Sample code for 30+ languages & platforms
Objective-C

Save a Private Key as a Traditional DER File

See more Private Key Examples

Demonstrates the Chilkat PrivateKey.SavePkcs1File method, which saves the key using the traditional/preferred unencrypted DER representation. The only argument is the destination path.

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

Background: This writes the older, algorithm-specific DER structure — useful for compatibility with tools that predate or do not accept PKCS #8. For new work, PKCS #8 (SavePkcs8File) is more interoperable. The output is unencrypted, so protect the file accordingly.

Chilkat Objective-C Downloads

Objective-C
#import <CkoPrivateKey.h>

BOOL success = NO;

//  Load a private key to export.
CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
success = [privKey LoadPemFile: @"qa_data/private.pem"];
if (success == NO) {
    NSLog(@"%@",privKey.LastErrorText);
    return;
}

//  Save using the traditional/preferred unencrypted DER representation.
success = [privKey SavePkcs1File: @"qa_output/private_pkcs1.der"];
if (success == NO) {
    NSLog(@"%@",privKey.LastErrorText);
    return;
}

NSLog(@"%@",@"Saved.");