Obj-c getPublicKeyFromCertificate

getPublicKeyFromCertificate.m

- (SecKeyRef)getPublicKeyFromCertificate:(NSData *)data
{
    //create certificate.
    CFDataRef dataRef=CFDataCreate(kCFAllocatorDefault, [data bytes], (CFIndex)[data length]);
    SecCertificateRef certiRef=SecCertificateCreateWithData(kCFAllocatorDefault, dataRef);
    (CFRelease(dataRef));
    //evaluate certificate.
    CFArrayRef certs = CFArrayCreate(kCFAllocatorDefault, (const void **) &certiRef, 1, NULL);
    SecPolicyRef policy = SecPolicyCreateBasicX509();
    SecTrustRef trust;
    SecTrustCreateWithCertificates(certs, policy, &trust);
    (CFRelease(certs));
    SecTrustResultType trustResult;
    SecTrustEvaluate(trust, &trustResult);
    //get publickey
    SecKeyRef oPublicKey = SecTrustCopyPublicKey(trust);
    (CFRelease(trust));
    (CFRelease(policy));
    (CFRelease(certiRef));
    return oPublicKey;
}