Obj-c verify ECDSA signature

verifyECDSASignature.m

- (IBAction)ecdsaAction:(id)sender {
    
    
    
    NSData *privateKeyPEMData = [[NSFileManager defaultManager] contentsAtPath: [[NSBundle mainBundle] pathForResource:@"ec_private_key" ofType:@"p12"  ]];
    if(privateKeyPEMData){
        NSLog(@"privateKeyPEMData NOT NULL");
        SecKeyRef privateKey = [self getPrivateKeyRefrenceFromData:privateKeyPEMData password:@"12345678"];
        if(privateKey){
            NSLog(@"private key is NOT NULL!!");
            
            SecKeyAlgorithm algorithm = kSecKeyAlgorithmECDSASignatureDigestX962SHA512;
            
            BOOL canSign = SecKeyIsAlgorithmSupported(privateKey, kSecKeyOperationTypeSign, algorithm);
            
            NSLog(@"canSign %i\n",canSign);
            
            NSString *plainText = @"Hello World";
            NSData *plainTextData = [plainText dataUsingEncoding:NSUTF8StringEncoding];
            
            NSData* signature = nil;
            if (canSign) {
                CFErrorRef error = NULL;
                signature = (NSData*)CFBridgingRelease(       // ARC takes ownership
                                                       SecKeyCreateSignature(privateKey,
                                                                             algorithm,
                                                                             (__bridge CFDataRef)plainTextData,
                                                                             &error));
                if (!signature) {
                    NSError *err = CFBridgingRelease(error);  // ARC takes ownership
                    // Handle the error. . .
                    NSLog(@"failed to sign.\n");
                }
            }
            NSString *sigString = [[NSString alloc]initWithData:signature encoding:NSASCIIStringEncoding];
            NSLog(@"signature: %@",signature);
            NSLog(@"sigString: %@", sigString);
            
            
            NSData *publicKeyPEMData = [[NSFileManager defaultManager] contentsAtPath: [[NSBundle mainBundle] pathForResource:@"ec_public_key" ofType:@"der"  ]];
            if(publicKeyPEMData){
                NSLog(@"publicKeyPEMData NOT NULL!!");
                SecKeyRef publicKey = [self getPublicKeyRefrenceFromeData:publicKeyPEMData];  //[self getPublicKeyRef];
                if(PublicKey){
                    NSLog(@"publicKey is NOT NULL");
                    
                    BOOL canVerify = SecKeyIsAlgorithmSupported(PublicKey,
                                                                kSecKeyOperationTypeVerify,
                                                                algorithm);
                    NSLog(@"canVerify : %i",canVerify);
                    
                    BOOL result = NO;
                    if (canVerify) {
                       result = SecKeyVerifySignature(newPublicKey,
                                                      algorithm,
                                                      (__bridge CFDataRef)plainTextData,
                                                      (__bridge CFDataRef)signature,
                                                      &error);
                      
                        if (!result) {
                            NSError *err = CFBridgingRelease(error);  // ARC takes ownership
                            // Handle the error. . .
                            
                            NSLog(@"failed to verify signature");
                            NSLog(@"error: %@",error);
                        }else{
                            NSLog(@"yes signed");
                        }
                    }
                    
                }else{
                    NSLog(@"publicKey IS NULL!!");
                }
            }else{
                NSLog(@"publicKeyPEMData is NULL");
            }
            
            
            
            
        }else{
            NSLog(@"private key is null");
        }
    }else{
        NSLog(@"sad privateKeyPEMData is NULL");
    }
    
}

Shouldn't you be using kSecKeyAlgorithmECDSASignatureMessageX962SHA512 instead of kSecKeyAlgorithmECDSASignatureDigestX962SHA512 if you are using the entire message in SecKeyCreateSignature and SecKeyVerifySignature?

kSecKeyAlgorithmECDSASignatureDigestX962SHA512 is only useful if you're using the message digest?