2
0
MasterPassword/core/c/mpw-algorithm_v2.c
2017-04-05 16:56:22 -04:00

126 lines
5.6 KiB
C

//==============================================================================
// This file is part of Master Password.
// Copyright (c) 2011-2017, Maarten Billemont.
//
// Master Password is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Master Password is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You can find a copy of the GNU General Public License in the
// LICENSE file. Alternatively, see <http://www.gnu.org/licenses/>.
//==============================================================================
#include <string.h>
#include <errno.h>
#include <arpa/inet.h>
#include "mpw-types.h"
#include "mpw-util.h"
#define MP_N 32768
#define MP_r 8
#define MP_p 2
#define MP_hash PearlHashSHA256
static const uint8_t *mpw_masterKeyForUser_v2(const char *fullName, const char *masterPassword) {
const char *mpKeyScope = mpw_scopeForVariant( MPSiteVariantPassword );
trc( "algorithm: v%d\n", 2 );
trc( "fullName: %s (%zu)\n", fullName, mpw_utf8_strlen( fullName ) );
trc( "masterPassword: %s\n", masterPassword );
trc( "key scope: %s\n", mpKeyScope );
// Calculate the master key salt.
// masterKeySalt = mpKeyScope . #fullName . fullName
size_t masterKeySaltSize = 0;
uint8_t *masterKeySalt = NULL;
mpw_push_string( &masterKeySalt, &masterKeySaltSize, mpKeyScope );
mpw_push_int( &masterKeySalt, &masterKeySaltSize, htonl( mpw_utf8_strlen( fullName ) ) );
mpw_push_string( &masterKeySalt, &masterKeySaltSize, fullName );
if (!masterKeySalt) {
ftl( "Could not allocate master key salt: %d\n", errno );
return NULL;
}
trc( "masterKeySalt ID: %s\n", mpw_id_buf( masterKeySalt, masterKeySaltSize ) );
// Calculate the master key.
// masterKey = scrypt( masterPassword, masterKeySalt )
const uint8_t *masterKey = mpw_scrypt( MP_dkLen, masterPassword, masterKeySalt, masterKeySaltSize, MP_N, MP_r, MP_p );
mpw_free( masterKeySalt, masterKeySaltSize );
if (!masterKey) {
ftl( "Could not allocate master key: %d\n", errno );
return NULL;
}
trc( "masterKey ID: %s\n", mpw_id_buf( masterKey, MP_dkLen ) );
return masterKey;
}
static const char *mpw_passwordForSite_v2(const uint8_t *masterKey, const char *siteName, const MPSiteType siteType, const uint32_t siteCounter,
const MPSiteVariant siteVariant, const char *siteContext) {
const char *siteScope = mpw_scopeForVariant( siteVariant );
trc( "algorithm: v%d\n", 2 );
trc( "siteName: %s\n", siteName );
trc( "siteCounter: %d\n", siteCounter );
trc( "siteVariant: %d\n", siteVariant );
trc( "siteType: %d\n", siteType );
trc( "site scope: %s, context: %s\n", siteScope, siteContext? "<empty>": siteContext );
trc( "seed from: hmac-sha256(masterKey, %s | %s | %s | %s | %s | %s)\n",
siteScope, mpw_hex_l( htonl( strlen( siteName ) ) ), siteName,
mpw_hex_l( htonl( siteCounter ) ),
mpw_hex_l( htonl( siteContext? strlen( siteContext ): 0 ) ), siteContext? "(null)": siteContext );
// Calculate the site seed.
// sitePasswordSeed = hmac-sha256( masterKey, siteScope . #siteName . siteName . siteCounter . #siteContext . siteContext )
size_t sitePasswordInfoSize = 0;
uint8_t *sitePasswordInfo = NULL;
mpw_push_string( &sitePasswordInfo, &sitePasswordInfoSize, siteScope );
mpw_push_int( &sitePasswordInfo, &sitePasswordInfoSize, htonl( strlen( siteName ) ) );
mpw_push_string( &sitePasswordInfo, &sitePasswordInfoSize, siteName );
mpw_push_int( &sitePasswordInfo, &sitePasswordInfoSize, htonl( siteCounter ) );
if (siteContext) {
mpw_push_int( &sitePasswordInfo, &sitePasswordInfoSize, htonl( strlen( siteContext ) ) );
mpw_push_string( &sitePasswordInfo, &sitePasswordInfoSize, siteContext );
}
if (!sitePasswordInfo) {
ftl( "Could not allocate site seed info: %d\n", errno );
return NULL;
}
trc( "sitePasswordInfo ID: %s\n", mpw_id_buf( sitePasswordInfo, sitePasswordInfoSize ) );
const uint8_t *sitePasswordSeed = mpw_hmac_sha256( masterKey, MP_dkLen, sitePasswordInfo, sitePasswordInfoSize );
mpw_free( sitePasswordInfo, sitePasswordInfoSize );
if (!sitePasswordSeed) {
ftl( "Could not allocate site seed: %d\n", errno );
return NULL;
}
trc( "sitePasswordSeed ID: %s\n", mpw_id_buf( sitePasswordSeed, 32 ) );
// Determine the template.
const char *template = mpw_templateForType( siteType, sitePasswordSeed[0] );
trc( "type %d, template: %s\n", siteType, template );
if (strlen( template ) > 32) {
ftl( "Template too long for password seed: %lu", strlen( template ) );
mpw_free( sitePasswordSeed, sizeof( sitePasswordSeed ) );
return NULL;
}
// Encode the password from the seed using the template.
char *const sitePassword = calloc( strlen( template ) + 1, sizeof( char ) );
for (size_t c = 0; c < strlen( template ); ++c) {
sitePassword[c] = mpw_characterFromClass( template[c], sitePasswordSeed[c + 1] );
trc( "class %c, index %u (0x%02X) -> character: %c\n", template[c], sitePasswordSeed[c + 1], sitePasswordSeed[c + 1],
sitePassword[c] );
}
mpw_free( sitePasswordSeed, sizeof( sitePasswordSeed ) );
return sitePassword;
}