Initial commit

6 files changed, 517 insertions, 0 deletions

diff --git a/blowfish.hpp b/blowfish.hpp
new file mode 100644
index 0000000..e0468cd
--- /dev/null
+++ b/blowfish.hpp
@@ -0,0 +1,103 @@
+#pragma once
+
+// https://www.schneier.com/academic/archives/1994/09/description_of_a_new.html
+
+#include "blowfish_init.hpp"
+#include <algorithm>
+
+class Blowfish {
+public:
+  struct Block {
+    constexpr Block(uint64_t x) {
+      L = x >> 32;
+      R = x & 0xffffffff;
+    }
+    constexpr Block(uint32_t l, uint32_t r) : L(l), R(r) {}
+
+    constexpr operator uint64_t() const {
+      return (static_cast<uint64_t>(L) << 32) + R;
+    }
+    uint32_t L;
+    uint32_t R;
+  };
+
+  constexpr Blowfish(const uint8_t key[], size_t keylen) {
+    for (size_t i = 0; i < BOXES; ++i) {
+      for (size_t j = 0; j < ENTRIES; ++j) {
+        S[i][j] = S_INIT[i][j];
+      }
+    }
+
+    //
+    size_t k = 0;
+    for (size_t i = 0; i < SUBKEYS; ++i) {
+      uint32_t qk = 0;
+      for (size_t j = 0; j < 4; ++j) {
+        qk = (qk << 8) | key[k];
+        ++k;
+        if (k >= keylen) {
+          k = 0;
+        }
+      }
+      P[i] = P_INIT[i] ^ qk;
+    }
+
+    Block x(0, 0);
+
+    for (size_t i = 0; i < SUBKEYS; i += 2) {
+      x = encrypt(x);
+      P[i] = x.L;
+      P[i + 1] = x.R;
+    }
+    for (size_t i = 0; i < BOXES; ++i) {
+      for (size_t j = 0; j < ENTRIES; j += 2) {
+        x = encrypt(x);
+        S[i][j] = x.L;
+        S[i][j + 1] = x.R;
+      }
+    }
+  }
+
+  constexpr Block encrypt(const Block &x) const {
+    Block y(x);
+    for (size_t i = 0; i < ROUNDS; ++i) {
+      y.L = y.L ^ P[i];
+      y.R = F(y.L) ^ y.R;
+      std::swap(y.L, y.R);
+    }
+    std::swap(y.L, y.R);
+    y.R = y.R ^ P[16];
+    y.L = y.L ^ P[17];
+
+    return y;
+  }
+
+  constexpr Block decrypt(const Block &x) const {
+    Block y(x);
+    for (size_t i = ROUNDS + 1; i > 1; --i) {
+      y.L = y.L ^ P[i];
+      y.R = F(y.L) ^ y.R;
+      std::swap(y.L, y.R);
+    }
+    std::swap(y.L, y.R);
+    y.R = y.R ^ P[1];
+    y.L = y.L ^ P[0];
+    return y;
+  }
+
+private:
+  constexpr uint32_t F(uint32_t x) const {
+    const uint8_t a = (x >> 24) & 0xff;
+    const uint8_t b = (x >> 16) & 0xff;
+    const uint8_t c = (x >> 8) & 0xff;
+    const uint8_t d = x & 0xff;
+
+    uint32_t y = S[0][a] + S[1][b];
+    y = y ^ S[2][c];
+    y = y + S[3][d];
+    return y;
+  }
+
+  uint32_t P[SUBKEYS];
+  uint32_t S[BOXES][ENTRIES];
+};
diff --git a/blowfish_init.hpp b/blowfish_init.hpp
new file mode 100644
index 0000000..3dee01a
--- /dev/null
+++ b/blowfish_init.hpp
@@ -0,0 +1,197 @@
+#pragma once
+#include <cstddef>
+#include <cstdint>
+
+constexpr size_t ROUNDS = 16;
+constexpr size_t SUBKEYS = ROUNDS + 2;
+constexpr size_t BOXES = 4;
+constexpr size_t ENTRIES = 256;
+
+constexpr uint32_t P_INIT[SUBKEYS]{
+    0x243f6a88, 0x85a308d3, 0x13198a2e, 0x03707344, 0xa4093822, 0x299f31d0,
+    0x082efa98, 0xec4e6c89, 0x452821e6, 0x38d01377, 0xbe5466cf, 0x34e90c6c,
+    0xc0ac29b7, 0xc97c50dd, 0x3f84d5b5, 0xb5470917, 0x9216d5d9, 0x8979fb1b,
+};
+
+constexpr uint32_t S_INIT[BOXES][ENTRIES]{
+    {
+        0xd1310ba6, 0x98dfb5ac, 0x2ffd72db, 0xd01adfb7, 0xb8e1afed, 0x6a267e96,
