DecryptAndVerifySignature Method
Decrypts and verifies the signature of the current message.
procedure DecryptAndVerifySignature();
Remarks
This method decrypts the input data and verifies the signature. Decryption certificates are specified by calling AddCertificate or setting the Certificates property. Certificates used to verify the signature will be taken from the message itself if included, or from the SignerCerts property.
If the certificate used to encrypt the message is not known ahead of time GetRecipientInfo may be called prior to calling Decrypt to obtain information about the recipient (the entity the for which the message was encrypted). If GetRecipientInfo is called, the RecipientInfo event is fired with information about the recipient which may be used to load an appropriate decryption certificate.
In order to perform signature verification the public signer's certificate must be present or explicitly specified. In many cases the certificate itself is included in the input message and a certificate does not need to explicitly be set. If a certificate does need to be set for signature verification the certificate may be specified by calling AddRecipientCert or setting RecipientCerts.
When this method is called the SignerCertInfo event fires once for each signature on the message. This event provides details about the signer certificate, as well as the signer certificate itself (if present). The information provided via SignerCertInfo may be used to load an appropriate certificate for verification from within the event. If the CertEncoded parameter of SignerCertInfo is populated the certificate required for verification is already present in the message.
The following properties are applicable when calling this method:
- Certificates (Required)
- DetachedSignature
- DetachedSignatureData
- EnableCompression
- SignerCerts
If the input message is a detached signature, the original data that was signed must be specified in DetachedSignatureData. In addition the DetachedSignature property must be set to True to instruct the component to treat the input message as a detached signature.
If the input message is compressed EnableCompression must be set to True before calling this method.
Input and Output Properties
The component will determine the source and destination of the input and output based on which properties are set.
The order in which the input properties are checked is as follows:
When a valid source is found the search stops. The order in which the output properties are checked is as follows:
- SetOutputStream
- OutputFile
- OutputMessage: The output data is written to this property if no other destination is specified.
When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.