Hello,
I
run a client that has been ported MbedTLS, but the client connect
server faild. I check the debug log, the end client state is 15. In the
client state 3, the client receive only one certificate from server,
and the log printing "Certificate verification flags 8". Here are part
of logs:
..\MbedTLS\library\ssl_tls.c:4232: dumping 'input record from network' (4467 bytes)
..\MbedTLS\library\ssl_tls.c:4232: 0000: 16 03 03 11 6e 0b 00 11 6a 00 11 67 00 05 c2 30 ....n...j..g...0
..\MbedTLS\library\ssl_tls.c:4232: 0010: -------- omit some network input data --------
..\MbedTLS\library\ssl_tls.c:4232: 0ff0: 38 a0 36 a0 34 86 32 68 74 74 70 3a 2f 2f 63 72 8.6.4.2http://cr
..\MbedTLS\library\ssl_tls.c:3624: handshake message: msglen = 4462, type = 11, hslen = 4462
..\MbedTLS\library\ssl_tls.c:4385: <= read record
..\MbedTLS\library\ssl_tls.c:5606: peer certificate #1:
..\MbedTLS\library\ssl_tls.c:5606: cert. version : 3
..\MbedTLS\library\ssl_tls.c:5606: serial number : F0:57:5F:65:80:A9:70:B4:F9:8E:42:91:AE:D0:70:27
..\MbedTLS\library\ssl_tls.c:5606:
issuer name : C=GB, ST=Greater Manchester, L=Salford, O=Sectigo
Limited, CN=Sectigo RSA Domain Validation Secure Server CA
..\MbedTLS\library\ssl_tls.c:5606: subject name : CN=*.xxxxxxxx.com
..\MbedTLS\library\ssl_tls.c:5606: issued on : 2020-06-01 00:00:00
..\MbedTLS\library\ssl_tls.c:5606: expires on : 2021-05-26 23:59:59
..\MbedTLS\library\ssl_tls.c:5606: signed using : RSA with SHA-256
..\MbedTLS\library\ssl_tls.c:5606: RSA key size : 2048 bits
..\MbedTLS\library\ssl_tls.c:5606: basic constraints : CA=false
..\MbedTLS\library\ssl_tls.c:5606: subject alt name : *.xxxxxxxx.com, xxxxxxxx.com
..\MbedTLS\library\ssl_tls.c:5606: key usage : Digital Signature, Key Encipherment
..\MbedTLS\library\ssl_tls.c:5606: ext key usage : TLS Web Server Authentication, TLS Web Client Authentication
..\MbedTLS\library\ssl_tls.c:5606: value of 'crt->rsa.N' (2048 bits) is:
..\MbedTLS\library\ssl_tls.c:5606: af b7 73 1a f9 8a 2d 5e a2 e8 0f fd 89 5d 60 1d
..\MbedTLS\library\ssl_tls.c:5606: -------- omit some bits --------
..\MbedTLS\library\ssl_tls.c:5606: e6 8e f8 3e ed ec 8e dd ec 46 48 85 9a b4 c8 71
..\MbedTLS\library\ssl_tls.c:5606: value of 'crt->rsa.E' (17 bits) is:
..\MbedTLS\library\ssl_tls.c:5606: 01 00 01
..\MbedTLS\library\ssl_tls.c:5757: x509_verify_cert() returned -9984 (-0x2700)
..\MbedTLS\library\ssl_tls.c:5851: ! Certificate verification flags 8
..\MbedTLS\library\ssl_tls.c:5863: <= parse certificate
At
the client side, I download certificate of server, and get CA and root
CA base on this certificate. Loading any one of these certificates into
the client can't connect server.
I
did a test with another server. The different of the handshark is that
the server issued two certificates, one is server's cert and another is
CA cert. Loading CA or root CA into the client both can connect server
successfully.
problems:
1. Must the server send CA certificate in handshake phase?
2. The client holds CA certificate, dose MbedTLS client support downloading CA base on server's certificate?
3. In the source code, the certificate chain only contains the
certificate issued by the server during handshake, not the CA
certificate downloaded by the client according to the server
certificate?
Thank you very much for the answers.
Best regards,
berry chen
Hi Raoul,
Do I understand correctly that the problem with Mbed TLS as it is now is
that you need MBEDTLS_HAVE_ASM enabled for AESNI and disabled for
bignum? Would you want even more granularity?
In principle, we could create a new compile-time option MBEDTLS_MPI_ASM,
defaulting to what it does now (enabled if MBEDTLS_HAVE_ASM if the
platform is one of the known ones) but overridable in either direction.
However I don't like it much because we're trying to cut down on
compilation options to reduce the maintenance burden: each compilation
option adds complexity which makes it harder to understand all
interactions between different parts of the library, and adds some
testing burden. Symmetric and asymmetric crypto are mostly decoupled, so
this one wouldn't be too bad, but it all adds up.
In the long term, I expect that the different cryptographic algorithms
will become more decoupled, with a possibility to treat each one as a
black box that could be implemented by a hardware driver, and with a
uniform mechanism to select drivers (or maybe they should be called
engines). The evolution of the crypto part of the library to PSA is
going in this direction. But we aren't there yet.
Sorry that I don't have a more satisfying answer here.
--
Gilles Peskine
Mbed TLS developer
On 31/03/2021 09:13, Raoul Strackx via mbed-tls wrote:
> Hi all,
>
> We have a product that requires very strong security measures. When
> compiling the mbedtls library, we face the following issue: Compiling C
> code with LVI-mitigations is often much faster than relying on automatic
> LVI mitigations on assembly code. The MPI functions are a good example
> where we wish to rely on C source code. For other functions, we need to
> rely on assembly code in order to mitigate other vulnerabilities (e.g.,
> we require AESNI assembly instructions over C implementations of AES).
> Currently there isn't an option to choose between C/assembly per function.
>
> What would be an acceptable solution for this?
>
> greetings,
>
> Raoul
>
>
>
Hello,
In a nutshell:
1. Must Mbed TLS support Python 3.4 to configure and test, or can 3.6 be
enough?
2. Must the supplied CMake scripts support 2.8.12.2, or can 3.5.2 be enough?
This thread is about minimum tool versions to configure, build and test
Mbed TLS (excluding TLS interoperability testing and some maintainer
scripts) on Linux and similar (Unix-like) platforms. (This is not about
the set of platforms where Mbed TLS will _run_, which is as close to
“anything with CHAR_BIT==8 and sizeof(size_t) >= 4” as we can make it.)
Our general guideline is that Mbed TLS should build out of the box on
supported versions of major desktop and server operating systems. In
practice, this has tended to mean supporting tool versions from
RHEL/CentOS, SLES and Ubuntu LTS releases (but not necessarily extended
security maintenance releases).
Last year
(https://lists.trustedfirmware.org/pipermail/mbed-tls/2020-April/thread.html)
we concluded that we should support the following minimum versions,
which will remain supported in the Mbed TLS 2.16 long-time support (LTS)
branch:
clang 3.8
cmake 2.8.12.2
gcc 4.4
make 3.81
python 3.4 (in 2.16: only to build the unit tests, not to configure)
Since then, RHEL 6 and Ubuntu 16.04 have reached their end of life, the
CentOS world has changed considerably. Looking at maintained platforms
after April 2021
(https://github.com/ARMmbed/mbedtls/issues/2896#issuecomment-603471273),
our current goal for the upcoming Mbed TLS 2.x LTS (last release before
3.0) is:
clang 6.0
cmake 2.8.12.2 (or 3.5.2? or 3.10.2?)
gcc 4.8
make 3.82
python 3.6 (or 3.4.10?)
Regarding Python: is there any demand for supporting Python versions
older than 3.6? Python 3 is required to fine-tune the library
configuration (it is not needed if you use the default config.h or a
handwritten one) and build the unit tests.
Regarding CMake: it is increasingly problematic for us to support CMake
2.8.12, which is only required for RHEL 7: other distributions under
consideration have at least CMake 3.5. There is an ongoing effort to
improve our CMake scripts to make it easier to integrate Mbed TLS into a
larger project, but it is difficult to preserve backward compatibility
with 2.8.12. Would it be acceptable to require CMake >= 3.5? CMake >=
3.10.2?
If you have any constraints that are not captured here or if you have an
opinion regarding Python and CMake versions, please let us know quickly.
--
Gilles Peskine
Mbed TLS developer
Hi all,
We have a product that requires very strong security measures. When
compiling the mbedtls library, we face the following issue: Compiling C
code with LVI-mitigations is often much faster than relying on automatic
LVI mitigations on assembly code. The MPI functions are a good example
where we wish to rely on C source code. For other functions, we need to
rely on assembly code in order to mitigate other vulnerabilities (e.g.,
we require AESNI assembly instructions over C implementations of AES).
Currently there isn't an option to choose between C/assembly per function.
What would be an acceptable solution for this?
greetings,
Raoul
Also, if you're looking for a hardware platform with PSA Crypto drivers,
Silicon Labs has one available. They've been participating in Mbed TLS
development recently and a large part of the driver support code added
in the past few months comes from them. You can see the documentation of
their development kit at https://docs.silabs.com/mbed-tls/latest/ . (If
you want to know about getting sample hardware and driver code … I'm not
the right person to ask.)
--
Gilles Peskine
On 24/02/2021 22:26, Gilles Peskine via mbed-tls wrote:
> Hi Frank,
>
> I'm not sure what you're looking for. Do you mean open source projects
> like Curl and Hiawatha that can use Mbed TLS as a cryptography provider?
> Those are generally using the classic API, and so can't make generic use
> of secure elements. I am aware of private projects using the limited
> features available today (for example, TLS servers can use async private
> key operations to put the key in an HSM — see
> https://tls.mbed.org/kb/how-to/ssl_async).
>
> I've used SoftHSM in the past as a way to test portable PKCS#11 client
> code without hardware. It did the job well. I can't speak for the
> quality of its cryptography since I was only using it for testing.
>
> If you're looking for a generic interface between applications and
> secure elements, then I would recommend PSA crypto over PKCS#11. We did
> try to make PSA Crypto a better PKCS#11. Obviously I'm biased :) But of
> course PKCS#11 is old and venerable, whereas PSA is new and the support
> for hardware secure elements is still a work in progress.
>
Hi Frank,
I'm not sure what you're looking for. Do you mean open source projects
like Curl and Hiawatha that can use Mbed TLS as a cryptography provider?
Those are generally using the classic API, and so can't make generic use
of secure elements. I am aware of private projects using the limited
features available today (for example, TLS servers can use async private
key operations to put the key in an HSM — see
https://tls.mbed.org/kb/how-to/ssl_async).