+        0xba7c9045, 0xf12c7f99, 0x24a19947, 0xb3916cf7, 0x0801f2e2, 0x858efc16,
+        0x636920d8, 0x71574e69, 0xa458fea3, 0xf4933d7e, 0x0d95748f, 0x728eb658,
+        0x718bcd58, 0x82154aee, 0x7b54a41d, 0xc25a59b5, 0x9c30d539, 0x2af26013,
+        0xc5d1b023, 0x286085f0, 0xca417918, 0xb8db38ef, 0x8e79dcb0, 0x603a180e,
+        0x6c9e0e8b, 0xb01e8a3e, 0xd71577c1, 0xbd314b27, 0x78af2fda, 0x55605c60,
+        0xe65525f3, 0xaa55ab94, 0x57489862, 0x63e81440, 0x55ca396a, 0x2aab10b6,
+        0xb4cc5c34, 0x1141e8ce, 0xa15486af, 0x7c72e993, 0xb3ee1411, 0x636fbc2a,
+        0x2ba9c55d, 0x741831f6, 0xce5c3e16, 0x9b87931e, 0xafd6ba33, 0x6c24cf5c,
+        0x7a325381, 0x28958677, 0x3b8f4898, 0x6b4bb9af, 0xc4bfe81b, 0x66282193,
+        0x61d809cc, 0xfb21a991, 0x487cac60, 0x5dec8032, 0xef845d5d, 0xe98575b1,
+        0xdc262302, 0xeb651b88, 0x23893e81, 0xd396acc5, 0x0f6d6ff3, 0x83f44239,
+        0x2e0b4482, 0xa4842004, 0x69c8f04a, 0x9e1f9b5e, 0x21c66842, 0xf6e96c9a,
+        0x670c9c61, 0xabd388f0, 0x6a51a0d2, 0xd8542f68, 0x960fa728, 0xab5133a3,
+        0x6eef0b6c, 0x137a3be4, 0xba3bf050, 0x7efb2a98, 0xa1f1651d, 0x39af0176,
+        0x66ca593e, 0x82430e88, 0x8cee8619, 0x456f9fb4, 0x7d84a5c3, 0x3b8b5ebe,
+        0xe06f75d8, 0x85c12073, 0x401a449f, 0x56c16aa6, 0x4ed3aa62, 0x363f7706,
+        0x1bfedf72, 0x429b023d, 0x37d0d724, 0xd00a1248, 0xdb0fead3, 0x49f1c09b,
+        0x075372c9, 0x80991b7b, 0x25d479d8, 0xf6e8def7, 0xe3fe501a, 0xb6794c3b,
+        0x976ce0bd, 0x04c006ba, 0xc1a94fb6, 0x409f60c4, 0x5e5c9ec2, 0x196a2463,
+        0x68fb6faf, 0x3e6c53b5, 0x1339b2eb, 0x3b52ec6f, 0x6dfc511f, 0x9b30952c,
+        0xcc814544, 0xaf5ebd09, 0xbee3d004, 0xde334afd, 0x660f2807, 0x192e4bb3,
+        0xc0cba857, 0x45c8740f, 0xd20b5f39, 0xb9d3fbdb, 0x5579c0bd, 0x1a60320a,
+        0xd6a100c6, 0x402c7279, 0x679f25fe, 0xfb1fa3cc, 0x8ea5e9f8, 0xdb3222f8,
+        0x3c7516df, 0xfd616b15, 0x2f501ec8, 0xad0552ab, 0x323db5fa, 0xfd238760,
+        0x53317b48, 0x3e00df82, 0x9e5c57bb, 0xca6f8ca0, 0x1a87562e, 0xdf1769db,
+        0xd542a8f6, 0x287effc3, 0xac6732c6, 0x8c4f5573, 0x695b27b0, 0xbbca58c8,
+        0xe1ffa35d, 0xb8f011a0, 0x10fa3d98, 0xfd2183b8, 0x4afcb56c, 0x2dd1d35b,
+        0x9a53e479, 0xb6f84565, 0xd28e49bc, 0x4bfb9790, 0xe1ddf2da, 0xa4cb7e33,
+        0x62fb1341, 0xcee4c6e8, 0xef20cada, 0x36774c01, 0xd07e9efe, 0x2bf11fb4,
+        0x95dbda4d, 0xae909198, 0xeaad8e71, 0x6b93d5a0, 0xd08ed1d0, 0xafc725e0,
+        0x8e3c5b2f, 0x8e7594b7, 0x8ff6e2fb, 0xf2122b64, 0x8888b812, 0x900df01c,
+        0x4fad5ea0, 0x688fc31c, 0xd1cff191, 0xb3a8c1ad, 0x2f2f2218, 0xbe0e1777,
+        0xea752dfe, 0x8b021fa1, 0xe5a0cc0f, 0xb56f74e8, 0x18acf3d6, 0xce89e299,
+        0xb4a84fe0, 0xfd13e0b7, 0x7cc43b81, 0xd2ada8d9, 0x165fa266, 0x80957705,
+        0x93cc7314, 0x211a1477, 0xe6ad2065, 0x77b5fa86, 0xc75442f5, 0xfb9d35cf,
+        0xebcdaf0c, 0x7b3e89a0, 0xd6411bd3, 0xae1e7e49, 0x00250e2d, 0x2071b35e,
+        0x226800bb, 0x57b8e0af, 0x2464369b, 0xf009b91e, 0x5563911d, 0x59dfa6aa,
+        0x78c14389, 0xd95a537f, 0x207d5ba2, 0x02e5b9c5, 0x83260376, 0x6295cfa9,
+        0x11c81968, 0x4e734a41, 0xb3472dca, 0x7b14a94a, 0x1b510052, 0x9a532915,
+        0xd60f573f, 0xbc9bc6e4, 0x2b60a476, 0x81e67400, 0x08ba6fb5, 0x571be91f,
+        0xf296ec6b, 0x2a0dd915, 0xb6636521, 0xe7b9f9b6, 0xff34052e, 0xc5855664,
