Objective-C

Working with PEM Encrypted Private Keys

See more PEM Examples

Demonstrates how to load and save PEM encrypted private keys. Objective-C

#import <CkoPem.h>
#import <NSString.h>
#import <CkoFileAccess.h>
#import <CkoPrivateKey.h>

BOOL success = NO;

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

success = NO;

CkoPem *pem = [[CkoPem alloc] init];

NSString *pemPassword = @"secret";

//  To load a PEM file containing encrypted private keys, simply
//  provide the password.
success = [pem LoadPemFile: @"/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem" password: pemPassword];
if (success == NO) {
    NSLog(@"%@",pem.LastErrorText);
    return;
}

CkoFileAccess *fac = [[CkoFileAccess alloc] init];
NSString *pemText = [fac ReadEntireTextFile: @"/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem" charset: pemPassword];

//  To load a PEM from a string, call LoadPem instead of LoadPemFile:
success = [pem LoadPem: pemText];
if (success == NO) {
    NSLog(@"%@",pem.LastErrorText);
    return;
}

//  A few notes:
//  The PEM may contain both private keys and certificates (or anything else).
//  The password is utilized for whatever content in the PEM is encrypted.  
//  It is OK to have both encrypted and non-encrypted content within a given PEM.

//  PEM private keys can be encrypted in different formats.  The LoadPem and LoadPemFile
//  methods automatically handle the different formats.
//  One format is PKCS8 and is indicated by this delimiter within the PEM:

//  -----BEGIN ENCRYPTED PRIVATE KEY-----
//  MIICoTAbBgkqhkiG9w0BBQMwDgQIfdD0zv24lgkCAggABIICgE0PdHJmRbNs6cBX
//  ...

//  Another format, we'll call "passphrase" looks like this in the PEM:
//  -----BEGIN RSA PRIVATE KEY-----
//  Proc-Type: 4,ENCRYPTED
//  DEK-Info: DES-EDE3-CBC,A4215544D11C5D0C
//  
//  paqy9XRexcSjurHfG0xhCaUD0HrvIdhuC0CbRxxxeMlkLaV6+uT80rBxt2AaibWG
//  ...

//  Show the bit length of each private key:
int i;
int numPrivateKeys = [pem.NumPrivateKeys intValue];
if (numPrivateKeys == 0) {
    NSLog(@"%@",(@"Error: Expected the PEM to contain private keys."));
    return;
}

CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
for (i = 1; i <= numPrivateKeys; i++) {
    [pem PrivateKeyAt: [NSNumber numberWithInt: (i - 1)] privKey: privKey];
    NSLog(@"%d%@%d%@",i,@": ",[privKey.BitLength intValue],@" bits");
}