commit 6f286779a6711669911989f8ff744e4acf18f768
author Fabio Utzig <utzig@apache.org> Sun Sep 04 20:03:11 2022 -0300
committer David Brown <davidb@davidb.org> Thu Sep 22 11:34:43 2022 -0600
tree 7ca0474c275ffc70f67cbb72b5eb77fdd40ea259
parent 3fd4cd4faca4aaa71f7991a55f02a90105690207

imgtool: add option to export public PEM

Update `getpub` with new `lang` option, "pem", which allows exporting a
public key as a PEM file. This can later be distributed to be used for
encrypting an image, and gets away with having to use openssl for this
step.

Signed-off-by: Fabio Utzig <utzig@apache.org>

scripts/imgtool/keys/rsa.py

diff --git a/scripts/imgtool/keys/rsa.py b/scripts/imgtool/keys/rsa.py
index d8543ed..d51d36d 100644
--- a/scripts/imgtool/keys/rsa.py
+++ b/scripts/imgtool/keys/rsa.py
@@ -44,6 +44,11 @@
                 encoding=serialization.Encoding.DER,
                 format=serialization.PublicFormat.PKCS1)
 
+    def get_public_pem(self):
+        return self._get_public().public_bytes(
+                encoding=serialization.Encoding.PEM,
+                format=serialization.PublicFormat.SubjectPublicKeyInfo)
+
     def get_private_bytes(self, minimal):
         self._unsupported('get_private_bytes')