diff options
Diffstat (limited to 'src/libs/3rdparty/botan/src/lib/math/bigint/big_code.cpp')
-rw-r--r-- | src/libs/3rdparty/botan/src/lib/math/bigint/big_code.cpp | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/src/libs/3rdparty/botan/src/lib/math/bigint/big_code.cpp b/src/libs/3rdparty/botan/src/lib/math/bigint/big_code.cpp new file mode 100644 index 0000000000..c428199659 --- /dev/null +++ b/src/libs/3rdparty/botan/src/lib/math/bigint/big_code.cpp @@ -0,0 +1,166 @@ +/* +* BigInt Encoding/Decoding +* (C) 1999-2010,2012 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/bigint.h> +#include <botan/divide.h> +#include <botan/charset.h> +#include <botan/hex.h> + +namespace Botan { + +/* +* Encode a BigInt +*/ +void BigInt::encode(uint8_t output[], const BigInt& n, Base base) + { + if(base == Binary) + { + n.binary_encode(output); + } + else if(base == Hexadecimal) + { + secure_vector<uint8_t> binary(n.encoded_size(Binary)); + n.binary_encode(binary.data()); + + hex_encode(cast_uint8_ptr_to_char(output), + binary.data(), binary.size()); + } + else if(base == Decimal) + { + BigInt copy = n; + BigInt remainder; + copy.set_sign(Positive); + const size_t output_size = n.encoded_size(Decimal); + for(size_t j = 0; j != output_size; ++j) + { + divide(copy, 10, copy, remainder); + output[output_size - 1 - j] = + Charset::digit2char(static_cast<uint8_t>(remainder.word_at(0))); + if(copy.is_zero()) + break; + } + } + else + throw Invalid_Argument("Unknown BigInt encoding method"); + } + +/* +* Encode a BigInt +*/ +std::vector<uint8_t> BigInt::encode(const BigInt& n, Base base) + { + std::vector<uint8_t> output(n.encoded_size(base)); + encode(output.data(), n, base); + if(base != Binary) + for(size_t j = 0; j != output.size(); ++j) + if(output[j] == 0) + output[j] = '0'; + return output; + } + +/* +* Encode a BigInt +*/ +secure_vector<uint8_t> BigInt::encode_locked(const BigInt& n, Base base) + { + secure_vector<uint8_t> output(n.encoded_size(base)); + encode(output.data(), n, base); + if(base != Binary) + for(size_t j = 0; j != output.size(); ++j) + if(output[j] == 0) + output[j] = '0'; + return output; + } + +/* +* Encode a BigInt, with leading 0s if needed +*/ +secure_vector<uint8_t> BigInt::encode_1363(const BigInt& n, size_t bytes) + { + secure_vector<uint8_t> output(bytes); + BigInt::encode_1363(output.data(), output.size(), n); + return output; + } + +//static +void BigInt::encode_1363(uint8_t output[], size_t bytes, const BigInt& n) + { + const size_t n_bytes = n.bytes(); + if(n_bytes > bytes) + throw Encoding_Error("encode_1363: n is too large to encode properly"); + + const size_t leading_0s = bytes - n_bytes; + encode(&output[leading_0s], n, Binary); + } + +/* +* Encode two BigInt, with leading 0s if needed, and concatenate +*/ +secure_vector<uint8_t> BigInt::encode_fixed_length_int_pair(const BigInt& n1, const BigInt& n2, size_t bytes) + { + secure_vector<uint8_t> output(2 * bytes); + BigInt::encode_1363(output.data(), bytes, n1); + BigInt::encode_1363(output.data() + bytes, bytes, n2); + return output; + } + +/* +* Decode a BigInt +*/ +BigInt BigInt::decode(const uint8_t buf[], size_t length, Base base) + { + BigInt r; + if(base == Binary) + r.binary_decode(buf, length); + else if(base == Hexadecimal) + { + secure_vector<uint8_t> binary; + + if(length % 2) + { + // Handle lack of leading 0 + const char buf0_with_leading_0[2] = + { '0', static_cast<char>(buf[0]) }; + + binary = hex_decode_locked(buf0_with_leading_0, 2); + + binary += hex_decode_locked(cast_uint8_ptr_to_char(&buf[1]), + length - 1, + false); + } + else + binary = hex_decode_locked(cast_uint8_ptr_to_char(buf), + length, false); + + r.binary_decode(binary.data(), binary.size()); + } + else if(base == Decimal) + { + for(size_t i = 0; i != length; ++i) + { + if(Charset::is_space(buf[i])) + continue; + + if(!Charset::is_digit(buf[i])) + throw Invalid_Argument("BigInt::decode: " + "Invalid character in decimal input"); + + const uint8_t x = Charset::char2digit(buf[i]); + + if(x >= 10) + throw Invalid_Argument("BigInt: Invalid decimal string"); + + r *= 10; + r += x; + } + } + else + throw Invalid_Argument("Unknown BigInt decoding method"); + return r; + } + +} |