I've used SoftHSM in the past as a way to test portable PKCS#11 client
code without hardware. It did the job well. I can't speak for the
quality of its cryptography since I was only using it for testing.
If you're looking for a generic interface between applications and
secure elements, then I would recommend PSA crypto over PKCS#11. We did
try to make PSA Crypto a better PKCS#11. Obviously I'm biased :) But of
course PKCS#11 is old and venerable, whereas PSA is new and the support
for hardware secure elements is still a work in progress.
--
Gilles Peskine
Mbed TLS developer and PSA Crypto architect
On 21/02/2021 17:11, Frank Bergmann via mbed-tls wrote:
> Hi Gilles,
>
> thank you for your detailled answer.
> Honestly I was in fear that your answer would look like this. ;-)
>
> Do you maybe know of any plans of any software project to use mbed TLS
> together with a secure element?
>
> I asked SoftHSM because it looks much promising for our goals but they
> answered that they don't have any plans to use different ssl libs.
>
>
> cheers,
> Frank
>
>
> On 08.02.21 23:07, Gilles Peskine via mbed-tls wrote:
>> Hi Frank,
>>
>> Support for HSM keys in Mbed TLS is a work in progress. The way it will
>> work eventually is by plugging an HSM driver under the PSA crypto API,
>> which supports both transparent and opaque keys.
>>
>> The TLS code can already use the PSA crypto API for some things,
>> including client signature. Enable MBEDTLS_USE_PSA_CRYPTO, call
>> mbedtls_pk_setup_opaque() to create a PK object for the key, and declare
>> the key to the TLS code with mbedtls_ssl_conf_own_cert() as usual.
>>
>> To create the key, you will need to write a PKCS#11 secure element
>> driver. ("Secure element" = "HSM" for this purpose.) I think it would
>> make sense to have one in Mbed TLS, but I don't know when we might get
>> around to writing one.
>>
>> There are two secure element driver interfaces in Mbed TLS right now:
>> MBEDTLS_PSA_CRYPTO_SE_C (dynamic secure element interface) and
>> MBEDTLS_PSA_CRYPTO_DRIVERS (unified driver interface). Both are still
>> experimental: we can't guarantee API stability at this stage.
>> MBEDTLS_PSA_CRYPTO_SE_C was the first proposal, and its development is
>> currently frozen and may be abandonned, so I don't recommend investing
>> any effort in it at the moment, but if you need something fast (e.g. for
>> a demo/proof-of-concept), it's your best bet. MBEDTLS_PSA_CRYPTO_DRIVERS
>> is the way of the future, but it's an active work in progress.
>>
>> If you're creating the key from your application, just call
>> psa_generate_key. If the key was provisioned externally, it's
>> unfortunately not so easy. With MBEDTLS_PSA_CRYPTO_SE_C, you can
>> register a key that's already present in the secure element with
>> mbedtls_psa_register_se_key(). The corresponding facility in the
>> MBEDTLS_PSA_CRYPTO_DRIVERS interface is a "get_builtin_key" entry point,
>> but this is not implemented yet. (There's a prototype at
>> https://github.com/ARMmbed/mbedtls/pull/3822 but nobody is working on
>> it. The specification is in docs/proposed/psa-driver-interface.md.)
>>
>> There's an example application with a MBEDTLS_PSA_CRYPTO_SE_C driver at
>> https://github.com/ARMmbed/mbed-os-example-atecc608a . We don't have
>> example code for MBEDTLS_PSA_CRYPTO_DRIVERS yet, or good documentation,
>> or an easy-to-use build system — those are still a few months in the future.
>>
>> If you write a driver in the next few months, I recommend that you stay
>> in touch with the Mbed TLS development team and follow the development
>> branch of Mbed TLS closely, since it's a very active area of development
>> at the moment.
>>
Hi Gábor,
Yes, it is ready for review, I have added the corresponding labels. Now there is nothing else to do just to wait for the reviews.
Best regards,
Janos
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of Gábor Tóth via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
Date: Tuesday, 23 February 2021 at 06:29
To: mbed-tls(a)lists.trustedfirmware.org <mbed-tls(a)lists.trustedfirmware.org>
Subject: [mbed-tls] PR-4161-merge TLS Testing — Failures: ABI-API-checking
Hello Guys!
AFter a week of debugging yesterday I was able to solve the issues on my PR, but the ABI-API failure is still on. I was told that based on my changes it is OK, I should not worry.
Does this mean that my PR is ready for review or it should have disappeared by now? In the second case could someone provide me the jenkins reports and some idea where should I start searching?
This is my PR:
https://github.com/ARMmbed/mbedtls/pull/4161
Thank you in advance!
BR,
Gábor
Hello Guys!
AFter a week of debugging yesterday I was able to solve the issues on my
PR, but the ABI-API failure is still on. I was told that based on my
changes it is OK, I should not worry.
Does this mean that my PR is ready for review or it should have disappeared
by now? In the second case could someone provide me the jenkins reports and
some idea where should I start searching?
This is my PR:
https://github.com/ARMmbed/mbedtls/pull/4161
Thank you in advance!
BR,
Gábor
Helló János!
Yes I tried that one (and plenty of other stuff). Finally I just reset the
branch and recommited the changes solving this particular issue.
Unfortunately I had to create a new PR, because git did not let me reopen
it, but that is another topic.
Thank you for the help!
BR,
Gábor
Janos Follath <Janos.Follath(a)arm.com> ezt írta (időpont: 2021. febr. 22.,
H, 13:17):
> Hi Gábor,
>
>
>
> Have you tried running `git commit --amend` (without --no-edit --signoff)
> and adding the “Signed-off-by: toth92g <toth92g(a)gmail.com>" line by hand?
>
>
>
> Best regards,
>
> Janos
>
>
>
> *From: *Gábor Tóth <toth92g(a)gmail.com>
> *Date: *Monday, 22 February 2021 at 11:44
> *To: *Janos Follath <Janos.Follath(a)arm.com>
> *Subject: *Re: [mbed-tls] Failing signoff (DCO) on:
> https://github.com/ARMmbed/mbedtls/pull/4140
>
> Helló János!
>
>
>
> Yes, I know which one, but I do not know how to change the commit message
> in git. I have used the provided commands (amend), but it did not correct
> the error.
>
>
>
> Do you know how to change it manually?
>
>
>
> BR,
>
> Gábor
>
>
>
> Janos Follath <Janos.Follath(a)arm.com> ezt írta (időpont: 2021. febr. 22.,
> H, 12:38):
>
> Hi Gábor,
>
>
>
> If you click on the “details” link on the DCO check it will tell you which
> commits are missing the sign-off:
>
> https://github.com/ARMmbed/mbedtls/pull/4140/checks?check_run_id=1950600200
>
>
>
> In this case you have one commit that is not signed off:
>
>
> https://github.com/ARMmbed/mbedtls/pull/4140/commits/fdd3c65ee47ab80f69cfa4…
>
>
>
> Best regards,
>
> Janos
>
>
>
> *From: *mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf
> of Gábor Tóth via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
> *Date: *Monday, 22 February 2021 at 11:05
> *To: *mbed-tls(a)lists.trustedfirmware.org <
> mbed-tls(a)lists.trustedfirmware.org>
> *Subject: *[mbed-tls] Failing signoff (DCO) on:
> https://github.com/ARMmbed/mbedtls/pull/4140
>
> Hello Guys!
>
>
>
> I know it is a newbie question, but I am not able to pass this freaking
> DCO test...I have used the provided commands to signoff all the commits and
> as I see all of them has signoff, but it still failes on one. Do you have
> any idea what's wrong or how could I correct it?
>
>
>
> Till now I was able to correct it, but now it seems to be bugged.
>
>
>
> Thank you!
>
>
>
> BR?
> Gábor
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
>
Hi Gábor,
If you click on the “details” link on the DCO check it will tell you which commits are missing the sign-off:
https://github.com/ARMmbed/mbedtls/pull/4140/checks?check_run_id=1950600200
In this case you have one commit that is not signed off:
https://github.com/ARMmbed/mbedtls/pull/4140/commits/fdd3c65ee47ab80f69cfa4…
Best regards,
Janos
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of Gábor Tóth via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
Date: Monday, 22 February 2021 at 11:05
To: mbed-tls(a)lists.trustedfirmware.org <mbed-tls(a)lists.trustedfirmware.org>
Subject: [mbed-tls] Failing signoff (DCO) on: https://github.com/ARMmbed/mbedtls/pull/4140
Hello Guys!
I know it is a newbie question, but I am not able to pass this freaking DCO test...I have used the provided commands to signoff all the commits and as I see all of them has signoff, but it still failes on one. Do you have any idea what's wrong or how could I correct it?
Till now I was able to correct it, but now it seems to be bugged.
Thank you!
BR?
Gábor
Hello Guys!
I know it is a newbie question, but I am not able to pass this freaking DCO
test...I have used the provided commands to signoff all the commits and as
I see all of them has signoff, but it still failes on one. Do you have any
idea what's wrong or how could I correct it?
Till now I was able to correct it, but now it seems to be bugged.
Thank you!
BR?
Gábor
Hi Gilles,
thank you for your detailled answer.
Honestly I was in fear that your answer would look like this. ;-)
Do you maybe know of any plans of any software project to use mbed TLS
together with a secure element?
I asked SoftHSM because it looks much promising for our goals but they
answered that they don't have any plans to use different ssl libs.
cheers,
Frank
On 08.02.21 23:07, Gilles Peskine via mbed-tls wrote:
> Hi Frank,
>
> Support for HSM keys in Mbed TLS is a work in progress. The way it will
> work eventually is by plugging an HSM driver under the PSA crypto API,
> which supports both transparent and opaque keys.
>
> The TLS code can already use the PSA crypto API for some things,
> including client signature. Enable MBEDTLS_USE_PSA_CRYPTO, call
> mbedtls_pk_setup_opaque() to create a PK object for the key, and declare
> the key to the TLS code with mbedtls_ssl_conf_own_cert() as usual.
>
> To create the key, you will need to write a PKCS#11 secure element
> driver. ("Secure element" = "HSM" for this purpose.) I think it would
> make sense to have one in Mbed TLS, but I don't know when we might get
> around to writing one.
>
> There are two secure element driver interfaces in Mbed TLS right now:
> MBEDTLS_PSA_CRYPTO_SE_C (dynamic secure element interface) and
> MBEDTLS_PSA_CRYPTO_DRIVERS (unified driver interface). Both are still
> experimental: we can't guarantee API stability at this stage.
