Objective-C

Check if a MIME Entity is Encrypted (S/MIME)

Demonstrates the Chilkat Mime.IsEncrypted method, which returns whether the entity is a CMS/PKCS #7 encrypted S/MIME wrapper. It takes no arguments.

Note: The file path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own file.

Background: This tells you a message is encrypted and must be decrypted before its real content is available — the trigger for supplying a recipient certificate and private key to Decrypt. Reading the body without decrypting first would just yield the opaque PKCS #7 blob.

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Objective-C

#import <CkoMime.h>

BOOL success = NO;

//  Demonstrates the Mime.IsEncrypted method, which returns whether the entity is a CMS/PKCS #7 encrypted S/MIME wrapper.  It takes no arguments.

CkoMime *mime = [[CkoMime alloc] init];
success = [mime LoadMimeFile: @"qa_data/encrypted.eml"];
if (success == NO) {
    NSLog(@"%@",mime.LastErrorText);
    return;
}

if ([mime IsEncrypted]) {
    NSLog(@"%@",@"This is an encrypted S/MIME message.");
}
else {
    NSLog(@"%@",@"This is not an encrypted S/MIME message.");
}