- mbed-tls - lists.trustedfirmware.org

by Sawyer Liu

Hello ARM Support, About below CVEs, any update? Thanks. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16150<https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcve.mitre…> https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1000520 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3739 Best Regards Sawyer Liu Microcontrollers, NXP Semiconductors

4 years, 11 months

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Re: [mbed-tls] Availability of GPLv2 releases in the future

by Gilles Peskine

Hi Fabian, Unfortunately https://tls.mbed.org/how-to-get is out of date. As indicated on https://tls.mbed.org/download, newer releases (since 2.17) are distributed under Apache license only. Only the long-time support branches (2.7.x and 2.16.x) still have GPL releases. -- Gilles Peskine Mbed TLS developer On 20/10/2020 14:19, Fabian Keil via mbed-tls wrote: > Hi, > > tls.mbed.org currently sends mixed signals regarding > the license of future MbedTLS releases. > > Quoting https://tls.mbed.org/download: > | In packaged form, mbed TLS 2.1.0 to mbed TLS 2.16 are > | available in both an Apache 2.0 licensed version (our > | primary open source license) and in a GPL 2.0 licensed version. > | > | Newer versions will be available under the Apache 2.0 license. > > Quoting https://tls.mbed.org/how-to-get: > | All the current versions of the mbed TLS library are distributed > | under the Apache 2.0 license and available from our Download area. > | In addition there are packaged versions of the mbed TLS library > | that are distributed with the GNU Public License Version 2.0 (GPL v2.0). > | > | The Apache-licensed and GPL-licensed versions of mbed TLS are > | identical in source code (with the exception of the license > | headers at the top of files). > | > | We plan to keep both licensed versions around. > > Can anyone estimate when "newer releases" will no longer > be dual licensed? > > We recently added MbedTLS support for Privoxy and a > MbedTLS license switch from dual license to Apache 2.0 > complicates the license terms. > > Thanks > Fabian >

4 years, 11 months

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Re: [mbed-tls] Clarification regarding the mbedtls_pk_context object and the PEM format, an a question about the example TLS server

by Gilles Peskine

Hi Máté, On 26/10/2020 12:04, Z.Máté via mbed-tls wrote: > Dear mbedtls mailing list members! > > I hope you recieve my message now, previously I had problems posting > to this list. :( > > My first question is actually about the PEM format. As far as I'm > aware the PEM format either contains the Private key (signalled by the > ---- BEGIN PRIVATE KEY ---- header) or a public key (---- BEGIN PUBLIC > KEY -----). In my application I have to work on an app that stores key > pairs in a special, secure storage solution (Secure Storage of OPTEE > if you've heard about it). I decided to export the keys in PEM format, > so that reading and handling them is equal to moving a large string > buffer around. Using the PEM format, is there a way to store both > private and public keys in the same "file"? Does mbedtls allow for > such a solution (does such a solution even exist?). There are actually several PEM formats. Some private key formats actually store both the private key and the public key, while others only store the private key. However, it is always possible to calculate the public key from the private key. So if you want to have the whole key pair, just write the private key in any format. If you have a private key file, you can extract the public key with the Mbed TLS sample program key_app_writer (untested command line, typed directly into my mail client): programs/pkey/key_app_writer mode=private filename=my_private_key.pem output_mode=public output_file=my_public_key.pem or with OpenSSL: openssl pkey -in my_private_key.pem -pubout -out my_public_key.pem > > If not, is there a simple way to get the public key from a private key > object? Does the mbedtls_pk_context, (that parsed up with a private > key) contain the information needed to export the public key into a > PEM buffer? As far as I know mbedtls allows for exporting the private > key and the public key with the functions mbedtls_write_key_pem and > ...write_pubkey_pem (or something along those lines) does that mean I > can only export one at a time and there's no way to save the > information for both into one PEM buffer? > > If there's a way to save both private and public keys into one PEM > file, do I have to parse the private key and public key into separate > objects then? With parse_key and parse_pubkey? This isn't really a > problem just clarifying. Once you have an mbedtls_pk_context, if you want to export both keys to a file, use mbedtls_write_key_pem(). If you want to have a separate file that only contains the public key, call mbedtls_write_pubkey_pem() on the same mbedtls_pk_context. > > If you can point me to an actually good description of the PEM format > and what CAN be stored inside of it, I'd be very grateful! :) PEM is just an encoding: base64 data between a header and footer. The base64-encoded data can have several different formats depending on the header. It can represent a private key (several formats depending on the header), a public key or a certificate. A complete description is spread across about half a dozen RFC. Fortunately, I don't think you need to dig into those. > > I also have a question regarding the example SSL server program. In > it, the server needs a private key and a certificate for obvious > reasons. It also loads a certificate and as far as I know, the > certificate has to be tied to a known CA for it to be valid. > > I would like to test the program with a self generated key pair, do I > need to change the Certificate and CAs to a new one as well? To > authenticate the new keypair? Does the mbedtls ssl_client1 example > program work with self signed certs? Or do I need to take care of the > CA validation myself (that would probably beyond the scope of the > project I'm working on). The sample program ssl_server does not check the client certificate. The test program ssl_server2 can check the client certificate: pass the command line options "auth_mode=required ca_file=my_ca.crt". If you have a self-signed client certificate, you can pass it as the ca_file. -- Gilles Peskine Mbed TLS developer > > Thank you in advance! > > Yours truly, > Máté Zombor >

