path: root/src/tpm2/crypto/openssl/CryptSym.c

/********************************************************************************/
/*										*/
/*			     Symmetric block cipher modes			*/
/*			     Written by Ken Goldman				*/
/*		       IBM Thomas J. Watson Research Center			*/
/*            $Id: CryptSym.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, 2016 - 2021				*/
/*										*/
/********************************************************************************/

/* 10.2.19 CryptSym.c */
/* 10.2.19.1 Introduction */
/* This file contains the implementation of the symmetric block cipher modes allowed for a
   TPM. These functions only use the single block encryption functions of the selected symmetric
   crypto library. */

/* 10.2.19.2	Includes, Defines, and Typedefs */
#include "Tpm.h"
#include "CryptSym.h"
#include "Helpers_fp.h"  // libtpms changed


#define     KEY_BLOCK_SIZES(ALG, alg)					\
    static const INT16       alg##KeyBlockSizes[] = {			\
						     ALG##_KEY_SIZES_BITS, -1, ALG##_BLOCK_SIZES };

FOR_EACH_SYM(KEY_BLOCK_SIZES)

/* 10.2.19.3	Initialization and Data Access Functions */
/* 10.2.19.3.1	CryptSymInit() */
/* This function is called to do _TPM_Init() processing */
BOOL
CryptSymInit(
	     void
	     )
{
    return TRUE;
}
/* 10.2.19.3.2	CryptSymStartup() */
/* This function is called to do TPM2_Startup() processing */
BOOL
CryptSymStartup(
		void
		)
{
    return TRUE;
}
/* 10.2.20.4 Data Access Functions */
/* 10.2.20.4.1 CryptGetSymmetricBlockSize() */
/* This function returns the block size of the algorithm. The table of bit sizes has an entry for
   each allowed key size. The entry for a key size is 0 if the TPM does not implement that key
   size. The key size table is delimited with a negative number (-1). After the delimiter is a list
   of block sizes with each entry corresponding to the key bit size. For most symmetric algorithms,
   the block size is the same regardless of the key size but this arrangement allows them to be
   different. */
/* Return Values Meaning */
/* <= 0 cipher not supported */
/* > 0 the cipher block size in bytes */

LIB_EXPORT INT16
CryptGetSymmetricBlockSize(
			   TPM_ALG_ID      symmetricAlg,   // IN: the symmetric algorithm
			   UINT16          keySizeInBits   // IN: the key size
			   )
{
    const INT16    *sizes;
    INT16            i;
#if 0	// libtpms added
#define ALG_CASE(SYM, sym)  case TPM_ALG_##SYM: sizes = sym##KeyBlockSizes; break
#endif	// libtpms added
    switch(symmetricAlg)
	{
#define GET_KEY_BLOCK_POINTER(SYM, sym)					\
	    case TPM_ALG_##SYM:						\
	      sizes =  sym##KeyBlockSizes;				\
	      break;
	    // Get the pointer to the block size array
	    FOR_EACH_SYM(GET_KEY_BLOCK_POINTER);

	  default:
	    return 0;
	}
    // Find the index of the indicated keySizeInBits
    for(i = 0; *sizes >= 0; i++, sizes++)
	{
	    if(*sizes == keySizeInBits)
		break;
	}
    // If sizes is pointing at the end of the list of key sizes, then the desired
    // key size was not found so set the block size to zero.
    if(*sizes++ < 0)
	return 0;
    // Advance until the end of the list is found
    while(*sizes++ >= 0);
    // sizes is pointing to the first entry in the list of block sizes. Use the
    // ith index to find the block size for the corresponding key size.
    return sizes[i];
}

