Ed448 + X448

[karel-m]

Implemented Ed448 / X448 support

Since I could not find any reasonable CC0/public-domain reference implementation for Ed448 + X448, I took the existing src/pk/ec25519/tweetnacl.c and tweaked it into src/pk/ec448/ec448_common.c (yes, this is a custom implementation with the usual caveats around performance, security and other potential issues).

So it more or less blindly follows the existing Ed25519 / X25519 code and is basically a 1:1 adaptation - for any issues in the 448 part, the 25519 author is probably the more appropriate target of blame :)

File layout

Area	25519	448
Shared internal layer	src/pk/ec25519/tweetnacl.c	src/pk/ec448/ec448_common.c
	src/pk/ec25519/ec25519_export.c	src/pk/ec448/ec448_export.c
	src/pk/ec25519/ec25519_import_pkcs8.c	src/pk/ec448/ec448_import_pkcs8.c
	src/pk/ec25519/ec25519_crypto_ctx.c	src/pk/ec448/ec448_crypto_ctx.c
Ed* public functions	src/pk/ed25519/ed25519_make_key.c	src/pk/ed448/ed448_make_key.c
	src/pk/ed25519/ed25519_export.c	src/pk/ed448/ed448_export.c
	src/pk/ed25519/ed25519_import.c	src/pk/ed448/ed448_import.c
	src/pk/ed25519/ed25519_import_raw.c	src/pk/ed448/ed448_import_raw.c
	src/pk/ed25519/ed25519_import_x509.c	src/pk/ed448/ed448_import_x509.c
	src/pk/ed25519/ed25519_import_pkcs8.c	src/pk/ed448/ed448_import_pkcs8.c
	src/pk/ed25519/ed25519_sign.c	src/pk/ed448/ed448_sign.c
	src/pk/ed25519/ed25519_verify.c	src/pk/ed448/ed448_verify.c
X* public functions	src/pk/x25519/x25519_make_key.c	src/pk/x448/x448_make_key.c
	src/pk/x25519/x25519_export.c	src/pk/x448/x448_export.c
	src/pk/x25519/x25519_import.c	src/pk/x448/x448_import.c
	src/pk/x25519/x25519_import_raw.c	src/pk/x448/x448_import_raw.c
	src/pk/x25519/x25519_import_x509.c	src/pk/x448/x448_import_x509.c
	src/pk/x25519/x25519_import_pkcs8.c	src/pk/x448/x448_import_pkcs8.c
	src/pk/x25519/x25519_shared_secret.c	src/pk/x448/x448_shared_secret.c
Tests	tests/ed25519_test.c	tests/ed448_test.c
	tests/x25519_test.c	tests/x448_test.c

EdDSA APIs

25519	448
ed25519_make_key	ed448_make_key
ed25519_export	ed448_export
ed25519_import	ed448_import
ed25519_import_raw	ed448_import_raw
ed25519_import_x509	ed448_import_x509
ed25519_import_pkcs8	ed448_import_pkcs8
ed25519_sign	ed448_sign
ed25519ctx_sign	ed448ctx_sign
ed25519ph_sign	ed448ph_sign
ed25519_verify	ed448_verify
ed25519ctx_verify	ed448ctx_verify
ed25519ph_verify	ed448ph_verify

DH APIs

25519	448
x25519_make_key	x448_make_key
x25519_export	x448_export
x25519_import	x448_import
x25519_import_raw	x448_import_raw
x25519_import_x509	x448_import_x509
x25519_import_pkcs8	x448_import_pkcs8
x25519_shared_secret	x448_shared_secret

Checklist

• documentation is added or updated
• tests are added or updated