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 :^)
ModularFunctions::random_number calls into AK::fill_with_random calls (on
Serenity) into arc4random_buf calls into Process::sys calls into
get_good_random_bytes, which is cryptographically secure.
All the magic is happening in a "while != 0" loop, so we ended up with
an empty string for zero-value BigIntegers. Now we just check that
upfront and return early.
This patchset adds a simple SignedBigInteger that is entirely defined in
terms of UnsignedBigInteger.
It also adds a NumberTheory::Power function, which is terribly
inefficient, but since the use of exponentiation is very much
discouraged for large inputs, no particular attempts were made
to make it more performant.
.. 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.
Use Vector::resize_and_keep_capacity() to resize BigInt vectors to just
the right size without risking deallocation. Then do direct indexed
accesses to the underlying words (or use memset/memcpy.)
This gives a ~40% speed-up on the RSA tests in "test-crypto -t pk" :^)
This change leads to between 10% and 35% performance improvement when executing
the RSA decryption method.
The main impact is to drastically reduce the number of allocations done in this
method from around 50% of the profile hits to less than 2%.
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.
The decrypted data is legally allowed to have any amount of padding, so
long as it is block-aligned, we should not assume that padding bytes
fall inside the same block, or that an entire block cannot be padding.
Fixes#2072
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)
This is in preparation for the upcoming Galois/Counter mode, which
conventionally has 12 bytes of IV as opposed to CBC's 16 bytes.
...Also fixes a lot of style issues, since the author finally found the
project's clang config file in the repository root :^)
This commit fixes up the following:
- HMAC should not reuse a single hasher when successively updating
- AES Key should not assume its user key is valid signed char*
- Mode should have a virtual destructor
And adds a RFC5246 padding mode, which is required for TLS
