doc: clarify openssl-based key and certificate generation process

Add some basic clarification that the dev.key file generated by OpenSSL
contains both the public and private key, and further highlight that
the certificate generated here contains the public key only.

Signed-off-by: Andreas Dannenberg <[email protected]>

diff --git a/doc/uImage.FIT/signature.txt b/doc/uImage.FIT/signature.txt
index b2f89fcc65d0fd2a14693b26ce7f93ce0fe3412d..e4874018faddc1a1783f5519da9e057e7bac9802 100644 (file)
--- a/doc/uImage.FIT/signature.txt
+++ b/doc/uImage.FIT/signature.txt
@@ -62,14 +62,14 @@ placed alongside rsa.c, and its functions added to the table in image-sig.c
 also.
 
 
-Creating an RSA key and certificate
------------------------------------
-To create a new public key, size 2048 bits:
+Creating an RSA key pair and certificate
+----------------------------------------
+To create a new public/private key pair, size 2048 bits:
 
 $ openssl genpkey -algorithm RSA -out keys/dev.key \
     -pkeyopt rsa_keygen_bits:2048 -pkeyopt rsa_keygen_pubexp:65537
 
-To create a certificate for this:
+To create a certificate for this containing the public key:
 
 $ openssl req -batch -new -x509 -key keys/dev.key -out keys/dev.crt