Fixes#6811 which found an issue where connecting to scripts.google.com
would *occasionally* cause a crash. On inspection, it was found that up
to 5828 bytes of stack were used once in a while, so expand the stack to
5900 bytes to cover this case plus a little extra.
BearSSLX509List, BearSSLSession, BearSSLPublicKey, and BearSSLPrivateKey
were all in the global namespace and not in the BearSSL:: one, due to an
oversight when they were originally created. Move them to the proper
namespace with the following mapping:
BearSSLX509List => BearSSL::X509List
BearSSLSession => BearSSL::Session
BearSSLPublicKey => BearSSL::PublicKey
BearSSLPrivateKey => BearSSL::PrivateKey
Allow the unused stack to be reset to the check value at any time in
the application, allowing for delta-stack calculations to be done.
Add ESP.resetFreeContStack() class method for general use.
Add in some dumping in the BearSSL_Validation example to show the
usage for those that care.
Add a method allowing a user to send in a character string for the
fingerprint, like axTLS supported.
Implements part of PR #4833 from @d-a-v with changes requested in
discussion.
* Allow cipher specification for BearSSL
BearSSL has many more ciphers than axTLS, but they are more compute intensive
and slower. Add an option to use only the same, limited security, axTLS ciphers
as well as allow users to specify any suite of ciphers they want using standard
BearSSL formats.
Fixes#5110
* Rename methods to avoid axtls references.
* Allow std::vector to set a list of allowed ciphers
For C++ afficionados, allow std::vectors to be passed in to the setCipher()
routine.
The BearSSL object will now keep a copy of any set ciphers and free on object
destruction. These custom lists should normally only be 1-4 entries long, so it
is not expected to be a memory hog having this extra copy.
As part of the "clear connection configuration for reused objects"
patch, a ::stop would reset the self-signed, trust anchors, etc.
WiFiClient, unfortunately, calls ::stop as part of the connection
process, so all of these settings were lost.
Now only clear the connection settings on ::stop if we've already
been connected.
Also update the github public key which changed yet again.
Fixes#5086
Fixes#4882 and updates GitHub certificate fingerprint to the current one
in BearSSL_Validation example.
When setting a authentication mode or stopping, clear all others out in case
the object is being re-used.
Add in a yield during the SSL handshake to allow a graceful timeout and not
a WDT error when the remote server hiccups. Thanks to @Jeroen88 for
finding and testing this.
BearSSL (https://www.bearssl.org) is a TLS(SSL) library written by
Thomas Pornin that is optimized for lower-memory embedded systems
like the ESP8266. It supports a wide variety of modern ciphers and
is unique in that it doesn't perform any memory allocations during
operation (which is the unfortunate bane of the current axTLS).
BearSSL is also absolutely focused on security and by default performs
all its security checks on x.509 certificates during the connection
phase (but if you want to be insecure and dangerous, that's possible
too).
While it does support unidirectional SSL buffers, like axTLS,
as implemented the ESP8266 wrappers only support bidirectional
buffers. These bidirectional buffers avoid deadlocks in protocols
which don't have well separated receive and transmit periods.
This patch adds several classes which allow connecting to TLS servers
using this library in almost the same way as axTLS:
BearSSL::WiFiClientSecure - WiFiClient that supports TLS
BearSSL::WiFiServerSecure - WiFiServer supporting TLS and client certs
It also introduces objects for PEM/DER encoded keys and certificates:
BearSSLX509List - x.509 Certificate (list) for general use
BearSSLPrivateKey - RSA or EC private key
BearSSLPublicKey - RSA or EC public key (i.e. from a public website)
Finally, it adds a Certificate Authority store object which lets
BearSSL access a set of trusted CA certificates on SPIFFS to allow it
to verify the identity of any remote site on the Internet, without
requiring RAM except for the single matching certificate.
CertStoreSPIFFSBearSSL - Certificate store utility
Client certificates are supported for the BearSSL::WiFiClientSecure, and
what's more the BearSSL::WiFiServerSecure can also *require* remote clients
to have a trusted certificate signed by a specific CA (or yourself with
self-signing CAs).
Maximum Fragment Length Negotiation probing and usage are supported, but
be aware that most sites on the Internet don't support it yet. When
available, you can reduce the memory footprint of the SSL client or server
dramatically (i.e. down to 2-8KB vs. the ~22KB required for a full 16K
receive fragment and 512b send fragment). You can also manually set a
smaller fragment size and guarantee at your protocol level all data will
fit within it.
Examples are included to show the usage of these new features.
axTLS has been moved to its own namespace, "axtls". A default "using"
clause allows existing apps to run using axTLS without any changes.
The BearSSL::WiFi{client,server}Secure implements the axTLS
client/server API which lets many end user applications take advantage
of BearSSL with few or no changes.
The BearSSL static library used presently is stored at
https://github.com/earlephilhower/bearssl-esp8266 and can be built
using the standard ESP8266 toolchain.
