Signed-off-by: Michael Brown <mcb30@ipxe.org>

Add an implementation of RSA that uses the iPXE big-integer support.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Avoid a compiler warning on some versions of gcc by using real
function prototypes.

Reported-by: Rob Shelley <Rob@cirris.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

RSA requires modular exponentiation using arbitrarily large integers.
Given the sizes of the modulus and exponent, all required calculations
can be done without any further dynamic storage allocation.  The x86
architecture allows for efficient large integer support via inline
assembly using the instructions that take advantage of the carry flag
(e.g. "adcl", "rcrl").

This implemention is approximately 80% smaller than the (more generic)
AXTLS implementation.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

All axTLS files are now vanilla versions of the upstream axTLS files,
with one minor exception: the unused "ctx" parameter of
bi_int_divide() has been marked with "__unused" to avoid a compilation
error.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Replace SHA-1 implementation from AXTLS with a dedicated iPXE
implementation which is around 40% smaller.  This implementation has
been verified using the existing SHA-1 self-tests (including the NIST
SHA-1 test vectors).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Changes were made to files where the licence text within the files
themselves confirms that the files are GPL version 2 or later.

Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

Use our own, more robust, ASN.1 parsing routines to extract the RSA
public key from a server certificate.  Remove the now-unused AXTLS
ASN.1 parser.