image: Add RSA support for image signing
RSA provides a public key encryption facility which is ideal for image
signing and verification.
Images are signed using a private key by mkimage. Then at run-time, the
images are verified using a private key.
This implementation uses openssl for the host part (mkimage). To avoid
bringing large libraries into the U-Boot binary, the RSA public key
is encoded using a simple numeric representation in the device tree.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index d3e03d7..0f417b5 100644
--- a/README
+++ b/README
@@ -2581,6 +2581,16 @@
Note: There is also a sha1sum command, which should perhaps
be deprecated in favour of 'hash sha1'.
+- Signing support:
+ CONFIG_RSA
+
+ This enables the RSA algorithm used for FIT image verification
+ in U-Boot. See doc/uImage/signature for more information.
+
+ The signing part is build into mkimage regardless of this
+ option.
+
+
- Show boot progress:
CONFIG_SHOW_BOOT_PROGRESS