(Objective-C) 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.

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#import <CkoEmail.h>

CkoEmail *email = [[CkoEmail alloc] init];

// 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.)
BOOL success = [email AddPfxSourceFile: @"/pfxFiles/certs_and_keys_1.pfx" password: @"pfxPassword1"];
if (success != YES) {
    NSLog(@"%@",email.LastErrorText);
    return;
}

success = [email AddPfxSourceFile: @"/pfxFiles/certs_and_keys_2.pfx" password: @"pfxPassword2"];
if (success != YES) {
    NSLog(@"%@",email.LastErrorText);
    return;
}

// ...

// 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 == YES) {

    NSLog(@"%@",@"This email was encrypted.");
    if (email.Decrypted == YES) {
        NSLog(@"%@",@"This email was successfully decrypted.  It was encrypted by:");
        NSLog(@"%@",email.EncryptedBy);
    }
    else {
        NSLog(@"%@",@"This email was not decrypted.");
    }

}

if (email.ReceivedSigned == YES) {

    NSLog(@"%@",@"This email was signed.");
    if (email.SignaturesValid == YES) {
        NSLog(@"%@",@"The signature was verified.  It was signed by:");
        NSLog(@"%@",email.SignedBy);
    }
    else {
        NSLog(@"%@",@"The signature verification failed.");
    }

}

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