[U-Boot] [RFC 1/3] lib: rsa: decouple rsa from FIT image verification

[AKASHI Takahiro]

Introduce new configuration, CONFIG_RSA_VERIFY which will decouple building
RSA functions from FIT verification and allow for adding a RSA-based
signature verification for other file formats, in particular PE file
for UEFI secure boot.

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 lib/rsa/Kconfig  | 7 +++++++
 lib/rsa/Makefile | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig
index 2b33f323bccc..338c8124da59 100644
--- a/lib/rsa/Kconfig
+++ b/lib/rsa/Kconfig
@@ -1,5 +1,6 @@
 config RSA
 	bool "Use RSA Library"
+	select RSA_VERIFY
 	select RSA_FREESCALE_EXP if FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5
 	select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP
 	help
@@ -17,6 +18,12 @@ if RSA
 
 config SPL_RSA
 	bool "Use RSA Library within SPL"
+	select RSA_VERIFY
+
+config RSA_VERIFY
+	bool
+	help
+	  Add RSA signature verification support.
 
 config RSA_SOFTWARE_EXP
 	bool "Enable driver for RSA Modular Exponentiation in software"
diff --git a/lib/rsa/Makefile b/lib/rsa/Makefile
index a51c6e1685fb..226d8f3514a9 100644
--- a/lib/rsa/Makefile
+++ b/lib/rsa/Makefile
@@ -5,5 +5,5 @@
 # (C) Copyright 2000-2007
 # Wolfgang Denk, DENX Software Engineering, wd at denx.de.
 
-obj-$(CONFIG_$(SPL_)FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o
+obj-$(CONFIG_RSA_VERIFY) += rsa-verify.o rsa-checksum.o
 obj-$(CONFIG_RSA_SOFTWARE_EXP) += rsa-mod-exp.o
-- 
2.21.0