(PowerShell) Load Signed and/or Encrypted Email and Unwrap Security Layers

The LoadEml method loads an email (.eml file containing the MIME of an email) and automatically unwraps the digital signature and encryption security layers. A program can then examine the properties of the email object to see what was unwrapped.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

$email = New-Object Chilkat.Email

# Provide PFX/.p12 files for any certs+keys needed for decryption.
# Signature verification does not need anything extra.  
# (Also, Chilkat will automatically find and use pre-installed certs + private keys needed for decryption
# on a Windows system.)
$success = $email.AddPfxSourceFile("/pfxFiles/certs_and_keys_1.pfx","pfxPassword1")
if ($success -ne $true) {
    $($email.LastErrorText)
    exit
}

$success = $email.AddPfxSourceFile("/pfxFiles/certs_and_keys_2.pfx","pfxPassword2")
if ($success -ne $true) {
    $($email.LastErrorText)
    exit
}

# ...

# Load a potentially signed and/or encrypted email.
$success = $email.LoadEml("someDir/someEmail.eml")

# If the email was signed and/or encrypted, it was "unwrapped", i.e.
# the email is already decrypted and in a state as if it were never signed or encrypted.

# You may check to see if the email was received encrypted or signed, and if so,
# whether it was successfully unwrapped and who signed or encrypted it:
if ($email.ReceivedEncrypted -eq $true) {

    $("This email was encrypted.")
    if ($email.Decrypted -eq $true) {
        $("This email was successfully decrypted.  It was encrypted by:")
        $($email.EncryptedBy)
    }
    else {
        $("This email was not decrypted.")
    }

}

if ($email.ReceivedSigned -eq $true) {

    $("This email was signed.")
    if ($email.SignaturesValid -eq $true) {
        $("The signature was verified.  It was signed by:")
        $($email.SignedBy)
    }
    else {
        $("The signature verification failed.")
    }

}

# At this point, the contents of the email, including attachments, can be accessed normally..