February 2024 - mbed-tls - lists.trustedfirmware.org

Reminder: MBed TLS Tech Forum - Asia/Europe

by Don Harbin

Hi All, A gentle reminder that the Asia-Europe timezone-friendly MBed TLS Tech forum is next Monday at 10:00am PM UK time. Invite details can be found on the online calendar here <https://www.trustedfirmware.org/meetings/>. If you have any topics, please let Dave Rodgman know. :) Best regards, Don Harbin TrustedFirmware Community Manager don.harbin(a)linaro.org ReplyReply to allForward Compose: Community activity: OpenCV, Sensors, AI [image: Minimise][image: Pop-out][image: Close] Compose: Reminder: MBed TLS Tech Forum - Asia/Europe [image: Minimise][image: Pop-out][image: Close] Recipients

2 weeks

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Error while parsing certificate

by Subramanian Gopi Krishnan

Hi, I have an inhouse developed secure authentication program that uses certificate for authentication. I have used mbedtls library for the x.509 certificate verification purpose. In our custom PKI we have only three level of certificates, Root-CA -> Intermediate-CA -> Device-Cert. The embedded device has very limited memory, so instead of sending whole certificate chain, the devices communicates intermediate_CA and device cert (in der format base64 encoded) in separate packet. Root-CA will be available on node as trusted-ca. Intermediate is verified against Root; then device cert is verified against intermediate. The problem is, the poc developed on linux platform is working fine - but on embedded platform I encounter either 0x3b00(parsing failed) or 0x2700(with flag 8). Also the error code are inconsistent. I verified the integrity of packet with certificate using crc16. So no chance of certificate getting corrupted. Also verified the certificate's base64 format integrity using crc16. All certificates are sha256WithRSAEncryption; RSA Public-Key: (4096 bit) Attached config.h on target platform for reference - could you help me if anything wrong with configuration. While trying to trace, the flag was set from x509_crt.c from below code. /* No parent? We're done here */ if( parent == NULL ) { printf("NO_PARENT\r\n"); *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; return( 0 ); } Any clue would be helpful. Thanks, Gopi Krishnan

2 months, 3 weeks

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Reminder: MBed TLS Tech Forum - US/Europe

by Don Harbin

Hi All, A gentle reminder that the US-Europe timezone-friendly MBed TLS Tech forum is next Monday at 4:30 PM UK time. Invite details can be found on the online calendar here <https://www.trustedfirmware.org/meetings/>. If you have any topics, please let Dave Rodgman know. :) Best regards, Don Harbin TrustedFirmware Community Manager don.harbin(a)linaro.org

2 months, 3 weeks

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MBed TLS - Generic Question

by Satya Prakash Prasad

Hi Team, Referring to MBed release page - https://github.com/Mbed-TLS/mbedtls/releases?page=1 I see that there has been constant release periodically from Jul 27, 2018 mbedtls-2.1.14 till Nov 8, 2023 v3.5.1. In the same context I understand that with each release there have been fixes and new features / enhancement implementation. There was a project that I was working in year 2020 were we tried to integrate MBed TLS in EAP https://github.com/prplfoundation/hostap. It was a practice exercise that our team did that time. I have not much idea as to which MBed TLS version was opted and integrated then. Now that so many new releases are made after 2020 - are older versions can be taken as stable? Is it that we should take the latest version and try again from scratch? Thanks in advance. Regards, Prakash

4 months, 2 weeks

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Importing ECC privatekey (from PEM) into PSA and mbedtls_ecp_export undefined reference error

by mathi.naickan＠gmail.com

Hi, Iam trying to import an ECC privatekey(parsed through mbedtls_parse_key()) to PSA (psa_import_key()) (for ECDSA NIST-P256-SECP-R1), by following the suggestions here ==> https://github.com/Mbed-TLS/mbedtls/blob/development/docs/psa-transition.md (under the heading - Importing a PK key by export-import for an ECC private key). But, i get an undefined reference to `mbedtls_ecp_export' error. Is there a special flag that controls this? I can see that the definition of this function does exist in ecp.c. Kind Regards, Mathi.