#if !USE_OPENSSL_FUNCTIONS_SYMMETRIC // libtpms added
/* 10.2.20.5 Symmetric Encryption */
/* This function performs symmetric encryption based on the mode. */
/* Error Returns Meaning */
/* TPM_RC_SIZE dSize is not a multiple of the block size for an algorithm that requires it */
/* TPM_RC_FAILURE Fatal error */
LIB_EXPORT TPM_RC
CryptSymmetricEncrypt(
		      BYTE                *dOut,          // OUT:
		      TPM_ALG_ID           algorithm,     // IN: the symmetric algorithm
		      UINT16               keySizeInBits, // IN: key size in bits
		      const BYTE          *key,           // IN: key buffer. The size of this buffer
		      //     in bytes is (keySizeInBits + 7) / 8
		      TPM2B_IV            *ivInOut,       // IN/OUT: IV for decryption.
		      TPM_ALG_ID           mode,          // IN: Mode to use
		      INT32                dSize,         // IN: data size (may need to be a
		      //     multiple of the blockSize)
		      const BYTE          *dIn            // IN: data buffer
		      )
{
    BYTE                *pIv;
    int                  i;
    BYTE                 tmp[MAX_SYM_BLOCK_SIZE];
    BYTE                *pT;
    tpmCryptKeySchedule_t        keySchedule;
    INT16                blockSize;
    TpmCryptSetSymKeyCall_t        encrypt;
    BYTE                *iv;
    BYTE                 defaultIv[MAX_SYM_BLOCK_SIZE] = {0};
    //
    memset(&keySchedule, 0, sizeof(keySchedule));	// libtpms added; coverity
    pAssert(dOut != NULL && key != NULL && dIn != NULL);
    if(dSize == 0)
	return TPM_RC_SUCCESS;
    TEST(algorithm);
    blockSize = CryptGetSymmetricBlockSize(algorithm, keySizeInBits);
    if(blockSize == 0)
	return TPM_RC_FAILURE;
    // If the iv is provided, then it is expected to be block sized. In some cases,
    // the caller is providing an array of 0's that is equal to [MAX_SYM_BLOCK_SIZE]
    // with no knowledge of the actual block size. This function will set it.
    if((ivInOut != NULL) && (mode != TPM_ALG_ECB))
	{
	    ivInOut->t.size = blockSize;
	    iv = ivInOut->t.buffer;
	}
    else
	iv = defaultIv;
    pIv = iv;
    // Create encrypt key schedule and set the encryption function pointer.
    switch (algorithm)
	{
	    FOR_EACH_SYM(ENCRYPT_CASE)

