When creating your own custom yum repository, it is a good idea to create your own gpg signature and sign all the rpms in that repository. That way, should someone manage to place an rpm in there, none of your systems will install that rpm.
Create GPG Key
[thomas@host ~]$ gpg --gen-key
gpg (GnuPG) 1.4.5; Copyright (C) 2006 Free Software Foundation, Inc.
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions. See the file COPYING for details.
Please select what kind of key you want:
(1) DSA and Elgamal (default)
(2) DSA (sign only)
(5) RSA (sign only)
Your selection? 1
DSA keypair will have 1024 bits.
ELG-E keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048)
Requested keysize is 2048 bits
Please specify how long the key should be valid.
0 = key does not expire
= key expires in n days
w = key expires in n weeks
m = key expires in n months
y = key expires in n years
Key is valid for? (0) 0
Key does not expire at all
Is this correct? (y/N) y
You need a user ID to identify your key; the software constructs the user ID
from the Real Name, Comment and Email Address in this form:
"Heinrich Heine (Der Dichter) "
Real name: Repository Owner
Email address: repository@example.org
Comment:
You selected this USER-ID:
"Repository Owner "
Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
You need a Passphrase to protect your secret key.
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
+++++.+++++++++++++++++++++++++..+++++...+++++++++++++++....++++++++++++++++++++....++++++++++++++++++++++++++++++..+++++..+++++++++++++++.++++++++++.+++++.........+++++
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
+++++++++++++++++++++++++++++++++++++++++++++....+++++...+++++.+++++++++++++++..++++++++++++++++++++++++++++++.+++++++++++++++....+++++..+++++...+++++++++++++++..+++++>++++++++++>+++++>+++++.............+++++....>.+++++..............+++++^^^
gpg: key 79E7E0DB marked as ultimately trusted
public and secret key created and signed.
gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, classic trust model
gpg: depth: 0 valid: 2 signed: 13 trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: depth: 1 valid: 13 signed: 2 trust: 13-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2007-12-31
pub 1024D/79E7E0DB 2007-10-08
Key fingerprint = 5ACE 5EBF ED46 BAF7 93BD 8F02 E0BB DB6B 79E7 E0DB
uid Repository Owner
sub 2048g/04F5FDBA 2007-10-08
configuring RPM for GPG
In your home directory, create a .rpmmacros (if you don't already have such a file).
%_signature gpg
%_gpg_name Repository Owner
The tag
%_gpg_name should match the output of your key creation, this will tell rpm which key you wish to use to sign by default.
Signing the RPM
[thomas@host ~]$ rpm --resign sabayon-2.12.1-1.src.rpm
Enter pass phrase:
Pass phrase is good.
sabayon-2.12.1-1.src.rpm:
Now verify your rpm was signed:
[thomas@host ~]$ rpm -K sabayon-2.12.1-1.src.rpm
sabayon-2.12.1-1.src.rpm: (SHA1) DSA sha1 md5 (GPG) NOT OK (MISSING KEYS: GPG#79e7e0db)
Note that our key is not known to RPM yet, we cover that in
this post.