4 years, 12 months

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Clarification regarding the mbedtls_pk_context object and the PEM format, an a question about the example TLS server

by Z.Máté

Dear mbedtls mailing list members! I hope you recieve my message now, previously I had problems posting to this list. :( My first question is actually about the PEM format. As far as I'm aware the PEM format either contains the Private key (signalled by the ---- BEGIN PRIVATE KEY ---- header) or a public key (---- BEGIN PUBLIC KEY -----). In my application I have to work on an app that stores key pairs in a special, secure storage solution (Secure Storage of OPTEE if you've heard about it). I decided to export the keys in PEM format, so that reading and handling them is equal to moving a large string buffer around. Using the PEM format, is there a way to store both private and public keys in the same "file"? Does mbedtls allow for such a solution (does such a solution even exist?). If not, is there a simple way to get the public key from a private key object? Does the mbedtls_pk_context, (that parsed up with a private key) contain the information needed to export the public key into a PEM buffer? As far as I know mbedtls allows for exporting the private key and the public key with the functions mbedtls_write_key_pem and ...write_pubkey_pem (or something along those lines) does that mean I can only export one at a time and there's no way to save the information for both into one PEM buffer? If there's a way to save both private and public keys into one PEM file, do I have to parse the private key and public key into separate objects then? With parse_key and parse_pubkey? This isn't really a problem just clarifying. If you can point me to an actually good description of the PEM format and what CAN be stored inside of it, I'd be very grateful! :) I also have a question regarding the example SSL server program. In it, the server needs a private key and a certificate for obvious reasons. It also loads a certificate and as far as I know, the certificate has to be tied to a known CA for it to be valid. I would like to test the program with a self generated key pair, do I need to change the Certificate and CAs to a new one as well? To authenticate the new keypair? Does the mbedtls ssl_client1 example program work with self signed certs? Or do I need to take care of the CA validation myself (that would probably beyond the scope of the project I'm working on). Thank you in advance! Yours truly, Máté Zombor

4 years, 12 months

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Invitation: Mbed TLS Virtual Workshop @ Tue Nov 3, 2020 7am - 11am (MST) (mbed-tls@lists.trustedfirmware.org)

