Engineering Elegance

Photo by John Salvino on Unsplash

The Fault in My Code

So last week, we discovered that client certificates could not successfully be imported in both macOS and Windows operating systems. Testing out with a manually generated certificate using XCA, we were able to confirm that the problem was that the PKCS#12 generated by our application does not contain the full certificate chain (i.e: from end-entity certificate to all the way to the root certificate), or so we thought. Currently, the server application generates PKCS#12 files using OpenSSL’s libraries since Botan Read more

By Gabriel Tan, ago

Setup and Testing Week

The Setup Now that I have access to the production server, I had to pull the project’s code from our git repository into the server’s filesystem. Shortly after that, I needed to check if the server application could be built and executed. No major issues in that regard. Everything seemed to be going well at that point. Dr Shawn had already set up the actual Woocommerce site and gave me access as a Store Manager. Before doing anything else in Read more

By Gabriel Tan, ago
Photo by John Salvino on Unsplash

Week Eight

This is my eighth week of being an intern at Aeste Works. This week was about setting up and integrating the lwIP stack with the USB CDC ECM device. The device currently does not run with an operating system and so must be configured for the lwIP NOSYS mode using the raw (or native API).  The first step was to create a cc.h file that that describes the compiler and machine architecture to lwIP. The following are defined here: data types, printf formatters for Read more

By Marcos Concon, ago

Creating a Wishbone RAM (Update March 2019)

Time was passing really fast and this was the eighth week of internship. In this week I was working on a Wishbone RAM. To start off, I had to understand the mechanism of a dual port RAM. The dual port RAM fundamentally consisted of an instruction port (read only) and a read/write port. An address of 0x00000000 would be passed into the instruction port whereas 0x80000000 would be passed into the read/write port. However, they should have the same data Read more

By Jun Wen, ago
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Reaching a Milestone

So I managed to implement the reusing of private keys as part of the renewal process. The problem was that I was calling the wrong API for Botan, which yields an unexpected outcome. Shortly after that, Dr Shawn wanted me to implement one more feature for the application. It basically involves checking whether the user receives the email for the certificate download or not. This can be done using the Post Office Protocol version 3 (POP3). When we send the Read more

By Gabriel Tan, ago

A triangular timing diagram

In this week I was modifying the Wishbone switch so that it would gave correct signal outputs. To give an overview, the strobe signal from the previous wire must be passed to the next wire after one clock cycle, until it reached the I/O port. As a result, the I/O would asset an acknowledgement signal, which would negate the current strobe signal. And the acknowledgement signal would be passed to the next wire after one clock cycle as well. This Read more

By Jun Wen, ago
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Week Seven

This is my seventh week as an intern at Aeste Works. This week was about figuring out which part of my USB CDC ECM code interfaces between the host and device in sending and receiving network packets so that I could integrate the lwIP TCP/IP stack later on. There are two functions that were found in the code that sends and receives data.  First, the application can send data to the Host by using the USB_DEVICE_CDC_Write function.  This function requests Read more

By Marcos Concon, ago

Week 2 in 2019

Nothing much to be said for this week. I attempted to implement based on what Dr Shawn suggested to me last week, i.e storing the public and private key pairs in the database, so that the private key could be reused for subsequent certificate renewals. This relies on the user having to present the old certificate, which contains the public key that would be used to find the matching private key in the database. If no certificate is given, then Read more

By Gabriel Tan, ago
Photo by rawpixel on Unsplash

Week Six

This is week six of my internship at Aeste Works. After configuring the company’s board to enumerate successfully on a Windows environment, it was time to configure it on Linux. On Windows, the usb drivers loads according to the Vendor ID and Product ID which was for Microchip’s USB CDC Abstract Control Model demo. USB CDC Ethernet Control Model is widely used for interoperability with non-Microsoft operating systems, but does not work with Windows and this meant that even with the Read more

By Marcos Concon, ago

Connecting Wishbone switches

I continued to work on the Wishbone switch throughout the week. First of all, I added some additional signal ports to the Wishbone switch I created last week. Those additional signals were described as follows, based on the Wishbone specification. MASTER signals SEL_O: It denoted the location of valid data. WE_O: It would be asserted during WRITE cycles and negated during READ cycles. CYC_O: It would be asserted throughout all bus cycles. SLAVE signals SEL_I: It denoted the location of Read more

By Jun Wen, ago