Send email using OpenSSL

Question

With OpenSSL module under openSUSE I can send an email using this list of commands

openssl s_client -starttls smtp -connect smtp.gmail.com:587 -crlf
helo
auth login
(Put base64 encoded username)
(Put base64 encoded password)
mail from:<email>
rcpt to:<email>
Data
From: email
To: email1, email2, .....
Subject: 
(Message body goes here)
.

Is it possible for such a list of commands to be executed at one shot? For example a script?

Note: There is an embedded-Linux system which contains the OpenSSL module, same thing will be applied to it.

Solution

have you tried

openssl s_client -starttls smtp -connect smtp.gmail.com:587 -crlf  <<EOF
helo
auth login
$(echo $username | base64)
$(echo $password | base64)
mail from:$email0
rcpt to:$email0
Data
From: $email0
To: $emaildest
Subject: $(echo $subject)

$(< body.txt)
.
EOF

• you must but message's body in body.txt (and remove after)
• you must set all $var ...

On a side note, if you sign and encrypt mail, you may wish to look at this question

Comments

[wurtel]

Many mail servers will disconnect if the client sends the next command before the response to the previous command has been given, as that is more often than not what a spam tool will do.

[Edward Falk]

Perhaps expect(1) will do what you want?

[s3lph]

I was just about to answer something like this...

[Арсений Черенков]

try to add -pause option ? (after -crlf but before <<EOF

[Alessio]

Don't forget to insert a blank line between the last header (Subject: in this case) and the first line of the body.

[Yaroslav Nikitenko]

I'd like to note that I used this solution, but it didn't work for large attachments (about 4 Mb). I hade to use a python script for that (using smtplib). OpenSSL returned "RENEGOTIATING error in s_client", but fortunately python worked fine.

[tripleee]

You should use double quotes around every string which doesn't specifically require wildcard expansion and whitespace tokenization. In particular, the password might well contain shell metacharacters.

[Dmitry Grigoryev]

Could you make it a standalone answer? "The script as above" doesn't make sense as answers can be added, removed and voted on.