+        0x53b02d5d, 0xa99f8fa1, 0x08ba4799, 0x6e85076a,
+    },
+    {
+        0x4b7a70e9, 0xb5b32944, 0xdb75092e, 0xc4192623, 0xad6ea6b0, 0x49a7df7d,
+        0x9cee60b8, 0x8fedb266, 0xecaa8c71, 0x699a17ff, 0x5664526c, 0xc2b19ee1,
+        0x193602a5, 0x75094c29, 0xa0591340, 0xe4183a3e, 0x3f54989a, 0x5b429d65,
+        0x6b8fe4d6, 0x99f73fd6, 0xa1d29c07, 0xefe830f5, 0x4d2d38e6, 0xf0255dc1,
+        0x4cdd2086, 0x8470eb26, 0x6382e9c6, 0x021ecc5e, 0x09686b3f, 0x3ebaefc9,
+        0x3c971814, 0x6b6a70a1, 0x687f3584, 0x52a0e286, 0xb79c5305, 0xaa500737,
+        0x3e07841c, 0x7fdeae5c, 0x8e7d44ec, 0x5716f2b8, 0xb03ada37, 0xf0500c0d,
+        0xf01c1f04, 0x0200b3ff, 0xae0cf51a, 0x3cb574b2, 0x25837a58, 0xdc0921bd,
+        0xd19113f9, 0x7ca92ff6, 0x94324773, 0x22f54701, 0x3ae5e581, 0x37c2dadc,
+        0xc8b57634, 0x9af3dda7, 0xa9446146, 0x0fd0030e, 0xecc8c73e, 0xa4751e41,
+        0xe238cd99, 0x3bea0e2f, 0x3280bba1, 0x183eb331, 0x4e548b38, 0x4f6db908,
+        0x6f420d03, 0xf60a04bf, 0x2cb81290, 0x24977c79, 0x5679b072, 0xbcaf89af,
+        0xde9a771f, 0xd9930810, 0xb38bae12, 0xdccf3f2e, 0x5512721f, 0x2e6b7124,
+        0x501adde6, 0x9f84cd87, 0x7a584718, 0x7408da17, 0xbc9f9abc, 0xe94b7d8c,
+        0xec7aec3a, 0xdb851dfa, 0x63094366, 0xc464c3d2, 0xef1c1847, 0x3215d908,
+        0xdd433b37, 0x24c2ba16, 0x12a14d43, 0x2a65c451, 0x50940002, 0x133ae4dd,
+        0x71dff89e, 0x10314e55, 0x81ac77d6, 0x5f11199b, 0x043556f1, 0xd7a3c76b,
+        0x3c11183b, 0x5924a509, 0xf28fe6ed, 0x97f1fbfa, 0x9ebabf2c, 0x1e153c6e,
+        0x86e34570, 0xeae96fb1, 0x860e5e0a, 0x5a3e2ab3, 0x771fe71c, 0x4e3d06fa,
+        0x2965dcb9, 0x99e71d0f, 0x803e89d6, 0x5266c825, 0x2e4cc978, 0x9c10b36a,
+        0xc6150eba, 0x94e2ea78, 0xa5fc3c53, 0x1e0a2df4, 0xf2f74ea7, 0x361d2b3d,
+        0x1939260f, 0x19c27960, 0x5223a708, 0xf71312b6, 0xebadfe6e, 0xeac31f66,
+        0xe3bc4595, 0xa67bc883, 0xb17f37d1, 0x018cff28, 0xc332ddef, 0xbe6c5aa5,
+        0x65582185, 0x68ab9802, 0xeecea50f, 0xdb2f953b, 0x2aef7dad, 0x5b6e2f84,
+        0x1521b628, 0x29076170, 0xecdd4775, 0x619f1510, 0x13cca830, 0xeb61bd96,
+        0x0334fe1e, 0xaa0363cf, 0xb5735c90, 0x4c70a239, 0xd59e9e0b, 0xcbaade14,
+        0xeecc86bc, 0x60622ca7, 0x9cab5cab, 0xb2f3846e, 0x648b1eaf, 0x19bdf0ca,
+        0xa02369b9, 0x655abb50, 0x40685a32, 0x3c2ab4b3, 0x319ee9d5, 0xc021b8f7,
+        0x9b540b19, 0x875fa099, 0x95f7997e, 0x623d7da8, 0xf837889a, 0x97e32d77,
+        0x11ed935f, 0x16681281, 0x0e358829, 0xc7e61fd6, 0x96dedfa1, 0x7858ba99,
+        0x57f584a5, 0x1b227263, 0x9b83c3ff, 0x1ac24696, 0xcdb30aeb, 0x532e3054,
+        0x8fd948e4, 0x6dbc3128, 0x58ebf2ef, 0x34c6ffea, 0xfe28ed61, 0xee7c3c73,
+        0x5d4a14d9, 0xe864b7e3, 0x42105d14, 0x203e13e0, 0x45eee2b6, 0xa3aaabea,
+        0xdb6c4f15, 0xfacb4fd0, 0xc742f442, 0xef6abbb5, 0x654f3b1d, 0x41cd2105,
+        0xd81e799e, 0x86854dc7, 0xe44b476a, 0x3d816250, 0xcf62a1f2, 0x5b8d2646,
+        0xfc8883a0, 0xc1c7b6a3, 0x7f1524c3, 0x69cb7492, 0x47848a0b, 0x5692b285,
+        0x095bbf00, 0xad19489d, 0x1462b174, 0x23820e00, 0x58428d2a, 0x0c55f5ea,
+        0x1dadf43e, 0x233f7061, 0x3372f092, 0x8d937e41, 0xd65fecf1, 0x6c223bdb,
+        0x7cde3759, 0xcbee7460, 0x4085f2a7, 0xce77326e, 0xa6078084, 0x19f8509e,