4 months, 2 weeks

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Release all memory held by mbedtls_ssl_context

by Satya Prakash Prasad

Hi, We are writing a client code which can accept or decline connection to the server - so for each connection I understand there is a mbedtls_ssl_context data established. Once the same is closed or not required we need to do deinitialize or free memory allocated to its member variables like - we need to free all memory allocated since we need it back else our application will run out of memory like: os_free(mbed_ctx->handshake); os_free(mbed_ctx->transform_negotiate); os_free(mbed_ctx->session_negotiate); os_free(mbed_ctx->in_buf); os_free(mbed_ctx->out_buf); But there are many member variables which also need to free memory if allocated and assigned to it. Is there a function / method that can free all memory for mbedtls_ssl_context instance variable? Thanks in advance. Regards, Prakash

5 months

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Reminder: MBed TLS Tech Forum - Asia/Europe

by Don Harbin

Hi All, A gentle reminder that the Asia-Europe timezone-friendly MBed TLS Tech forum is next Monday at 10:00am PM UK time. Invite details can be found on the online calendar here <https://www.trustedfirmware.org/meetings/>. If you have any topics, please let Dave Rodgman know. :) Best regards, Don Harbin TrustedFirmware Community Manager don.harbin(a)linaro.org

5 months

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Building mbedtls-2.19.1

by Satya Prakash Prasad

Hi, Please note that I needed to compile and work with MBed TLS version 2.19.1 https://github.com/Mbed-TLS/mbedtls/releases/tag/mbedtls-2.19.1 However I am unable to compile the code / examples in it - i get below error: *$ cmake .CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required): Compatibility with CMake < 2.8.12 will be removed from a future version of CMake. Update the VERSION argument <min> value or use a ...<max> suffix to tell CMake that the project does not need compatibility with older versions.-- Selecting Windows SDK version 10.0.19041.0 to target Windows 10.0.22631.CMake Error at CMakeLists.txt:192 (add_subdirectory): add_subdirectory given source "crypto/3rdparty" which is not an existing directory.CMake Error at CMakeLists.txt:199 (add_subdirectory): add_subdirectory given source "crypto/library" which is not an existing directory.CMake Error at CMakeLists.txt:200 (add_subdirectory): add_subdirectory given source "crypto/include" which is not an existing directory.CMake Warning (dev) at programs/ssl/CMakeLists.txt:37 (target_sources): Policy CMP0076 is not set: target_sources() command converts relative paths to absolute. Run "cmake --help-policy CMP0076" for policy details. Use the cmake_policy command to set the policy and suppress this warning. An interface source of target "ssl_client2" has a relative path.This warning is for project developers. Use -Wno-dev to suppress it.CMake Warning (dev) at programs/ssl/CMakeLists.txt:44 (target_sources): Policy CMP0076 is not set: target_sources() command converts relative paths to absolute. Run "cmake --help-policy CMP0076" for policy details. Use the cmake_policy command to set the policy and suppress this warning. An interface source of target "ssl_server2" has a relative path.This warning is for project developers. Use -Wno-dev to suppress it.CMake Warning (dev) at programs/test/CMakeLists.txt:31 (target_sources): Policy CMP0076 is not set: target_sources() command converts relative paths to absolute. Run "cmake --help-policy CMP0076" for policy details. Use the cmake_policy command to set the policy and suppress this warning. An interface source of target "query_compile_time_config" has a relative path.This warning is for project developers. Use -Wno-dev to suppress it.* I tried removing the errors from the CmakeFile.txt but now get below error: *$ cmake --build .Microsoft (R) Build Engine version 16.11.2+f32259642 for .NET FrameworkCopyright (C) Microsoft Corporation. All rights reserved.MSBUILD : error MSB1009: Project file does not exist.Switch: ALL_BUILD.vcxproj* Also make all Makefile:84: ../crypto/3rdparty/Makefile.inc: No such file or directory make[1]: *** No rule to make target '../crypto/3rdparty/Makefile.inc'. Stop. Makefile:19: recipe for target 'lib' failed make: *** [lib] Error 2 Please let me know how to resolve them and compile MBedTLS version 2.19.1 code? Thanks in advance. Regards, Prakash

