Objective-C

RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature. Objective-C

#import <CkoCertStore.h>
#import <CkoJsonObject.h>
#import <CkoCert.h>
#import <CkoPrivateKey.h>
#import <CkoRsa.h>
#import <NSString.h>

BOOL success = NO;

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

// Create an instance of a certificate store object, load a PFX file,
// locate the certificate we need, and use it for signing.
// (a PFX file may contain more than one certificate.)
CkoCertStore *certStore = [[CkoCertStore alloc] init];

// The 1st argument is the filename, the 2nd arg is the 
// PFX file's password:
success = [certStore LoadPfxFile: @"chilkat.pfx" password: @"test"];
if (success == NO) {
    NSLog(@"%@",certStore.LastErrorText);
    return;
}

// Find the certificate by the subject common name:
CkoJsonObject *jsonCN = [[CkoJsonObject alloc] init];
[jsonCN UpdateString: @"CN" value: @"cert common name"];

CkoCert *cert = [[CkoCert alloc] init];
success = [certStore FindCert: jsonCN cert: cert];
if (success == NO) {
    NSLog(@"%@",certStore.LastErrorText);
    return;
}

CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
success = [cert GetPrivateKey: privKey];
if (success == NO) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

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

success = [rsa UsePrivateKey: privKey];
if (success == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

// Encode the signature as a hex string
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 "sha-256", "md2" and "md5".
NSString *hexSig = [rsa SignStringENC: strData hashAlg: @"sha-1"];

NSLog(@"%@",hexSig);

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