+        0xe8efd855, 0x61d99735, 0xa969a7aa, 0xc50c06c2, 0x5a04abfc, 0x800bcadc,
+        0x9e447a2e, 0xc3453484, 0xfdd56705, 0x0e1e9ec9, 0xdb73dbd3, 0x105588cd,
+        0x675fda79, 0xe3674340, 0xc5c43465, 0x713e38d8, 0x3d28f89e, 0xf16dff20,
+        0x153e21e7, 0x8fb03d4a, 0xe6e39f2b, 0xdb83adf7,
+    },
+    {
+        0xe93d5a68, 0x948140f7, 0xf64c261c, 0x94692934, 0x411520f7, 0x7602d4f7,
+        0xbcf46b2e, 0xd4a20068, 0xd4082471, 0x3320f46a, 0x43b7d4b7, 0x500061af,
+        0x1e39f62e, 0x97244546, 0x14214f74, 0xbf8b8840, 0x4d95fc1d, 0x96b591af,
+        0x70f4ddd3, 0x66a02f45, 0xbfbc09ec, 0x03bd9785, 0x7fac6dd0, 0x31cb8504,
+        0x96eb27b3, 0x55fd3941, 0xda2547e6, 0xabca0a9a, 0x28507825, 0x530429f4,
+        0x0a2c86da, 0xe9b66dfb, 0x68dc1462, 0xd7486900, 0x680ec0a4, 0x27a18dee,
+        0x4f3ffea2, 0xe887ad8c, 0xb58ce006, 0x7af4d6b6, 0xaace1e7c, 0xd3375fec,
+        0xce78a399, 0x406b2a42, 0x20fe9e35, 0xd9f385b9, 0xee39d7ab, 0x3b124e8b,
+        0x1dc9faf7, 0x4b6d1856, 0x26a36631, 0xeae397b2, 0x3a6efa74, 0xdd5b4332,
+        0x6841e7f7, 0xca7820fb, 0xfb0af54e, 0xd8feb397, 0x454056ac, 0xba489527,
+        0x55533a3a, 0x20838d87, 0xfe6ba9b7, 0xd096954b, 0x55a867bc, 0xa1159a58,
+        0xcca92963, 0x99e1db33, 0xa62a4a56, 0x3f3125f9, 0x5ef47e1c, 0x9029317c,
+        0xfdf8e802, 0x04272f70, 0x80bb155c, 0x05282ce3, 0x95c11548, 0xe4c66d22,
+        0x48c1133f, 0xc70f86dc, 0x07f9c9ee, 0x41041f0f, 0x404779a4, 0x5d886e17,
+        0x325f51eb, 0xd59bc0d1, 0xf2bcc18f, 0x41113564, 0x257b7834, 0x602a9c60,
+        0xdff8e8a3, 0x1f636c1b, 0x0e12b4c2, 0x02e1329e, 0xaf664fd1, 0xcad18115,
+        0x6b2395e0, 0x333e92e1, 0x3b240b62, 0xeebeb922, 0x85b2a20e, 0xe6ba0d99,
+        0xde720c8c, 0x2da2f728, 0xd0127845, 0x95b794fd, 0x647d0862, 0xe7ccf5f0,
+        0x5449a36f, 0x877d48fa, 0xc39dfd27, 0xf33e8d1e, 0x0a476341, 0x992eff74,
+        0x3a6f6eab, 0xf4f8fd37, 0xa812dc60, 0xa1ebddf8, 0x991be14c, 0xdb6e6b0d,
+        0xc67b5510, 0x6d672c37, 0x2765d43b, 0xdcd0e804, 0xf1290dc7, 0xcc00ffa3,
+        0xb5390f92, 0x690fed0b, 0x667b9ffb, 0xcedb7d9c, 0xa091cf0b, 0xd9155ea3,
+        0xbb132f88, 0x515bad24, 0x7b9479bf, 0x763bd6eb, 0x37392eb3, 0xcc115979,
+        0x8026e297, 0xf42e312d, 0x6842ada7, 0xc66a2b3b, 0x12754ccc, 0x782ef11c,
+        0x6a124237, 0xb79251e7, 0x06a1bbe6, 0x4bfb6350, 0x1a6b1018, 0x11caedfa,
+        0x3d25bdd8, 0xe2e1c3c9, 0x44421659, 0x0a121386, 0xd90cec6e, 0xd5abea2a,
+        0x64af674e, 0xda86a85f, 0xbebfe988, 0x64e4c3fe, 0x9dbc8057, 0xf0f7c086,
+        0x60787bf8, 0x6003604d, 0xd1fd8346, 0xf6381fb0, 0x7745ae04, 0xd736fccc,
+        0x83426b33, 0xf01eab71, 0xb0804187, 0x3c005e5f, 0x77a057be, 0xbde8ae24,
+        0x55464299, 0xbf582e61, 0x4e58f48f, 0xf2ddfda2, 0xf474ef38, 0x8789bdc2,
+        0x5366f9c3, 0xc8b38e74, 0xb475f255, 0x46fcd9b9, 0x7aeb2661, 0x8b1ddf84,
+        0x846a0e79, 0x915f95e2, 0x466e598e, 0x20b45770, 0x8cd55591, 0xc902de4c,
+        0xb90bace1, 0xbb8205d0, 0x11a86248, 0x7574a99e, 0xb77f19b6, 0xe0a9dc09,
+        0x662d09a1, 0xc4324633, 0xe85a1f02, 0x09f0be8c, 0x4a99a025, 0x1d6efe10,
+        0x1ab93d1d, 0x0ba5a4df, 0xa186f20f, 0x2868f169, 0xdcb7da83, 0x573906fe,
+        0xa1e2ce9b, 0x4fcd7f52, 0x50115e01, 0xa70683fa, 0xa002b5c4, 0x0de6d027,
