iOS SecKeyRef from NSString

问题

I need to encrypt a user password to base64 string using a public key.

The public key is a NSString.

Something like this:

"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCgWO7p1AvCaHUeaM6rSczBBAqt mKObHxGW3VgTom2zGwswGj9t/Hr7NdJQCGAiq0ijcW9/oYnM/JobbsyEijHKqIQm OVMsV4JRoG68PEDszH/ebkqWhzu7vG9IQ6VYIkaKHqk7cg+mQ1qFDoigOooFJ2Pf Uzbmg+Z/DuYDuwg+bwIDAQBC"

How do I make a SecKeyRef from it ?

I found a tutorial here

But I couldn't make it work because SecCertificateCreateWithData always return nil.

This is my code

NSData* data = [NSString base64DataFromString:PUBLIC_KEY];
SecCertificateRef   cert    = NULL;
SecPolicyRef        policy  = NULL;

cert = SecCertificateCreateWithData(kCFAllocatorDefault, (__bridge CFDataRef)(data));
policy = SecPolicyCreateBasicX509();

OSStatus        status      = noErr;
SecKeyRef       *publicKey  = NULL;
SecTrustRef     trust       = NULL;
SecTrustResultType  trustType   = kSecTrustResultInvalid;

if (cert != NULL){
    SecCertificateRef   certArray[1] = {cert};
    CFArrayRef certs = CFArrayCreate(kCFAllocatorDefault, (void *)certArray, 1, NULL);
    status = SecTrustCreateWithCertificates(certs, policy, &trust);

    if (status == errSecSuccess){
        status = SecTrustEvaluate(trust, &trustType);

        // Evaulate the trust.
        switch (trustType) {
            case kSecTrustResultInvalid:
            case kSecTrustResultConfirm:
            case kSecTrustResultDeny:
            case kSecTrustResultUnspecified:
            case kSecTrustResultFatalTrustFailure:
            case kSecTrustResultOtherError:
                break;
            case kSecTrustResultRecoverableTrustFailure:
                *publicKey = SecTrustCopyPublicKey(trust);
                break;
            case kSecTrustResultProceed:
                *publicKey = SecTrustCopyPublicKey(trust);
                break;
        }

    }
} else {
    NSLog(@"CERT == NULL");
}

if (publicKey == NULL) {
    NSLog(@"PUBLIC KEY == NULL");
}

The SecKeyRef is always nil because the cert is nil too. Please help me.

回答1:

You can't just pass key data. You have to pass a certificate signed by your key to be able to pull the key out of the certificate. See this answer to a similar question.

来源：https://stackoverflow.com/questions/26119952/ios-seckeyref-from-nsstring

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ios

objective-c

iphone

nsstring