From 4ec94878f661ef482e94f62fb9a03b251ea21363 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Thu, 7 Jun 2018 23:44:57 +0200 Subject: [PATCH] add README.md Signed-off-by: Daniel Golle This work was sponsored by WIO (wiowireless.com) --- README.md | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 README.md diff --git a/README.md b/README.md new file mode 100644 index 0000000..7ec5e14 --- /dev/null +++ b/README.md @@ -0,0 +1,48 @@ +# ucert + +ucert is a signature-chaining wrapper around usign using libubox blob and blobmsg. + +## a few words about security +ucert inherits all its cryptographic properties from the underlying usign implementation which as such wasn't meant to be used in such a way. +To maintain a high cryptographic standard, it is likely that further optimization of the signed payload format (reduce known-plaintext by normalization, add salts in case usign doesn't, ...) has to be carried out. + +## usage +```shell +Usage: ucert +Commands: + -A: append signature (needs -c and -x) + -D: dump (needs -c) + -I: issue cert and revoker (needs -c and -p and -s) + -R: process revoker certificate (needs -c and -P) + -V: verify (needs -c and -p|-P, may have -m) +Options: + -c : certificate file + -m : message file (verify only) + -p : public key file + -P : public key directory (verify only) + -q: quiet (do not print verification result, use return code only) + -s : secret key file (issue only) + -x : signature file +``` + +### examples +```shell +# on airgap system +# create root keypair (which never leaves airgap) +usign -G -p capubkey -s caseckey +# create delegate keypair +usign -G -p pubkey -s seckey +# create ca-signed delegate cert (and revoker) +ucert -I -p pubkey -s caseckey -c newcert + +# eg. on buildbot worker +# got newcert and seckey from airgap +# sign content +usign -S -m message.bin -s seckey -x message.bin.sig +# create cert for message +cp newcert message.bin.ucrt +ucert -A -c message.bin.ucrt -x message.bin.sig + +# on client +ucert -V -P /etc/opkg/keys -m message.bin -c message.bin.ucrt && echo message.bin verified successfully +``` -- 2.30.2