How can I enable both ed25519 and tinycrypt?

[dillonj-sentient]

I see from this page that ed25519 signature validation can now build without using Mbed TLS by relying on a bundled tinycrypt based sha-512 implementation. was added in MCUboot 1.5.0.
I am using MCUboot 2.1.0.

With both MCUBOOT_SIGN_ED25519 and MCUBOOT_USE_TINYCRYPT defined in my mcuboot_config.h file, I am getting the following error during compilation:
mcuboot/boot/bootutil/src/image_ed25519.c:15:10: fatal error: mbedtls/oid.h: No such file or directory

image_ed25519.c clearly references mbedtls. Is the ed25519/tinycrypt combination no longer supported? Do I need to use an older version of image_ed25519.c?

[dillonj-sentient]

I'm reporting in on this issue. MCUBOOT_SIGN_ED25519 and MCUBOOT_USE_TINYCRYPT can indeed be used together, but it's not as simple as just defining them in your mcuboot_config.h file. (image_ed25519.c is used when MCUBOOT_SIGN_ED25519 is defined but it assumes mbedtls)

I found a great hint in sim/mcuboot-sys/build.rs:

mcuboot/sim/mcuboot-sys/build.rs

Lines 239 to 253 in c136f4a

	} else if sig_ed25519 {
	conf.conf.define("MCUBOOT_SIGN_ED25519", None);
	conf.conf.define("MCUBOOT_USE_TINYCRYPT", None);
	conf.conf.include("../../ext/tinycrypt/lib/include");
	conf.conf.include("../../ext/tinycrypt-sha512/lib/include");
	conf.conf.include("../../ext/mbedtls/include");
	conf.file("../../ext/tinycrypt/lib/source/sha256.c");
	conf.file("../../ext/tinycrypt-sha512/lib/source/sha512.c");
	conf.file("../../ext/tinycrypt/lib/source/utils.c");
	conf.file("csupport/keys.c");
	conf.file("../../ext/fiat/src/curve25519.c");
	conf.file("../../ext/mbedtls/library/platform_util.c");
	conf.file("../../ext/mbedtls/library/asn1parse.c");
	} else if !enc_ec256 && !enc_x25519 {

These lines list the include paths that need to be added and the source files that need to be compiled in order to use ed25519 with tinycrypt.