/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Commands for key derivation.

 */

#import "KeyDerivationCommands.h"

#import "QCCPBKDF2SHAKeyDerivation.h"

#import "ToolCommon.h"

#import "QHex.h"

NS_ASSUME_NONNULL_BEGIN

@interface PBKDF2KeyDerivationCommand ()

@property (nonatomic, assign, readwrite)           QCCPBKDF2SHAKeyDerivationAlgorithm   algorithm;

@property (nonatomic, copy,   readwrite, nullable) NSString *                           passwordString;

@property (nonatomic, copy,   readwrite, nullable) NSData *                             saltData;

@property (nonatomic, assign, readwrite)           NSInteger                            rounds;

@property (nonatomic, assign, readwrite)           NSInteger                            derivedKeyLength;

@end

NS_ASSUME_NONNULL_END

@implementation PBKDF2KeyDerivationCommand

+ (NSString *)commandName {

    return @"pbkdf2-key-derivation";

}

+ (NSString *)commandUsage {

    return [NSString stringWithFormat:@"%@ -a sha1|sha2-224|sha2-256|sha2-384|sha2-512 -p passwordStr -s saltHexStr [-r rounds] [-z derivedKeyLength]", [self commandName]];

}

- (NSString *)commandOptions {

    return @"a:p:s:r:z:";

}

- (BOOL)setOption_a_argument:(NSString *)argument {

    BOOL    result;

    result = YES;

    if ([argument isEqual:@"sha1"]) {

        self.algorithm = QCCPBKDF2SHAKeyDerivationAlgorithmSHA1;

    } else if ([argument isEqual:@"sha2-224"]) {

        self.algorithm = QCCPBKDF2SHAKeyDerivationAlgorithmSHA2_224;

    } else if ([argument isEqual:@"sha2-256"]) {

        self.algorithm = QCCPBKDF2SHAKeyDerivationAlgorithmSHA2_256;

    } else if ([argument isEqual:@"sha2-384"]) {

        self.algorithm = QCCPBKDF2SHAKeyDerivationAlgorithmSHA2_384;

    } else if ([argument isEqual:@"sha2-512"]) {

        self.algorithm = QCCPBKDF2SHAKeyDerivationAlgorithmSHA2_512;

    } else {

        result = NO;

    }

    return result;

}

- (BOOL)setOption_p_argument:(NSString *)argument {

    self.passwordString = argument;

    return YES;

}

- (BOOL)setOption_s_argument:(NSString *)argument {

    self.saltData = [QHex optionalDataWithHexString:argument];

    return (self.saltData != nil);

}

- (BOOL)setOption_r_argument:(NSString *)argument {

    self.rounds = argument.integerValue;

    return (self.rounds >= 0);

}

- (BOOL)setOption_z_argument:(NSString *)argument {

    self.derivedKeyLength = argument.integerValue;

    return (self.derivedKeyLength >= 0);

}

- (BOOL)validateOptionsAndArguments:(NSArray *)optionsAndArguments {

    BOOL    success;

    success = [super validateOptionsAndArguments:optionsAndArguments];

    if (success) {

        if (self.arguments.count != 0) {

            success = NO;

        } else if (self.passwordString == nil) {

            success = NO;

        } else if (self.saltData == nil) {

            success = NO;

        }

        // We don't check self.algorithm because the default, SHA1, is fine.

    }

    return success;

}

- (BOOL)runError:(NSError **)errorPtr {

    BOOL                            success;

    QCCPBKDF2SHAKeyDerivation *     op;

    success = YES;

    op = [[QCCPBKDF2SHAKeyDerivation alloc] initWithAlgorithm:self.algorithm passwordString:self.passwordString saltData:self.saltData];

    if (self.rounds != 0) {

        op.rounds = self.rounds;

    }

    if (self.derivedKeyLength != 0) {

        op.derivedKeyLength = self.derivedKeyLength;

    }

    [[ToolCommon sharedInstance] synchronouslyRunOperation:op];

    if (op.error == nil) {

        fprintf(stdout, "%s\n", [QHex hexStringWithData:op.derivedKeyData].UTF8String);

    } else {

        if (errorPtr != NULL) {

            *errorPtr = op.error;

        }

        success = NO;

    }

    return success;

}

@end