/* $Id: alt-md2.cpp $ */ /** @file * IPRT - Message-Digest Algorithm 2, Alternative Implementation. */ /* * Copyright (C) 2009-2019 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ /********************************************************************************************************************************* * Defined Constants And Macros * *********************************************************************************************************************************/ /** The MD2 block size. */ #define RTMD2_BLOCK_SIZE 16 /** The offset of the buffer into RTMD2ALTPRIVATECTX::abStateX. */ #define RTMD2_BUF_OFF RTMD2_BLOCK_SIZE /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include "internal/iprt.h" #include /** Our private context structure. */ typedef struct RTMD2ALTPRIVATECTX { /** The state (X). * The staging buffer starts byte 16. */ uint8_t abStateX[RTMD2_BLOCK_SIZE * 3]; /** The checksum. */ uint8_t abChecksum[RTMD2_BLOCK_SIZE]; /** The number of buffered bytes. */ uint8_t cbBuffer; } RTMD2ALTPRIVATECTX; #define RT_MD2_PRIVATE_ALT_CONTEXT #include #include #include AssertCompile(RT_SIZEOFMEMB(RTMD2CONTEXT, abPadding) >= RT_SIZEOFMEMB(RTMD2CONTEXT, AltPrivate)); /********************************************************************************************************************************* * Global Variables * *********************************************************************************************************************************/ /** PI substitation used by MD2. */ static uint8_t const g_PiSubst[256] = { 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6, 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251, 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63, 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50, 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165, 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210, 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157, 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27, 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15, 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197, 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65, 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123, 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233, 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228, 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237, 31, 26, 219, 153, 141, 51, 159, 17, 131, 20, }; RTDECL(void) RTMd2Init(PRTMD2CONTEXT pCtx) { pCtx->AltPrivate.cbBuffer = 0; RT_ZERO(pCtx->AltPrivate.abStateX); RT_ZERO(pCtx->AltPrivate.abChecksum); } RT_EXPORT_SYMBOL(RTMd2Init); /** * Initializes the processing of a whole block directly from the input buffer. * * This will update the checksum as well as initializing abStateX. * * @param pCtx The MD2 context. * @param pbBlock The block. */ DECLINLINE(void) rtMd2BlockInit(PRTMD2CONTEXT pCtx, const uint8_t *pbBlock) { uint8_t bL = pCtx->AltPrivate.abChecksum[15]; for (unsigned j = 0; j < RTMD2_BLOCK_SIZE; j++) { uint8_t bIn = pbBlock[j]; pCtx->AltPrivate.abStateX[j + RTMD2_BLOCK_SIZE] = bIn; pCtx->AltPrivate.abStateX[j + RTMD2_BLOCK_SIZE * 2] = bIn ^ pCtx->AltPrivate.abStateX[j]; bL = pCtx->AltPrivate.abChecksum[j] ^= g_PiSubst[bIn ^ bL]; } } /** * Special version of rtMd2BlockInit that does not update the checksum. * * This is used in the final round when adding the checksum to the calculation. * * @param pCtx The MD2 context. * @param pbBlock The block (i.e. the checksum). */ DECLINLINE(void) rtMd2BlockInitNoChecksum(PRTMD2CONTEXT pCtx, const uint8_t *pbBlock) { for (unsigned j = 0; j < RTMD2_BLOCK_SIZE; j++) { uint8_t bIn = pbBlock[j]; pCtx->AltPrivate.abStateX[j + RTMD2_BLOCK_SIZE] = bIn; pCtx->AltPrivate.abStateX[j + RTMD2_BLOCK_SIZE * 2] = bIn ^ pCtx->AltPrivate.abStateX[j]; } } /** * Initalizes the abStateX from a full buffer and update the checksum. * * The buffer is part of the abStateX structure (bytes 16 thru 31), so this * is a somewhat reduced version of rtMd2BlockInit. * * @param pCtx The MD2 context. */ DECLINLINE(void) rtMd2BlockInitBuffered(PRTMD2CONTEXT pCtx) { uint8_t bL = pCtx->AltPrivate.abChecksum[15]; for (unsigned j = 0; j < RTMD2_BLOCK_SIZE; j++) { uint8_t bIn = pCtx->AltPrivate.abStateX[j + RTMD2_BLOCK_SIZE]; pCtx->AltPrivate.abStateX[j + RTMD2_BLOCK_SIZE * 2] = bIn ^ pCtx->AltPrivate.abStateX[j]; bL = pCtx->AltPrivate.abChecksum[j] ^= g_PiSubst[bIn ^ bL]; } } /** * Process the current block. * * Requires one of the rtMd2BlockInit functions to be called first. * * @param pCtx The MD2 context. */ DECLINLINE(void) rtMd2BlockProcess(PRTMD2CONTEXT pCtx) { uint8_t bT = 0; for (unsigned j = 0; j < 18; j++) /* 18 rounds */ { for (unsigned k = 0; k < RTMD2_BLOCK_SIZE * 3; k++) pCtx->AltPrivate.abStateX[k] = bT = pCtx->AltPrivate.abStateX[k] ^ g_PiSubst[bT]; bT += (uint8_t)j; } } RTDECL(void) RTMd2Update(PRTMD2CONTEXT pCtx, const void *pvBuf, size_t cbBuf) { Assert(pCtx->AltPrivate.cbBuffer < RTMD2_BLOCK_SIZE); uint8_t const *pbBuf = (uint8_t const *)pvBuf; /* * Deal with buffered bytes first. */ if (pCtx->AltPrivate.cbBuffer) { uint8_t cbMissing = RTMD2_BLOCK_SIZE - pCtx->AltPrivate.cbBuffer; if (cbBuf >= cbMissing) { memcpy(&pCtx->AltPrivate.abStateX[RTMD2_BUF_OFF + pCtx->AltPrivate.cbBuffer], pbBuf, cbMissing); pbBuf += cbMissing; cbBuf -= cbMissing; rtMd2BlockInitBuffered(pCtx); rtMd2BlockProcess(pCtx); pCtx->AltPrivate.cbBuffer = 0; } else { memcpy(&pCtx->AltPrivate.abStateX[RTMD2_BUF_OFF + pCtx->AltPrivate.cbBuffer], pbBuf, cbBuf); pCtx->AltPrivate.cbBuffer += (uint8_t)cbBuf; return; } } /* * Process full blocks directly from the input buffer. */ while (cbBuf >= RTMD2_BLOCK_SIZE) { rtMd2BlockInit(pCtx, pbBuf); rtMd2BlockProcess(pCtx); pbBuf += RTMD2_BLOCK_SIZE; cbBuf -= RTMD2_BLOCK_SIZE; } /* * Stash any remaining bytes into the context buffer. */ if (cbBuf > 0) { memcpy(&pCtx->AltPrivate.abStateX[RTMD2_BUF_OFF], pbBuf, cbBuf); pCtx->AltPrivate.cbBuffer = (uint8_t)cbBuf; } } RT_EXPORT_SYMBOL(RTMd2Update); RTDECL(void) RTMd2Final(PRTMD2CONTEXT pCtx, uint8_t pabDigest[RTMD2_HASH_SIZE]) { Assert(pCtx->AltPrivate.cbBuffer < RTMD2_BLOCK_SIZE); /* * Pad the message to a multiple of 16 bytes. This is done even if the * message already is a multiple of 16. */ unsigned cbPad = RTMD2_BLOCK_SIZE - pCtx->AltPrivate.cbBuffer; memset(&pCtx->AltPrivate.abStateX[RTMD2_BUF_OFF + pCtx->AltPrivate.cbBuffer], cbPad, cbPad); rtMd2BlockInitBuffered(pCtx); rtMd2BlockProcess(pCtx); pCtx->AltPrivate.cbBuffer = 0; /* * Add the checksum. */ rtMd2BlockInitNoChecksum(pCtx, pCtx->AltPrivate.abChecksum); rtMd2BlockProcess(pCtx); /* * Done. Just copy out the digest. */ memcpy(pabDigest, pCtx->AltPrivate.abStateX, RTMD2_HASH_SIZE); RT_ZERO(pCtx->AltPrivate); pCtx->AltPrivate.cbBuffer = UINT8_MAX; } RT_EXPORT_SYMBOL(RTMd2Final); RTDECL(void) RTMd2(const void *pvBuf, size_t cbBuf, uint8_t pabDigest[RTMD2_HASH_SIZE]) { RTMD2CONTEXT Ctx; RTMd2Init(&Ctx); RTMd2Update(&Ctx, pvBuf, cbBuf); RTMd2Final(&Ctx, pabDigest); } RT_EXPORT_SYMBOL(RTMd2);