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LibCrypto: Replace from_base{2,8,10,16}() & to_base10 with from_base(N)

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This allows us to support parsing and serializing BigIntegers to and
from any base N (such that 2 <= N <= 36).
This commit is contained in:
Idan Horowitz 2021-06-29 17:51:52 +03:00 • committed by Linus Groh
parent a768131720
commit 005d75656e
14 changed files with 56 additions and 132 deletions
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63
Userland/Libraries/LibCrypto/BigInt/UnsignedBigInteger.cpp
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@ -66,60 +66,23 @@ size_t UnsignedBigInteger::export_data(Bytes data, bool remove_leading_zeros) co
return out;
}
UnsignedBigInteger UnsignedBigInteger::from_base10(const String& str)
UnsignedBigInteger UnsignedBigInteger::from_base(u16 N, const String& str)
{
VERIFY(N <= 36);
UnsignedBigInteger result;
UnsignedBigInteger ten { 10 };
UnsignedBigInteger base { N };
for (auto& c : str) {
if (c == '_')
continue;
result = result.multiplied_by(ten).plus(parse_ascii_digit(c));
result = result.multiplied_by(base).plus(parse_ascii_base36_digit(c));
}
return result;
}
UnsignedBigInteger UnsignedBigInteger::from_base2(const String& str)
{
UnsignedBigInteger result;
UnsignedBigInteger two { 2 };
for (auto& c : str) {
if (c == '_')
continue;
result = result.multiplied_by(two).plus(parse_ascii_digit(c));
}
return result;
}
UnsignedBigInteger UnsignedBigInteger::from_base8(const String& str)
{
UnsignedBigInteger result;
UnsignedBigInteger eight { 8 };
for (auto& c : str) {
if (c == '_')
continue;
result = result.multiplied_by(eight).plus(parse_ascii_digit(c));
}
return result;
}
UnsignedBigInteger UnsignedBigInteger::from_base16(const String& str)
{
UnsignedBigInteger result;
UnsignedBigInteger sixteen { 16 };
for (auto& c : str) {
if (c == '_')
continue;
result = result.multiplied_by(sixteen).plus(parse_ascii_hex_digit(c));
}
return result;
}
String UnsignedBigInteger::to_base10() const
String UnsignedBigInteger::to_base(u16 N) const
{
VERIFY(N <= 36);
if (*this == UnsignedBigInteger { 0 })
return "0";
@ -129,19 +92,13 @@ String UnsignedBigInteger::to_base10() const
UnsignedBigInteger remainder;
while (temp != UnsignedBigInteger { 0 }) {
UnsignedBigIntegerAlgorithms::divide_u16_without_allocation(temp, 10, quotient, remainder);
VERIFY(remainder.words()[0] < 10);
builder.append(static_cast<char>(remainder.words()[0] + '0'));
UnsignedBigIntegerAlgorithms::divide_u16_without_allocation(temp, N, quotient, remainder);
VERIFY(remainder.words()[0] < N);
builder.append(to_ascii_base36_digit(remainder.words()[0]));
temp.set_to(quotient);
}
auto reversed_string = builder.to_string();
builder.clear();
for (int i = reversed_string.length() - 1; i >= 0; --i) {
builder.append(reversed_string[i]);
}
return builder.to_string();
return builder.to_string().reverse();
}
u64 UnsignedBigInteger::to_u64() const