1 Reply by matangk

(3 replies, posted in wolfSSL)

Hi chris,
Thank you for your very detailed reply..!

All I want to do is be able to send email from my application. I understand that SMTP is the way to go. Since SMTP without authentication is no longer an option (port 25 frequently blocked etc) I need to do TLS handshake. Specifically, I am aiming to send emails from gmail accounts to gmail accounts (easiest for me for now) by connecting to SMTP server on port 587. Since I am a complete beginner in this field, I am not even shure what I need for that..

If I get it correctly, email providers do not support cipher suit negotiation, but I have no experoence so if you know something else please do tell.

I do not know if email providers support smaller TLS fragment length. Tried to find online but didn't yet.

Anyway - I think I can handle either 60KB or 21KB on flash.
I can also handle one 16KB TLS buffer. Im am worried wether or not I must have 16KB X2 buffers (one for Tx, one for Rx) allocated for racords. If so, isn't 32KB RAM prohibitively small?

Thanks for the link!
-Matan

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2 Topic by matangk

(3 replies, posted in wolfSSL)

Hi, I have a simple bare-metal application running webserver + smtp client. My device has 256KB Flash and 32KB SRAM. I am using UIP TCP/IP stack and have no hardware ecryption. In order to send emails I need, to my best understanding, TLS handshake. With this regard I wonder if incorporating WolSSL in my application is feasable:

1.Can anyone help me with estimating the minimum size of the TLS library I will have to use? SRAM is probably my most limited resource.


2. From reading online, I understand 16Kbyte(!) TLS buffer size must be used unless "both sides support the max_fragment_length SSL extension". I tried to figure out if this is absolutely required for secure smtp email via gmail/yahoo but didnt find any useful data. does anyone have any info regarding to this issue?


3.Is there any documented use of Wolf/cyaSSL with UIP stack?


4.If not, Is there any guide which can help me figuring out what are the required steps to get my device to perform TLS handshake with smtp server, using only the required parts of wolSSL, such that the memory footprint is minimal? Performance tradeoff is not an issue.


Any help will be welcome!!
cheers
-Matan

Go to forum: wolfSSL