+        0x9af88c27, 0x773f8641, 0xc3604c06, 0x61a806b5, 0xf0177a28, 0xc0f586e0,
+        0x006058aa, 0x30dc7d62, 0x11e69ed7, 0x2338ea63, 0x53c2dd94, 0xc2c21634,
+        0xbbcbee56, 0x90bcb6de, 0xebfc7da1, 0xce591d76, 0x6f05e409, 0x4b7c0188,
+        0x39720a3d, 0x7c927c24, 0x86e3725f, 0x724d9db9, 0x1ac15bb4, 0xd39eb8fc,
+        0xed545578, 0x08fca5b5, 0xd83d7cd3, 0x4dad0fc4, 0x1e50ef5e, 0xb161e6f8,
+        0xa28514d9, 0x6c51133c, 0x6fd5c7e7, 0x56e14ec4, 0x362abfce, 0xddc6c837,
+        0xd79a3234, 0x92638212, 0x670efa8e, 0x406000e0,
+    },
+    {
+        0x3a39ce37, 0xd3faf5cf, 0xabc27737, 0x5ac52d1b, 0x5cb0679e, 0x4fa33742,
+        0xd3822740, 0x99bc9bbe, 0xd5118e9d, 0xbf0f7315, 0xd62d1c7e, 0xc700c47b,
+        0xb78c1b6b, 0x21a19045, 0xb26eb1be, 0x6a366eb4, 0x5748ab2f, 0xbc946e79,
+        0xc6a376d2, 0x6549c2c8, 0x530ff8ee, 0x468dde7d, 0xd5730a1d, 0x4cd04dc6,
+        0x2939bbdb, 0xa9ba4650, 0xac9526e8, 0xbe5ee304, 0xa1fad5f0, 0x6a2d519a,
+        0x63ef8ce2, 0x9a86ee22, 0xc089c2b8, 0x43242ef6, 0xa51e03aa, 0x9cf2d0a4,
+        0x83c061ba, 0x9be96a4d, 0x8fe51550, 0xba645bd6, 0x2826a2f9, 0xa73a3ae1,
+        0x4ba99586, 0xef5562e9, 0xc72fefd3, 0xf752f7da, 0x3f046f69, 0x77fa0a59,
+        0x80e4a915, 0x87b08601, 0x9b09e6ad, 0x3b3ee593, 0xe990fd5a, 0x9e34d797,
+        0x2cf0b7d9, 0x022b8b51, 0x96d5ac3a, 0x017da67d, 0xd1cf3ed6, 0x7c7d2d28,
+        0x1f9f25cf, 0xadf2b89b, 0x5ad6b472, 0x5a88f54c, 0xe029ac71, 0xe019a5e6,
+        0x47b0acfd, 0xed93fa9b, 0xe8d3c48d, 0x283b57cc, 0xf8d56629, 0x79132e28,
+        0x785f0191, 0xed756055, 0xf7960e44, 0xe3d35e8c, 0x15056dd4, 0x88f46dba,
+        0x03a16125, 0x0564f0bd, 0xc3eb9e15, 0x3c9057a2, 0x97271aec, 0xa93a072a,
+        0x1b3f6d9b, 0x1e6321f5, 0xf59c66fb, 0x26dcf319, 0x7533d928, 0xb155fdf5,
+        0x03563482, 0x8aba3cbb, 0x28517711, 0xc20ad9f8, 0xabcc5167, 0xccad925f,
+        0x4de81751, 0x3830dc8e, 0x379d5862, 0x9320f991, 0xea7a90c2, 0xfb3e7bce,
+        0x5121ce64, 0x774fbe32, 0xa8b6e37e, 0xc3293d46, 0x48de5369, 0x6413e680,
+        0xa2ae0810, 0xdd6db224, 0x69852dfd, 0x09072166, 0xb39a460a, 0x6445c0dd,
+        0x586cdecf, 0x1c20c8ae, 0x5bbef7dd, 0x1b588d40, 0xccd2017f, 0x6bb4e3bb,
+        0xdda26a7e, 0x3a59ff45, 0x3e350a44, 0xbcb4cdd5, 0x72eacea8, 0xfa6484bb,
+        0x8d6612ae, 0xbf3c6f47, 0xd29be463, 0x542f5d9e, 0xaec2771b, 0xf64e6370,
+        0x740e0d8d, 0xe75b1357, 0xf8721671, 0xaf537d5d, 0x4040cb08, 0x4eb4e2cc,
+        0x34d2466a, 0x0115af84, 0xe1b00428, 0x95983a1d, 0x06b89fb4, 0xce6ea048,
+        0x6f3f3b82, 0x3520ab82, 0x011a1d4b, 0x277227f8, 0x611560b1, 0xe7933fdc,
+        0xbb3a792b, 0x344525bd, 0xa08839e1, 0x51ce794b, 0x2f32c9b7, 0xa01fbac9,
+        0xe01cc87e, 0xbcc7d1f6, 0xcf0111c3, 0xa1e8aac7, 0x1a908749, 0xd44fbd9a,
+        0xd0dadecb, 0xd50ada38, 0x0339c32a, 0xc6913667, 0x8df9317c, 0xe0b12b4f,
+        0xf79e59b7, 0x43f5bb3a, 0xf2d519ff, 0x27d9459c, 0xbf97222c, 0x15e6fc2a,
+        0x0f91fc71, 0x9b941525, 0xfae59361, 0xceb69ceb, 0xc2a86459, 0x12baa8d1,
+        0xb6c1075e, 0xe3056a0c, 0x10d25065, 0xcb03a442, 0xe0ec6e0e, 0x1698db3b,
+        0x4c98a0be, 0x3278e964, 0x9f1f9532, 0xe0d392df, 0xd3a0342b, 0x8971f21e,
+        0x1b0a7441, 0x4ba3348c, 0xc5be7120, 0xc37632d8, 0xdf359f8d, 0x9b992f2e,
+        0xe60b6f47, 0x0fe3f11d, 0xe54cda54, 0x1edad891, 0xce6279cf, 0xcd3e7e6f,
