Creating, Modifying, Etc, SSH Keys

Another "remind myself how to do things" post.

To create a new ssh key:

ssh-keygen -t rsa -b 2048 -C "COMMENT"

 To change the passphrase on a key:

ssh-keygen -p -f KEYFILE [-P OLDPASS] [-N NEWPASS]

 There's a nice guide to this sort of thing here.

Simple Encryption With OpenSSL

Every once in a while, I need to transfer something from one computer to another, and emailing it to myself is an easy way to do it. But sometimes what I want to transfer isn't something I want out in the open. So the obvious thing to do is encrypt it, and the obvious tool to use to do this is openssl.

Here, so I remember it, is the command for doing this:

openssl enc -des -a -e -pass pass:PASSWORD -in INFILE -out OUTFILE

If you leave out INFILE or OUTFILE, it defaults to stdin and stdout. So you can do:

echo "This is  a secret" | openssl enc -des -a -e -pass pass:PASSWORD

and the encrypted version will be written to the terminal.

To decrypt:

openssl enc -des -a -d -pass pass:PASSWORD -in ENCRYPTED -out DECRTYPED

Or, again:

echo "U2FsdGVkX1+Kqcs+25e+6MiQBr4NT8ykx3POhv9yAf9gnvSn4D2L0A==" | openssl enc -des -a -d -pass pass:PASSWORD

And again you'll get the decrypted version written to the terminal.