NSData SHA256 hash category

NSData+Hash.h

#import <Foundation/Foundation.h>

@interface NSData (Hash)

- (NSData *)SHA256;

- (NSString *)stringSHA256;

@end

NSData+Hash.m

#import "NSData+Hash.h"
#import <CommonCrypto/CommonCrypto.h>
#import "NSString+Hash.h"

@implementation NSData (Hash)

- (NSData *)SHA256 {
    unsigned char buffer[CC_SHA256_DIGEST_LENGTH];
    NSData *hashedData = nil;
    
    if (CC_SHA256(self.bytes, (CC_LONG)self.length, buffer)) {
        hashedData = [NSData dataWithBytes:buffer length:CC_SHA256_DIGEST_LENGTH];
    }
    
    return hashedData;
}

- (NSString *)stringSHA256 {
    unsigned char buffer[CC_SHA256_DIGEST_LENGTH];
    NSString *hashedString = nil;
    
    if (CC_SHA256(self.bytes, (CC_LONG)self.length, buffer)) {
        hashedString = [NSString stringWithHash:buffer digestLength:CC_SHA256_DIGEST_LENGTH];
    }
    
    return hashedString;
}

@end