8c7c084e0f
The null crypto algorithms are intended to do nothing: the null digest algorithm accepts all input and generates a zero-length digest, and the null cipher algorithm simply copies the input unmodifed to the output. The null public-key algorithm currently does nothing successfully. Unlike the null digest and cipher algorithms, the null public-key algorithm's methods are never called. Change the null public-key algorithm to fail all operations, thereby allowing its methods to be used as stubs by algorithms such as ECDSA that do not implement all of the possible public-key operations. Signed-off-by: Michael Brown <mcb30@ipxe.org>