commit a00abc6b6508e17bd216a4a91ba67fc2cdaa5996
author Gilles Peskine <Gilles.Peskine@arm.com> Tue Mar 16 18:25:14 2021 +0100
committer Gilles Peskine <Gilles.Peskine@arm.com> Mon Mar 29 14:55:44 2021 +0200
tree 7220dc7d2b948ea5d040723abc50cd48ae881e2f
parent 7e54a29bead535131fc4b1bf03cf3a1470348848

Consistently describe Ed25519 as a 255-bit curve

The coordinates are over $F_{2^{255}-19}$, so by the general
definition of the bit size associated with the curve in the
specification, the value for size attribute of keys is 255.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

scripts/mbedtls_dev/crypto_knowledge.py

diff --git a/scripts/mbedtls_dev/crypto_knowledge.py b/scripts/mbedtls_dev/crypto_knowledge.py
index 642e725..500acea 100644
--- a/scripts/mbedtls_dev/crypto_knowledge.py
+++ b/scripts/mbedtls_dev/crypto_knowledge.py
@@ -78,7 +78,7 @@
         'PSA_ECC_FAMILY_SECT_R2': (163,),
         'PSA_ECC_FAMILY_BRAINPOOL_P_R1': (160, 192, 224, 256, 320, 384, 512),
         'PSA_ECC_FAMILY_MONTGOMERY': (255, 448),
-        'PSA_ECC_FAMILY_TWISTED_EDWARDS': (256, 448),
+        'PSA_ECC_FAMILY_TWISTED_EDWARDS': (255, 448),
     }
     KEY_TYPE_SIZES = {
         'PSA_KEY_TYPE_AES': (128, 192, 256), # exhaustive