/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Calculates the SHA digest of some data.

 */

#import "QCCSHADigest.h"

#include <CommonCrypto/CommonCrypto.h>

NS_ASSUME_NONNULL_BEGIN

@interface QCCSHADigest ()

// read/write versions of public properties

@property (atomic, copy,   readwrite, nullable) NSData *        outputDigest;

@end

NS_ASSUME_NONNULL_END

@implementation QCCSHADigest

- (instancetype)init {

    abort();

}

- (instancetype)initWithAlgorithm:(QCCSHADigestAlgorithm)algorithm inputData:(NSData *)inputData {

    NSParameterAssert(inputData != nil);

    self = [super init];

    if (self != nil) {

        self->_algorithm = algorithm;

        self->_inputData = [inputData copy];

    }

    return self;

}

- (void)main {

    NSMutableData *     digest;

    // You can ignore the result CC_SHAxxx because it never fails.

    switch (self.algorithm) {

        case QCCSHADigestAlgorithmSHA1: {

            digest = [[NSMutableData alloc] initWithLength:CC_SHA1_DIGEST_LENGTH];

            (void) CC_SHA1(self.inputData.bytes, (CC_LONG) self.inputData.length, digest.mutableBytes);

        } break;

        case QCCSHADigestAlgorithmSHA2_224: {

            digest = [[NSMutableData alloc] initWithLength:CC_SHA224_DIGEST_LENGTH];

            (void) CC_SHA224(self.inputData.bytes, (CC_LONG) self.inputData.length, digest.mutableBytes);

        } break;

        case QCCSHADigestAlgorithmSHA2_256: {

            digest = [[NSMutableData alloc] initWithLength:CC_SHA256_DIGEST_LENGTH];

            (void) CC_SHA256(self.inputData.bytes, (CC_LONG) self.inputData.length, digest.mutableBytes);

        } break;

        case QCCSHADigestAlgorithmSHA2_384: {

            digest = [[NSMutableData alloc] initWithLength:CC_SHA384_DIGEST_LENGTH];

            (void) CC_SHA384(self.inputData.bytes, (CC_LONG) self.inputData.length, digest.mutableBytes);

        } break;

        case QCCSHADigestAlgorithmSHA2_512: {

            digest = [[NSMutableData alloc] initWithLength:CC_SHA512_DIGEST_LENGTH];

            (void) CC_SHA512(self.inputData.bytes, (CC_LONG) self.inputData.length, digest.mutableBytes);

        } break;

        default: {

            abort();

        } break;

    }

    self.outputDigest = digest;

}

@end