mirror of
https://github.com/PurpleI2P/i2pd.git
synced 2024-10-31 09:20:38 +00:00
99 lines
2.4 KiB
C++
99 lines
2.4 KiB
C++
#include "Crypto.h"
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#include "Elligator.h"
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namespace i2p
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{
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namespace crypto
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{
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static const uint8_t p_[32]=
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{
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0xed, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
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0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
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};
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static const uint8_t n1_[32] =
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{
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0xec, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
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0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
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};
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static const uint8_t n2_[32] =
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{
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0xeb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
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0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
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};
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static const uint8_t A_[32] =
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{
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0x06, 0x6d, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
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};
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static const uint8_t u_[32] =
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{
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0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
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};
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#define decode_bytes(x) { x = BN_new (); BN_bin2bn (x##_, 32, x); }
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Elligator2::Elligator2 ()
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{
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decode_bytes (p);
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decode_bytes (n1);
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decode_bytes (n2);
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decode_bytes (A);
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decode_bytes (u);
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BN_CTX * ctx = BN_CTX_new ();
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BN_mod_inverse (iu, u, p, ctx);
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BN_CTX_free (ctx);
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}
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Elligator2::~Elligator2 ()
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{
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BN_free (p);
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BN_free (n1);
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BN_free (n2);
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BN_free (A);
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}
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void Elligator2::Encode (const uint8_t * key, uint8_t * encoded) const
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{
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BN_CTX * ctx = BN_CTX_new ();
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BN_CTX_start (ctx);
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BIGNUM * a = BN_CTX_get (ctx); BN_bin2bn (key, 32, a);
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BIGNUM * b = BN_CTX_get (ctx);
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BN_add (a, A, b);
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BIGNUM * c = BN_CTX_get (ctx);
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BN_mod_exp (c, b, n2, p, ctx);
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BN_mod_mul (b, c, a, p, ctx);
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BN_sub (b, p, b);
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//BN_mod_exp (c, b, n2, p, ctx);
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BN_mod_mul (c, b, iu, p, ctx);
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// TODO:
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bn2buf (b, encoded, 32);
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BN_CTX_end (ctx);
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BN_CTX_free (ctx);
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}
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static std::unique_ptr<Elligator2> g_Elligator;
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std::unique_ptr<Elligator2>& GetElligator ()
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{
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if (!g_Elligator)
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{
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auto el = new Elligator2();
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if (!g_Elligator) // make sure it was not created already
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g_Elligator.reset (el);
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else
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delete el;
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}
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return g_Elligator;
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}
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}
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}
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