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LibCrypto: Add ::import_data() and ::export_data() to UnsignedBigInteger

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These functions allow conversion to-and-from big-endian buffers
This commit also adds a ""_bigint operator for easy bigint use
This commit is contained in:
AnotherTest 2020-04-10 01:00:37 +04:30 • committed by Andreas Kling
parent c52d3e65b9
commit 6b742c69bd
3 changed files with 66 additions and 0 deletions
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28
Libraries/LibCrypto/BigInt/UnsignedBigInteger.cpp
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@ -312,4 +312,32 @@ UnsignedBigInteger UnsignedBigInteger::create_invalid()
invalid.invalidate();
return invalid;
}
// FIXME: in great need of optimisation
UnsignedBigInteger UnsignedBigInteger::import_data(const u8* ptr, size_t length)
{
UnsignedBigInteger integer { 0 };
for (size_t i = 0; i < length; ++i) {
auto part = UnsignedBigInteger { ptr[length - i - 1] }.shift_left(8 * i);
integer = integer.add(part);
}
return integer;
}
size_t UnsignedBigInteger::export_data(AK::ByteBuffer& data)
{
UnsignedBigInteger copy { *this };
size_t size = trimmed_length() * sizeof(u32);
size_t i = 0;
for (; i < size; ++i) {
if (copy.length() == 0)
break;
data[size - i - 1] = copy.m_words[0] & 0xff;
copy = copy.divide(256).quotient;
}
return i;
}
}

17
Libraries/LibCrypto/BigInt/UnsignedBigInteger.h
View file

@ -25,6 +25,7 @@
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/LogStream.h>
#include <AK/String.h>
#include <AK/Types.h>
@ -48,6 +49,16 @@ public:
static UnsignedBigInteger from_base10(const String& str);
static UnsignedBigInteger create_invalid();
static UnsignedBigInteger import_data(const AK::StringView& data) { return import_data((const u8*)data.characters_without_null_termination(), data.length()); }
static UnsignedBigInteger import_data(const u8* ptr, size_t length);
size_t export_data(AK::ByteBuffer& data);
size_t export_data(const u8* ptr, size_t length)
{
auto buffer = ByteBuffer::wrap(ptr, length);
return export_data(buffer);
}
const AK::Vector<u32>& words() const { return m_words; }
UnsignedBigInteger add(const UnsignedBigInteger& other) const;
@ -103,3 +114,9 @@ operator<<(const LogStream& stream, const Crypto::UnsignedBigInteger value)
}
return stream;
}
inline Crypto::UnsignedBigInteger
operator""_bigint(const char* string, size_t length)
{
return Crypto::UnsignedBigInteger::from_base10({ string, length });
}