	  default:
	    return TPM_RC_SYMMETRIC;
	}
    switch(mode)
	{
#if ALG_CTR
	  case TPM_ALG_CTR:
	    for(; dSize > 0; dSize -= blockSize)
		{
		    // Encrypt the current value of the IV(counter)
		    ENCRYPT(&keySchedule, iv, tmp);
		    //increment the counter (counter is big-endian so start at end)
		    for(i = blockSize - 1; i >= 0; i--)
			if((iv[i] += 1) != 0)
			    break;
		    // XOR the encrypted counter value with input and put into output
		    pT = tmp;
		    for(i = (dSize < blockSize) ? dSize : blockSize; i > 0; i--)
			*dOut++ = *dIn++ ^ *pT++;
		}
	    break;
#endif
#if ALG_OFB
	  case TPM_ALG_OFB:
	    // This is written so that dIn and dOut may be the same
	    for(; dSize > 0; dSize -= blockSize)
		{
		    // Encrypt the current value of the "IV"
		    ENCRYPT(&keySchedule, iv, iv);
		    // XOR the encrypted IV into dIn to create the cipher text (dOut)
		    pIv = iv;
		    for(i = (dSize < blockSize) ? dSize : blockSize; i > 0; i--)
			*dOut++ = (*pIv++ ^ *dIn++);
		}
	    break;
#endif
#if ALG_CBC
	  case TPM_ALG_CBC:
	    // For CBC the data size must be an even multiple of the
	    // cipher block size
	    if((dSize % blockSize) != 0)
		return TPM_RC_SIZE;
	    // XOR the data block into the IV, encrypt the IV into the IV
	    // and then copy the IV to the output
	    for(; dSize > 0; dSize -= blockSize)
		{
		    pIv = iv;
		    for(i = blockSize; i > 0; i--)
			*pIv++ ^= *dIn++;
		    ENCRYPT(&keySchedule, iv, iv);
		    pIv = iv;
		    for(i = blockSize; i > 0; i--)
			*dOut++ = *pIv++;
		}
	    break;
#endif
	    // CFB is not optional
	  case TPM_ALG_CFB:
	    // Encrypt the IV into the IV, XOR in the data, and copy to output
	    for(; dSize > 0; dSize -= blockSize)
		{
		    // Encrypt the current value of the IV
		    ENCRYPT(&keySchedule, iv, iv);
		    pIv = iv;
		    for(i = (int)(dSize < blockSize) ? dSize : blockSize; i > 0; i--)
			// XOR the data into the IV to create the cipher text
			// and put into the output
			*dOut++ = *pIv++ ^= *dIn++;
		}
	    // If the inner loop (i loop) was smaller than blockSize, then dSize
	    // would have been smaller than blockSize and it is now negative. If
	    // it is negative, then it indicates how many bytes are needed to pad
	    // out the IV for the next round.
	    for(; dSize < 0; dSize++)
		*pIv++ = 0;
	    break;
#if ALG_ECB
	  case TPM_ALG_ECB:
	    // For ECB the data size must be an even multiple of the
	    // cipher block size
	    if((dSize % blockSize) != 0)
		return TPM_RC_SIZE;
	    // Encrypt the input block to the output block
	    for(; dSize > 0; dSize -= blockSize)
		{
		    ENCRYPT(&keySchedule, dIn, dOut);
		    dIn = &dIn[blockSize];
		    dOut = &dOut[blockSize];
		}
	    break;
#endif
	  default:
	    return TPM_RC_FAILURE;
	}
    return TPM_RC_SUCCESS;
}
/* 10.2.20.5.1 CryptSymmetricDecrypt() */
/* This function performs symmetric decryption based on the mode. */
/* Error Returns Meaning */
/* TPM_RC_FAILURE A fatal error */
/* TPM_RCS_SIZE dSize is not a multiple of the block size for an algorithm that requires it */
LIB_EXPORT TPM_RC
CryptSymmetricDecrypt(
		      BYTE                *dOut,          // OUT: decrypted data
		      TPM_ALG_ID           algorithm,     // IN: the symmetric algorithm
		      UINT16               keySizeInBits, // IN: key size in bits
		      const BYTE          *key,           // IN: key buffer. The size of this buffer
		      //     in bytes is (keySizeInBits + 7) / 8
		      TPM2B_IV            *ivInOut,       // IN/OUT: IV for decryption.
		      TPM_ALG_ID           mode,          // IN: Mode to use
		      INT32                dSize,         // IN: data size (may need to be a
		      //     multiple of the blockSize)
		      const BYTE          *dIn            // IN: data buffer
		      )
{
    BYTE                *pIv;
    int                  i;
    BYTE                 tmp[MAX_SYM_BLOCK_SIZE];
    BYTE                *pT;
    tpmCryptKeySchedule_t        keySchedule;
    INT16                blockSize;
    BYTE                *iv;
    TpmCryptSetSymKeyCall_t        encrypt;
    TpmCryptSetSymKeyCall_t        decrypt;
    BYTE                 defaultIv[MAX_SYM_BLOCK_SIZE] = {0};

