succeeds, call the CoTaskMemFree function to free the memory.

To set the signature method, call the IOpcSigningOptions::SetSignatureMethod method.

To access the signature method before the signature is generated, call the IOpcSigningOptions::GetSignatureMethod. To access the signature method after the signature is generated, call the IOpcDigitalSignature::GetSignatureMethod method.

Important A valid signature method must be set before the signature is generated by calling the IOpcDigitalSignatureManager::Sign method.

When a signature is generated it is serialized as signature markup. The signature method is used to calculate the value in the SignatureValue element in the signature markup.

When a signature is validated, the signature method is used to recalculate that value, and the recalculated value is compared to the value in the SignatureValue element in the signature markup.

Thread Safety

Packaging objects are not thread-safe.

For more information, see the Getting Started with the Packaging API.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	msopc.h