Re: Singing with certificate

[Bernhard Froehlich]

Rory Vieira wrote:

Hi,

For our customers we make backups (like everyone else).




My command to encrypt using DES was:


Now I'm looking for the command to use their public key :)

Thanks in advance...

However, legal restrictions apply to the specific branche we work in. We are required to encrypt the data. In the past I was using simple DES3 encryption, but now I would like to use the customers secure certificate to encrypt the data with (like email). The customer has a .p12 certificate that they install in Windows. I first need to export the public key from that in a usuable format. Then I want to encrypt the data on the fly (as I did in the past). tar -cvzf - <what> 2>/dev/null | openssl des3 -salt -k <pass> | dd of=<tar-file> 2>/dev/null

As far as I know there is no tool in openssl you can just drop in to use a public key to encrypt a stream. If someone knows better please tell.

   * Generate a key from /dev/random and store it in a file
   * Use this key to do openssl des3 ... like you did before
   * Encrypt the key using openssl smime with you client's certificate
   * Delete the unencrypted key (this might not be as trivial as it
     sounds if secutity requirements are high)



Hope it helps,
Ted
;)

--
PGP Public Key Information
Download complete Key from http://www.convey.de/ted/tedkey_convey.asc
Key fingerprint = 31B0 E029 BCF9 6605 DAC1  B2E1 0CC8 70F4 7AFB 8D26

There is the smime-tool which can encrypt files, but I don't think this is what you want/need. One way to work around this problem (other than writing your own tool) might be a sequence of shell commands which may work like this: This way your customer could use the reverse procedure (decrypt key with openssl smime and decrypt data with the key) to recover the data.

smime.p7s
Description: S/MIME Cryptographic Signature