    memset(&keySchedule, 0, sizeof(keySchedule));	// libtpms added; coverity
    // These are used but the compiler can't tell because they are initialized
    // in case statements and it can't tell if they are always initialized
    // when needed, so... Comment these out if the compiler can tell or doesn't
    // care that these are initialized before use.
    encrypt = NULL;
    decrypt = NULL;
    pAssert(dOut != NULL && key != NULL && dIn != NULL);
    if(dSize == 0)
	return TPM_RC_SUCCESS;
    TEST(algorithm);
    blockSize = CryptGetSymmetricBlockSize(algorithm, keySizeInBits);
    if(blockSize == 0)
	return TPM_RC_FAILURE;
    // If the iv is provided, then it is expected to be block sized. In some cases,
    // the caller is providing an array of 0's that is equal to [MAX_SYM_BLOCK_SIZE]
    // with no knowledge of the actual block size. This function will set it.
    if((ivInOut != NULL) && (mode != TPM_ALG_ECB))
	{
	    ivInOut->t.size = blockSize;
	    iv = ivInOut->t.buffer;
	}
    else
	iv = defaultIv;
    pIv = iv;
    // Use the mode to select the key schedule to create. Encrypt always uses the
    // encryption schedule. Depending on the mode, decryption might use either
    // the decryption or encryption schedule.
    switch(mode)
	{
#if ALG_CBC || ALG_ECB
	  case TPM_ALG_CBC: // decrypt = decrypt
	  case TPM_ALG_ECB:
	    // For ECB and CBC, the data size must be an even multiple of the
	    // cipher block size
	    if((dSize % blockSize) != 0)
		return TPM_RC_SIZE;
	    switch (algorithm)
		{
		    FOR_EACH_SYM(DECRYPT_CASE)
		  default:
		    return TPM_RC_SYMMETRIC;
		}
	    break;
#endif
	  default:
	    // For the remaining stream ciphers, use encryption to decrypt
	    switch (algorithm)
		{
		    FOR_EACH_SYM(ENCRYPT_CASE)
		  default:
		    return TPM_RC_SYMMETRIC;
		}
	}
    // Now do the mode-dependent decryption
    switch(mode)
	{
#if ALG_CBC
	  case TPM_ALG_CBC:
	    // Copy the input data to a temp buffer, decrypt the buffer into the
	    // output, XOR in the IV, and copy the temp buffer to the IV and repeat.
	    for(; dSize > 0; dSize -= blockSize)
		{
		    pT = tmp;
		    for(i = blockSize; i > 0; i--)
			*pT++ = *dIn++;
		    DECRYPT(&keySchedule, tmp, dOut);
		    pIv = iv;
		    pT = tmp;
		    for(i = blockSize; i > 0; i--)
			{
			    *dOut++ ^= *pIv;
			    *pIv++ = *pT++;
			}
		}
	    break;
#endif
	  case TPM_ALG_CFB:
	    for(; dSize > 0; dSize -= blockSize)
		{
		    // Encrypt the IV into the temp buffer
		    ENCRYPT(&keySchedule, iv, tmp);
		    pT = tmp;
		    pIv = iv;
		    for(i = (dSize < blockSize) ? dSize : blockSize; i > 0; i--)
			// Copy the current cipher text to IV, XOR
			// with the temp buffer and put into the output
			*dOut++ = *pT++ ^ (*pIv++ = *dIn++);
		}
	    // If the inner loop (i loop) was smaller than blockSize, then dSize
	    // would have been smaller than blockSize and it is now negative
	    // If it is negative, then it indicates how may fill bytes
	    // are needed to pad out the IV for the next round.
	    for(; dSize < 0; dSize++)
		*pIv++ = 0;
	    break;
#if ALG_CTR
	  case TPM_ALG_CTR:
	    for(; dSize > 0; dSize -= blockSize)
		{
		    // Encrypt the current value of the IV(counter)
		    ENCRYPT(&keySchedule, iv, tmp);
		    //increment the counter (counter is big-endian so start at end)
		    for(i = blockSize - 1; i >= 0; i--)
			if((iv[i] += 1) != 0)
			    break;
		    // XOR the encrypted counter value with input and put into output
		    pT = tmp;
		    for(i = (dSize < blockSize) ? dSize : blockSize; i > 0; i--)
			*dOut++ = *dIn++ ^ *pT++;
		}
	    break;
#endif
#if ALG_ECB
	  case TPM_ALG_ECB:
	    for(; dSize > 0; dSize -= blockSize)
		{
		    DECRYPT(&keySchedule, dIn, dOut);
		    dIn = &dIn[blockSize];
		    dOut = &dOut[blockSize];
		}
	    break;
#endif
#if ALG_OFB
	  case TPM_ALG_OFB:
	    // This is written so that dIn and dOut may be the same
	    for(; dSize > 0; dSize -= blockSize)
		{
		    // Encrypt the current value of the "IV"
		    ENCRYPT(&keySchedule, iv, iv);
		    // XOR the encrypted IV into dIn to create the cipher text (dOut)
		    pIv = iv;
		    for(i = (dSize < blockSize) ? dSize : blockSize; i > 0; i--)
			*dOut++ = (*pIv++ ^ *dIn++);
		}
	    break;
#endif
	  default:
	    return TPM_RC_FAILURE;
	}
    return TPM_RC_SUCCESS;
}