> MBEDTLS_PSA_CRYPTO_SE_C was the first proposal, and its development is
> currently frozen and may be abandonned, so I don't recommend investing
> any effort in it at the moment, but if you need something fast (e.g. for
> a demo/proof-of-concept), it's your best bet. MBEDTLS_PSA_CRYPTO_DRIVERS
> is the way of the future, but it's an active work in progress.
>
> If you're creating the key from your application, just call
> psa_generate_key. If the key was provisioned externally, it's
> unfortunately not so easy. With MBEDTLS_PSA_CRYPTO_SE_C, you can
> register a key that's already present in the secure element with
> mbedtls_psa_register_se_key(). The corresponding facility in the
> MBEDTLS_PSA_CRYPTO_DRIVERS interface is a "get_builtin_key" entry point,
> but this is not implemented yet. (There's a prototype at
> https://github.com/ARMmbed/mbedtls/pull/3822 but nobody is working on
> it. The specification is in docs/proposed/psa-driver-interface.md.)
>
> There's an example application with a MBEDTLS_PSA_CRYPTO_SE_C driver at
> https://github.com/ARMmbed/mbed-os-example-atecc608a . We don't have
> example code for MBEDTLS_PSA_CRYPTO_DRIVERS yet, or good documentation,
> or an easy-to-use build system — those are still a few months in the future.
>
> If you write a driver in the next few months, I recommend that you stay
> in touch with the Mbed TLS development team and follow the development
> branch of Mbed TLS closely, since it's a very active area of development
> at the moment.
>
--
Frank Bergmann, Pödinghauser Str. 5, D-32051 Herford, Tel. +49-5221-9249753
SAP Hybris & Linux LPIC-3, E-Mail tx2014(a)tuxad.de, USt-IdNr DE237314606
http://tdyn.de/freel -- Redirect to profile at freelancermap
http://www.gulp.de/freiberufler/2HNKY2YHW.html -- Profile at GULP
Hi Gábor,
To reproduce locally, the correct invocation would be
tests/scripts/all.sh test_memory_buffer_allocator
Specifically, the failing tests are SSL tests. To reproduce those tests,
build the right configuration and run
tests/ssl-opt.sh -f 'DTLS fragmenting: proxy MTU, * renego'
I've posted the relevant logs on the GitHub issue.
It's unusual for the memory_buffer tests to fail when memory sanitizers
are passing, so I don't know what's going on.
--
Gilles Peskine
Mbed TLS developer
On 16/02/2021 11:13, Gábor Tóth via mbed-tls wrote:
> Hello Guys!
>
> I have an error related to test_memory_buffer_allocator on the server
> in my PR (https://github.com/ARMmbed/mbedtls/pull/4140). Tried to find
> the issue locally on both the latest Ubuntu and on version 16.04 (same
> as on the server), but without success.
> All the tests pass if I run "make test" command (of course I changed
> config.h based on the component in all.sh)..
> I have also tried:
> "./tests/scripts/all.sh component_test_memory_buffer_allocator", but
> it does not do anything, just lists some tools. Maybe I am not using
> it right...
>
> The memory allocation/freeing mechanism was not touched by my changes
> except that in the function that frees a CRT I added a small part to
> free the new dynamic field.
>
> Do you have any idea what's wrong with my PR, how could I solve it or
> find out the cause?
>
> Thank you guys!
>
> BR,
> Gábor
>
Hello Guys!
I have an error related to test_memory_buffer_allocator on the server in my
PR (https://github.com/ARMmbed/mbedtls/pull/4140). Tried to find the issue
locally on both the latest Ubuntu and on version 16.04 (same as on the
server), but without success.
All the tests pass if I run "make test" command (of course I changed
config.h based on the component in all.sh)..
I have also tried:
"./tests/scripts/all.sh component_test_memory_buffer_allocator", but it
does not do anything, just lists some tools. Maybe I am not using it
right...
The memory allocation/freeing mechanism was not touched by my changes
except that in the function that frees a CRT I added a small part to free
the new dynamic field.
Do you have any idea what's wrong with my PR, how could I solve it or find
out the cause?
Thank you guys!
BR,
Gábor
Hello,
Sorry to bother with a noob question. I am trying to understand how
bignum.c works. For that, I'm trying to write a program to add two numbers.
Here is what I have https://pastebin.com/mbRaE5i5, I'm not sure if this is
the correct approach. I use the following to compile the code,
* gcc -o mpi_example mpi_example.c bignum.c*
But get the following error,
/tmp/ccMo7DMW.o: In function `main':
mpi_example.c:(.text+0x2d): undefined reference to `mbedtls_mpi_init'
mpi_example.c:(.text+0x39): undefined reference to `mbedtls_mpi_init'
mpi_example.c:(.text+0x45): undefined reference to `mbedtls_mpi_init'
mpi_example.c:(.text+0x6c): undefined reference to `mbedtls_mpi_add_int'
mpi_example.c:(.text+0x9a): undefined reference to `mbedtls_mpi_free'
mpi_example.c:(.text+0xa6): undefined reference to `mbedtls_mpi_free'
mpi_example.c:(.text+0xb2): undefined reference to `mbedtls_mpi_free'
collect2: error: ld returned 1 exit status
Any help what I'm doing wrong here? Or any sample code and how to compile
it?
Thanks,
~ Shariful
Hi,
I am working on adding HW acceleration to a NXP Kinetis MCU, but the HW accelerator happens to implement many operations which are defined in bignum.c, like "mbedtls_mpi_exp_mod", "mbedtls_mpi_gcd", "mbedtls_mpi_inv_mod" and so on. The bignum clients for me would be ecp.c and ecp_curves.c (as well as ecdh and ecdsa), and while I can override some of those using _ALT macros, for bignum it seems not possible to do so, short of not defining MBEDLTS_BIGNUM_C and all associated dependency issues.
Also bignum itself also has other call paths that happen to use the functions I am trying to accelerate, which are themselves called by other files. Since I am using an open-source OSS and can't just override stuff in a fork, so I would like to know if there is some technical reason for an option like "MBEDTLS_BIGNUM_ALT" not being available and if such change would be acceptable?
Fabio
Hi Manu,
f_entropy is the argument passed to mbedtls_ctr_drbg_seed, which is
mbedtls_entropy_func. This function obtains entropy from all configured
sources, which depends on the library configuration. Check if it might
be calling other sources (see what sources are added in
mbedtls_entropy_init in library/entropy.c).
I think there's a bug in your mbedtls_hardware_poll implementation. It's
receiving a buffer ent_buf with room for count BYTES, but you're filling
it with count WORDS. You need to pass the exact number of bytes. In
practice, unless the library is configured in a weird way, count will be
a multiple of 4, which can make your code a bit simpler.
--
Gilles Peskine
Mbed TLS developer
On 17/08/2020 19:16, Manu Abraham via mbed-tls wrote:
> Greetings,
>
> I am new to the list, please do excuse me, in case of any list
> specific etiquette issues.
>
> Trying to use a 1.6.1 release with a Cortex M7 port, specifically a STM32H7.
>
> After enabling MBEDTLS_ENTROPY_HARDWARE_ALT, did implement
> mbedtls_hardware_poll()
>
> It looks thus, and it does appear to work from a hardware perspective:
>
> /**
> * mbedtls_hardware_poll()
> * Read random data from the Hardware RNG for entropy applications
> */
> int mbedtls_hardware_poll(void *arg,
> unsigned char *ent_buf,
> size_t count,
> size_t *ent_len)
> {
> register uint8_t i = 0;
> uint32_t rand;
>
> if (!LL_RNG_IsEnabled(RNG))
> LL_RNG_Enable(RNG); /* Enable Random Number Generator */
>
> for (i = 0; i < count; i++) {
> while (!LL_RNG_IsActiveFlag_DRDY(RNG)) { } /* Wait for DRDY
> flag to be raised */
> if ((LL_RNG_IsActiveFlag_CECS(RNG)) ||
> (LL_RNG_IsActiveFlag_SECS(RNG))) { /* Check error, if any */
>
> /* Clock or Seed Error detected. Set Error */
> printf(" (%d) %s: Clock/Seed Error!\r\n", __LINE__, __FUNCTION__);
> }
> rand = LL_RNG_ReadRandData32(RNG); /* Read RNG data */
> memcpy(&(ent_buf[i * 4]), &rand, 4); /* *ent_len += 4 */
> }
> LL_RNG_Disable(RNG); /* Stop random numbers generation */
> *ent_len = ((i + 1) * 4);
> printf(" (%d) %s: Random Words: %d Word: %04d\r\n",
> __LINE__,
> __FUNCTION__,
> count,
> rand);
>
> return 0;
> }
>
> The code which causes the problem is this, in my tls_init()
>
> int tls_init(void)
> {
> int ret;
>
> /* inspired by https://tls.mbed.org/kb/how-to/mbedtls-tutorial */
> const char *pers = "SYS-LWH7";
>
> printf(" (%d) %s: Initializing\r\n", __LINE__, __FUNCTION__);
> /* initialize descriptors */
>
> mbedtls_ssl_init(&ssl);
> printf(" (%d) %s: SSL initialize\r\n", __LINE__, __FUNCTION__);
>
> mbedtls_ssl_config_init(&conf);
> printf(" (%d) %s: SSL Config initialized\r\n", __LINE__, __FUNCTION__);
>
> mbedtls_x509_crt_init(&cacert);work
> printf(" (%d) %s: x509 CRT initialized\r\n", __LINE__, __FUNCTION__);
>
> mbedtls_ctr_drbg_init(&ctr_drbg);
> printf(" (%d) %s: DRBG initialized\r\n", __LINE__, __FUNCTION__);
>
> mbedtls_entropy_init(&entropy);
> printf(" (%d) %s: Entropy initialized\r\n", __LINE__, __FUNCTION__);
>
>
> ret = mbedtls_ctr_drbg_seed(&ctr_drbg,
> mbedtls_entropy_func,
> &entropy,
> (const unsigned char *) pers,
> strlen(pers));
> if (ret) {
>
> LWIP_DEBUGF(MQTT_APP_DEBUG_TRACE,
> ("failed !\n mbedtls_ctr_drbg_seed returned %d\n",
> ret));
>
> printf(" (%d) %s: DRBG seed failed, ret=%d\r\n", __LINE__,
> __FUNCTION__, ret);
> return -1;
> }
> printf(" (%d) %s: DRBG seed returned:%d\r\n", __LINE__, __FUNCTION__, ret);
>
> /**
> * The transport type determines if we are using
> * TLS (MBEDTLS_SSL_TRANSPORT_STREAM) or
> * DTLS (MBEDTLS_SSL_TRANSPORT_DATAGRAM).
