Work on mbed TLS parse certificate

[josesimoes]

Description

• Fix issues with certificate length
• Update declarations to comply with coding guidelines

Motivation and Context

• Implements this API using mbed TLS
• Fixes issue with certificate length

How Has This Been Tested?

• SSL test pack from samples repo (tested with X509 RSA certificates 512, 1024 and 2048 bytes)

Screenshots

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Signed-off-by: José Simões jose.simoes@eclo.solutions

[nfbot]

Hi @josesimoes,

I'm nanoFramework bot.
Thank you for your contribution!

A human will be reviewing it shortly. 😉

[josesimoes]

@AdrianSoundy please take a look.
I've changed the way the certificate length was being used because the mbed TLS expectes a length INCLUDING the terminator.

On the test app that I've added to the samples repo: I basically took your code, add new certificates with a simpler strings and tidy up the code a bit.

[AdrianSoundy]

I can't see any issues with what you have done.

Should add a Networking section for these types of samples