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Diffstat (limited to 'src/constructs/tss/tss.cpp')
| -rw-r--r-- | src/constructs/tss/tss.cpp | 262 |
1 files changed, 0 insertions, 262 deletions
diff --git a/src/constructs/tss/tss.cpp b/src/constructs/tss/tss.cpp deleted file mode 100644 index 2024b39ec..000000000 --- a/src/constructs/tss/tss.cpp +++ /dev/null @@ -1,262 +0,0 @@ -/* -* RTSS (threshold secret sharing) -* (C) 2009 Jack Lloyd -* -* Distributed under the terms of the Botan license -*/ - -#include <botan/tss.h> -#include <botan/loadstor.h> -#include <botan/pipe.h> -#include <botan/hex.h> -#include <botan/sha2_32.h> -#include <botan/sha160.h> -#include <memory> - -namespace Botan { - -namespace { - -/** -Table for GF(2^8) arithmetic (exponentials) -*/ -const byte RTSS_EXP[256] = { -0x01, 0x03, 0x05, 0x0F, 0x11, 0x33, 0x55, 0xFF, 0x1A, 0x2E, 0x72, -0x96, 0xA1, 0xF8, 0x13, 0x35, 0x5F, 0xE1, 0x38, 0x48, 0xD8, 0x73, -0x95, 0xA4, 0xF7, 0x02, 0x06, 0x0A, 0x1E, 0x22, 0x66, 0xAA, 0xE5, -0x34, 0x5C, 0xE4, 0x37, 0x59, 0xEB, 0x26, 0x6A, 0xBE, 0xD9, 0x70, -0x90, 0xAB, 0xE6, 0x31, 0x53, 0xF5, 0x04, 0x0C, 0x14, 0x3C, 0x44, -0xCC, 0x4F, 0xD1, 0x68, 0xB8, 0xD3, 0x6E, 0xB2, 0xCD, 0x4C, 0xD4, -0x67, 0xA9, 0xE0, 0x3B, 0x4D, 0xD7, 0x62, 0xA6, 0xF1, 0x08, 0x18, -0x28, 0x78, 0x88, 0x83, 0x9E, 0xB9, 0xD0, 0x6B, 0xBD, 0xDC, 0x7F, -0x81, 0x98, 0xB3, 0xCE, 0x49, 0xDB, 0x76, 0x9A, 0xB5, 0xC4, 0x57, -0xF9, 0x10, 0x30, 0x50, 0xF0, 0x0B, 0x1D, 0x27, 0x69, 0xBB, 0xD6, -0x61, 0xA3, 0xFE, 0x19, 0x2B, 0x7D, 0x87, 0x92, 0xAD, 0xEC, 0x2F, -0x71, 0x93, 0xAE, 0xE9, 0x20, 0x60, 0xA0, 0xFB, 0x16, 0x3A, 0x4E, -0xD2, 0x6D, 0xB7, 0xC2, 0x5D, 0xE7, 0x32, 0x56, 0xFA, 0x15, 0x3F, -0x41, 0xC3, 0x5E, 0xE2, 0x3D, 0x47, 0xC9, 0x40, 0xC0, 0x5B, 0xED, -0x2C, 0x74, 0x9C, 0xBF, 0xDA, 0x75, 0x9F, 0xBA, 0xD5, 0x64, 0xAC, -0xEF, 0x2A, 0x7E, 0x82, 0x9D, 0xBC, 0xDF, 0x7A, 0x8E, 0x89, 0x80, -0x9B, 0xB6, 0xC1, 0x58, 0xE8, 0x23, 0x65, 0xAF, 0xEA, 0x25, 0x6F, -0xB1, 0xC8, 0x43, 0xC5, 0x54, 0xFC, 0x1F, 0x21, 0x63, 0xA5, 0xF4, -0x07, 0x09, 0x1B, 0x2D, 0x77, 0x99, 0xB0, 0xCB, 0x46, 0xCA, 0x45, -0xCF, 0x4A, 0xDE, 0x79, 0x8B, 0x86, 0x91, 0xA8, 0xE3, 0x3E, 0x42, -0xC6, 0x51, 0xF3, 0x0E, 0x12, 0x36, 0x5A, 0xEE, 0x29, 0x7B, 0x8D, -0x8C, 0x8F, 0x8A, 0x85, 0x94, 0xA7, 0xF2, 0x0D, 0x17, 0x39, 0x4B, -0xDD, 0x7C, 0x84, 0x97, 0xA2, 0xFD, 0x1C, 0x24, 0x6C, 0xB4, 0xC7, -0x52, 0xF6, 0x01 }; - -/** -Table for GF(2^8) arithmetic (logarithms) -*/ -const byte RTSS_LOG[] = { -0x90, 0x00, 0x19, 0x01, 0x32, 0x02, 0x1A, 0xC6, 0x4B, 0xC7, 0x1B, -0x68, 0x33, 0xEE, 0xDF, 0x03, 0x64, 0x04, 0xE0, 0x0E, 0x34, 0x8D, -0x81, 0xEF, 0x4C, 0x71, 0x08, 0xC8, 0xF8, 0x69, 0x1C, 0xC1, 0x7D, -0xC2, 0x1D, 0xB5, 0xF9, 0xB9, 0x27, 0x6A, 0x4D, 0xE4, 0xA6, 0x72, -0x9A, 0xC9, 0x09, 0x78, 0x65, 0x2F, 0x8A, 0x05, 0x21, 0x0F, 0xE1, -0x24, 0x12, 0xF0, 0x82, 0x45, 0x35, 0x93, 0xDA, 0x8E, 