/*
* Copyright (c) 2016, Jonathan Schleifer <js@heap.zone>
*
* https://heap.zone/git/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, keyfile = _keyfile, passphrase = _passphrase;
@synthesize output = _output;
+ (instancetype)generator
{
return [[[self alloc] init] autorelease];
}
- (instancetype)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];
size_t passphraseLength, combinedPassphraseLength;
char *combinedPassphrase;
[siteHash updateWithBuffer: _site.UTF8String
length: _site.UTF8StringLength];
if (_output != NULL) {
of_explicit_memset(_output, 0, _length);
[self freeMemory: _output];
}
_output = [self allocMemoryWithSize: _length + 1];
passphraseLength = combinedPassphraseLength = strlen(_passphrase);
if (_keyfile != nil) {
if (SIZE_MAX - combinedPassphraseLength < _keyfile.count)
@throw [OFOutOfRangeException exception];
combinedPassphraseLength += _keyfile.count;
}
if ((combinedPassphrase = malloc(combinedPassphraseLength)) == NULL)
@throw [OFOutOfMemoryException
exceptionWithRequestedSize: combinedPassphraseLength];
@try {
memcpy(combinedPassphrase, _passphrase, passphraseLength);
if (_keyfile != nil)
memcpy(combinedPassphrase + passphraseLength,
_keyfile.items, _keyfile.count);
of_scrypt(8, 524288, 2, siteHash.digest,
[siteHash.class digestSize], combinedPassphrase,
combinedPassphraseLength, _output, _length);
} @finally {
of_explicit_memset(combinedPassphrase, 0,
combinedPassphraseLength);
free(combinedPassphrase);
}
/*
* 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