Replace the implementation of maths in `UnsignedBigInteger`
and `SignedBigInteger` with LibTomMath. This gives benefits in terms of
less code to maintain, correctness and speed.
These changes also remove now-unsued methods and improve the error
propagation for functions allocating lots of memory. Additionally, the
new implementation is always trimmed and won't have dangling zeros when
exporting it.
Having it as a method instead of a free function is necessary for the
next commits and generally allows for optimizations that require deeper
access into the `UnsignedBigInteger` / `SignedBigInteger`.
Also restrict the exponent to 32 bits to avoid huge memory allocations.
Having it as a method instead of a free function is necessary for the
next commits and generally allows for optimizations that require deeper
access into the `UnsignedBigInteger`.
This concept is rarely used in codebase and very much error-prone
if you forget to check it.
Instead, make it so that operations that would produce invalid integers
return an error instead.
This fixes the issue with the exported data having a leading zero,
causing RSA::encrypt to trim the block down, and ruining the encryption.
Fixes#2691 :^)
.. and make travis run it.
I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.
It also checks the presence of a (single) blank line above and below the
"#pragma once" line.
I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.
I also ran clang-format on the files I modified.
This changes the plus, minus, etc... operators from UnsignedBigInteger to use a
static helper method. The static methods do not allocate any variables, instead
all the required BigInteger output and temporary variables are required on call
as parameters.
This change already optimizes the number of allocations in complex operations
such as multiply or divide, by having a single allocation per call (instead of
one per loop).
This new API also provides a way to limit the number of allocations for complex
computations in other parts of the code. This is done by using these helpers in
any place that currently makes use of the standard operators.
This commit attempts to make UnsignedBigInteger as fast as possible
without changing the underlaying architecture.
This effort involves
- Preallocating space for vector operations
- Avoiding calls to computationally expensive functions
- Inlining or flattening functions (sensibly)
