+++ Stefan Berger [20/04/21 17:02 -0400]:

quoted

On 4/20/21 10:03 AM, Jessica Yu wrote:

quoted

+++ Stefan Berger [08/04/21 11:24 -0400]:

quoted

diff --git a/crypto/asymmetric_keys/pkcs7_parser.c 

b/crypto/asymmetric_keys/pkcs7_parser.c
index 967329e0a07b..2546ec6a0505 100644

--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c

@@ -269,6 +269,10 @@ int pkcs7_sig_note_pkey_algo(void *context, 

size_t hdrlen,
        ctx->sinfo->sig->pkey_algo = "rsa";
        ctx->sinfo->sig->encoding = "pkcs1";
        break;
+    case OID_id_ecdsa_with_sha256:
+        ctx->sinfo->sig->pkey_algo = "ecdsa";
+        ctx->sinfo->sig->encoding = "x962";
+        break;

Hi Stefan,

Does CONFIG_MODULE_SIG_KEY_TYPE_ECDSA have a dependency on 
MODULE_SIG_SHA256?

You are right, per the code above it does have a dependency on 
SHA256. ECDSA is using NIST p384 (secp384r1) for signing and per my 
tests it can be paired with all the sha hashes once the code above is 
extended. Now when it comes to module signing, should we pair it with 
a particular hash? I am not currently aware of a guidance document on 
this but sha256 and sha384 seem to be good choices these days, so 
maybe selecting ECDSA module signing should have a 'depends on' on 
these?

Yeah, I would tack on the 'depends on' until the code above has been
extended to cover more sha hashes - because currently if someone
builds and signs a bunch of modules with an ECDSA key, they will fail
to load if they picked something other than sha256. I am unfortunately
not knowledgeable enough to suggest an official guideline on choice of
hash, but for now it is reasonable to have a 'depends on' for which
hashes the code currently supports, so that users don't run into
module loading rejection issues.