#else // libtpms added begin

#if ALG_TDES && ALG_CTR
// Emulated TDES Counter mode since OpenSSL does not implement it
static void TDES_CTR(const BYTE *key,            // IN
                     INT32       keySizeInBits,  // IN
                     INT32       dSize,          // IN
                     const BYTE *dIn,            // IN
                     BYTE       *iv,             // IN
                     BYTE       *dOut,           // OUT
                     INT16       blockSize       // IN
                     )
{
    tpmCryptKeySchedule_t   keySchedule;
    int                     i;
    BYTE                    tmp[MAX_SYM_BLOCK_SIZE];
    BYTE                   *pT;

    TDES_set_encrypt_key(key, keySizeInBits,
                         (tpmKeyScheduleTDES *)&keySchedule.tdes);

    for(; dSize > 0; dSize -= blockSize)
	{
	    // Encrypt the current value of the IV(counter)
	    TDES_encrypt(iv, tmp, (tpmKeyScheduleTDES *)&keySchedule.tdes);
	    //increment the counter (counter is big-endian so start at end)
	    for(i = blockSize - 1; i >= 0; i--)
		if((iv[i] += 1) != 0)
		    break;
	    // XOR the encrypted counter value with input and put into output
	    pT = tmp;
	    for(i = (dSize < blockSize) ? dSize : blockSize; i > 0; i--)
		*dOut++ = *dIn++ ^ *pT++;
	}
}
#endif

/* 10.2.20.5 Symmetric Encryption */
/* This function performs symmetric encryption based on the mode. */
/* Error Returns Meaning */
/* TPM_RC_SIZE dSize is not a multiple of the block size for an algorithm that requires it */
/* TPM_RC_FAILURE Fatal error */
LIB_EXPORT TPM_RC
CryptSymmetricEncrypt(
		      BYTE                *dOut,          // OUT:
		      TPM_ALG_ID           algorithm,     // IN: the symmetric algorithm
		      UINT16               keySizeInBits, // IN: key size in bits
		      const BYTE          *key,           // IN: key buffer. The size of this buffer
		      //     in bytes is (keySizeInBits + 7) / 8
		      TPM2B_IV            *ivInOut,       // IN/OUT: IV for decryption.
		      TPM_ALG_ID           mode,          // IN: Mode to use
		      INT32                dSize,         // IN: data size (may need to be a
		      //     multiple of the blockSize)
		      const BYTE          *dIn            // IN: data buffer
		      )
{
    INT16                blockSize;
    BYTE                *iv;
    BYTE                 defaultIv[MAX_SYM_BLOCK_SIZE] = {0};
    evpfunc              evpfn;
    EVP_CIPHER_CTX      *ctx = NULL;
    int                  outlen1 = 0;
    int                  outlen2 = 0;
    BYTE                *pOut = dOut;
    BYTE                *buffer = NULL; // for in-place encryption
    UINT32               buffersize = 0;
    BYTE                 keyToUse[MAX_SYM_KEY_BYTES];
    UINT16               keyToUseLen = (UINT16)sizeof(keyToUse);
    TPM_RC               retVal = TPM_RC_SUCCESS;
    int                  ivLen;

    pAssert(dOut != NULL && key != NULL && dIn != NULL);
    if(dSize == 0)
	return TPM_RC_SUCCESS;
    TEST(algorithm);
    blockSize = CryptGetSymmetricBlockSize(algorithm, keySizeInBits);
    if(blockSize == 0)
	return TPM_RC_FAILURE;
    // If the iv is provided, then it is expected to be block sized. In some cases,
    // the caller is providing an array of 0's that is equal to [MAX_SYM_BLOCK_SIZE]
    // with no knowledge of the actual block size. This function will set it.
    if((ivInOut != NULL) && (mode != TPM_ALG_ECB))
	{
	    ivInOut->t.size = blockSize;
	    iv = ivInOut->t.buffer;
	}
    else
	iv = defaultIv;

    switch (mode)
        {
          case TPM_ALG_ECB:
          case TPM_ALG_CBC:
	    // For ECB & CBC the data size must be an even multiple of the
	    // cipher block size
	    if((dSize % blockSize) != 0)
		return TPM_RC_SIZE;
        }

    evpfn = GetEVPCipher(algorithm, keySizeInBits, mode, key,
                         keyToUse, &keyToUseLen);
    if (evpfn == NULL)
        return TPM_RC_FAILURE;