> */
> ret = mbedtls_ssl_config_defaults(&conf,
> MBEDTLS_SSL_IS_CLIENT,
> MBEDTLS_SSL_TRANSPORT_STREAM,
> MBEDTLS_SSL_PRESET_DEFAULT);
> if (ret) {
> LWIP_DEBUGF(MQTT_APP_DEBUG_TRACE,
> ("failed !\n mbedtls_ssl_config_defaults returned %d\n\n",
> ret));
>
> printf("(%d) %s: SSL config defaults failed, ret=%d\r\n",
> __LINE__, __FUNCTION__, ret);
> return -1;
> }
> printf("(%d) %s: SSL config defaults returned:%d\r\n", __LINE__,
> __FUNCTION__, ret);
>
> ret = mbedtls_x509_crt_parse(&cacert,
> (const unsigned char *)test_ca_crt,
> test_ca_crt_len);
> if (ret)
> printf(" (%d) %s: failed!\n mbedtls_x509_crt_parse returned
> %d\r\n", __LINE__, __FUNCTION__, ret);
> else
> printf(" (%d) %s: mbedtls_x509_crt_parse returned %d\r\n",
> __LINE__, __FUNCTION__, ret);
>
> mbedtls_ssl_conf_ca_chain(&conf, &cacert, NULL);
> mbedtls_ssl_conf_authmode(&conf, MBEDTLS_SSL_VERIFY_REQUIRED);
>
> /**
> * The library needs to know which random engine
> * to use and which debug function to use as callback.
> */
> mbedtls_ssl_conf_rng(&conf, mbedtls_ctr_drbg_random, &ctr_drbg);
> mbedtls_ssl_conf_dbg(&conf, my_debug, stdout);
> mbedtls_ssl_setup(&ssl, &conf);
> }
>
>
> The output of which looks thus, in a serial terminal:
>
> (1217) print_dhcp_state: Try connect to Broker
> (174) tls_init: Initializing
> (178) tls_init: SSL initialize
> (181) tls_init: SSL Config initialized
> (184) tls_init: x509 CRT initialized
> (187) tls_init: DRBG initialized
> (190) tls_init: Entropy initialized
> (1027) mbedtls_hardware_poll: Random Words: 128 Word: -558876895
>
>
> Any thoughts/ideas, what could be wrong ?
> Any kind soul in here ?
>
> Thanks,
> Manu
Hi Gábor,
Congrats on fixing the previous issues and getting Travis to pass.
Unfortunately, the complete logs of the Jenkins part of the CI can only be accessed by Arm employees so far. We have plans to move to a fully-public CI system, but this won't happen before the second half of this year. In the meantime I'm afraid you'll have to ask a team member to get you the results.
> continuous-integration/jenkins/pr-head — This commit cannot be built
> continuous-integration/jenkins/pr-merge — This commit cannot be buil
Note: this can be ignore, these are the results of the parent jobs that spawn the other jobs.
> PR-4117-head TLS Testing — Failures: all_sh-ubuntu-16.04-test_m32_o1 all_sh-ubuntu-16.04-test_memory_buffer_allocator
> PR-4117-merge TLS Testing — Failures: ABI-API-checking all_sh-ubuntu-16.04-test_memory_buffer_allocator
Note: this is a partial list of failed components (truncated due to limits in the Github notifications API). Most of them as components of tests/scripts/all.sh - if you have access to a Linux/Unix machine with the proper dependencies, you can run them locally, for example here the first one would be tests/scripts/all.sh test_m32_o1, the second one tests/scripts/all.sh test_memory_buffer_allocator.
Regarding your question about coverage: I _think_ it should work on Windows if you exclude ssl-opt.sh and compat.sh. As your work is related to X.509, excluding those SSL-related scripts should not affect coverage of the areas of interest. I'm not sure if lcov (the programs that turns gcov's raw data to human-readable form) works on Windows, I'm sure your favourite search engine will have more information than me about this 🙂
Note however that most of the development/testing tools are made with Linux in mind, so you might have an easier time running a Linux VM to use them.
As a last resort, one of the reviewers of the PRs can measure coverage on their machine - that's something I often do for PRs adding features, especially when some form of parsing is involved. Thanks for paying attention to coverage, by the way, that's really appreciated!
Best regards,
Manuel.
________________________________
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of Gábor Tóth via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
Sent: 11 February 2021 11:39
To: mbed-tls(a)lists.trustedfirmware.org <mbed-tls(a)lists.trustedfirmware.org>
Subject: [mbed-tls] Failing CI tests, Generating coverage report
Hello Guys!
I have a branch that has been successfully built, but 4/10 tests are failing. Unfortunately I am not even able to read a log, because if I click on the details button I am redirected to a "This site can't be reached" page.
Could you help me how to check the logs regarding the Jenkins CI builds?
This is the pull request https://github.com/ARMmbed/mbedtls/pull/4117
These are the failing tests:
continuous-integration/jenkins/pr-head — This commit cannot be built
continuous-integration/jenkins/pr-merge — This commit cannot be buil
PR-4117-head TLS Testing — Failures: all_sh-ubuntu-16.04-test_m32_o1 all_sh-ubuntu-16.04-test_memory_buffer_allocator
PR-4117-merge TLS Testing — Failures: ABI-API-checking all_sh-ubuntu-16.04-test_memory_buffer_allocator
I am also working on tests to cover the new functionality, but can not run coverage report. In the makefile of the base directory of mbedtls I have found this part:
ifndef WINDOWS
# note: for coverage testing, build with:
# make CFLAGS='--coverage -g3 -O0'
covtest:
$(MAKE) check
programs/test/selftest
tests/compat.sh
tests/ssl-opt.sh
So am I right, that coverage check is only supported ot linux platform? Do I need to use that one or are there any solutions on windows?
Thank you in advance!
BR,
Gábor
Hello Guys!
I have a branch that has been successfully built, but 4/10 tests are
failing. Unfortunately I am not even able to read a log, because if I click
on the details button I am redirected to a "This site can't be reached"
page.
Could you help me how to check the logs regarding the Jenkins CI builds?
This is the pull request https://github.com/ARMmbed/mbedtls/pull/4117
These are the failing tests:
*continuous-integration/jenkins/pr-head *— This commit cannot be built
*continuous-integration/jenkins/pr-merge *— This commit cannot be buil
*PR-4117-head TLS Testing *— Failures: all_sh-ubuntu-16.04-test_m32_o1
all_sh-ubuntu-16.04-test_memory_buffer_allocator
*PR-4117-merge TLS Testing *— Failures: ABI-API-checking
all_sh-ubuntu-16.04-test_memory_buffer_allocator
I am also working on tests to cover the new functionality, but can not run
coverage report. In the makefile of the base directory of mbedtls I have
found this part:
ifndef WINDOWS
# note: for coverage testing, build with:
# make CFLAGS='--coverage -g3 -O0'
covtest:
$(MAKE) check
programs/test/selftest
tests/compat.sh
tests/ssl-opt.sh
So am I right, that coverage check is only supported ot linux platform? Do
I need to use that one or are there any solutions on windows?
Thank you in advance!
BR,
Gábor
Hello Gilles!
Thank you for your helpful answer! Unfortunately this solution to find
memory leakage problems is not working under windows (as I read), but
fortunately I was able to locate the source and now my changes are green on
the server.
Thank you, again :)
BR,
Gábor
Gilles Peskine via mbed-tls <mbed-tls(a)lists.trustedfirmware.org> ezt írta
(időpont: 2021. febr. 10., Sze, 12:03):
> Hi Gábor,
>
> Thank you for contributing to Mbed TLS!
>
> For the memory leaks, compile with ASan(+UBSan):
> export ASAN_OPTIONS='symbolize=1'
> # also export ASAN_SYMBOLIZER_PATH=/path/to/llvm-symbolizer if it's not
> found automatically
> export ASAN_FLAGS='-O2 -fsanitize=address,undefined
> -fno-sanitize-recover=all'
> make CFLAGS="$ASAN_FLAGS" LDFLAGS="$ASAN_FLAGS"
>
> The SSL test scripts depend on precise versions of OpenSSL and GnuTLS.
> Versions that are too old are missing some features and recent versions
> have removed some features. Even some versions from Linux distributions
> have removed obsolete algorithms that we're still testing. If you want
> to pass all the tests on your machine, I recommend that you install them
> from source. There's a list of the versions we use on our CI at
> https://developer.trustedfirmware.org/w/mbed-tls/testing/ci/ .
>
> When you're debugging, it's useful to run a single test case or a small
> number of test cases with ssl-opt -f 'regexp' . The logs are in
> tests/o-cli-<number>.log and tests/o-srv-<number>.log .
>
> Hope this helps.
>
> --
> Gilles Peskine
> Mbed TLS developer
>
> On 10/02/2021 10:17, Gábor Tóth via mbed-tls wrote:
> > Hello Guys!
> >
> > I am working on an update of MBEDTLS that will support AuthorityKeyId
> > and SubjetKeyId V3 extensions of X509. I have created a pull request,
> > but I have not been able to solve the issues on Travis:
> > https://github.com/ARMmbed/mbedtls/pull/4117
> >
> > As I see the problems are: memory leakage and the failure of two tests
> > suites.
> > I tried to run these suites and a memory leakage check on my host
> > machine, but the .sh scripts are just flashing once and disappearing
> > in a few seconds after catching some kind of exception.
> >
> > I have Python2, Perl, Mingw64 (with gcc) installed and added to the
> > Path. These commands are working:
> > - make CC=gcc
> > - make tests
> > All the 87 tests pass.
> >
> > Tried running ssl-opt.sh without arguments and with "-m", but it exits
> > after a few lines.
> >
> > Do you have any idea what I am missing? It would make the work much
> > easier if I could run the testsuites reproducing the error and if I
> > could find the memory leaks.
> >
> > Thank you in advance!
> >
> > BR,
> > Gábor
> >
>
>
> --
> mbed-tls mailing list
> mbed-tls(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/mbed-tls
>
Hi Gábor,
Thank you for contributing to Mbed TLS!
For the memory leaks, compile with ASan(+UBSan):
export ASAN_OPTIONS='symbolize=1'
# also export ASAN_SYMBOLIZER_PATH=/path/to/llvm-symbolizer if it's not
found automatically
export ASAN_FLAGS='-O2 -fsanitize=address,undefined
-fno-sanitize-recover=all'
make CFLAGS="$ASAN_FLAGS" LDFLAGS="$ASAN_FLAGS"
The SSL test scripts depend on precise versions of OpenSSL and GnuTLS.
Versions that are too old are missing some features and recent versions
have removed some features. Even some versions from Linux distributions
have removed obsolete algorithms that we're still testing. If you want
to pass all the tests on your machine, I recommend that you install them
from source. There's a list of the versions we use on our CI at
https://developer.trustedfirmware.org/w/mbed-tls/testing/ci/ .