+        0x1618b166, 0xfd2c1d05, 0x848fd2c5, 0xf6fb2299, 0xf523f357, 0xa6327623,
+        0x93a83531, 0x56cccd02, 0xacf08162, 0x5a75ebb5, 0x6e163697, 0x88d273cc,
+        0xde966292, 0x81b949d0, 0x4c50901b, 0x71c65614, 0xe6c6c7bd, 0x327a140a,
+        0x45e1d006, 0xc3f27b9a, 0xc9aa53fd, 0x62a80f00, 0xbb25bfe2, 0x35bdd2f6,
+        0x71126905, 0xb2040222, 0xb6cbcf7c, 0xcd769c2b, 0x53113ec0, 0x1640e3d3,
+        0x38abbd60, 0x2547adf0, 0xba38209c, 0xf746ce76, 0x77afa1c5, 0x20756060,
+        0x85cbfe4e, 0x8ae88dd8, 0x7aaaf9b0, 0x4cf9aa7e, 0x1948c25c, 0x02fb8a8c,
+        0x01c36ae4, 0xd6ebe1f9, 0x90d4f869, 0xa65cdea0, 0x3f09252d, 0xc208e69f,
+        0xb74e6132, 0xce77e25b, 0x578fdfe3, 0x3ac372e6,
+    },
+};
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..263438d
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,50 @@
+#include "blowfish.hpp"
+#include "vectors.h"
+#include <cstdio>
+
+constexpr uint64_t k(const uint8_t key[8]) {
+  uint64_t r = 0;
+  for (int i = 0; i < 8; ++i) {
+    r += static_cast<uint64_t>(key[i]) << (64 - 8 * (i + 1));
+  }
+  return r;
+}
+
+template <int i> struct wrapper {
+  constexpr void operator()() const {
+    constexpr Blowfish b(variable_key[i], 8);
+    constexpr Blowfish::Block x(plaintext_l[i], plaintext_r[i]);
+
+    constexpr auto y = b.encrypt(x);
+    static_assert(y.L == ciphertext_l[i]);
+    static_assert(y.R == ciphertext_r[i]);
+
+    constexpr auto z = b.decrypt(y);
+    static_assert(x.L == z.L);
+    static_assert(x.R == z.R);
+
+    printf("0x%016lx\t", k(variable_key[i]));
+    printf("0x%016lx\t", static_cast<uint64_t>(x));
+    printf("0x%016lx\t", static_cast<uint64_t>(y));
+    printf("0x%016lx\n", static_cast<uint64_t>(z));
+  }
+};
+
+template <template <int> class W, std::size_t... I>
+void caller_impl(std::index_sequence<I...>) {
+  int t[] = {0, ((void)W<I>()(), 1)...};
+  (void)t;
+}
+
+template <template <int> class W, std::size_t N,
+          typename Indices = std::make_index_sequence<N>>
+void call_times() {
+  caller_impl<W>(Indices());
+}
+
+int main(int, char **) {
+  printf("%-18s\t%-18s\t%-18s\t%-18s\n", "/ key", "/ cleartext", "/ encrypt",
+         "/ decrypt");
+  call_times<wrapper, NUM_VARIABLE_KEY_TESTS>();
+  return 0;
+}
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..ed10a1a
--- /dev/null
+++ b/makefile
@@ -0,0 +1,20 @@
+CXX = g++
+CXXFLAGS = -Wall -Wextra -Wpedantic -std=c++2a -g
+RELEASE = -O3 -march=native -mtune=native
+
+objects = main.o
+
+default: main
+
+release:
+	$(CXX) -c $(CXXFLAGS) $(RELEASE) main.cpp
+	$(CXX) -o main main.o
+
+%.o: %.cpp
+	$(CXX) -c $(CXXFLAGS) $<
+
+main: $(objects)
+	g++ -o $@ $^
+
+clean:
+	rm $(objects)
diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..c48a256
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,33 @@
+## blowfish.hpp
+
+what is blowfish: https://www.schneier.com/academic/blowfish/
+
+test vectors: https://www.schneier.com/wp-content/uploads/2015/12/vectors2-1.txt
+
+## license
+
+~~~
+Copyright (c) 2020 aqua@iserlohn-fortress.net
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+~~~
+
diff --git a/vectors.h b/vectors.h
new file mode 100644
index 0000000..a34a040
--- /dev/null
+++ b/vectors.h
@@ -0,0 +1,114 @@
+#pragma once