0x96, 0x8F, -0xDB, 0xBD, 0x36, 0xD0, 0xCE, 0x94, 0x13, 0x5C, 0xD2, 0xF1, 0x40, -0x46, 0x83, 0x38, 0x66, 0xDD, 0xFD, 0x30, 0xBF, 0x06, 0x8B, 0x62, -0xB3, 0x25, 0xE2, 0x98, 0x22, 0x88, 0x91, 0x10, 0x7E, 0x6E, 0x48, -0xC3, 0xA3, 0xB6, 0x1E, 0x42, 0x3A, 0x6B, 0x28, 0x54, 0xFA, 0x85, -0x3D, 0xBA, 0x2B, 0x79, 0x0A, 0x15, 0x9B, 0x9F, 0x5E, 0xCA, 0x4E, -0xD4, 0xAC, 0xE5, 0xF3, 0x73, 0xA7, 0x57, 0xAF, 0x58, 0xA8, 0x50, -0xF4, 0xEA, 0xD6, 0x74, 0x4F, 0xAE, 0xE9, 0xD5, 0xE7, 0xE6, 0xAD, -0xE8, 0x2C, 0xD7, 0x75, 0x7A, 0xEB, 0x16, 0x0B, 0xF5, 0x59, 0xCB, -0x5F, 0xB0, 0x9C, 0xA9, 0x51, 0xA0, 0x7F, 0x0C, 0xF6, 0x6F, 0x17, -0xC4, 0x49, 0xEC, 0xD8, 0x43, 0x1F, 0x2D, 0xA4, 0x76, 0x7B, 0xB7, -0xCC, 0xBB, 0x3E, 0x5A, 0xFB, 0x60, 0xB1, 0x86, 0x3B, 0x52, 0xA1, -0x6C, 0xAA, 0x55, 0x29, 0x9D, 0x97, 0xB2, 0x87, 0x90, 0x61, 0xBE, -0xDC, 0xFC, 0xBC, 0x95, 0xCF, 0xCD, 0x37, 0x3F, 0x5B, 0xD1, 0x53, -0x39, 0x84, 0x3C, 0x41, 0xA2, 0x6D, 0x47, 0x14, 0x2A, 0x9E, 0x5D, -0x56, 0xF2, 0xD3, 0xAB, 0x44, 0x11, 0x92, 0xD9, 0x23, 0x20, 0x2E, -0x89, 0xB4, 0x7C, 0xB8, 0x26, 0x77, 0x99, 0xE3, 0xA5, 0x67, 0x4A, -0xED, 0xDE, 0xC5, 0x31, 0xFE, 0x18, 0x0D, 0x63, 0x8C, 0x80, 0xC0, -0xF7, 0x70, 0x07 }; - -byte gfp_mul(byte x, byte y) - { - if(x == 0 || y == 0) - return 0; - return RTSS_EXP[(RTSS_LOG[x] + RTSS_LOG[y]) % 255]; - } - -byte rtss_hash_id(const std::string& hash_name) - { - if(hash_name == "SHA-160") - return 1; - else if(hash_name == "SHA-256") - return 2; - else - throw Invalid_Argument("RTSS only supports SHA-1 and SHA-256"); - } - -HashFunction* get_rtss_hash_by_id(byte id) - { - if(id == 1) - return new SHA_160; - else if(id == 2) - return new SHA_256; - else - throw Decoding_Error("Bad RTSS hash identifier"); - } - -} - -RTSS_Share::RTSS_Share(const std::string& hex_input) - { - contents = hex_decode_locked(hex_input); - } - -byte RTSS_Share::share_id() const - { - if(!initialized()) - throw Invalid_State("RTSS_Share::share_id not initialized"); - - return contents[20]; - } - -std::string RTSS_Share::to_string() const - { - return hex_encode(&contents[0], contents.size()); - } - -std::vector<RTSS_Share> -RTSS_Share::split(byte M, byte N, - const byte S[], u16bit S_len, - const byte identifier[16], - RandomNumberGenerator& rng) - { - if(M == 0 || N == 0 || M > N) - throw Encoding_Error("RTSS_Share::split: M == 0 or N == 0 or M > N"); - - SHA_256 hash; // always use SHA-256 when generating shares - - std::vector<RTSS_Share> shares(N); - - // Create RTSS header in each share - for(byte i = 0; i != N; ++i) - { - shares[i].contents += std::make_pair(identifier, 16); - shares[i].contents += rtss_hash_id(hash.name()); - shares[i].contents += M; - shares[i].contents += get_byte(0, S_len); - shares[i].contents += get_byte(1, S_len); - } - - // Choose sequential values for X starting from 1 - for(byte i = 0; i != N; ++i) - shares[i].contents.push_back(i+1); - - // secret = S || H(S) - secure_vector<byte> secret(S, S + S_len); - secret += hash.process(S, S_len); - - for(size_t i = 0; i != secret.size(); ++i) - { - std::vector<byte> coefficients(M-1); - rng.randomize(&coefficients[0], coefficients.size()); - - for(byte j = 0; j != N; ++j) - { - const byte X = j + 1; - - byte sum = secret[i]; - byte X_i = X; - - for(size_t k = 0; k != coefficients.size(); ++k) - { - sum ^= gfp_mul(X_i, coefficients[k]); - X_i = gfp_mul(X_i, X); - } - - shares[j].contents.push_back(sum); - } - } - - return shares; - } - -secure_vector<byte> -RTSS_Share::reconstruct(const std::vector<RTSS_Share>& shares) - { - const size_t RTSS_HEADER_SIZE = 20; - - for(size_t i = 0; i != shares.size(); ++i) - { - if(shares[i].size() != shares[0].size()) - throw Decoding_Error("Different sized RTSS shares detected"); - if(shares[i].share_id() == 0) - throw Decoding_Error("Invalid (id = 0) RTSS share detected"); - if(shares[i].size() < RTSS_HEADER_SIZE) - throw Decoding_Error("Missing or malformed RTSS header"); - - if(!same_mem(&shares[0].contents[0], - &shares[i].contents[0], RTSS_HEADER_SIZE)) - throw Decoding_Error("Different RTSS headers detected"); - } - - if(shares.size() < shares[0].contents[17]) - throw Decoding_Error("Insufficient shares to do TSS reconstruction"); - - u16bit secret_len = make_u16bit(shares[0].contents[18], - shares[0].contents[19]); - - byte hash_id = shares[0].contents[16]; - - std::unique_ptr<HashFunction> hash(get_rtss_hash_by_id(hash_id)); - - if(shares[0].size() != secret_len + hash->output_length() + RTSS_HEADER_SIZE + 1) - throw Decoding_Error("Bad RTSS length field in header"); - - std::vector<byte> V(shares.size()); - secure_vector<byte> secret; - - for(size_t i = RTSS_HEADER_SIZE + 1; i != shares[0].size(); ++i) - { - for(size_t j = 0; j != V.size(); ++j) - V[j] = shares[j].contents[i]; - - byte r = 0; - for(size_t k = 0; k != shares.size(); ++k) - { - // L_i function: - byte r2 = 1; - for(size_t l = 0; l != shares.size(); ++l) - { - if(k == l) - continue; - - byte share_k = shares[k].share_id(); - byte share_l = shares[l].share_id(); - - if(share_k == share_l) - throw Decoding_Error("Duplicate shares found in RTSS recovery"); - - byte div = RTSS_EXP[(255 + - RTSS_LOG[share_l] - - RTSS_LOG[share_k ^ share_l]) % 255]; - - r2 = gfp_mul(r2, div); - } - - r ^= gfp_mul(V[k], r2); - } - secret.push_back(r); - } - - if(secret.size() != secret_len + hash->output_length()) - throw Decoding_Error("Bad length in RTSS output"); - - hash->update(&secret[0], secret_len); - secure_vector<byte> hash_check = hash->final(); - - if(!same_mem(&hash_check[0], - &secret[secret_len], hash->output_length())) - throw Decoding_Error("RTSS hash check failed"); - - return secure_vector<byte>(&secret[0], &secret[secret_len]); - } - -} |