When you're debugging, it's useful to run a single test case or a small
number of test cases with ssl-opt -f 'regexp' . The logs are in
tests/o-cli-<number>.log and tests/o-srv-<number>.log .
Hope this helps.
--
Gilles Peskine
Mbed TLS developer
On 10/02/2021 10:17, Gábor Tóth via mbed-tls wrote:
> Hello Guys!
>
> I am working on an update of MBEDTLS that will support AuthorityKeyId
> and SubjetKeyId V3 extensions of X509. I have created a pull request,
> but I have not been able to solve the issues on Travis:
> https://github.com/ARMmbed/mbedtls/pull/4117
>
> As I see the problems are: memory leakage and the failure of two tests
> suites.
> I tried to run these suites and a memory leakage check on my host
> machine, but the .sh scripts are just flashing once and disappearing
> in a few seconds after catching some kind of exception.
>
> I have Python2, Perl, Mingw64 (with gcc) installed and added to the
> Path. These commands are working:
> - make CC=gcc
> - make tests
> All the 87 tests pass.
>
> Tried running ssl-opt.sh without arguments and with "-m", but it exits
> after a few lines.
>
> Do you have any idea what I am missing? It would make the work much
> easier if I could run the testsuites reproducing the error and if I
> could find the memory leaks.
>
> Thank you in advance!
>
> BR,
> Gábor
>
Hello Guys!
I am working on an update of MBEDTLS that will support AuthorityKeyId and
SubjetKeyId V3 extensions of X509. I have created a pull request, but I
have not been able to solve the issues on Travis:
https://github.com/ARMmbed/mbedtls/pull/4117
As I see the problems are: memory leakage and the failure of two tests
suites.
I tried to run these suites and a memory leakage check on my host machine,
but the .sh scripts are just flashing once and disappearing in a few
seconds after catching some kind of exception.
I have Python2, Perl, Mingw64 (with gcc) installed and added to the Path.
These commands are working:
- make CC=gcc
- make tests
All the 87 tests pass.
Tried running ssl-opt.sh without arguments and with "-m", but it exits
after a few lines.
Do you have any idea what I am missing? It would make the work much easier
if I could run the testsuites reproducing the error and if I could find the
memory leaks.
Thank you in advance!
BR,
Gábor
Hi, im using mbedtls 2.7.17 in my project on stm32f417 (168Mhz) with config similar to config-mini-tls1_1.h for server HTTPS support (Keil).
mbedtls_rsa_private is executed ~19seconds on key_exchange phase on browser connection. I’m use default embedded test RSA ca, cert and pkey. Compilation with speed optimization and without not signaficantly reduces this time. Is it normal time of caclulation or something wrong with my platform? I’m expected about 1-2s, not 19..How can i reduce execution time as an expected?
Thanks.
#ifndef MBEDTLS_CONFIG_H
#define MBEDTLS_CONFIG_H
/* System support */
#define MBEDTLS_HAVE_ASM
#define MBEDTLS_HAVE_TIME
/* mbed TLS feature support */
#define MBEDTLS_CIPHER_MODE_CBC
#define MBEDTLS_PKCS1_V15
#define MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
#define MBEDTLS_SSL_PROTO_TLS1_1
/* mbed TLS modules */
#define MBEDTLS_AES_C
#define MBEDTLS_ASN1_PARSE_C
#define MBEDTLS_ASN1_WRITE_C
#define MBEDTLS_BIGNUM_C
#define MBEDTLS_CIPHER_C
#define MBEDTLS_CTR_DRBG_C
#define MBEDTLS_DES_C
#define MBEDTLS_ENTROPY_C
#define MBEDTLS_MD_C
#define MBEDTLS_MD5_C
//#define MBEDTLS_NET_C
#define MBEDTLS_OID_C
#define MBEDTLS_PK_C
#define MBEDTLS_PK_PARSE_C
#define MBEDTLS_RSA_C
#define MBEDTLS_SHA1_C
#define MBEDTLS_SHA256_C
//#define MBEDTLS_SSL_CLI_C
#define MBEDTLS_SSL_SRV_C
#define MBEDTLS_SSL_TLS_C
#define MBEDTLS_X509_CRT_PARSE_C
#define MBEDTLS_X509_USE_C
/* For test certificates */
#define MBEDTLS_BASE64_C
#define MBEDTLS_CERTS_C
#define MBEDTLS_PEM_PARSE_C
/* For testing with compat.sh */
//#define MBEDTLS_FS_IO
#define MBEDTLS_NO_PLATFORM_ENTROPY
#include "mbedtls/check_config.h"
#endif /* MBEDTLS_CONFIG_H */
--
Dmitry X
Hello,
RSA key objects include a mutex. `mbedtls_rsa_private` locks the mutex
because it caches some auxiliary values used for blinding in the key
object. (`mbedtls_rsa_public` also locks the mutex but it seems
pointless.) This allows applications to create a key (this must be done
in a single-threaded way), then use that key concurrently.
This feature has a number of downsides. From a high-level architectural
perspective, the RSA module is a low-level part of the code dedicated to
peforming calculations; managing concurrency is outside its scope. The
presence of the mutex complicates the lifecycle of RSA contexts, leading
to unmet expectations (https://github.com/ARMmbed/mbedtls/issues/2621)
and bugs on certain platforms
(https://github.com/ARMmbed/mbedtls/pull/4104). ECC contexts do not have
a mutex, even though they would need one, so a multithreaded application
that works with RSA keys can't easily be changed to ECC keys.
As a consequence, I propose to remove mutexes from RSA keys in Mbed TLS
3.0. Applications that currently rely on the mutex should either migrate
to the PSA API or wrap an RSA object (or a pk object, which would allow
algorithm agility) in a mutex.
This proposal is also recorded with more details at
https://github.com/ARMmbed/mbedtls/issues/4124 .
--
Gilles Peskine
Mbed TLS developer
Hi Frank,
Support for HSM keys in Mbed TLS is a work in progress. The way it will
work eventually is by plugging an HSM driver under the PSA crypto API,
which supports both transparent and opaque keys.
The TLS code can already use the PSA crypto API for some things,
including client signature. Enable MBEDTLS_USE_PSA_CRYPTO, call
mbedtls_pk_setup_opaque() to create a PK object for the key, and declare
the key to the TLS code with mbedtls_ssl_conf_own_cert() as usual.
To create the key, you will need to write a PKCS#11 secure element
driver. ("Secure element" = "HSM" for this purpose.) I think it would
make sense to have one in Mbed TLS, but I don't know when we might get
around to writing one.
There are two secure element driver interfaces in Mbed TLS right now:
MBEDTLS_PSA_CRYPTO_SE_C (dynamic secure element interface) and
MBEDTLS_PSA_CRYPTO_DRIVERS (unified driver interface). Both are still
experimental: we can't guarantee API stability at this stage.
MBEDTLS_PSA_CRYPTO_SE_C was the first proposal, and its development is
currently frozen and may be abandonned, so I don't recommend investing
any effort in it at the moment, but if you need something fast (e.g. for
a demo/proof-of-concept), it's your best bet. MBEDTLS_PSA_CRYPTO_DRIVERS
is the way of the future, but it's an active work in progress.
If you're creating the key from your application, just call
psa_generate_key. If the key was provisioned externally, it's
unfortunately not so easy. With MBEDTLS_PSA_CRYPTO_SE_C, you can
register a key that's already present in the secure element with
mbedtls_psa_register_se_key(). The corresponding facility in the
MBEDTLS_PSA_CRYPTO_DRIVERS interface is a "get_builtin_key" entry point,
but this is not implemented yet. (There's a prototype at
https://github.com/ARMmbed/mbedtls/pull/3822 but nobody is working on
it. The specification is in docs/proposed/psa-driver-interface.md.)
There's an example application with a MBEDTLS_PSA_CRYPTO_SE_C driver at
https://github.com/ARMmbed/mbed-os-example-atecc608a . We don't have
example code for MBEDTLS_PSA_CRYPTO_DRIVERS yet, or good documentation,
or an easy-to-use build system — those are still a few months in the future.
If you write a driver in the next few months, I recommend that you stay
in touch with the Mbed TLS development team and follow the development
branch of Mbed TLS closely, since it's a very active area of development
at the moment.
--
Gilles Peskine
Mbed TLS developer
On 06/02/2021 16:59, Frank Bergmann via mbed-tls wrote:
> Hi,
>
> I want to use PKCS#11 with mbed TLS...
>
> - cross platform: Windows, mobile device (e.g. Android), *nix
> - on *client* side
> - to create keys (for certs) and store private keys in an HSM (could also be e.g. softhsm as fallback)
>
> How to "integrate" PKCS#11 with mbed TLS and achieve those requirements?
>
>
> cheers,
> Frank
>
Dear Farhad,
Sure, the thing you need to do is to call mbedtls_ssl_conf_authmode( conf, MBEDTLS_SSL_VERIFY_REQUIRED ) where conf is the ssl_config of the server. For more details, see that function's documentation (in ssl.h). For an example, see the command-line option auth_mode in programs/ssl/ssl_server2.c.
Hope this helps!
Best regards,
Manuel
________________________________
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of saghili via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
Sent: 05 February 2021 17:34
To: mbed-tls(a)lists.trustedfirmware.org <mbed-tls(a)lists.trustedfirmware.org>
Subject: [mbed-tls] DTLS Mutual authentication
Dear,
I would like to have mutual authentication using dtls_client.c and
dtls_server.c examples.
In the current version of the example, the client does not send his own
certificate and the server does not verify the certificate of the
client.
Could you please provide me the changes that I need to make in both
dtls_client.c and dtls_server.c examples?
Best regards,
Farhad
--
mbed-tls mailing list
mbed-tls(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/mbed-tls
Hi,
I want to use PKCS#11 with mbed TLS...
- cross platform: Windows, mobile device (e.g. Android), *nix
- on *client* side
- to create keys (for certs) and store private keys in an HSM (could also be e.g. softhsm as fallback)
How to "integrate" PKCS#11 with mbed TLS and achieve those requirements?
cheers,
Frank
Dear,
I would like to have mutual authentication using dtls_client.c and
dtls_server.c examples.
In the current version of the example, the client does not send his own
certificate and the server does not verify the certificate of the
client.
Could you please provide me the changes that I need to make in both
dtls_client.c and dtls_server.c examples?
Best regards,
Farhad
Hello,
We've now created the branch to allow Mbed TLS 3.0 development to begin.
