Comment 48 for bug 312536

I haven't read the patch. I only read the prototypes of
the new public functions. What I proposed in comment 36
would not require adding new functions. I proposed a new
error code, SEC_ERROR_WEAK_CRYPTO, for our signature and
certificate verification functions. If any signature
involved (except the signature in root CA certs) uses a
weak hash algorithm such as MD2 and MD4, the signature or
certificate verification function would fail with
SEC_ERROR_WEAK_CRYPTO.

I think my proposal is difficult to implement right, so
you should feel free to continue work on your proposal.
But it's important that your proposal also be "secure
by default". I suspect that's what your code in comment 37
does. Only the apps that still want to support RSA-MD2
and RSA-MD4 signatures have to do extra work.