Objective-C

Create PKCS1 RSA Signature with PEM Private Key

See more RSA Examples

Demonstrates how to load a private key from a PEM file and create a PKCS1 RSA digital signature. Objective-C

#import <CkoPrivateKey.h>
#import <CkoRsa.h>
#import <NSString.h>

BOOL success = NO;

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

CkoPrivateKey *pkey = [[CkoPrivateKey alloc] init];

// Load the private key from an RSA PEM file:
success = [pkey LoadPemFile: @"pvkey2_rsa.pem"];
if (success == NO) {
    NSLog(@"%@",pkey.LastErrorText);
    return;
}

CkoRsa *rsa = [[CkoRsa alloc] init];

// Import the private key into the RSA object:
success = [rsa UsePrivateKey: pkey];
if (success == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// Get the signature as hex.
rsa.EncodingMode = @"hex";

NSString *strData = @"This is the string to be signed.";

// Sign the string using the sha-1 hash algorithm.
// Other valid choices are "md2", "md5", "sha256",
// "sha384", and "sha512".
NSString *hexSig = [rsa SignStringENC: strData hashAlg: @"sha-1"];

NSLog(@"%@",hexSig);

NSLog(@"%@",@"Success!");