Mbed TLS 3.0 development will take place on development_3.0 in the short term. Mbed TLS 2.x development will continue on development. We'll regularly merge changes to development into development_3.0 so that they stay aligned.
At the point of the release of Mbed TLS 2.26, we will rename development to become mbedtls-2.26 and rename development_3.0 to become development, so that the focus for new work becomes the upcoming Mbed TLS 3.0 release.
Regards,
Dave Rodgman
On 17/12/2020, 10:04, "Mbed-tls-announce on behalf of Dave Rodgman via Mbed-tls-announce" <mbed-tls-announce-bounces(a)lists.trustedfirmware.org on behalf of Mbed-tls-announce(a)lists.trustedfirmware.org> wrote:
Hello,
We are planning to release Mbed TLS 3.0 around June 2021, alongside an LTS release of Mbed TLS 2.x. Our major version numbers indicate API breaking changes, and this is no exception: Mbed TLS 3.0 will have changes that make it incompatible with 2.x (as an obvious example, functions that are deprecated in 2.x will be removed).
In setting a near-term release date, we have chosen some key areas that we want to focus on for 3.0. Some other API-breaking items (i.e., those requiring significant design time) won't make the cut and we will hold those back for a future major version, in order to have time to get them right. The main focus for 3.0 will be reduction in API surface, and changes that are low-impact for almost everyone.
Work towards 3.0 will start in late January, on the development branch which will contain a public work-in-progress view of Mbed TLS 3.0. Any work for 2.x in this timeframe will take place on a separate branch (provisionally named like "mbedtls-2.x").
During the 3.0 development period, bug fixes and security fixes will continue to be a priority, but we will have slightly less capacity for other features. While 3.0 is in development, any new features will by default be landed in 3.0 only, unless there is a strong case for back-porting to 2.x. The 2.x LTS branches will still be supported with bug fixes and security fixes for the normal three year lifetime (i.e., the final LTS release of 2.x in mid-2021 will be supported until mid-2024).
In terms of content, we are taking a cautious approach to what we plan for 3.0. In the past we've been ambitious here and as a result, have slipped on the release date; by being cautious on feature set we can be confident about hitting the mid-year release date. We won't try to make all of the changes that would be nice-to-have; instead, we will focus on tasks that reduce maintenance, unlock other improvements in a 3.x timeframe, are still valuable if only partially completed, and can fit within this time frame. Currently we're looking at the following areas for 3.0:
* Reduce the public surface of the API
* Clean-up existing APIs
* Changes to default options
Regards
Dave Rodgman
--
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Mbed-tls-announce(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/mbed-tls-announce
Hi,
As suggested by @Gilles Peskine , I did try enabling MBEDTLS_ENTROPY_FORCE_SHA256 , but even after enabling this mbedtls_ctr_drbg_seed was still returning 0X0034 (MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED ), please note that I'm using NVRAM for Seeding. I'm attaching my config.h file along with this mail for you reference.
PFA
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Today's Topics:
1. Re: ENTROPY_SOURCE_FAILED :0x0034 (Gilles Peskine)
2. Re: Reduce mbedTLS memory and storage footprint (Gilles Peskine)
----------------------------------------------------------------------
Message: 1
Date: Wed, 27 Jan 2021 20:36:18 +0100
From: Gilles Peskine <gilles.peskine(a)arm.com>
To: mbed-tls(a)lists.trustedfirmware.org
Subject: Re: [mbed-tls] ENTROPY_SOURCE_FAILED :0x0034
Message-ID: <9fcd3d55-ad54-05cf-63f9-7f3d09f3ee0d(a)arm.com>
Content-Type: text/plain; charset=windows-1252
Hello,
The entropy module uses a hash to mix the entropy. It uses SHA-512 if present and SHA-256 otherwise. Depending on the hash function, the entropy module can return either up to 64 bytes (SHA-512) or 32 bytes (SHA-256). The CTR_DRBG module knows about this and requests only 32 bytes at a time if the entropy module only delivers 32 bytes at a time.
It looks like something goes wrong when CTR_DRBG tries to request 64 bytes. This could be, for example, because a buffer is too small somewhere, or because of a limitation of the entropy source. You would need to debug the call to mbedtls_entropy_func to know more.
As a workaround, you can enable MBEDTLS_ENTROPY_FORCE_SHA256. Then the entropy module will use SHA-256 (even if MBEDTLS_SHA512_C is enabled) and only return 32 bytes at a time, and CTR_DRBG understands this and will only request 32 bytes.
--
Gilles Peskine
Mbed TLS developer
On 27/01/2021 06:08, T V LIJIN (EXT) via mbed-tls wrote:
> Hi,
> After enabling *MBEDTLS_NO_PLATFORM_ENTROPY* and*MBEDTLS_SHA512_C* ,
> /mbedtls_ctr_drbg_seed/ is returning *0x0034
> */(MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED)/
> But if I just enable *MBEDTLS_NO_PLATFORM_ENTROPY* and keep
> *MBEDTLS_SHA512_C* disabled, it does not return any error for
> /mbedtls_ctr_drbg_seed./ / / My project uses certificates with SHA384
> signature, so it requires***MBEDTLS_SHA512_C *to be enabled.
> /*MBEDTLS_NO_PLATFORM_ENTROPY* and*MBEDTLS_SHA512_C* /both needs to be
> enabled in my project , but Iam facing issue with
> mbedtls_ctr_drbg_seed returning 0x0034. Please guide me on this. What
> might be the reason for mbedtls_ctr_drbg_seed to fail while
> enabling/////*MBEDTLS_SHA512_C.*/////
> How to overcome this issue?
>
>
> Thanks,
> LIJIN T V
>
------------------------------
Message: 2
Date: Wed, 27 Jan 2021 20:48:27 +0100
From: Gilles Peskine <gilles.peskine(a)arm.com>
To: mbed-tls(a)lists.trustedfirmware.org
Subject: Re: [mbed-tls] Reduce mbedTLS memory and storage footprint
Message-ID: <b59f3e91-ae60-fae6-5fca-402894b0a890(a)arm.com>
Content-Type: text/plain; charset=windows-1252
Hello,
The most important thing is to make sure you've disabled all the features you don't need in config.h. The default configuration enables most cryptographic mechanisms, but typical constrained systems usually only need a few.
If your toolchain supports it, use link-time optimization (e.g. gcc -Os -flto or clang -Oz -flto). I've seen that this makes a significant improvement for Mbed TLS (I got -30% on one build, obviously the numbers depend heavily on the configuration and the compiler). (In contrast LTO when optimizing for performance doesn't seem to improve anything.)
MBEDTLS_MPI_WINDOW_SIZE, MBEDTLS_MPI_MAX_SIZE and MBEDTLS_ECP_MAX_BITS only impact memory usage (stack and heap), not code size.
--
Gilles Peskine
Mbed TLS developer
On 27/01/2021 05:36, T V LIJIN (EXT) via mbed-tls wrote:
> Hi,
> I'm trying to optimize the size of my binary file by making the
> following changes in "*mbedtls/config.h*"
>
> #define MBEDTLS_MPI_WINDOW_SIZE 1
> #define MBEDTLS_MPI_MAX_SIZE 32
> #define MBEDTLS_ECP_MAX_BITS 256
> #define MBEDTLS_SHA256_SMALLER
>
> Even after making the above changes I couldn't see any change in the
> binary size.
> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftls.
> mbed.org%2Fkb%2Fhow-to%2Freduce-mbedtls-memory-and-storage-footprint&a
> mp;data=04%7C01%7Clijin.tv%40kone.com%7C1a138332ca084342827b08d8c2fc9d
> b9%7C2bb82c642eb143f78862fdc1d2333b50%7C0%7C0%7C637473737538267015%7CU
> nknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1ha
> WwiLCJXVCI6Mn0%3D%7C1000&sdata=ql17fsSC0eX7Hq5ofrsWAe%2BEenOc2piLq
> 4jBix%2Bjr20%3D&reserved=0
> - This is the link I referred to follow the above-mentioned steps.
> Is there anything else I can try to reduce my final binary file size
> (ROM size) ?
>
>
> Thanks,
> LIJIN T V
>
------------------------------
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***************************************
Hello,
The most important thing is to make sure you've disabled all the
features you don't need in config.h. The default configuration enables
most cryptographic mechanisms, but typical constrained systems usually
only need a few.
If your toolchain supports it, use link-time optimization (e.g. gcc -Os
-flto or clang -Oz -flto). I've seen that this makes a significant
improvement for Mbed TLS (I got -30% on one build, obviously the numbers
depend heavily on the configuration and the compiler). (In contrast LTO
when optimizing for performance doesn't seem to improve anything.)
MBEDTLS_MPI_WINDOW_SIZE, MBEDTLS_MPI_MAX_SIZE and MBEDTLS_ECP_MAX_BITS
only impact memory usage (stack and heap), not code size.
--
Gilles Peskine
Mbed TLS developer
On 27/01/2021 05:36, T V LIJIN (EXT) via mbed-tls wrote:
> Hi,
> I'm trying to optimize the size of my binary file by making the
> following changes in "*mbedtls/config.h*"
>
> #define MBEDTLS_MPI_WINDOW_SIZE 1
> #define MBEDTLS_MPI_MAX_SIZE 32
> #define MBEDTLS_ECP_MAX_BITS 256
> #define MBEDTLS_SHA256_SMALLER
>
> Even after making the above changes I couldn't see any change in the
> binary size.
> https://tls.mbed.org/kb/how-to/reduce-mbedtls-memory-and-storage-footprint
> - This is the link I referred to follow the above-mentioned steps.
> Is there anything else I can try to reduce my final binary file size
> (ROM size) ?
>
>
> Thanks,
> LIJIN T V
>
Hello,
The entropy module uses a hash to mix the entropy. It uses SHA-512 if
present and SHA-256 otherwise. Depending on the hash function, the
entropy module can return either up to 64 bytes (SHA-512) or 32 bytes
(SHA-256). The CTR_DRBG module knows about this and requests only 32
bytes at a time if the entropy module only delivers 32 bytes at a time.
It looks like something goes wrong when CTR_DRBG tries to request 64
bytes. This could be, for example, because a buffer is too small
somewhere, or because of a limitation of the entropy source. You would
need to debug the call to mbedtls_entropy_func to know more.
As a workaround, you can enable MBEDTLS_ENTROPY_FORCE_SHA256. Then the
entropy module will use SHA-256 (even if MBEDTLS_SHA512_C is enabled)
and only return 32 bytes at a time, and CTR_DRBG understands this and
will only request 32 bytes.
