Objective-C

RSA Encrypt with SHA-256 hash function and SHA-256 mask function

See more RSA Examples

How can this Javascript be duplicated using Chilkat?

function a(e, t) {
                var r = s.pki.publicKeyFromPem(e)
                  , n = r.encrypt(t, "RSA-OAEP", {
                    md: s.md.sha256.create(),
                    mgf1: {
                        md: s.md.sha1.create()
                    }
                });
                return s.util.encode64(n)
            }

Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens, even using the same data and key, the result will be different -- but still valid. One should not expect to get the same output.

Objective-C

#import <CkoPublicKey.h>
#import <CkoStringBuilder.h>
#import <NSString.h>
#import <CkoCrypt2.h>
#import <CkoRsa.h>

BOOL success = NO;

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

CkoPublicKey *pubkey = [[CkoPublicKey alloc] init];

CkoStringBuilder *sbPem = [[CkoStringBuilder alloc] init];
BOOL bCrlf = YES;
[sbPem AppendLine: @"-----BEGIN PUBLIC KEY-----" crlf: bCrlf];
[sbPem AppendLine: @"MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF" crlf: bCrlf];
[sbPem AppendLine: @"3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA" crlf: bCrlf];
[sbPem AppendLine: @"04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s" crlf: bCrlf];
[sbPem AppendLine: @"Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF" crlf: bCrlf];
[sbPem AppendLine: @"wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE" crlf: bCrlf];
[sbPem AppendLine: @"f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W" crlf: bCrlf];
[sbPem AppendLine: @"SwIDAQAB" crlf: bCrlf];
[sbPem AppendLine: @"-----END PUBLIC KEY-----" crlf: bCrlf];

// Load the public key object from the PEM. 
success = [pubkey LoadFromString: [sbPem GetAsString]];
if (success == NO) {
    NSLog(@"%@",pubkey.LastErrorText);
    return;
}

NSString *originalData = @"This is the original data to be SHA-256 hashed and RSA encrypted.";

// First we SHA-256 hash the original data.
CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];
crypt.HashAlgorithm = @"SHA-256";
NSData hashBytes;
hashBytes = [crypt HashString: originalData];

// Now to RSA encrypt using OAEP padding with SHA-256 for the mask function.
CkoRsa *rsa = [[CkoRsa alloc] init];
rsa.PkcsPadding = NO;
rsa.OaepHash = @"SHA256";
[rsa UsePublicKey: pubkey];
rsa.EncodingMode = @"base64";

// Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
// even using the same data and key, the result will be different --  but still valid.  One should not expect
// to get the same output.
BOOL bUsePrivateKey = NO;
NSString *encryptedStr = [rsa EncryptBytesENC: hashBytes bUsePrivateKey: bUsePrivateKey];
if (rsa.LastMethodSuccess == NO) {
    NSLog(@"%@",rsa.LastErrorText);
    return;
}

NSLog(@"%@%@",@"Base64 RSA encrypted output: ",encryptedStr);