Objective-C

RSA Signature SHA256withRSA, iso-8859-1, base64

See more RSA Examples

RSA sign the iso-8859-1 byte representation of a string with SHA256withRSA, and return the signature in the base64 encoding. Objective-C

#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.

//  This example will duplicate the following Java code:
//  
//  Signature sign = Signature.getInstance("SHA256withRSA");
//  sign.initSign(privateKey);
//  sign.update(original.getBytes(Charset.forName("ISO-8859-1")));
//  
//  ...
//  byte[] resultado = sign.sign();
//  sello = encodeByteArrayToBase64(resultado);
//  

//  Load an RSA private key for signing.
//  You can load any format file.  This example loads a .pem, but you can provide path to any type of file holding a private key.
CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
success = [privKey LoadAnyFormatFile: @"qa_data/pem/rsa_passwd.pem" password: @"passwd"];
if (success == NO) {
    NSLog(@"%@",privKey.LastErrorText);
    return;
}

CkoRsa *rsa = [[CkoRsa alloc] init];
[rsa UsePrivateKey: privKey];

NSString *originalData = @"This is the string to be hashed an RSA signed.";

//  Indicate that we want the iso-8859-1 byte representation of the string to be signed
rsa.Charset = @"iso-8859-1";

//  We want the RSA signature in base64 format
rsa.EncodingMode = @"base64";

NSString *sigBase64 = [rsa SignStringENC: originalData hashAlg: @"sha256"];
NSLog(@"%@",sigBase64);