--
Gilles Peskine
Mbed TLS developer
On 27/01/2021 06:08, T V LIJIN (EXT) via mbed-tls wrote:
> Hi,
> After enabling *MBEDTLS_NO_PLATFORM_ENTROPY* and*MBEDTLS_SHA512_C* ,
> /mbedtls_ctr_drbg_seed/ is returning *0x0034
> */(MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED)/
> But if I just enable *MBEDTLS_NO_PLATFORM_ENTROPY* and keep
> *MBEDTLS_SHA512_C* disabled, it does not return any error for
> /mbedtls_ctr_drbg_seed./
> /
> /
> My project uses certificates with SHA384 signature, so it
> requires***MBEDTLS_SHA512_C *to be enabled.
> /*MBEDTLS_NO_PLATFORM_ENTROPY* and*MBEDTLS_SHA512_C* /both needs to be
> enabled in my project , but Iam facing issue with
> mbedtls_ctr_drbg_seed returning 0x0034. Please guide me on this. What
> might be the reason for mbedtls_ctr_drbg_seed to fail while
> enabling/////*MBEDTLS_SHA512_C.*/////
> How to overcome this issue?
>
>
> Thanks,
> LIJIN T V
>
Hi,
After enabling MBEDTLS_NO_PLATFORM_ENTROPY and MBEDTLS_SHA512_C , mbedtls_ctr_drbg_seed is returning 0x0034 (MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED)
But if I just enable MBEDTLS_NO_PLATFORM_ENTROPY and keep MBEDTLS_SHA512_C disabled, it does not return any error for mbedtls_ctr_drbg_seed.
My project uses certificates with SHA384 signature, so it requires MBEDTLS_SHA512_C to be enabled.
MBEDTLS_NO_PLATFORM_ENTROPY and MBEDTLS_SHA512_C both needs to be enabled in my project , but Iam facing issue with mbedtls_ctr_drbg_seed returning 0x0034. Please guide me on this. What might be the reason for mbedtls_ctr_drbg_seed to fail while enabling MBEDTLS_SHA512_C.
How to overcome this issue?
Thanks,
LIJIN T V
Hi,
I'm trying to optimize the size of my binary file by making the following changes in "mbedtls/config.h"
#define MBEDTLS_MPI_WINDOW_SIZE 1
#define MBEDTLS_MPI_MAX_SIZE 32
#define MBEDTLS_ECP_MAX_BITS 256
#define MBEDTLS_SHA256_SMALLER
Even after making the above changes I couldn't see any change in the binary size.
https://tls.mbed.org/kb/how-to/reduce-mbedtls-memory-and-storage-footprint - This is the link I referred to follow the above-mentioned steps.
Is there anything else I can try to reduce my final binary file size (ROM size) ?
Thanks,
LIJIN T V
Dear,
In our project, our device should act as both client and server. Is it
possible for both TLS and DTLS? If yes, how about the certificate? Do we
need only 2 certs for this divice (one for the server role and one for
the client role)?
Best regards,
Farhad
Hello,
There is work in progress by community members to implement PKCS#7
SignedData parsing and generation.
https://github.com/ARMmbed/mbedtls/pull/3970https://github.com/ARMmbed/mbedtls/pull/3431
Arm has no particular plans in this area, but if you need other parts of
PKCS#7, we'd be happy to accept more contributions. We'll can't commit
to doing any development, but we'll assist with submissions and review
code as usual.
--
Gilles Peskine
Mbed TLS developer
On 13/01/2021 07:31, Subramanian Gopi Krishnan via mbed-tls wrote:
>
> Hi,
>
>
>
> Is there a plan to support PKCS#7 Certificate in
> future? We are work with rfc7030 service, which issues certificate in
> PKCS#7 format.
>
>
>
> Thanks,
>
> Gopi Krishnan
>
>
Hi,
Is there a plan to support PKCS#7 Certificate in future? We are work with rfc7030 service, which issues certificate in PKCS#7 format.
Thanks,
Gopi Krishnan
This is a notice that Mbed TLS 2.7 will no longer be supported or maintained after February 5th 2021. Mbed TLS 2.7.0 was released on February 5th 2018 with a three year support period.
The current version of Mbed TLS 2.7 is 2.7.18, which was released on December 11th 2020. There are no pending bug or security fixes, so unless new issues arise during the next month, there will not be another release of 2.7. We do not plan to merge any non-critical backports to 2.7 in the next month.
We recommend that where practical, users upgrade to either 2.16, which will be supported until the end of 2021, or to the development branch, which will be released as an LTS in mid 2021, with an expected support period until mid 2024.
Dave Rodgman
Hi,
Hanno suggested me to post our discussion here:
We use mbedtls in Facebook family apps. One of missing features is the ability to delegate cert verification to application. Hanno has pointed us to a similar ask in https://github.com/ARMmbed/mbedtls/pull/2091
We implemented cert verification process in Android/java and iOS/objective-C. Having this feature enables us to use the OS module for cert verification. The motivation is reduced maintenance cost. Some mobile APPs use OS TLS stack (rather than bundle mbedtls or openssl in the binary), so we have to maintain our OS-specific cert verification modules anyways. It’ll be ideal if we only keep the Android and iOS implementations as source of truth.
Any thoughts on supporting this?
Thanks,
Junqi
Hi all,
Back in June 2019, we added support for the experimental DTLS Connection ID extension in Mbed TLS 2.18.0. This extension makes it possible to keep a connection alive even when the client's connectivity changes (eg new IP address). Since this was based on a draft rather than an established standard, it is disabled in the default config, and the option to enable it comes with a warning about us not being able to make any stability promises.
As it turns out, a couple of months ago an extension number was assigned by IANA for this extension, which is different from the one we picked up when implementing the draft, so we'll have to change that in a future version of Mbed TLS. This change is trivial to do but would break compatibility in the following sense: and old client and a new server (or a new client and a new server) would no longer be able to negotiate this extension; only old-old and new-new would work. (Thanks to Achim Kraus for bringing that to our attention by the way: https://github.com/ARMmbed/mbedtls/issues/3892 )
One obvious solution to that issue would be to make sure all users upgrade all the clients and the servers at the same time. This can probably be managed in a development/testing environment as well as some tightly controlled production environments, but is probably less suitable for large-scale deployments where clients and servers might not even be manged by the same party.
So, before we plan this changed, we'll like to know if anyone already has a production deployment relying on Connection ID where updating all the clients and servers at the same time would not be an option.
If that is the case, we may consider implementing a compatibility mode that would allow a server to negotiate use of the extension with both old and new clients. However, such compatibility code would be non-standard and a testing burden (not to mention, significantly more work that just updating the relevant #define), so that's something we'd like to avoid doing unless we know that there is an actual need for it.
Please let us know what you think by replying to this email either on-list, or privately if you'd rather not share deployment information publicly (in that case, please mention it explicitly so that we know you didn't just forget to Cc the list).
Thanks,
Manuel
Dear Xiao Nian Jun,
Thanks for your response! Knowing the practical impact of the issue will help us prioritize it.
Best regards,
Manuel
________________________________
From: Xiao, Nian Jun <nianjun.xiao(a)siemens.com>
Sent: 29 December 2020 02:43
To: Manuel Pegourie-Gonnard <Manuel.Pegourie-Gonnard(a)arm.com>
Cc: He, Shu Shan <shushan.he(a)siemens.com>; Xia, Juan <juan.xia(a)siemens.com>
Subject: RE: MBEDTLS issue I found
Dear Manuel,
Really appreciate for your quick and detail feedback.
We think this is more like an interoperability issue, we found this issue during we developing webserver feature using MBEDTLS. Google Chrome treat such certificate as invalid. Follow below steps will reproduce this issue.
1. Generate a self-signed root certificate with ECC256 key.(using genKey and certWrite program of MBEDTLS)
2. Using above root certificate to sign a device certificate which also using ECC256 as its private key. (using genKey and certWrite program of MBEDTLS)
3. Install root certificate so Chrome can see it.
4. using Nginx or some other opensource web server, modify its configuration so it will use the device certificate and corresponding private key as the ciphers to setup TLS communication.
5. Open Chrome and visit default Nginx web page(or some other web server tools’ default web page), you can see Chrome won’t let user to continue because it treat the device certificate as invalid.
6. According to our test, Chrome has this issue, fire fox, IE, etc. doesn’t have this issue.
7. If I modify function mbedtls_asn1_write_algorithm_identifier like I said yesterday, Chrome will accept it and other browser also will accept it, happy life back again.
Have a good day and looking for your feedback again!
B.R.
Xiao Nian Jun.
From: Manuel Pegourie-Gonnard <Manuel.Pegourie-Gonnard(a)arm.com>
Sent: Monday, December 28, 2020 9:23 PM
To: mbed-tls(a)lists.trustedfirmware.org; Xiao, Nian Jun (RC-CN DI FA BL CTR-SL PRC2) <nianjun.xiao(a)siemens.com>
Cc: He, Shu Shan (RC-CN DI FA BL CTR-SL PRC2) <shushan.he(a)siemens.com>
Subject: Re: MBEDTLS issue I found
Dear Xiao Nian Jun,
Thanks for your kind words and for reporting this issue you found.
I checked RFC 7427 and indeed while parameters must be present and NULL for all RSA algorithms, appendix A.3 is clear that they must be absent for ECDSA. Since RFC 7427 is about IKEv2 rather than about X.509 certificates, I also checked RFC 5480 (updating RFC 3279 which defines the X.509 profile used by the IETF), and it concurs: for ECDSA, parameters are absent (appendix A).
Our behaviour is not conformant, and this should be fixed. Just to help us evaluate the severity of the issue, I'd like to know if this is something you found by inspecting the generated certificate yourself, or if it caused the generate certificate to be rejected by some other X.509 implementation or verification tool. Said otherwise, is this only a compliance issue, or also an interoperability issue?
Regarding your fix, I think it works as long as you are only generating ECC-signed X.509 certificates, but as you suggest, I'm afraid it only fixes the problem by creating another one: it would suppress the NULL parameters for RSA as well, but unfortunately, they're mandatory there (I wish the standards were more consistent). So, we'll probably have to do something similar, but only for ECDSA.
I was going to create a ticket for that in our bug tracker when I noticed we already have a ticket tracking that: https://github.com/ARMmbed/mbedtls/issues/2924 - Ill add a link to your message in the ticket.
Thanks again for your report.