+// https://www.schneier.com/wp-content/uploads/2015/12/vectors2-1.txt

+

+/*

+ *  Author     :  Randy L. Milbert

+ *  E-mail     :  rmilbert@mit.edu

+ *  Date       :  18 Jun 97

+ *  Description:  Eric Young's test vectors for Blowfish.

+ */

+

+#define NUM_VARIABLE_KEY_TESTS	34

+#define NUM_SET_KEY_TESTS			24

+

+/* plaintext bytes -- left halves */

+constexpr uint32_t plaintext_l[NUM_VARIABLE_KEY_TESTS + NUM_SET_KEY_TESTS] = {

+    0x00000000l, 0xFFFFFFFFl, 0x10000000l, 0x11111111l, 0x11111111l,

+    0x01234567l, 0x00000000l, 0x01234567l, 0x01A1D6D0l, 0x5CD54CA8l,

+    0x0248D438l, 0x51454B58l, 0x42FD4430l, 0x059B5E08l, 0x0756D8E0l,

+    0x762514B8l, 0x3BDD1190l, 0x26955F68l, 0x164D5E40l, 0x6B056E18l,

+    0x004BD6EFl, 0x480D3900l, 0x437540C8l, 0x072D43A0l, 0x02FE5577l,

+    0x1D9D5C50l, 0x30553228l, 0x01234567l, 0x01234567l, 0x01234567l,

+    0xFFFFFFFFl, 0x00000000l, 0x00000000l, 0xFFFFFFFFl, 0xFEDCBA98l,

+    0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l,

+    0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l,

+    0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l,

+    0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l,

+    0xFEDCBA98l, 0xFEDCBA98l, 0xFEDCBA98l};

+

+/* plaintext bytes -- right halves */

+constexpr uint32_t plaintext_r[NUM_VARIABLE_KEY_TESTS + NUM_SET_KEY_TESTS] = {

+    0x00000000l, 0xFFFFFFFFl, 0x00000001l, 0x11111111l, 0x11111111l,

+    0x89ABCDEFl, 0x00000000l, 0x89ABCDEFl, 0x39776742l, 0x3DEF57DAl,

+    0x06F67172l, 0x2DDF440Al, 0x59577FA2l, 0x51CF143Al, 0x774761D2l,

+    0x29BF486Al, 0x49372802l, 0x35AF609Al, 0x4F275232l, 0x759F5CCAl,

+    0x09176062l, 0x6EE762F2l, 0x698F3CFAl, 0x77075292l, 0x8117F12Al,

+    0x18F728C2l, 0x6D6F295Al, 0x89ABCDEFl, 0x89ABCDEFl, 0x89ABCDEFl,

+    0xFFFFFFFFl, 0x00000000l, 0x00000000l, 0xFFFFFFFFl, 0x76543210l,

+    0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l,

+    0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l,

+    0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l,

+    0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l, 0x76543210l,

+    0x76543210l, 0x76543210l, 0x76543210l};

