PowerBuilder

Decrypt S/MIME and Verify S/MIME Signatures

See more MIME Examples

_LANGUAGE_ example to decrypt S/MIME and verify S/MIME signatures. The S/MIME is unwrapped to get the original MIME prior to signing/encrypting. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Mime
integer li_IsEncrypted
integer li_IsSigned
oleobject loo_SignerCert
oleobject loo_DecryptCert

li_Success = 0

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

loo_Mime = create oleobject
li_rc = loo_Mime.ConnectToNewObject("Chilkat.Mime")
if li_rc < 0 then
    destroy loo_Mime
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Load an S/MIME message from a file:
li_Success = loo_Mime.LoadMimeFile("signedMime.txt")
if li_Success = 0 then
    Write-Debug loo_Mime.LastErrorText
    destroy loo_Mime
    return
end if

// The ContainsEncryptedParts/ContainsSignedParts methods
// can be called to determine if the MIME is encrypted and/or signed:
li_IsEncrypted = loo_Mime.ContainsEncryptedParts()
li_IsSigned = loo_Mime.ContainsSignedParts()

// We don't want the "unwrap extras".  You'll see what those
// are in a few moments...
loo_Mime.UnwrapExtras = 0

// To verify the signature, call UnwrapSecurity.  This will
// verify the signature(s) and decrypt the S/MIME and restore
// the MIME to the unsigned/unencrypted state.
// The results of what was found are present in the MIME object's
// properties, as well as extra header fields that are added
// to the unwrapped MIME.
li_Success = loo_Mime.UnwrapSecurity()
if li_Success <> 1 then
    // UnwrapSecurity returns 1 if all signatures were
    // verified and all parts decrypted.
    Write-Debug loo_Mime.LastErrorText
    destroy loo_Mime
    return
end if

// The mime.UnwrapExtras property controls whether or not
// these additional fields are added to the unwrapped MIME:
// 
// X-NumPartsSigned: 1
// X-SignaturesValid: yes
// X-NumPartsEncrypted: 1
// X-Decrypted: no
// 
// The X-NumPartsSigned/X-SignaturesValid headers are added
// if the MIME was signed.  
// 
// The X-NumPartsEncrypted/X-Decrypted headers are added
// if the MIME was encrypted.
// 

// If the MIME was signed, get the certificate used for signing.
if li_IsSigned = 1 then
    loo_SignerCert = create oleobject
    li_rc = loo_SignerCert.ConnectToNewObject("Chilkat.Cert")

    // The NumSignerCerts property indicates how many certificates
    // were used for signing.  This example will assume the value is 1.
    // To get the 1st signer cert, call LastSignerCert with an index of 0:
    li_Success = loo_Mime.LastSignerCert(0,loo_SignerCert)
    if li_Success = 1 then
        Write-Debug "**** Signer Cert: " + loo_SignerCert.SubjectCN
    end if

end if

// If the MIME was encrypted, get the certificate used for decryption
if li_IsEncrypted = 1 then
    // The NumDecryptCerts property indicates how many certificates
    // were used for decrypting.  This example will assume the value is 1.
    // To get the 1st decrypt cert, call LastDecryptCert with an index of 0:
    loo_DecryptCert = create oleobject
    li_rc = loo_DecryptCert.ConnectToNewObject("Chilkat.Cert")

    li_Success = loo_Mime.LastDecryptCert(0,loo_DecryptCert)
    if li_Success = 1 then
        Write-Debug "**** Decrypt Cert: " + loo_DecryptCert.SubjectCN
    end if

end if

// Display the unwrapped MIME:
Write-Debug loo_Mime.GetMime()

// Save the unwrapped MIME to a file:
li_Success = loo_Mime.SaveMime("unwrappedMime.txt")


destroy loo_Mime
destroy loo_SignerCert
destroy loo_DecryptCert