by Don Harbin

You have been invited to the following event. Title: Mbed TLS Virtual Workshop Hi,Trustedfirmware.org community project would like to invite you to the Mbed TLS Virtual Workshop. The purpose of the workshop is to bring together the Mbed TLS community including maintainers, contributors and users to discussThe future direction of the project andWays to improve community collaborationHere is the agenda for the workshop.Topic                                                                         Time (in GMT)Welcome                                                                   2.00 - 2.10pmConstant-time code                                                2.10 – 2.30pmProcesses - how does work get scheduled?      2.30 – 2.50pmPSA Crypto APIs                                                     2.50 – 3.20pmPSA Crypto for Silicon Labs Wireless         MCUs - Why, What, Where and When          3.20 – 3.50pmBreak                                                                          Roadmap, TLS1.3 Update                                      4.10 – 4.30pmMbed TLS 3.0 Plans, Scope                                   4.30 – 5.00pmHow do I contribute my first review         and be an effective Mbed TLS reviewer      5.00 – 5.30pmRegards,Don Harbin Trusted Firmware Community Manager==============Zoom details below:====================Trusted Firmware is inviting you to a scheduled Zoom meeting.Topic: Mbed TLS Virtual WorkshopTime: Nov 3, 2020 02:00 PM Greenwich Mean TimeJoin Zoom Meetinghttps://linaro-org.zoom.us/j/95315200315?pwd=ZDJGc1BZMHZLV29DTmpGUllmMjB1UT09Meeting ID: 953 1520 0315Passcode: 143755One tap mobile+16699009128,,95315200315# US (San Jose)+12532158782,,95315200315# US (Tacoma)Dial by your location        +1 669 900 9128 US (San Jose)        +1 253 215 8782 US (Tacoma)        +1 346 248 7799 US (Houston)        +1 646 558 8656 US (New York)        +1 301 715 8592 US (Germantown)        +1 312 626 6799 US (Chicago)        888 788 0099 US Toll-free        877 853 5247 US Toll-freeMeeting ID: 953 1520 0315Find your local number: https://linaro-org.zoom.us/u/apL3hgti4 When: Tue Nov 3, 2020 7am – 11am Mountain Standard Time - Phoenix Where: Zoom: https://linaro-org.zoom.us/j/95315200315?pwd=ZDJGc1BZMHZLV29DTmpGUllmMjB1UT… Calendar: mbed-tls(a)lists.trustedfirmware.org Who: * Don Harbin - creator * shebu.varghesekuriakose(a)arm.com * mbed-tls(a)lists.trustedfirmware.org * psa-crypto(a)lists.trustedfirmware.org * dave.rodgman(a)arm.com Event details: https://www.google.com/calendar/event?action=VIEW&eid=NHVvY2FxY2o4Njk3MWZkd… Invitation from Google Calendar: https://www.google.com/calendar/ You are receiving this courtesy email at the account mbed-tls(a)lists.trustedfirmware.org because you are an attendee of this event. To stop receiving future updates for this event, decline this event. Alternatively you can sign up for a Google account at https://www.google.com/calendar/ and control your notification settings for your entire calendar. Forwarding this invitation could allow any recipient to send a response to the organizer and be added to the guest list, or invite others regardless of their own invitation status, or to modify your RSVP. Learn more at https://support.google.com/calendar/answer/37135#forwarding

4 years, 12 months

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Availability of GPLv2 releases in the future

by Fabian Keil

Hi, tls.mbed.org currently sends mixed signals regarding the license of future MbedTLS releases. Quoting https://tls.mbed.org/download: | In packaged form, mbed TLS 2.1.0 to mbed TLS 2.16 are | available in both an Apache 2.0 licensed version (our | primary open source license) and in a GPL 2.0 licensed version. | | Newer versions will be available under the Apache 2.0 license. Quoting https://tls.mbed.org/how-to-get: | All the current versions of the mbed TLS library are distributed | under the Apache 2.0 license and available from our Download area. | In addition there are packaged versions of the mbed TLS library | that are distributed with the GNU Public License Version 2.0 (GPL v2.0). | | The Apache-licensed and GPL-licensed versions of mbed TLS are | identical in source code (with the exception of the license | headers at the top of files). | | We plan to keep both licensed versions around. Can anyone estimate when "newer releases" will no longer be dual licensed? We recently added MbedTLS support for Privoxy and a MbedTLS license switch from dual license to Apache 2.0 complicates the license terms. Thanks Fabian

5 years

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Fwd: Working on TLS handshake record fragmentation (#1840)

