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/*
* FreeRTOS V202112.00
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
/* Standard includes. */
#include "stdio.h"
/* PKCS #11 includes. */
#include "core_pkcs11_config.h"
#include "core_pkcs11.h"
#include "pkcs11.h"
/* Demo includes. */
#include "demo_helpers.h"
#include "pkcs11_demos.h"
/**
* This function details what Cryptoki mechanisms are, how to query a slot's
* support for them, and how to use those mechanisms to generate a hash of a buffer.
* This can then be used as a message digest.
*
* http://docs.oasis-open.org/pkcs11/pkcs11-base/v2.40/os/pkcs11-base-v2.40-os.html
* please consult the standard for more information.
*
* The standard has grouped the functions presented in this demo as:
* Slot and token management functions.
* Message digesting functions.
*
*/
void vPKCS11MechanismsAndDigestDemo( void )
{
/*
* This demo builds upon the demo found in "management_and_rng.c". It borrows
* code and terminology defined and explained, and it is recommended to complete
* the "management and rng" demo before this one.
*/
configPRINTF( ( "\r\nStarting PKCS #11 Mechanisms and Digest Demo.\r\n" ) );
CK_SESSION_HANDLE hSession = CK_INVALID_HANDLE;
CK_SLOT_ID * pxSlotId = 0;
CK_FUNCTION_LIST_PTR pxFunctionList = NULL;
CK_ULONG ulIndex = 0;
CK_RV xResult = CKR_OK;
/* The PKCS #11 standard defines a mechanism to be a "A process for
* implementing a cryptographic operation." For example the SHA-256 algorithm
* will be the mechanism used in this demo to perform a digest (hash operation).
*
* The mechanism types are defined in "pkcs11t.h", and are prefixed CKM_, to
* provide a portable way to identify mechanisms.
*/
CK_MECHANISM_TYPE xMechanismType = 0;
/* This variable is not directly used, but is instantiated for demonstration
* purposes.
*/
( void ) xMechanismType;
/* The CK_MECHANISM_INFO allows the application to retrieve the minimum and
* maximum key sizes supported by the mechanism (could be in bits or bytes).
* The structure also has a flags field, that is populated with bit flags
* for what features the mechanism supports.
*/
CK_MECHANISM_INFO MechanismInfo = { 0 };
/* The CK_MECHANISM type contains the mechanism type, as well as a pointer
* for mechanism parameters and a CK_ULONG indicating the length of the
* parameters.
*/
CK_MECHANISM xDigestMechanism = { 0 };
/* The digest will return a hash of the known SHA-256 hash size, 32 bytes.
* Please see this page for further explanation of the SHA-256 hash.
* https://en.wikipedia.org/wiki/SHA-2
*/
CK_BYTE xDigestResult[ pkcs11SHA256_DIGEST_LENGTH ] = { 0 };
CK_ULONG ulDigestLength = pkcs11SHA256_DIGEST_LENGTH;
CK_BYTE pxKnownMessage[] = "Hello world!";
vStart( &hSession, &pxSlotId );
xResult = C_GetFunctionList( &pxFunctionList );
configASSERT( CKR_OK == xResult );
configASSERT( pxFunctionList->C_GetMechanismInfo != NULL );
configASSERT( pxFunctionList->C_DigestInit != NULL );
configASSERT( pxFunctionList->C_DigestUpdate != NULL );
configASSERT( pxFunctionList->C_DigestFinal != NULL );
/*************************** RSA Capabilities ***************************/
xResult = pxFunctionList->C_GetMechanismInfo( pxSlotId[ 0 ],
CKM_RSA_PKCS,
&MechanismInfo );
configASSERT( CKR_OK == xResult );
/* Check to see if the slot supports signing. This capability is important
* because we want to use the Cryptoki API to sign messages, without directly
* accessing the private key. This concept will be explained further in the
* "sign_verify.c" demo, but for now we will just check that the slot has the
* capabilities we need. See https://en.wikipedia.org/wiki/Public-key_cryptography
* for more information regarding private keys and public keys.
*/
if( 0 != ( CKF_SIGN & MechanismInfo.flags ) )
{
configPRINTF( ( "This Cryptoki library supports signing messages with RSA" \
" private keys.\r\n" ) );
}
else
{
configPRINTF( ( "This Cryptoki library does not support signing messages" \
" with RSA private keys.\r\n" ) );
}
/* This Cryptoki library assumes that RSA private keys are 2048 bit . */
configASSERT( MechanismInfo.ulMaxKeySize >= pkcs11RSA_2048_MODULUS_BITS );
configASSERT( MechanismInfo.ulMinKeySize <= pkcs11RSA_2048_MODULUS_BITS );
/* Check for pre-padded signature verification support, this feature will
* be used in the "sign_verify.c" demo.
