This email keeps the event up to date in your calendar.
MBed-TLS Technical Forum - Asia
Every 4 weeks from 10am to 10:50am on Monday
United Kingdom Time
Location
https://linaro-org.zoom.us/j/97758661706?pwd=baMjUvnWbY20z3ignQca7QVahhozkI…https://www.google.com/url?q=https%3A%2F%2Flinaro-org.zoom.us%2Fj%2F9775866…
Trusted Firmware is inviting you to a scheduled Zoom meeting.Topic:
MBed-TLS Technical Forum - AsiaTime: Jun 16, 2025 10:00 AM London
Every 4 weeks on Mon, 39 occurrence(s)Please download and import the
following iCalendar (.ics) files to your calendar system.Weekly:
https://linaro-org.zoom.us/meeting/tJMqcuGuqDotGtIbACm498ytl0ZhydWKdu1b/ics…
Zoom
Meetinghttps://linaro-org.zoom.us/j/97758661706?pwd=baMjUvnWbY20z3ignQca7QVahhozkI.1Meeting
ID: 977 5866 1706Passcode: 577208---One tap
mobile+16892781000,,97758661706# US+17193594580,,97758661706# US---Dial by
your location• +1 689 278 1000 US• +1 719 359 4580 US• +1 253 205 0468 US•
+1 253 215 8782 US (Tacoma)• +1 301 715 8592 US (Washington DC)• +1 305 224
1968 US• +1 309 205 3325 US• +1 312 626 6799 US (Chicago)• +1 346 248 7799
US (Houston)• +1 360 209 5623 US• +1 386 347 5053 US• +1 507 473 4847 US•
+1 564 217 2000 US• +1 646 558 8656 US (New York)• +1 646 931 3860 US• +1
669 444 9171 US• +1 669 900 9128 US (San Jose)• 833 548 0282 US Toll-free•
833 928 4608 US Toll-free• 833 928 4609 US Toll-free• 833 928 4610 US
Toll-free• 877 853 5247 US Toll-free• 888 788 0099 US Toll-free• 833 548
0276 US Toll-freeMeeting ID: 977 5866 1706Find your local number:
https://linaro-org.zoom.us/u/acdtApJNbc
Guests
mbed-tls(a)lists.trustedfirmware.org
psa-crypto(a)lists.trustedfirmware.org
~~//~~
Invitation from Google Calendar: https://calendar.google.com/calendar/
You are receiving this email because you are an attendee on the event.
Forwarding this invitation could allow any recipient to send a response to
the organizer, be added to the guest list, invite others regardless of
their own invitation status, or modify your RSVP.
Learn more https://support.google.com/calendar/answer/37135#forwarding
This event has been updated with a note:
"Pushing to fix meeting link issue"
Changed: location
MBed TLS Technical Forum - US
Every 4 weeks from 4:30pm to 5:30pm on Monday
United Kingdom Time
Location
https://linaro-org.zoom.us/j/93546216467?pwd=ja9Nxd0uLBn04jg1Be0NTy17Konzfl…https://www.google.com/url?q=https%3A%2F%2Flinaro-org.zoom.us%2Fj%2F9354621…
Trusted Firmware is inviting you to a scheduled Zoom meeting.Topic: MBed
TLS Technical Forum - USTime: May 4, 2026 04:30 PM LondonEvery 4 weeks on
Mon, 38 occurrence(s)Please download and import the following iCalendar
(.ics) files to your calendar
system.Weekly: https://linaro-org.zoom.us/meeting/tJcoc--qrz0uHNNmuZMtfpylBgIZjC2so7xz/ics…
Zoom
Meetinghttps://linaro-org.zoom.us/j/93546216467?pwd=ja9Nxd0uLBn04jg1Be0NTy17Konzfl.1Meeting
ID: 935 4621 6467Passcode: 683772---One tap
mobile+13126266799,,93546216467# US (Chicago)+13462487799,,93546216467# US
(Houston)---Dial by your location• +1 312 626 6799 US (Chicago)• +1 346 248
7799 US (Houston)• +1 360 209 5623 US• +1 386 347 5053 US• +1 507 473 4847
US• +1 564 217 2000 US• +1 646 558 8656 US (New York)• +1 646 931 3860 US•
+1 669 444 9171 US• +1 669 900 9128 US (San Jose)• +1 689 278 1000 US• +1
719 359 4580 US• +1 253 205 0468 US• +1 253 215 8782 US (Tacoma)• +1 301
715 8592 US (Washington DC)• +1 305 224 1968 US• +1 309 205 3325 US• 833
928 4609 US Toll-free• 833 928 4610 US Toll-free• 877 853 5247 US
Toll-free• 888 788 0099 US Toll-free• 833 548 0276 US Toll-free• 833 548
0282 US Toll-free• 833 928 4608 US Toll-freeMeeting ID: 935 4621 6467Find
your local number:https://linaro-org.zoom.us/u/azKzC20VI
Guests
psa-crypto(a)lists.trustedfirmware.org
mbed-tls(a)lists.trustedfirmware.org
hordijk(a)aurora.tech
Ben Taylor
cjej65eug(a)gmail.com
View all guest info
https://calendar.google.com/calendar/event?action=VIEW&eid=dm9wcGhnbnZvMnRh…
Reply for mbed-tls(a)lists.trustedfirmware.org and view more details
https://calendar.google.com/calendar/event?action=VIEW&eid=dm9wcGhnbnZvMnRh…
Your attendance is optional.
~~//~~
Invitation from Google Calendar: https://calendar.google.com/calendar/
You are receiving this email because you are an attendee on the event.
Forwarding this invitation could allow any recipient to send a response to
the organizer, be added to the guest list, invite others regardless of
their own invitation status, or modify your RSVP.
