IX509CertificateRequestPkcs7::InitializeDecode method (certenroll.h)

The InitializeDecode method decodes an existing signed or unsigned PKCS #7 request object and uses it to initialize the new PKCS #7 object. The existing request is contained in a byte array that has been encoded by using Distinguished Encoding Rules (DER) as defined by the Abstract Syntax Notation One (ASN.1) standard. The byte array is represented by a string that is either a pure binary sequence or is Unicode encoded.

Syntax

HRESULT InitializeDecode(
  [in] BSTR         strEncodedData,
  [in] EncodingType Encoding
);

Parameters

[in] strEncodedData

A BSTR variable that contains the DER-encoded request.

[in] Encoding

An EncodingType enumeration value that specifies the type of Unicode encoding applied to the input string that contains the DER-encoded request. The default value is XCN_CRYPT_STRING_BASE64.

Return value

If the function succeeds, the function returns S_OK.

If the function fails, it returns an HRESULT value that indicates the error. Possible values include, but are not limited to, those in the following table. For a list of common error codes, see Common HRESULT Values.

Remarks

The InitializeDecode method:

• Decodes the PKCS #7 request specified on input.
• Uses the decoded object to create an inner PKCS #10 request with the following collections:
  • An empty ICryptAttributes collection.
  • An empty IX509Extensions collection.
  • An empty IObjectIds collection for critical extensions.
  • An empty IObjectIds collection for attribute and extension OIDs to be suppressed from the new request.
• Adds the decoded extensions to the IX509Extensions collection.
• Adds the decoded attributes to the ICryptAttributes collection
• Sets the ClientId property.
• Sets the TemplateObjectId property.
• Uses the signature on the original PKCS #7 request to create a new ISignerCertificate object.
• Retrieves an IX509SignatureInformation object from the ISignerCertificate object.
• Initializes the new IX509SignatureInformation object by using the original signature and hash algorithms.
• Sets the PKCS #10 request as the inner request object.

By default, the InitializeDecode method assumes that the certificate request to be decoded is for an end user. Beginning with Windows 8 and Windows Server 2012, you can change this default behavior. After creating an instance of the IX509CertificateRequestPkcs7 interface, call InitializeDecode by setting the Encoding parameter to XCN_CRYPT_STRING_BINARY and the strEncodedData parameter to one of the following values:

Then, call the InitializeDecode method again with the encoded certificate set in the strEncodedData argument.

Requirements

See also

IX509CertificateRequestPkcs7