Demonstration package

AN4683

22/31

DocID027745 Rev 1

3.5

Example 3: Gmail SMTP server access with anonymous

negotiation

To protect SMTP communications, server can use SSL/TLS encryption to provide

authentication and information encryption. To enable the SMTP client to verify the SMTP

server certificate, the issuing CA certificates should be made available to the client. In this

case the CA certificate is not provided and the client is not expected to verify server

certificate. Even the SMTP client is not providing its certificate, so the negotiation is

anonymous.

For the purpose of the example, the Gmail SMTP server is used. Since it requires SMTP

authorization, a Gmail account is needed for <username> (the full Gmail address, e.g.

example@gmail.com) and <password> options.

To access SMTP server, it is recommended to run AT+S.TLSCERT2=clean,all to clean the

Flash memory and then open a secure connection on port 465:

AT+S.SOCKON=smtp.gmail.com,465,s

In this example, the parameter ind is omitted: if enabled, this option requires to read the

socket when a pending indication message is received.

When the TLS handshake is successful, the AT+S.SOCKON gives back the sock id: only

then is it possible to use the AT+S.SOCKW to make the login on Gmail server by sending

first “EHLO” command and then “AUTH PLAIN” with your credentials using the base64

encoded username/password.

3.6

Example 4: Xively example with anonymous negotiation

Xively is a cloud platform for developing and managing commercial services on the Internet

of Things. Xively ensures protected communication channels by using SSL/TLS

authentication and encryption. In this example the CA certificate is not provided and the

client is not expected to verify the server certificate. The client is not providing its certificate,

so the negotiation is anonymous.

To access Xively server, it is recommended to run AT+S.TLSCERT2=clean,all to clean the

Flash memory and then open a secure connection on port 8091:

AT+S.SOCKON=api.xively.com,8091,s

In this example the parameter ind is omitted: if enabled, this option requires to read the

socket when a pending indication message is received.

3.7

Example 5: connect to HTTPS my.st.com

This example shows how to use the Wi-Fi module as a TLS client to connect to a secure

HTTPS server and to send/receive HTTP requests/replies.

The HTTPS server we want to connect to is https://my.st.com.

In this example we are not verifying the server’s certificate (anonymous negotiation), so we

are not uploading any certificate to the module. In case you need to authenticate the server,

you have to configure the module as in example 2 (properly set the appropriate CA

certificate, domain name and time).