    if (dIn == dOut) {
        // in-place encryption; we use a temp buffer
        buffersize = TPM2_ROUNDUP(dSize, blockSize);
        buffer = malloc(buffersize);
        if (buffer == NULL)
            ERROR_RETURN(TPM_RC_FAILURE);

        pOut = buffer;
    }

#if ALG_TDES && ALG_CTR
    if (algorithm == TPM_ALG_TDES && mode == TPM_ALG_CTR) {
        TDES_CTR(keyToUse, keyToUseLen * 8, dSize, dIn, iv, pOut, blockSize);
        outlen1 = dSize;
        ERROR_RETURN(TPM_RC_SUCCESS);
    }
#endif

    ctx = EVP_CIPHER_CTX_new();
    if (!ctx ||
        EVP_EncryptInit_ex(ctx, evpfn(), NULL, keyToUse, iv) != 1 ||
        EVP_CIPHER_CTX_set_padding(ctx, 0) != 1 ||
        EVP_EncryptUpdate(ctx, pOut, &outlen1, dIn, dSize) != 1)
        ERROR_RETURN(TPM_RC_FAILURE);

    pAssert(outlen1 <= dSize || dSize >= outlen1 + blockSize);

    if (EVP_EncryptFinal_ex(ctx, pOut + outlen1, &outlen2) != 1)
        ERROR_RETURN(TPM_RC_FAILURE);

    if (ivInOut) {
        ivLen = EVP_CIPHER_CTX_iv_length(ctx);
        if (ivLen < 0 || (size_t)ivLen > sizeof(ivInOut->t.buffer))
            ERROR_RETURN(TPM_RC_FAILURE);

        ivInOut->t.size = ivLen;
        memcpy(ivInOut->t.buffer, EVP_CIPHER_CTX_iv(ctx), ivInOut->t.size);
    }
 Exit:
    if (retVal == TPM_RC_SUCCESS && pOut != dOut)
        memcpy(dOut, pOut, outlen1 + outlen2);

    clear_and_free(buffer, buffersize);
    EVP_CIPHER_CTX_free(ctx);

    return retVal;
}

/* 10.2.20.5.1 CryptSymmetricDecrypt() */
/* This function performs symmetric decryption based on the mode. */
/* Error Returns Meaning */
/* TPM_RC_FAILURE A fatal error */
/* TPM_RCS_SIZE dSize is not a multiple of the block size for an algorithm that requires it */
LIB_EXPORT TPM_RC
CryptSymmetricDecrypt(
		      BYTE                *dOut,          // OUT: decrypted data
		      TPM_ALG_ID           algorithm,     // IN: the symmetric algorithm
		      UINT16               keySizeInBits, // IN: key size in bits
		      const BYTE          *key,           // IN: key buffer. The size of this buffer
		      //     in bytes is (keySizeInBits + 7) / 8
		      TPM2B_IV            *ivInOut,       // IN/OUT: IV for decryption.
		      TPM_ALG_ID           mode,          // IN: Mode to use
		      INT32                dSize,         // IN: data size (may need to be a
		      //     multiple of the blockSize)
		      const BYTE          *dIn            // IN: data buffer
		      )
{
    INT16                blockSize;
    BYTE                *iv;
    BYTE                 defaultIv[MAX_SYM_BLOCK_SIZE] = {0};
    evpfunc              evpfn;
    EVP_CIPHER_CTX      *ctx = NULL;
    int                  outlen1 = 0;
    int                  outlen2 = 0;
    BYTE                *buffer;
    UINT32               buffersize = 0;
    BYTE                 keyToUse[MAX_SYM_KEY_BYTES];
    UINT16               keyToUseLen = (UINT16)sizeof(keyToUse);
    TPM_RC               retVal = TPM_RC_SUCCESS;
    int                  ivLen;