Learn more https://support.google.com/calendar/answer/37135#forwarding
Hi,
How can I extract the AKI (Authority Key Identifier) from a certificate
using mbedtls ?
I could parse the certificate file itself, I guess, but isn't that what
mbedtls does?
Thanks,
Danny
https://www.rfc-editor.org/info/rfc5280#section-4.2.1.1
--
Danny Backx - dannybackx(a)telenet.be
Hi all,
We will be upgrading Cloudbees CI and clusters hosting review.trustedfirmware.org and ci.trustedfirmware.org on Wednesday, 3rd June 2025 at 16:00 GMT+1.
During this maintenance window, both services will be unavailable for approximately 8 hours.
A follow-up email will be sent once the services are fully restored.
Best regards,
Saheer
[LOGO SMALL]
Saheer Babu
Principal Software Engineer
CESW – Engineering Infrastructure
I'm currently working on adding MbedTLS 4.x support for
Privoxy [0] and noticed that mbedtls_ssl_read() frequently
returns MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET.
Apparently the error code was added in f8a4994ec7 and marked
experimental in da13072c5b.
It doesn't seem explicitly documented at [1], but of course
it's covered by "or another negative error code".
My current solution is to simply continue reading:
extern int ssl_recv_data(struct ssl_attr *ssl_attr, unsigned char *buf, size_t max_length)
{
[...]
do
{
ret = mbedtls_ssl_read(ssl, buf, max_length);
#if MBEDTLS_VERSION_MAJOR > 3
if (ret == MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET)
{
log_error(LOG_LEVEL_CONNECT,
"mbedtls_ssl_read() reported new session ticket for "
"the connection on socket %d.",
ssl_attr->mbedtls_attr.socket_fd.fd);
}
#endif
} while (ret == MBEDTLS_ERR_SSL_WANT_READ
#if MBEDTLS_VERSION_MAJOR > 3
|| ret == MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET
#endif
|| ret == MBEDTLS_ERR_SSL_WANT_WRITE);
When using MbedTLS 4.1.0 on ElectroBSD 14.4-STABLE this seems to work.
For some connections the log message is emitted once, for others
it's emitted twice:
09:20:58.982 024 Connect: Connected to 127.0.1.2[127.0.1.2]:9050.
09:20:59.222 024 Connect: Created new connection to www.electrobsd.org:443 on socket 9.
09:20:59.243 024 Connect: Performing the TLS handshake with the server.
09:20:59.583 024 Connect: Server successfully connected over TLSv1.3 (TLS1-3-CHACHA20-POLY1305-SHA256).
09:20:59.583 024 Connect: Encrypted request sent.
09:20:59.809 024 Connect: mbedtls_ssl_read() reported new session ticket for the connection on socket 9.
09:20:59.902 024 Connect: mbedtls_ssl_read() reported new session ticket for the connection on socket 9.
09:21:00.041 024 Header: scan: HTTP/1.1 200 OK
I noticed that there's already an open ticket [2] which contains
the sentence:
| For client side, mbedtls_ssl_{read,write} might return the error also,
| we should process it in the error handler also.
I haven't seen mbedtls_ssl_write() return MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET
yet, though.
Can you confirm that handling MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET
by continuing reading is currently the best option?
Thanks.
Fabian
[0]: <https://www.privoxy.org/>
[1]: <https://os.mbed.com/teams/sandbox/code/mbedtls/docs/tip/ssl_8h.html#aa2c29e…>
[2]: <https://github.com/Mbed-TLS/mbedtls/issues/6640>
Dear Mbed TLS contributors,
I am working on an embedded project where we need to verify an X509 certificate chain with up to 4 certificates (root cert + 2 intermediates + client cert) and a CRL. The certificates contain public keys for ECDSA for the SECP_R1_256 curve. We are using mbedTLS 4.x.
There is no heap memory in this project. It is a vehicle control ECU and all RAM is normally statically allocated for safety reasons. However, the certificate verification is not safety critical. It is OK for us to use mbedtls_memory_buffer_alloc_init() as a heap replacement for mbedTLS. I will refer to this as the "heap" for the rest of this mail.
I would like to find out how large the heap needs to be for the chain verification. The system requirements state that it shall support certificates and CRL in DER format with a size of up to 2 kB each. There are 10 kB of static RAM buffer to store 4 certificates and the CRL.
The certificates are parsed with mbedtls_x509_crt_parse_der_nocopy(), so the certificate raw data is not duplicated on the heap.
The CRL is parsed with mbedtls_x509_crl_parse_der(), so I am expecting that the CRL raw data will be copied to the heap. Thus, it needs to be at least 2 kB. Unfortunately, there seems to be no "_nocopy()" function for CRLs.
8 kB heap was enough in my tests to verify a chain of 3 test certificates with sizes of ca. 0.5 kB each. 6 kB heap wasn't enough to do this.
Is there a way to calculate or at least estimate the maximum required heap for the given maximum certificate and CRL sizes, such that a call of mbedtls_x509_crt_verify() for the chain will never fail due to insufficient memory?
Is the required heap size fixed for a given number of certificates, or does it depend on the content of the certificates? If it does depend on the content, is there some way to construct "worst case certificates" that result in maximum heap usage, so I could use them to measure the heap consumption?
Any help on this topic is kindly appreciated!
Best regards,
Ralf Huber
KION Supply Chain Solutions
Linde Material Handling GmbH,
Sitz der Gesellschaft: Aschaffenburg, Registergericht: Aschaffenburg HRB9963, Ust-IdNr. DE814809128, Gesch?ftsf?hrung: Andreas Krinninger (Vorsitzender), Dr. Karoline Jung-Senssfelder, Ulrike Just, Dr. Frank Schepp, Vorsitzende des Aufsichtsrats: Valeria Gargiulo