(Objective-C) Duplicate openssl smime -decrypt -in some_file.dat.enc -binary -inform DER -inkey private.key -out some_file.dat

Demonstrates how to decrypt binary DER that was encrypted using the following openssl command:

openssl smime -encrypt -binary -aes-256-cbc -in some_file.dat -out some_file.dat.enc -outform DER cert.crt

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoCert.h>
#import <CkoBinData.h>
#import <CkoPrivateKey.h>
#import <CkoCrypt2.h>

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

// Duplicates the following openssl command:
// openssl smime -decrypt -in hello.txt.enc -binary -inform DER -inkey private.key -out hello.txt

CkoCert *cert = [[CkoCert alloc] init];
BOOL success = [cert LoadFromFile: @"qa_data/openssl/EE.cer"];
if (success == NO) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

CkoBinData *bd = [[CkoBinData alloc] init];
success = [bd LoadFile: @"qa_data/openssl/EE.key"];
// Assuming success..

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

CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];
success = [crypt SetDecryptCert2: cert key: privKey];
if (success == NO) {
    NSLog(@"%@",crypt.LastErrorText);
    return;
}

crypt.CryptAlgorithm = @"PKI";
success = [crypt CkDecryptFile: @"qa_data/openssl/hello.txt.enc" destFile: @"qa_output/hello.txt"];
if (success == NO) {
    NSLog(@"%@",crypt.LastErrorText);
    return;
}

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