    // These are used but the compiler can't tell because they are initialized
    // in case statements and it can't tell if they are always initialized
    // when needed, so... Comment these out if the compiler can tell or doesn't
    // care that these are initialized before use.
    pAssert(dOut != NULL && key != NULL && dIn != NULL);
    if(dSize == 0)
	return TPM_RC_SUCCESS;
    TEST(algorithm);
    blockSize = CryptGetSymmetricBlockSize(algorithm, keySizeInBits);
    if(blockSize == 0)
	return TPM_RC_FAILURE;
    // If the iv is provided, then it is expected to be block sized. In some cases,
    // the caller is providing an array of 0's that is equal to [MAX_SYM_BLOCK_SIZE]
    // with no knowledge of the actual block size. This function will set it.
    if((ivInOut != NULL) && (mode != TPM_ALG_ECB))
	{
	    ivInOut->t.size = blockSize;
	    iv = ivInOut->t.buffer;
	}
    else
	iv = defaultIv;

    switch(mode)
	{
#if ALG_CBC || ALG_ECB
	  case TPM_ALG_CBC:
	  case TPM_ALG_ECB:
	    // For ECB and CBC, the data size must be an even multiple of the
	    // cipher block size
	    if((dSize % blockSize) != 0)
		return TPM_RC_SIZE;
	    break;
#endif
	  default:
	    break;
	}

    evpfn = GetEVPCipher(algorithm, keySizeInBits, mode, key,
                         keyToUse, &keyToUseLen);
    if (evpfn ==  NULL)
        return TPM_RC_FAILURE;

    /* a buffer with a 'safety margin' for EVP_DecryptUpdate */
    buffersize = TPM2_ROUNDUP(dSize + blockSize, blockSize);
    buffer = malloc(buffersize);
    if (buffer == NULL)
        ERROR_RETURN(TPM_RC_FAILURE);

#if ALG_TDES && ALG_CTR
    if (algorithm == TPM_ALG_TDES && mode == TPM_ALG_CTR) {
        TDES_CTR(keyToUse, keyToUseLen * 8, dSize, dIn, iv, buffer, blockSize);
        outlen1 = dSize;
        ERROR_RETURN(TPM_RC_SUCCESS);
    }
#endif

    ctx = EVP_CIPHER_CTX_new();
    if (!ctx ||
        EVP_DecryptInit_ex(ctx, evpfn(), NULL, keyToUse, iv) != 1 ||
        EVP_CIPHER_CTX_set_padding(ctx, 0) != 1 ||
        EVP_DecryptUpdate(ctx, buffer, &outlen1, dIn, dSize) != 1)
        ERROR_RETURN(TPM_RC_FAILURE);

    pAssert((int)buffersize >= outlen1);

    if ((int)buffersize <= outlen1 /* coverity */ ||
        EVP_DecryptFinal(ctx, &buffer[outlen1], &outlen2) != 1)
        ERROR_RETURN(TPM_RC_FAILURE);

    pAssert((int)buffersize >= outlen1 + outlen2);

    if (ivInOut) {
        ivLen = EVP_CIPHER_CTX_iv_length(ctx);
        if (ivLen < 0 || (size_t)ivLen > sizeof(ivInOut->t.buffer))
            ERROR_RETURN(TPM_RC_FAILURE);

        ivInOut->t.size = ivLen;
        memcpy(ivInOut->t.buffer, EVP_CIPHER_CTX_iv(ctx), ivInOut->t.size);
    }

 Exit:
    if (retVal == TPM_RC_SUCCESS) {
        pAssert(dSize >= outlen1 + outlen2);
        memcpy(dOut, buffer, outlen1 + outlen2);
    }

    clear_and_free(buffer, buffersize);
    EVP_CIPHER_CTX_free(ctx);

    return retVal;
}

#endif // libtpms added end

/* 10.2.20.5.2 CryptSymKeyValidate() */
/* Validate that a provided symmetric key meets the requirements of the TPM */
/* Error Returns Meaning */
/* TPM_RC_KEY_SIZE Key size specifiers do not match */
/* TPM_RC_KEY Key is not allowed */
TPM_RC
CryptSymKeyValidate(
		    TPMT_SYM_DEF_OBJECT *symDef,
		    TPM2B_SYM_KEY       *key
		    )
{
    if(key->t.size != BITS_TO_BYTES(symDef->keyBits.sym))
	return TPM_RCS_KEY_SIZE;
#if ALG_TDES
    if(symDef->algorithm == TPM_ALG_TDES && !CryptDesValidateKey(key))
	return TPM_RCS_KEY;
#endif // TPM_ALG_TDES
    return TPM_RC_SUCCESS;
}