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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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41
Userland/Libraries/LibCrypto/BigInt/SignedBigInteger.cpp
View file

@ -27,57 +27,30 @@ size_t SignedBigInteger::export_data(Bytes data, bool remove_leading_zeros) cons
return m_unsigned_data.export_data(bytes_view, remove_leading_zeros) + 1;
}
static bool parse_sign(StringView& str)
SignedBigInteger SignedBigInteger::from_base(u16 N, StringView str)
{
bool sign = false;
auto sign = false;
if (str.length() > 1) {
auto maybe_sign = str[0];
if (maybe_sign == '-') {
str = str.substring_view(1, str.length() - 1);
str = str.substring_view(1);
sign = true;
}
if (maybe_sign == '+')
str = str.substring_view(1, str.length() - 1);
str = str.substring_view(1);
}
return sign;
}
SignedBigInteger SignedBigInteger::from_base10(StringView str)
{
auto sign = parse_sign(str);
auto unsigned_data = UnsignedBigInteger::from_base10(str);
auto unsigned_data = UnsignedBigInteger::from_base(N, str);
return { move(unsigned_data), sign };
}
SignedBigInteger SignedBigInteger::from_base2(StringView str)
{
auto sign = parse_sign(str);
auto unsigned_data = UnsignedBigInteger::from_base2(str);
return { move(unsigned_data), sign };
}
SignedBigInteger SignedBigInteger::from_base8(StringView str)
{
auto sign = parse_sign(str);
auto unsigned_data = UnsignedBigInteger::from_base8(str);
return { move(unsigned_data), sign };
}
SignedBigInteger SignedBigInteger::from_base16(StringView str)
{
auto sign = parse_sign(str);
auto unsigned_data = UnsignedBigInteger::from_base16(str);
return { move(unsigned_data), sign };
}
String SignedBigInteger::to_base10() const
String SignedBigInteger::to_base(u16 N) const
{
StringBuilder builder;
if (m_sign)
builder.append('-');
builder.append(m_unsigned_data.to_base10());
builder.append(m_unsigned_data.to_base(N));
return builder.to_string();
}

9
Userland/Libraries/LibCrypto/BigInt/SignedBigInteger.h
View file

@ -62,11 +62,8 @@ public:
size_t export_data(Bytes, bool remove_leading_zeros = false) const;
static SignedBigInteger from_base2(StringView str);
static SignedBigInteger from_base8(StringView str);
static SignedBigInteger from_base10(StringView str);
String to_base10() const;
static SignedBigInteger from_base16(StringView str);
static SignedBigInteger from_base(u16 N, StringView str);
String to_base(u16 N) const;
u64 to_u64() const;
@ -144,5 +141,5 @@ struct SignedDivisionResult {
inline Crypto::SignedBigInteger
operator""_sbigint(const char* string, size_t length)
{
return Crypto::SignedBigInteger::from_base10({ string, length });
return Crypto::SignedBigInteger::from_base(10, { string, length });
}

63
Userland/Libraries/LibCrypto/BigInt/UnsignedBigInteger.cpp
View file

@ -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

9
Userland/Libraries/LibCrypto/BigInt/UnsignedBigInteger.h
View file

@ -53,11 +53,8 @@ public:
size_t export_data(Bytes, bool remove_leading_zeros = false) const;
static UnsignedBigInteger from_base2(const String& str);
static UnsignedBigInteger from_base8(const String& str);
static UnsignedBigInteger from_base10(const String& str);
String to_base10() const;
static UnsignedBigInteger from_base16(const String& str);
static UnsignedBigInteger from_base(u16 N, const String& str);
String to_base(u16 N) const;
u64 to_u64() const;
@ -131,5 +128,5 @@ struct AK::Formatter<Crypto::UnsignedBigInteger> : Formatter<StringView> {
inline Crypto::UnsignedBigInteger
operator""_bigint(const char* string, size_t length)
{
return Crypto::UnsignedBigInteger::from_base10({ string, length });
return Crypto::UnsignedBigInteger::from_base(10, { string, length });
}

2
Userland/Libraries/LibCrypto/NumberTheory/ModularFunctions.cpp
View file

@ -218,7 +218,7 @@ bool is_probably_prime(const UnsignedBigInteger& p)
UnsignedBigInteger random_big_prime(size_t bits)
{
VERIFY(bits >= 33);
UnsignedBigInteger min = UnsignedBigInteger::from_base10("6074001000").shift_left(bits - 33);
UnsignedBigInteger min = UnsignedBigInteger::from_base(10, "6074001000").shift_left(bits - 33);
UnsignedBigInteger max = UnsignedBigInteger { 1 }.shift_left(bits).minus(1);
for (;;) {
auto p = random_number(min, max);