TM4C1294KCPDT: Implementing mbedtls for mqtt/tls using lwip

Hi Charles,

I contact with mbed tls support team, and tried to implement as per their suggetions. The ssl context setup function 'mbedtls_ssl_setup' calls malloc function from 'ti/ccsv6/tools/compiler/arm_5.1.6/lib/src/memory.c' file.

In this file:

/*-----------------------------------------------------------------------*/
/* SCAN THROUGH FREE LIST FOR PACKET LARGE ENOUGH TO CONTAIN PACKET */
/*-----------------------------------------------------------------------*/
while (current && current->packet_size < newsize)
current = current->size_ptr;

if (!current)
{
_unlock();
return NULL;
}

it returns 'current=null', because of this I am unable to continue with my further tls handshaking process.

Kindly guide me through this.

Hi Charles,

I have already declared heap=stack size=8192 i.e. 8K. But then also the problem was there.

But I tried to increase heap size to 40k and then my problem get resolved. Thank you.

Now I have other problem: when I use 'mbedtls_threading_set_alt' function, it gives me following errors:

threading_mutex_free_pthread, threading_mutex_init_pthread, threading_mutex_lock_pthread , threading_mutex_unlock_pthread unresolved symbols.

How to resolve this issue?

Hi Charles,

threading_mutex_free_pthread functions are not really third party. It is actually under "third_party/mbedtls/ti/port/threading_alt.c" file; where port is belongs to core I guess.

I have msp432e401y eval kit and i am testing publish_subscribe example on it. Here they are using RTOS with ndk stack along with mbedtls. But in my case I am using non RTOS with lwip along with mbedtls. 

As I move further with debugging, threading_mutex_free_pthread function calls pthread_mutex_lock function. It further moves to acquireMutex function in 'C:\ti\simplelink_msp432e4_sdk_3_10_00_11\source\ti\posix\tirtos\pthread_mutex.c' file. So instead of msp432 tirtos posix, how can I use tm4c1294kcpdt nortos lwip for this?

Regards.

Hi,

TivaWare_C_Series_x doesn't has mbedtls. I am refering it from simplelink_msp432_sdk_x. See below attached image:

I have already contact mbedtls support team and as per their suggestions I tried to implement the steps and many of bugs get resolved. But at this point I got stuck in this errors that threading_mutex_free_pthread() functions are unresolved.

For reference you can also go through 'threading_alt.c/.h' and 'entropy_alt.c/.h' files here attached.

/*
 *  Threading abstraction layer
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 */
#include <mbedtls/threading.h>

#include "threading_alt.h"

void threading_mutex_init_pthread( mbedtls_threading_mutex_t *mutex )
{
    if( mutex == NULL || mutex->is_valid )
        return;

    mutex->is_valid = pthread_mutex_init( &mutex->mutex, NULL ) == 0;
}

void threading_mutex_free_pthread( mbedtls_threading_mutex_t *mutex )
{
    if( mutex == NULL || !mutex->is_valid )
        return;

    (void) pthread_mutex_destroy( &mutex->mutex );
    mutex->is_valid = 0;
}

int threading_mutex_lock_pthread( mbedtls_threading_mutex_t *mutex )
{
    if( mutex == NULL || ! mutex->is_valid )
        return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );

    if( pthread_mutex_lock( &mutex->mutex ) != 0 )
        return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );

    return( 0 );
}

int threading_mutex_unlock_pthread( mbedtls_threading_mutex_t *mutex )
{
    if( mutex == NULL || ! mutex->is_valid )
        return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );

    if( pthread_mutex_unlock( &mutex->mutex ) != 0 )
        return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );

    return( 0 );
}

/*
 *  Copyright (C) 2017, Texas Instruments Incorporated, All Rights Reserved
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
#include <stdlib.h>
#include <time.h>
#include <mbedtls/entropy.h>
#include <entropy_alt.h>

int entropy_source(void *data, unsigned char *output, size_t len, size_t *olen)
{
    int i;
    unsigned int seed;

    if (!output || !len || !olen) {
        return (MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
    }

    if (data != NULL) {
        seed = *(int *)data ^ time(NULL);
    }
    else {
        seed = time(NULL);
    }

    srand(seed);
    for (i = 0; i < len; i++) {
         output[i] = rand() % 256;
    }

    *olen = len;

    return (0);
}

MY MAIN PROBLEM IS I WANT TO  IMPLEMENT SECURE MQTT CLIENT ON TIVA TM4C1294KCPDT USING LWIP+MBEDTLS.

As for now I tried to implement mbedtls steps and now I am stuck where actually low level core relevant implemetation is there. For MSP IC they have given posix functions which are relevant to msp core; but I want to implement it on tm4c.

Any one having knowledge on both msp432_sdk and tivaware kindly help me through this....

Regards.

Hi Urvi,

  Now I understand you got from the simplelink for msp432. Please note that simplelink is a completely different platform for software development compared to the TivaWare. As a matter of fact, the msp432 and Tiva are two different product lines. I have no knowledge of simplelink SDK at all as Tiva does not support simplelink. We can't support you if you are trying to use simplelink software on  Tiva devices. Have you post your question to the MSP forum at https://e2e.ti.com/support/microcontrollers/msp430/f/166. I hope their experts can assist your question related to the Simplelink SDK.