PureBasic
PureBasic
Check if an Email Was Received Digitally Signed
See more Email Object Examples
Demonstrates the read-only Chilkat Email.ReceivedSigned property, which is true if the email was originally received carrying one or more digital signatures. Knowing a message was signed is separate from knowing the signature checked out, so this example also reads SignaturesValid to report whether the signed content verified.
Background: A digital signature on an email (S/MIME) provides two things: authenticity (it was really sent by the holder of a particular certificate) and integrity (the content was not altered in transit). The sender signs a hash of the message with their private key; the recipient verifies it with the sender's public certificate.
ReceivedSigned simply tells you a signature is present — verifying it is a separate step exposed through SignaturesValid.Chilkat PureBasic Downloads
IncludeFile "CkEmail.pb"
Procedure ChilkatExample()
success.i = 0
; Demonstrates the read-only Email.ReceivedSigned property, which is true if this
; email was originally received with a digital signature. Use SignaturesValid to
; determine whether the signed content actually verified.
email.i = CkEmail::ckCreate()
If email.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkEmail::ckLoadEml(email,"qa_data/eml/signed.eml")
If success = 0
Debug CkEmail::ckLastErrorText(email)
CkEmail::ckDispose(email)
ProcedureReturn
EndIf
If CkEmail::ckReceivedSigned(email) = 1
Debug "This email was received with a digital signature."
If CkEmail::ckSignaturesValid(email) = 1
Debug "All signatures are valid."
Else
Debug "One or more signatures are NOT valid."
EndIf
Else
Debug "This email was not signed."
EndIf
; Note: Paths such as "qa_data/..." are relative local filesystem paths,
; relative to the current working directory of the running application.
CkEmail::ckDispose(email)
ProcedureReturn
EndProcedure