/*
* Copyright (c) 2016, Jonathan Schleifer <js@heap.zone>
*
* https://heap.zone/git/?p=scrypt-pwgen.git
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#import "LegacyPasswordGenerator.h"
@implementation LegacyPasswordGenerator
@synthesize site = _site, passphrase = _passphrase, output = _output;
+ (instancetype)generator
{
return [[[self alloc] init] autorelease];
}
- init
{
self = [super init];
_length = 16;
return self;
}
- (void)setLength: (size_t)length
{
if (length < 3)
@throw [OFInvalidArgumentException exception];
_length = length;
}
- (size_t)length
{
return _length;
}
- (void)derivePassword
{
OFSHA256Hash *siteHash = [OFSHA256Hash cryptoHash];
[siteHash updateWithBuffer: [_site UTF8String]
length: [_site UTF8StringLength]];
if (_output != NULL) {
of_explicit_memset(_output, 0, _length);
[self freeMemory: _output];
}
_output = [self allocMemoryWithSize: _length + 1];
of_scrypt(8, 524288, 2, [siteHash digest],
[[siteHash class] digestSize], _passphrase, strlen(_passphrase),
_output, _length);
/*
* This has a bias, however, this is what scrypt-genpass does and the
* legacy mode wants to be compatible to scrypt-genpass.
*/
_output[0] = "abcdefghijklmnopqrstuvwxyz"[_output[0] % 26];
_output[1] = "0123456789"[_output[1] % 10];
_output[2] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"[_output[2] % 26];
for (size_t i = 3; i < _length; i++)
_output[i] = "abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789"[_output[i] % (26 + 26 + 10)];
}
@end