Best regards,
Manuel
________________________________
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org<mailto:mbed-tls-bounces@lists.trustedfirmware.org>> on behalf of Xiao, Nian Jun via mbed-tls <mbed-tls(a)lists.trustedfirmware.org<mailto:mbed-tls@lists.trustedfirmware.org>>
Sent: 28 December 2020 03:24
To: mbed-tls(a)lists.trustedfirmware.org<mailto:mbed-tls@lists.trustedfirmware.org> <mbed-tls(a)lists.trustedfirmware.org<mailto:mbed-tls@lists.trustedfirmware.org>>
Cc: He, Shu Shan <shushan.he(a)siemens.com<mailto:shushan.he@siemens.com>>
Subject: [mbed-tls] MBEDTLS issue I found
Dear MBEDTLS team,
I’m a developer at SIEMENS, my name is Xiao Nian Jun. Please accept my sincere gratitude for your excellent work and to spend extra time to read my email.
We are using MBEDTLS to generate ECC key and certificates, we found an issue regarding algorithm identifier in the final ASN.1 certificate. For certificate signed by ECC key, the algorithm identifier is “NULL” which doesn’t conforms to RFC7427 specification.
[cid:image001.png@01D6DDC1.DCE8CFC0]
You can see the “NULL” string in the certificate, Chrome will treat this kind of certificate as invalid.
This issue has blocked us for a while, and after some investigation, we found an easy fix –- probably immature fix --- to make it works right--- we just commented out this line of code “MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) )" in function mbedtls_asn1_write_algorithm_identifier.
To be honesty, we’ve been using MBEDTLS for very short time, probably this is not an issue, probably our fix will end up break up something…currently, it’s just looks correct.
Please check if my fix works or not, if not, please do not hesitate to correct me.
B.R.
Xiao Nian Jun.
Dear Xiao Nian Jun,
Thanks for your kind words and for reporting this issue you found.
I checked RFC 7427 and indeed while parameters must be present and NULL for all RSA algorithms, appendix A.3 is clear that they must be absent for ECDSA. Since RFC 7427 is about IKEv2 rather than about X.509 certificates, I also checked RFC 5480 (updating RFC 3279 which defines the X.509 profile used by the IETF), and it concurs: for ECDSA, parameters are absent (appendix A).
Our behaviour is not conformant, and this should be fixed. Just to help us evaluate the severity of the issue, I'd like to know if this is something you found by inspecting the generated certificate yourself, or if it caused the generate certificate to be rejected by some other X.509 implementation or verification tool. Said otherwise, is this only a compliance issue, or also an interoperability issue?
Regarding your fix, I think it works as long as you are only generating ECC-signed X.509 certificates, but as you suggest, I'm afraid it only fixes the problem by creating another one: it would suppress the NULL parameters for RSA as well, but unfortunately, they're mandatory there (I wish the standards were more consistent). So, we'll probably have to do something similar, but only for ECDSA.
I was going to create a ticket for that in our bug tracker when I noticed we already have a ticket tracking that: https://github.com/ARMmbed/mbedtls/issues/2924 - Ill add a link to your message in the ticket.
Thanks again for your report.
Best regards,
Manuel
________________________________
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of Xiao, Nian Jun via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
Sent: 28 December 2020 03:24
To: mbed-tls(a)lists.trustedfirmware.org <mbed-tls(a)lists.trustedfirmware.org>
Cc: He, Shu Shan <shushan.he(a)siemens.com>
Subject: [mbed-tls] MBEDTLS issue I found
Dear MBEDTLS team,
I’m a developer at SIEMENS, my name is Xiao Nian Jun. Please accept my sincere gratitude for your excellent work and to spend extra time to read my email.
We are using MBEDTLS to generate ECC key and certificates, we found an issue regarding algorithm identifier in the final ASN.1 certificate. For certificate signed by ECC key, the algorithm identifier is “NULL” which doesn’t conforms to RFC7427 specification.
[cid:image001.png@01D6DD01.C51C7290]
You can see the “NULL” string in the certificate, Chrome will treat this kind of certificate as invalid.
This issue has blocked us for a while, and after some investigation, we found an easy fix –- probably immature fix --- to make it works right--- we just commented out this line of code “MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) )" in function mbedtls_asn1_write_algorithm_identifier.
To be honesty, we’ve been using MBEDTLS for very short time, probably this is not an issue, probably our fix will end up break up something…currently, it’s just looks correct.
Please check if my fix works or not, if not, please do not hesitate to correct me.
B.R.
Xiao Nian Jun.
Dear MBEDTLS team,
I’m a developer at SIEMENS, my name is Xiao Nian Jun. Please accept my sincere gratitude for your excellent work and to spend extra time to read my email.
We are using MBEDTLS to generate ECC key and certificates, we found an issue regarding algorithm identifier in the final ASN.1 certificate. For certificate signed by ECC key, the algorithm identifier is “NULL” which doesn’t conforms to RFC7427 specification.
[cid:image001.png@01D6DD01.C51C7290]
You can see the “NULL” string in the certificate, Chrome will treat this kind of certificate as invalid.
This issue has blocked us for a while, and after some investigation, we found an easy fix –- probably immature fix --- to make it works right--- we just commented out this line of code “MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) )" in function mbedtls_asn1_write_algorithm_identifier.
To be honesty, we’ve been using MBEDTLS for very short time, probably this is not an issue, probably our fix will end up break up something…currently, it’s just looks correct.
Please check if my fix works or not, if not, please do not hesitate to correct me.
B.R.
Xiao Nian Jun.
Hello,
We are planning to release Mbed TLS 3.0 around June 2021, alongside an LTS release of Mbed TLS 2.x. Our major version numbers indicate API breaking changes, and this is no exception: Mbed TLS 3.0 will have changes that make it incompatible with 2.x (as an obvious example, functions that are deprecated in 2.x will be removed).
In setting a near-term release date, we have chosen some key areas that we want to focus on for 3.0. Some other API-breaking items (i.e., those requiring significant design time) won't make the cut and we will hold those back for a future major version, in order to have time to get them right. The main focus for 3.0 will be reduction in API surface, and changes that are low-impact for almost everyone.
Work towards 3.0 will start in late January, on the development branch which will contain a public work-in-progress view of Mbed TLS 3.0. Any work for 2.x in this timeframe will take place on a separate branch (provisionally named like "mbedtls-2.x").
During the 3.0 development period, bug fixes and security fixes will continue to be a priority, but we will have slightly less capacity for other features. While 3.0 is in development, any new features will by default be landed in 3.0 only, unless there is a strong case for back-porting to 2.x. The 2.x LTS branches will still be supported with bug fixes and security fixes for the normal three year lifetime (i.e., the final LTS release of 2.x in mid-2021 will be supported until mid-2024).
In terms of content, we are taking a cautious approach to what we plan for 3.0. In the past we've been ambitious here and as a result, have slipped on the release date; by being cautious on feature set we can be confident about hitting the mid-year release date. We won't try to make all of the changes that would be nice-to-have; instead, we will focus on tasks that reduce maintenance, unlock other improvements in a 3.x timeframe, are still valuable if only partially completed, and can fit within this time frame. Currently we're looking at the following areas for 3.0:
* Reduce the public surface of the API
* Clean-up existing APIs
* Changes to default options
Regards
Dave Rodgman
Hi Farhad,
I think for this question as well as the "packets lost" question, it's important to distinguish two phases of a DTLS connection: initially there's a handshake (to negotiate and establish security parameters and session keys), and then application data can be exchanged. Application data is what's passed to `mbedtls_ssl_write()` or written by `mbedtls_ssl_read()` (depending on whether you're the sender or receiver) - this can only happen once the handshake is completed.
During the handshake, there are indeed mechanisms to re-order packets that were received out of order and also retransmit packets that were lost. But that's only during the handshake (because it's a lockstep process where everything needs to happen in order), and only for data that's purely internal to the DTLS protocol and never seen by the application.
Once the handshake is completed and application data starts to be exchanged, there is no longer any kind of re-ordering or retransmission mechanism. The reason is, as you guessed, DTLS aims to provide similar properties to UDP - with cryptographic security in addition. So, if you send something with `mbedtls_ssl_write()` and the record gets lost, the DTLS protocol won't even know about it, and no retransmission will happen. If record N+1 arrives before record N, the DTLS protocol will know but do nothing, and just deliver the records in the order they arrived. Again, as you said, doing otherwise would introduce latency and be contrary to the goals of DTLS - people who want reliability at the expense of latency should use TLS.
The main exception to that principle that you can expect DTLS to behave like UDP is duplicated records: the DTLS protocol provide optional replay protection (that is, if record N arrives twice, the second occurrence is dropped). In Mbed TLS, this mechanism is enabled by default but can be disabled at compile-time by not defining MBEDTLS_SSL_DTLS_ANTI_REPLAY in config.h, or at runtime by calling mbedtls_ssl_conf_dtls_anti_replay().
I hope this answers your questions.
Regards,
Manuel.
________________________________
From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of saghili via mbed-tls <mbed-tls(a)lists.trustedfirmware.org>
Sent: 10 December 2020 18:31
To: mbed-tls(a)lists.trustedfirmware.org <mbed-tls(a)lists.trustedfirmware.org>
Subject: [mbed-tls] "Reordering" in DTLS
Hello,
I have a question about DTLS.
One thing that is not entirely clear to me from the RFC is this: suppose
2 records are received within a "short" period, e.g. seq# N+1 followed
by seq# N. In this case, what does DTLS do? My understanding is that it
will pass on packets in the order it was received (i.e. out of order).
But it can (should?) re-order at the DTLS layer and pass them on to the
upper layer in the right order. HOWEVER, this implies that the DTLS
"wait" for a certain window to see if the seq#=N packet arrives or not.
But doing so introduces additional delay at DTLS layer and also
contradicts with the UDP principle (i.e. no concept of order). Could you
please give me a hint regarding this issue?
Best regards,
Farhad
--
mbed-tls mailing list
mbed-tls(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/mbed-tls
Hello,
I have a question about DTLS.
One thing that is not entirely clear to me from the RFC is this: suppose
2 records are received within a "short" period, e.g. seq# N+1 followed
by seq# N. In this case, what does DTLS do? My understanding is that it
will pass on packets in the order it was received (i.e. out of order).
But it can (should?) re-order at the DTLS layer and pass them on to the
upper layer in the right order. HOWEVER, this implies that the DTLS
"wait" for a certain window to see if the seq#=N packet arrives or not.
But doing so introduces additional delay at DTLS layer and also
contradicts with the UDP principle (i.e. no concept of order). Could you
please give me a hint regarding this issue?
Best regards,
Farhad
Hello,
I have a question about DTLS.
Because of the latency, I need to disable the "packets lost" feature.
Does MbedTLS provide the flag that we can disable resending the packet
in case of the packet lost? For instance, if I have 3 packets 42, 43,
and 44, is it possible to decrypt packet 44 without receiving packets 42
and 43? It will be in the "Record" layer.
Thank you.
Best regards,
Farhad