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| -rw-r--r-- | src/tpm2/crypto/openssl/CryptCmac.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/src/tpm2/crypto/openssl/CryptCmac.c b/src/tpm2/crypto/openssl/CryptCmac.c new file mode 100644 index 0000000..0461e78 --- /dev/null +++ b/src/tpm2/crypto/openssl/CryptCmac.c @@ -0,0 +1,210 @@ +/********************************************************************************/ +/* */ +/* Message Authentication Codes Based on a Symmetric Block Cipher */ +/* Written by Ken Goldman */ +/* IBM Thomas J. Watson Research Center */ +/* $Id: CryptCmac.c 1658 2021-01-22 23:14:01Z kgoldman $ */ +/* */ +/* Licenses and Notices */ +/* */ +/* 1. Copyright Licenses: */ +/* */ +/* - Trusted Computing Group (TCG) grants to the user of the source code in */ +/* this specification (the "Source Code") a worldwide, irrevocable, */ +/* nonexclusive, royalty free, copyright license to reproduce, create */ +/* derivative works, distribute, display and perform the Source Code and */ +/* derivative works thereof, and to grant others the rights granted herein. */ +/* */ +/* - The TCG grants to the user of the other parts of the specification */ +/* (other than the Source Code) the rights to reproduce, distribute, */ +/* display, and perform the specification solely for the purpose of */ +/* developing products based on such documents. */ +/* */ +/* 2. Source Code Distribution Conditions: */ +/* */ +/* - Redistributions of Source Code must retain the above copyright licenses, */ +/* this list of conditions and the following disclaimers. */ +/* */ +/* - Redistributions in binary form must reproduce the above copyright */ +/* licenses, this list of conditions and the following disclaimers in the */ +/* documentation and/or other materials provided with the distribution. */ +/* */ +/* 3. Disclaimers: */ +/* */ +/* - THE COPYRIGHT LICENSES SET FORTH ABOVE DO NOT REPRESENT ANY FORM OF */ +/* LICENSE OR WAIVER, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, WITH */ +/* RESPECT TO PATENT RIGHTS HELD BY TCG MEMBERS (OR OTHER THIRD PARTIES) */ +/* THAT MAY BE NECESSARY TO IMPLEMENT THIS SPECIFICATION OR OTHERWISE. */ +/* Contact TCG Administration (admin@trustedcomputinggroup.org) for */ +/* information on specification licensing rights available through TCG */ +/* membership agreements. */ +/* */ +/* - THIS SPECIFICATION IS PROVIDED "AS IS" WITH NO EXPRESS OR IMPLIED */ +/* WARRANTIES WHATSOEVER, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR */ +/* FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, COMPLETENESS, OR */ +/* NONINFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS, OR ANY WARRANTY */ +/* OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION OR SAMPLE. */ +/* */ +/* - Without limitation, TCG and its members and licensors disclaim all */ +/* liability, including liability for infringement of any proprietary */ +/* rights, relating to use of information in this specification and to the */ +/* implementation of this specification, and TCG disclaims all liability for */ +/* cost of procurement of substitute goods or services, lost profits, loss */ +/* of use, loss of data or any incidental, consequential, direct, indirect, */ +/* or special damages, whether under contract, tort, warranty or otherwise, */ +/* arising in any way out of use or reliance upon this specification or any */ +/* information herein. */ +/* */ +/* (c) Copyright IBM Corp. and others, 2018 - 2021 */ +/* */ +/********************************************************************************/ + +/* 10.2.6 CryptCmac.c */ +/* 10.2.6.1 Introduction */ +/* This file contains the implementation of the message authentication codes based on a symmetric + block cipher. These functions only use the single block encryption functions of the selected + symmetric cryptographic library. */ +/* 10.2.6.2 Includes, Defines, and Typedefs */ +#define _CRYPT_HASH_C_ +#include "Tpm.h" +#include "CryptSym.h" +#if ALG_CMAC + /* 10.2.6.3 Functions */ + /* 10.2.6.3.1 CryptCmacStart() */ + /* This is the function to start the CMAC sequence operation. It initializes the dispatch + functions for the data and end operations for CMAC and initializes the parameters that are + used for the processing of data, including the key, key size and block cipher algorithm. */ +UINT16 +CryptCmacStart( + SMAC_STATE *state, + TPMU_PUBLIC_PARMS *keyParms, + TPM_ALG_ID macAlg, + TPM2B *key + ) +{ + tpmCmacState_t *cState = &state->state.cmac; + TPMT_SYM_DEF_OBJECT *def = &keyParms->symDetail.sym; + // + if(macAlg != TPM_ALG_CMAC) + return 0; + MemorySet(cState, 0, sizeof(*cState)); // libtpms bugfix + // set up the encryption algorithm and parameters + cState->symAlg = def->algorithm; + cState->keySizeBits = def->keyBits.sym; + cState->iv.t.size = CryptGetSymmetricBlockSize(def->algorithm, + def->keyBits.sym); + MemoryCopy2B(&cState->symKey.b, key, sizeof(cState->symKey.t.buffer)); + // Set up the dispatch methods for the CMAC + state->smacMethods.data = CryptCmacData; + state->smacMethods.end = CryptCmacEnd; + return cState->iv.t.size; +} + +/* 10.2.5.3.2 CryptCmacData() */ +/* This function is used to add data to the CMAC sequence computation. The function will XOR new + data into the IV. If the buffer is full, and there is additional input data, the data is + encrypted into the IV buffer, the new data is then XOR into the IV. When the data runs out, the + function returns without encrypting even if the buffer is full. The last data block of a sequence + will not be encrypted until the call to CryptCmacEnd(). This is to allow the proper subkey to be + computed and applied before the last block is encrypted. */ +void +CryptCmacData( + SMAC_STATES *state, + UINT32 size, + const BYTE *buffer + ) +{ + tpmCmacState_t *cmacState = &state->cmac; + TPM_ALG_ID algorithm = cmacState->symAlg; + BYTE *key = cmacState->symKey.t.buffer; + UINT16 keySizeInBits = cmacState->keySizeBits; + tpmCryptKeySchedule_t keySchedule; + TpmCryptSetSymKeyCall_t encrypt; + // + memset(&keySchedule, 0, sizeof(keySchedule)); /* libtpms added: coverity */ + // Set up the encryption values based on the algorithm + switch (algorithm) + { + FOR_EACH_SYM(ENCRYPT_CASE) + default: + FAIL(FATAL_ERROR_INTERNAL); + } + while(size > 0) + { + if(cmacState->bcount == cmacState->iv.t.size) + { + ENCRYPT(&keySchedule, cmacState->iv.t.buffer, cmacState->iv.t.buffer); + cmacState->bcount = 0; + } + for(;(size > 0) && (cmacState->bcount < cmacState->iv.t.size); + size--, cmacState->bcount++) + { + cmacState->iv.t.buffer[cmacState->bcount] ^= *buffer++; + } + } +} + +/* 10.2.6.3.3 CryptCmacEnd() */ +/* This is the completion function for the CMAC. It does padding, if needed, and selects the subkey + to be applied before the last block is encrypted. */ +UINT16 +CryptCmacEnd( + SMAC_STATES *state, + UINT32 outSize, + BYTE *outBuffer + ) +{ + tpmCmacState_t *cState = &state->cmac; + // Need to set algorithm, key, and keySizeInBits in the local context so that + // the SELECT and ENCRYPT macros will work here + TPM_ALG_ID algorithm = cState->symAlg; + BYTE *key = cState->symKey.t.buffer; + UINT16 keySizeInBits = cState->keySizeBits; + tpmCryptKeySchedule_t keySchedule; + TpmCryptSetSymKeyCall_t encrypt; + TPM2B_IV subkey = {{0, {0}}}; + BOOL xorVal; + UINT16 i; + memset(&keySchedule, 0, sizeof(keySchedule)); /* libtpms added: coverity */ + + subkey.t.size = cState->iv.t.size; + // Encrypt a block of zero + // Set up the encryption values based on the algorithm + switch (algorithm) + { + FOR_EACH_SYM(ENCRYPT_CASE) + default: + return 0; + } + ENCRYPT(&keySchedule, subkey.t.buffer, subkey.t.buffer); + + // shift left by 1 and XOR with 0x0...87 if the MSb was 0 + xorVal = ((subkey.t.buffer[0] & 0x80) == 0) ? 0 : 0x87; + ShiftLeft(&subkey.b); + subkey.t.buffer[subkey.t.size - 1] ^= xorVal; + // this is a sanity check to make sure that the algorithm is working properly. + // remove this check when debug is done + pAssert(cState->bcount <= cState->iv.t.size); + // If the buffer is full then no need to compute subkey 2. + if(cState->bcount < cState->iv.t.size) + { + //Pad the data + cState->iv.t.buffer[cState->bcount++] ^= 0x80; + // The rest of the data is a pad of zero which would simply be XORed + // with the iv value so nothing to do... + // Now compute K2 + xorVal = ((subkey.t.buffer[0] & 0x80) == 0) ? 0 : 0x87; + ShiftLeft(&subkey.b); + subkey.t.buffer[subkey.t.size - 1] ^= xorVal; + } + // XOR the subkey into the IV + for(i = 0; i < subkey.t.size; i++) + cState->iv.t.buffer[i] ^= subkey.t.buffer[i]; + ENCRYPT(&keySchedule, cState->iv.t.buffer, cState->iv.t.buffer); + i = (UINT16)MIN(cState->iv.t.size, outSize); + MemoryCopy(outBuffer, cState->iv.t.buffer, i); + + return i; +} + +#endif |