Configuration:

Most of the configuration of the library can be done in lib/openssl/eccx08_engine.h or via defines during build

The exception to this is in eccx08_platform.c where key slots are defaulted

If the ATCA_OPENSSL_ENGINE_STATIC_CONFIG define is set to 1 then device and signer certificate definitions will have to be linked into the library at build.

e.g. see the line in the makefile: #LIBATECCSSL_OBJECTS += cert_def_1_signer.c cert_def_2_signer.c

Makfile:

The makefile included in this archive is fairly basic and is not what one would consider appropriate for a package so there is likely some manual configuration that would be needed at this stage

To build the library:

make libateccssl

To run the test program:

make test

To extract certificates (if the engine is added to the openssl.cnf file):

openssl engine ateccx08 -t -post GET_DEVICE_CERT:./device.der openssl engine ateccx08 -t -post GET_SIGNER_CERT:./signer.der

Otherwise you'll have to use an interactive openssl session (see openssl engine -h and engine -vvv for details)

openssl

OpenSSL> engine dynamic -pre SO_PATH:/ -pre LIST_ADD:1 -pre ID:ateccx08 -pre LOAD OpenSSL> engine ateccx08 -t -post GET_DEVICE_CERT:./device.der OpenSSL> engine ateccx08 -t -post GET_SIGNER_CERT:./signer.der

Then to verify the certs:

openssl x509 -in device.der -inform der -text -noout openssl x509 -in signer.der -inform der -text -noout

To set up your openssl.cnf file

Find which openssl.cnf file your instance is using you can:

openssl version -a | grep OPENSSLDIR OPENSSLDIR: "/usr/lib/ssl"

will tell you the base location where openssl is looking for the openssl.cnf file. It may be a symbolic link to another location

ls -l /usr/lib/ssl lrwxrwxrwx 1 root root 14 Apr 24 15:22 certs -> /etc/ssl/certs lrwxrwxrwx 1 root root 20 Jan 31 05:53 openssl.cnf -> /etc/ssl/openssl.cnf

To set up the openssl.cnf to use the engine:

At the top:

openssl_conf = openssl_init

Append to the end:

[ openssl_init ] engines = engine_section

[ engine_section ] ateccx08 = ateccx08_config

[ ateccx08_config ] engine_id = ateccx08

Or if you sym link the libateccssl.so to the engine directory the next line is not needed

dynamic_path = device_key_slot = 0 init = 0

To use the engine in an application you can reference the openssl tests (test/openssl/test_engine.c) but the basic principle is that if the openssl.cnf file is configured correctly all an application really needs to do is add a call to OPENSSL_config if it is not already doing so and then to decide what functionality that the application wants and register it.