*/
xResult = pxFunctionList->C_GetMechanismInfo( pxSlotId[ 0 ],
CKM_RSA_X_509,
&MechanismInfo );
/* If this fails, the slot is not able to verify the signature using
* a RSA public key. Please see https://en.wikipedia.org/wiki/Public_key_infrastructure
* for more information regarding PKI (Public Key Infrastructure).
*/
if( 0 != ( CKF_VERIFY & MechanismInfo.flags ) )
{
configPRINTF( ( "This Cryptoki library supports verifying messages with RSA" \
" public keys.\r\n" ) );
}
else
{
configPRINTF( ( "This Cryptoki library does not support verifying messages" \
" with RSA public keys.\r\n" ) );
}
/* This Cryptoki library assumes that RSA public keys are 2048 bit . */
configASSERT( MechanismInfo.ulMaxKeySize >= pkcs11RSA_2048_MODULUS_BITS );
configASSERT( MechanismInfo.ulMinKeySize <= pkcs11RSA_2048_MODULUS_BITS );
/*************************** ECDSA Capabilities ***************************/
xResult = pxFunctionList->C_GetMechanismInfo( pxSlotId[ 0 ],
CKM_ECDSA,
&MechanismInfo );
configASSERT( CKR_OK == xResult );
if( 0 != ( CKF_SIGN & MechanismInfo.flags ) )
{
configPRINTF( ( "This Cryptoki library supports signing messages with" \
" ECDSA private keys.\r\n" ) );
}
else
{
configPRINTF( ( "This Cryptoki library does not support signing messages" \
" with ECDSA private keys.\r\n" ) );
}
if( 0 != ( CKF_VERIFY & MechanismInfo.flags ) )
{
configPRINTF( ( "This Cryptoki library supports verifying messages with" \
" ECDSA public keys.\r\n" ) );
}
else
{
configPRINTF( ( "This Cryptoki library does not support verifying" \
" messages with ECDSA public keys.\r\n" ) );
}
configASSERT( MechanismInfo.ulMaxKeySize >= pkcs11ECDSA_P256_KEY_BITS );
configASSERT( MechanismInfo.ulMinKeySize <= pkcs11ECDSA_P256_KEY_BITS );
/************************** Digest Capabilities **************************/
xResult = pxFunctionList->C_GetMechanismInfo( pxSlotId[ 0 ],
CKM_SHA256,
&MechanismInfo );
configASSERT( CKR_OK == xResult );
if( 0 != ( CKF_DIGEST & MechanismInfo.flags ) )
{
configPRINTF( ( "The Cryptoki library supports the " \
"SHA-256 algorithm.\r\n" ) );
}
else
{
configPRINTF( ( "The Cryptoki library doesn't support the " \
"SHA-256 algorithm.\r\n" ) );
}
/***************************** Buffer Digest *****************************/
/* Hash with SHA256 mechanism. */
xDigestMechanism.mechanism = CKM_SHA256;
/* Initializes the digest operation and sets what mechanism will be used
* for the digest. */
xResult = pxFunctionList->C_DigestInit( hSession,
&xDigestMechanism );
configASSERT( CKR_OK == xResult );
/* Pass a pointer to the buffer of bytes to be hashed, and it's size. */
xResult = pxFunctionList->C_DigestUpdate( hSession,
pxKnownMessage,
/* Strip NULL Terminator. */
sizeof( pxKnownMessage ) - 1 );
configASSERT( CKR_OK == xResult );
/* Retrieve the digest buffer. Since the mechanism is a SHA-256 algorithm,
* the size will always be 32 bytes. If the size cannot be known ahead of time,
* a NULL value to the second parameter pDigest, will set the third parameter,
* pulDigestLen to the number of required bytes. */
xResult = pxFunctionList->C_DigestFinal( hSession,
xDigestResult,
&ulDigestLength );
configASSERT( CKR_OK == xResult );
/* This will now print out the digest of the known message. You can compare
* the hash generated by the Cryptoki library in a UNIX shell by using the
* command '$ echo -n "{pxKnownMessage}" | shasum -a 256'
* this command should generate the same hash. */
configPRINTF( ( "Known message: %s\r\n", ( char * ) pxKnownMessage ) );
configPRINTF( ( "Hash of known message using SHA256:\r\n" ) );
for( ulIndex = 0; ulIndex < ulDigestLength; ulIndex++ )
{
configPRINTF( ( "%x", xDigestResult[ ulIndex ] ) );
}
configPRINTF( ( "\r\n" ) );
configPRINTF( ( "Finished PKCS #11 Mechanisms and Digest Demo.\r\n" ) );
vEnd( hSession, pxSlotId );
}
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