+

+/* key bytes for variable key tests */

+constexpr uint8_t variable_key[NUM_VARIABLE_KEY_TESTS][8] = {

+    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},

+    {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},

+    {0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},

+    {0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11},

+    {0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},

+    {0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11},

+    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},

+    {0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10},

+    {0x7C, 0xA1, 0x10, 0x45, 0x4A, 0x1A, 0x6E, 0x57},

+    {0x01, 0x31, 0xD9, 0x61, 0x9D, 0xC1, 0x37, 0x6E},

+    {0x07, 0xA1, 0x13, 0x3E, 0x4A, 0x0B, 0x26, 0x86},

+    {0x38, 0x49, 0x67, 0x4C, 0x26, 0x02, 0x31, 0x9E},

+    {0x04, 0xB9, 0x15, 0xBA, 0x43, 0xFE, 0xB5, 0xB6},

+    {0x01, 0x13, 0xB9, 0x70, 0xFD, 0x34, 0xF2, 0xCE},

+    {0x01, 0x70, 0xF1, 0x75, 0x46, 0x8F, 0xB5, 0xE6},

+    {0x43, 0x29, 0x7F, 0xAD, 0x38, 0xE3, 0x73, 0xFE},

+    {0x07, 0xA7, 0x13, 0x70, 0x45, 0xDA, 0x2A, 0x16},

+    {0x04, 0x68, 0x91, 0x04, 0xC2, 0xFD, 0x3B, 0x2F},

+    {0x37, 0xD0, 0x6B, 0xB5, 0x16, 0xCB, 0x75, 0x46},

+    {0x1F, 0x08, 0x26, 0x0D, 0x1A, 0xC2, 0x46, 0x5E},

+    {0x58, 0x40, 0x23, 0x64, 0x1A, 0xBA, 0x61, 0x76},

+    {0x02, 0x58, 0x16, 0x16, 0x46, 0x29, 0xB0, 0x07},

+    {0x49, 0x79, 0x3E, 0xBC, 0x79, 0xB3, 0x25, 0x8F},

+    {0x4F, 0xB0, 0x5E, 0x15, 0x15, 0xAB, 0x73, 0xA7},

+    {0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBF},

+    {0x01, 0x83, 0x10, 0xDC, 0x40, 0x9B, 0x26, 0xD6},

+    {0x1C, 0x58, 0x7F, 0x1C, 0x13, 0x92, 0x4F, 0xEF},

+    {0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01},

+    {0x1F, 0x1F, 0x1F, 0x1F, 0x0E, 0x0E, 0x0E, 0x0E},

+    {0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1, 0xFE},

+    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},

+    {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},

+    {0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},

+    {0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10}};

+

+/* key bytes for set key tests */

+unsigned char set_key[24] = {0xF0, 0xE1, 0xD2, 0xC3, 0xB4, 0xA5, 0x96, 0x87,

+                             0x78, 0x69, 0x5A, 0x4B, 0x3C, 0x2D, 0x1E, 0x0F,

+                             0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77};

+

+/* ciphertext bytes -- left halves */

+constexpr uint32_t ciphertext_l[NUM_VARIABLE_KEY_TESTS + NUM_SET_KEY_TESTS] = {

+    0x4EF99745l, 0x51866FD5l, 0x7D856F9Al, 0x2466DD87l, 0x61F9C380l,

+    0x7D0CC630l, 0x4EF99745l, 0x0ACEAB0Fl, 0x59C68245l, 0xB1B8CC0Bl,

+    0x1730E577l, 0xA25E7856l, 0x353882B1l, 0x48F4D088l, 0x432193B7l,

+    0x13F04154l, 0x2EEDDA93l, 0xD887E039l, 0x5F99D04Fl, 0x4A057A3Bl,

+    0x452031C1l, 0x7555AE39l, 0x53C55F9Cl, 0x7A8E7BFAl, 0xCF9C5D7Al,

+    0xD1ABB290l, 0x55CB3774l, 0xFA34EC48l, 0xA7907951l, 0xC39E072Dl,

+    0x014933E0l, 0xF21E9A77l, 0x24594688l, 0x6B5C5A9Cl, 0xF9AD597Cl,

+    0xE91D21C1l, 0xE9C2B70Al, 0xBE1E6394l, 0xB39E4448l, 0x9457AA83l,

+    0x8BB77032l, 0xE87A244El, 0x15750E7Al, 0x122BA70Bl, 0x3A833C9Al,

+    0x9409DA87l, 0x884F8062l, 0x1F85031Cl, 0x79D9373Al, 0x93142887l,

+    0x03429E83l, 0xA4299E27l, 0xAFD5AED1l, 0x10851C0El, 0xE6F51ED7l,

+    0x64A6E14Al, 0x80C7D7D4l, 0x05044B62l};

+

+/* ciphertext bytes -- right halves */

+constexpr uint32_t ciphertext_r[NUM_VARIABLE_KEY_TESTS + NUM_SET_KEY_TESTS] = {

+    0x6198DD78l, 0xB85ECB8Al, 0x613063F2l, 0x8B963C9Dl, 0x2281B096l,

+    0xAFDA1EC7l, 0x6198DD78l, 0xC6A0A28Dl, 0xEB05282Bl, 0x250F09A0l,

+    0x8BEA1DA4l, 0xCF2651EBl, 0x09CE8F1Al, 0x4C379918l, 0x8951FC98l,

+    0xD69D1AE5l, 0xFFD39C79l, 0x3C2DA6E3l, 0x5B163969l, 0x24D3977Bl,

+    0xE4FADA8El, 0xF59B87BDl, 0xB49FC019l, 0x937E89A3l, 0x4986ADB5l,

+    0x658BC778l, 0xD13EF201l, 0x47B268B2l, 0x08EA3CAEl, 0x9FAC631Dl,

+    0xCDAFF6E4l, 0xB71C49BCl, 0x5754369Al, 0x5D9E0A5Al, 0x49DB005El,

+    0xD961A6D6l, 0x1BC65CF3l, 0x08640F05l, 0x1BDB1E6El, 0xB1928C0Dl,

+    0xF960629Dl, 0x2CC85E82l, 0x4F4EC577l, 0x3AB64AE0l, 0xFFC537F6l,

+    0xA90F6BF2l, 0x5060B8B4l, 0x19E11968l, 0x714CA34Fl, 0xEE3BE15Cl,

+    0x8CE2D14Bl, 0x469FF67Bl, 0xC1BC96A8l, 0x3858DA9Fl, 0x9B9DB21Fl,

+    0xFD36B46Fl, 0x5A5479ADl, 0xFA52D080l};