From 213e29e25b771fea7146c7db2203759bc8c75e5a Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Sun, 21 Sep 2014 16:25:27 -0400 Subject: [PATCH] Don't call AuthenticodeVerify if vendor_cert_size is 0. Actually check the size of our vendor cert quite early, so that there's no confusion as to what's going on. This isn't strictly necessary, in that in all cases if vendor_cert_size is 0, then AuthenticodeVerify -> Pkcs7Verify() -> d2i_X509() will result in a NULL "Cert", and it will return FALSE, and we'll reject the signature, but better to avoid all that code in the first place. Belt and suspenders and whatnot. Based on a patch from https://github.com/TBOpen . Signed-off-by: Peter Jones --- shim.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/shim.c b/shim.c index cfa90d1..caa05d8 100644 --- a/shim.c +++ b/shim.c @@ -923,14 +923,13 @@ static EFI_STATUS verify_buffer (char *data, int datasize, return status; } - /* * And finally, check against shim's built-in key */ - if (AuthenticodeVerify(cert->CertData, - context->SecDir->Size - sizeof(cert->Hdr), - vendor_cert, vendor_cert_size, sha256hash, - SHA256_DIGEST_SIZE)) { + if (vendor_cert_size && AuthenticodeVerify(cert->CertData, + context->SecDir->Size - sizeof(cert->Hdr), + vendor_cert, vendor_cert_size, sha256hash, + SHA256_DIGEST_SIZE)) { status = EFI_SUCCESS; return status; }