by Omer Shapira

Hi Dave, Thanks for your reply. The particular reasons for bringing up 2.7 and 2.16 first is that my employer is currently using 2.7 and would prefer using a small increment. Having said that, if adding features to LTS is not advisable (especially given that 2.7 has less than 6 months of projected life), I think I can present the arguments against using the 2.7. Additional consideration is the timing. My employer needs fragmentation support as soon as possible, with the intent of running it on a desktop environment. Historically, when the engineers are able to provide my employer with what is needed now, they are allowed more time for incremental improvements. The third consideration involves the MPS project by Hanno Becker. I've been collaborating with Hanno, and with Hannes Tschofenig and Thomas Fosetti on the project of adding QUIC support to mbedTLS. This goal depends on TLS 1.3 support (Hannes has written a prototype, which I was able to add QUIC in an internal version), and on MPS. I would like to avoid putting a duplicate effort into non-MPS fragmentation support. Unfortunately, if I want to meet the timing requirements of my employer, I will not be able to use MPS, since it needs more maturing. Because of the above considerations, I would like to suggest the following plan of actions: As the first step, I would like to add the MVP (minimal viable product) fragmentation to the development version. The MVP takes the following assumptions: 1. The RAM footprint is not a concern for the MVP (my employer is going to run it in the desktop environment). 2. Unification of the fragmentation between TLS and DTLS is not a concern for the MVP 3. LTS is not a concern for the MVP (potentially not at all) Because of the above simplifying assumptions, I believe that the change can be small and focused. I think I can have code ready for review in a couple of weeks. As the second step, I would like to put my effort into helping Hanno Becker with his MPS system. Once sufficiently mature, the MPS will supersede the MVP fragmentation, and will open the doors for adding support for QUIC. The simplifying assumptions 1. (RAM) and 2. (TLS <=> DTLS) will be addressed by MPS. Addressing the last assumption may not be required. What are your thoughts? On Wed, Oct 14, 2020 at 10:28 AM Dave Rodgman <dave.rodgman(a)arm.com> wrote: > Hi Omer, > > > > Thanks for offering to help us with this feature. > > > > Normally, we wouldn’t add new features directly to an older branch, for a > few reasons. 2.7 is quite old and is in fact only guaranteed to be > supported until Feb 21, so it’s not the ideal place to spend effort on new > features. Introducing new features here would also create the situation > where 2.7 has features not in development, and vice-versa, creating an > upgrade dilemma for users (unless we were to port the feature to all > supported branches). And adding significant new features to LTS branches > can always introduce some risk of destabilising it. > > > > So for these reasons, we would normally recommend targeting the > development branch for new features (with backports only where there is a > strong reason to do so), and then picking up the next stable release that > contains the new feature. > > > > Is there a particular reason you’re focusing on 2.7, rather than > development, or would it be viable for you to add this to development and > pick up the next release? > > > > Thanks > > > > Dave > > > > *From: *mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf > of Omer Shapira via mbed-tls <mbed-tls(a)lists.trustedfirmware.org> > *Reply to: *Omer Shapira <omer.shapira(a)gmail.com> > *Date: *Monday, 12 October 2020 at 20:04 > *To: *"mbed-tls(a)lists.trustedfirmware.org" < > mbed-tls(a)lists.trustedfirmware.org> > *Subject: *[mbed-tls] Working on TLS handshake record fragmentation > (#1840) > > > > Hello, > > My employer (Facebook) is willing to give me some time to TLS handshake > fragmentation support to MbedTLS 2.7 [0] . This would be my first > contribution to MbedTLS, and I have several novice questions: > > 1. What is the best way to add the feature to MbedTLS 2.7? > 2. Trade-off between the consistency of the fragmentation code across the > branches, vs. the consistency of the branches. > > > Question 1: Best way to add the feature to MbedTLS 2.7 > > One constraint that I am facing is the code must be added to the upstream > branch that is as close as possible to the 2.7.xx. My understanding of the > Contribution Guidelines[1] is that while the LTS branches are mostly meant > for the bug fixes, backporting of the new features is welcomed as long as > the API/ABI compatibility is maintained and the disruption to the users is > minimized. > > If adding support to the LTS branches is not advisable, are there any > other possibilities of contributing the code to an upstream branch that is > very close to the 2.7.xx? > > Question 2: Trade-off between the consistency of the fragmentation code > across the branches, vs. the consistency of the branches. > > Assuming that adding features to 2.7 (and 2.16) *is* possible, there is a > trade-off between the consistency of the fragmentation code across the > branches, vs. the consistency of the branches. The `development` branch > supports variable-length buffers[2] . Variable messages sizes would make > the fragmentation easier in the development branch. In addition, there is > the MPS effort by Hanno Becker which would make the fragmentation support > even easier in the development branch. None of that is present in the 2.7 > or the 2.16 branches. > > What is the preferable trade-off in such a situation: > a. Minimizing the change to the "host" version (2.7 or 2.16), on the > expense the implementation of the feature differ between 2.7 and > `development`, or > b. Minimizing the differences in the implementation of the feature, on > the expense of more intrusive changes to the earlier versions? > > > [0] https://github.com/ARMmbed/mbedtls/issues/1840 > [1] https://github.com/ARMmbed/mbedtls/blob/development/CONTRIBUTING.md > [2] > https://github.com/ARMmbed/mbedtls/blob/development/include/mbedtls/config.… > > -- > > Sincerely Yours, > Omer Shapira > -- Sincerely Yours, Omer Shapira -- Sincerely Yours, Omer Shapira