5 months

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EAP TLS

by Satya Prakash Prasad

Hi, I am working on an issue related to memory leak in MBedTLS. We have integrated MBedTLS code for below 3rd party HostAPD code integration . https://github.com/prplfoundation/hostap [Hostapd] Please refer to the Hostapd peer code implementation as provided in the link below: https://github.com/prplfoundation/hostap/blob/master/eap_example/eap_exampl… https://github.com/prplfoundation/hostap/blob/master/eap_example/eap_exampl… The main function code snippet is provided below: https://github.com/prplfoundation/hostap/blob/master/eap_example/eap_exampl… if (eap_example_peer_init() < 0 || eap_example_server_init() < 0) return -1; do { printf("---[ server ]--------------------------------\n"); res_s = eap_example_server_step(); printf("---[ peer ]----------------------------------\n"); res_p = eap_example_peer_step(); } while (res_s || res_p); Since we are implementing code for peers hence we have removed the server step. Now we need to keep monitoring for new connections / failed connections and act accordingly we have modified the code to something like below - if (eap_example_peer_init() < 0 || eap_example_server_init() < 0) return -1; do { res_p = eap_example_peer_step(); if (eap_ctx.eapNoResp || eap_ctx.eapFail) { eap_client_peer_deinit(); eap_client_peer_init(); } } while (1); We have modified the loop such that it will keep iterating for new connections and in case of failure, re-initialization is required. Is my understanding correct? The issue I am facing is that the client peer deinit method is not releasing all memory allocated during eap_example_peer_step() function ( I understand while processing the EAP TLS server request). The deinit is purely implemented to deallocate memory initially allocated for a new connection using TLS? void eap_client_peer_deinit(void) { eap_peer_sm_deinit(eap_ctx.eap); eap_peer_unregister_methods(); wpabuf_free(eap_ctx.eapReqData); os_free(eap_ctx.eap_config.identity); os_free(eap_ctx.eap_config.password); os_free(eap_ctx.eap_config.cert.ca_cert); os_free(eap_ctx.eap_config.cert.client_cert); os_free(eap_ctx.eap_config.cert.private_key); } where void eap_peer_sm_deinit(struct eap_sm *sm) { if (sm == NULL) return; eap_deinit_prev_method(sm, "deinit"); eap_sm_abort(sm); if (sm->ssl_ctx2) tls_deinit(sm->ssl_ctx2); tls_deinit(sm->ssl_ctx); eap_peer_erp_free_keys(sm); os_free(sm); } Can you please let me know whether we are deallocating memory correctly? Thanks in advance. Regards, Prakash

5 months

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Handshake is successful if the intermediate CA is revoked.

by singaravelu Balasubramani

I am checking the certificate revocation with below scenario. I have Root CA, Intermediate CA and device certificate is signed by Intermediate CA. I am makeing chain certificate by combining Root CA, Intermediate CA and this chain certificate is my active CA certificate and loaded this and device certificate to the drive. From client, I am creating client certificate which is signed by same intermeidate CA. Making ssl handshake. Handshake is success as expected. Now i am revoking the intermediate CA and creating the crl which is signed by the Root CA. This crl has the serial number of intermediate CA. Now loading the CRL to the drive and setting the crl in "mbedtls_ssl_conf_ca_chain". Now i am establishing the ssl connection with the same client ceritificate and expecting the ssl handshake failure due to intermediate CA revoked. But i get handshake is success. Is my understanding right about intermediate CA revocation? I did little background debug, and my obervation is During handshake , it goes to static int x509_crt_verify_chain function in mbedtls. Its trying to find the parent using x509_crt_find_parent for the client certificate and get intermediate CA. During this time, parent_is_trusted is set as true. after this x509_crt_verifycrl is called with client certificate (child), intermediate CA (parent) and crl(has the intermediate CA serial number-issued by Root CA). During x509_crt_verifycrl check, it check for CRL issuer with ca subject and return 0, as its not matching. now in x509_crt_verify_chain , /* prepare for next iteration */ ., they are marking child_is_trusted = parent_is_trusted and child = parent, parent = NULL; and while loop continues, in loop, x509_crt_verify_chain checks for child_is_trusted is true and return as 0. But its not checking that intermediate CA is revoked or not. /* Stop here for trusted roots (but not for trusted EE certs) */ if( child_is_trusted ) return( 0 );

5 months

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mbed-tls February 2024