Creating SHA1 Hash from NSString

I have this in a category on NSString (available at https://github.com/hypercrypt/NSString-Hashes):

#import <CommonCrypto/CommonDigest.h>...- (NSString *)sha1{    NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];    uint8_t digest[CC_SHA1_DIGEST_LENGTH];    CC_SHA1(data.bytes, (CC_LONG)data.length, digest);    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];    for (int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)    {        [output appendFormat:@"%02x", digest[i]];    }    return output;}

Starting with Xcode 10.0, you should use import CommonCrypto instead since it is now natively available in Swift! If you have recently migrated to Xcode 10.0 and use the old approach, this can be your cue to make the change:

Command CompileSwift failed with a nonzero exit code

I quite like hypercrypt's answer, but I've been encouraged to post my comment.

You could look at CC_SHA1, or this related SO question.

- (NSString *)sha1:(NSString *)str {const char *cStr = [str UTF8String];unsigned char result[CC_SHA1_DIGEST_LENGTH];CC_SHA1(cStr, strlen(cStr), result);NSString *s = [NSString  stringWithFormat:           @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",           result[0], result[1], result[2], result[3], result[4],           result[5], result[6], result[7],           result[8], result[9], result[10], result[11], result[12],           result[13], result[14], result[15],           result[16], result[17], result[18], result[19]           ];return s;}