5 years

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Re: [mbed-tls] Working on TLS handshake record fragmentation (#1840)

by Dave Rodgman

Hi Omer, Thanks for offering to help us with this feature. Normally, we wouldn’t add new features directly to an older branch, for a few reasons. 2.7 is quite old and is in fact only guaranteed to be supported until Feb 21, so it’s not the ideal place to spend effort on new features. Introducing new features here would also create the situation where 2.7 has features not in development, and vice-versa, creating an upgrade dilemma for users (unless we were to port the feature to all supported branches). And adding significant new features to LTS branches can always introduce some risk of destabilising it. So for these reasons, we would normally recommend targeting the development branch for new features (with backports only where there is a strong reason to do so), and then picking up the next stable release that contains the new feature. Is there a particular reason you’re focusing on 2.7, rather than development, or would it be viable for you to add this to development and pick up the next release? Thanks Dave From: mbed-tls <mbed-tls-bounces(a)lists.trustedfirmware.org> on behalf of Omer Shapira via mbed-tls <mbed-tls(a)lists.trustedfirmware.org> Reply to: Omer Shapira <omer.shapira(a)gmail.com> Date: Monday, 12 October 2020 at 20:04 To: "mbed-tls(a)lists.trustedfirmware.org" <mbed-tls(a)lists.trustedfirmware.org> Subject: [mbed-tls] Working on TLS handshake record fragmentation (#1840) Hello, My employer (Facebook) is willing to give me some time to TLS handshake fragmentation support to MbedTLS 2.7 [0] . This would be my first contribution to MbedTLS, and I have several novice questions: 1. What is the best way to add the feature to MbedTLS 2.7? 2. Trade-off between the consistency of the fragmentation code across the branches, vs. the consistency of the branches. Question 1: Best way to add the feature to MbedTLS 2.7 One constraint that I am facing is the code must be added to the upstream branch that is as close as possible to the 2.7.xx. My understanding of the Contribution Guidelines[1] is that while the LTS branches are mostly meant for the bug fixes, backporting of the new features is welcomed as long as the API/ABI compatibility is maintained and the disruption to the users is minimized. If adding support to the LTS branches is not advisable, are there any other possibilities of contributing the code to an upstream branch that is very close to the 2.7.xx? Question 2: Trade-off between the consistency of the fragmentation code across the branches, vs. the consistency of the branches. Assuming that adding features to 2.7 (and 2.16) *is* possible, there is a trade-off between the consistency of the fragmentation code across the branches, vs. the consistency of the branches. The `development` branch supports variable-length buffers[2] . Variable messages sizes would make the fragmentation easier in the development branch. In addition, there is the MPS effort by Hanno Becker which would make the fragmentation support even easier in the development branch. None of that is present in the 2.7 or the 2.16 branches. What is the preferable trade-off in such a situation: a. Minimizing the change to the "host" version (2.7 or 2.16), on the expense the implementation of the feature differ between 2.7 and `development`, or b. Minimizing the differences in the implementation of the feature, on the expense of more intrusive changes to the earlier versions? [0] https://github.com/ARMmbed/mbedtls/issues/1840 [1] https://github.com/ARMmbed/mbedtls/blob/development/CONTRIBUTING.md [2] https://github.com/ARMmbed/mbedtls/blob/development/include/mbedtls/config.… -- Sincerely Yours, Omer Shapira

5 years

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Re: [mbed-tls] Working on TLS handshake record fragmentation (#1840)

by Omer Shapira

While waiting for opinions regarding the question of adding features to the LTS versions, I have written a draft design doc. I discussed the "design review process" with Hanno Becker, and we decided to try and use GitHub for the design review. I have created PR #3783 [0], which includes `docs/proposed/hs_fragmentation.md` [1]. I will appreciate your comments, and will update the design doc following the feedback. Once there is clarity on the approach, I will proceed with the implementation PRs. [0] https://github.com/ARMmbed/mbedtls/pull/3783 [1] https://github.com/ARMmbed/mbedtls/pull/3783/commits/8be34f22237ee3cd3c1db2… On Mon, Oct 12, 2020 at 12:04 PM Omer Shapira via mbed-tls < mbed-tls(a)lists.trustedfirmware.org> wrote: > Hello, > > My employer (Facebook) is willing to give me some time to TLS handshake > fragmentation support to MbedTLS 2.7 [0] . This would be my first > contribution to MbedTLS, and I have several novice questions: > > 1. What is the best way to add the feature to MbedTLS 2.7? > 2. Trade-off between the consistency of the fragmentation code across the > branches, vs. the consistency of the branches. > > Question 1: Best way to add the feature to MbedTLS 2.7 > > One constraint that I am facing is the code must be added to the upstream > branch that is as close as possible to the 2.7.xx. My understanding of the > Contribution Guidelines[1] is that while the LTS branches are mostly meant > for the bug fixes, backporting of the new features is welcomed as long as > the API/ABI compatibility is maintained and the disruption to the users is > minimized. > > If adding support to the LTS branches is not advisable, are there any > other possibilities of contributing the code to an upstream branch that is > very close to the 2.7.xx? > > Question 2: Trade-off between the consistency of the fragmentation code > across the branches, vs. the consistency of the branches. > > Assuming that adding features to 2.7 (and 2.16) *is* possible, there is a > trade-off between the consistency of the fragmentation code across the > branches, vs. the consistency of the branches. The `development` branch > supports variable-length buffers[2] . Variable messages sizes would make > the fragmentation easier in the development branch. In addition, there is > the MPS effort by Hanno Becker which would make the fragmentation support > even easier in the development branch. None of that is present in the 2.7 > or the 2.16 branches. > > What is the preferable trade-off in such a situation: > a. Minimizing the change to the "host" version (2.7 or 2.16), on the > expense the implementation of the feature differ between 2.7 and > `development`, or > b. Minimizing the differences in the implementation of the feature, on > the expense of more intrusive changes to the earlier versions? > > > [0] https://github.com/ARMmbed/mbedtls/issues/1840 > [1] https://github.com/ARMmbed/mbedtls/blob/development/CONTRIBUTING.md > [2] > https://github.com/ARMmbed/mbedtls/blob/development/include/mbedtls/config.… > > -- > Sincerely Yours, > Omer Shapira > -- > mbed-tls mailing list > mbed-tls(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/mbed-tls > -- Sincerely Yours, Omer Shapira

5 years

1
0
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Working on TLS handshake record fragmentation (#1840)

by Omer Shapira

Hello, My employer (Facebook) is willing to give me some time to TLS handshake fragmentation support to MbedTLS 2.7 [0] . This would be my first contribution to MbedTLS, and I have several novice questions: 1. What is the best way to add the feature to MbedTLS 2.7? 2. Trade-off between the consistency of the fragmentation code across the branches, vs. the consistency of the branches. Question 1: Best way to add the feature to MbedTLS 2.7 One constraint that I am facing is the code must be added to the upstream branch that is as close as possible to the 2.7.xx. My understanding of the Contribution Guidelines[1] is that while the LTS branches are mostly meant for the bug fixes, backporting of the new features is welcomed as long as the API/ABI compatibility is maintained and the disruption to the users is minimized. If adding support to the LTS branches is not advisable, are there any other possibilities of contributing the code to an upstream branch that is very close to the 2.7.xx? Question 2: Trade-off between the consistency of the fragmentation code across the branches, vs. the consistency of the branches. Assuming that adding features to 2.7 (and 2.16) *is* possible, there is a trade-off between the consistency of the fragmentation code across the branches, vs. the consistency of the branches. The `development` branch supports variable-length buffers[2] . Variable messages sizes would make the fragmentation easier in the development branch. In addition, there is the MPS effort by Hanno Becker which would make the fragmentation support even easier in the development branch. None of that is present in the 2.7 or the 2.16 branches. What is the preferable trade-off in such a situation: a. Minimizing the change to the "host" version (2.7 or 2.16), on the expense the implementation of the feature differ between 2.7 and `development`, or b. Minimizing the differences in the implementation of the feature, on the expense of more intrusive changes to the earlier versions? [0] https://github.com/ARMmbed/mbedtls/issues/1840 [1] https://github.com/ARMmbed/mbedtls/blob/development/CONTRIBUTING.md [2] https://github.com/ARMmbed/mbedtls/blob/development/include/mbedtls/config.… -- Sincerely Yours, Omer Shapira

5 years

1
0
0 0

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