/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read copying and usage conditions.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 *
 * Blowfish encryption for Vim; in Blowfish cipher feedback mode.
 * Contributed by Mohsin Ahmed, http://www.cs.albany.edu/~mosh
 * Based on http://www.schneier.com/blowfish.html by Bruce Schneier.
 *
 * There are two variants:
 * - The old one "blowfish" has a flaw which makes it much easier to crack the
 *   key.  To see this, make a text file with one line of 1000 "x" characters
 *   and write it encrypted.  Use "xxd" to inspect the bytes in the file.  You
 *   will see that a block of 8 bytes repeats 8 times.
 * - The new one "blowfish2" is better.  It uses an 8 byte CFB to avoid the
 *   repeats.
 */

#include "vim.h"

#if defined(FEAT_CRYPT) || defined(PROTO)

#define ARRAY_LENGTH(A)      (sizeof(A)/sizeof(A[0]))

#define BF_BLOCK    8
#define BF_BLOCK_MASK 7
#define BF_MAX_CFB_LEN  (8 * BF_BLOCK)

typedef union {
    UINT32_T ul[2];
    char_u   uc[8];
} block8;

#if defined(MSWIN)
  // MS-Windows is always little endian
#else
# ifdef HAVE_CONFIG_H
   // in configure.ac AC_C_BIGENDIAN() defines WORDS_BIGENDIAN when needed
# else
#  error Please change this code to define WORDS_BIGENDIAN for big-endian machines.
# endif
#endif

// The state of encryption, referenced by cryptstate_T.
typedef struct {
    UINT32_T	pax[18];	    // P-array
    UINT32_T	sbx[4][256];	    // S-boxes
    int		randbyte_offset;
    int		update_offset;
    char_u	cfb_buffer[BF_MAX_CFB_LEN]; // up to 64 bytes used
    int		cfb_len;	    // size of cfb_buffer actually used
} bf_state_T;


// Blowfish code
static UINT32_T pax_init[18] = {
    0x243f6a88u, 0x85a308d3u, 0x13198a2eu,
    0x03707344u, 0xa4093822u, 0x299f31d0u,
    0x082efa98u, 0xec4e6c89u, 0x452821e6u,
    0x38d01377u, 0xbe5466cfu, 0x34e90c6cu,
    0xc0ac29b7u, 0xc97c50ddu, 0x3f84d5b5u,
    0xb5470917u, 0x9216d5d9u, 0x8979fb1bu
};

static UINT32_T sbx_init[4][256] = {
   {0xd1310ba6u, 0x98dfb5acu, 0x2ffd72dbu, 0xd01adfb7u,
    0xb8e1afedu, 0x6a267e96u, 0xba7c9045u, 0xf12c7f99u,
    0x24a19947u, 0xb3916cf7u, 0x0801f2e2u, 0x858efc16u,
    0x636920d8u, 0x71574e69u, 0xa458fea3u, 0xf4933d7eu,
    0x0d95748fu, 0x728eb658u, 0x718bcd58u, 0x82154aeeu,
    0x7b54a41du, 0xc25a59b5u, 0x9c30d539u, 0x2af26013u,
    0xc5d1b023u, 0x286085f0u, 0xca417918u, 0xb8db38efu,
    0x8e79dcb0u, 0x603a180eu, 0x6c9e0e8bu, 0xb01e8a3eu,
    0xd71577c1u, 0xbd314b27u, 0x78af2fdau, 0x55605c60u,
    0xe65525f3u, 0xaa55ab94u, 0x57489862u, 0x63e81440u,
    0x55ca396au, 0x2aab10b6u, 0xb4cc5c34u, 0x1141e8ceu,
    0xa15486afu, 0x7c72e993u, 0xb3ee1411u, 0x636fbc2au,
    0x2ba9c55du, 0x741831f6u, 0xce5c3e16u, 0x9b87931eu,
    0xafd6ba33u, 0x6c24cf5cu, 0x7a325381u, 0x28958677u,
    0x3b8f4898u, 0x6b4bb9afu, 0xc4bfe81bu, 0x66282193u,
    0x61d809ccu, 0xfb21a991u, 0x487cac60u, 0x5dec8032u,
    0xef845d5du, 0xe98575b1u, 0xdc262302u, 0xeb651b88u,
    0x23893e81u, 0xd396acc5u, 0x0f6d6ff3u, 0x83f44239u,
    0x2e0b4482u, 0xa4842004u, 0x69c8f04au, 0x9e1f9b5eu,
    0x21c66842u, 0xf6e96c9au, 0x670c9c61u, 0xabd388f0u,
    0x6a51a0d2u, 0xd8542f68u, 0x960fa728u, 0xab5133a3u,
    0x6eef0b6cu, 0x137a3be4u, 0xba3bf050u, 0x7efb2a98u,
    0xa1f1651du, 0x39af0176u, 0x66ca593eu, 0x82430e88u,
    0x8cee8619u, 0x456f9fb4u, 0x7d84a5c3u, 0x3b8b5ebeu,
    0xe06f75d8u, 0x85c12073u, 0x401a449fu, 0x56c16aa6u,
    0x4ed3aa62u, 0x363f7706u, 0x1bfedf72u, 0x429b023du,
    0x37d0d724u, 0xd00a1248u, 0xdb0fead3u, 0x49f1c09bu,
    0x075372c9u, 0x80991b7bu, 0x25d479d8u, 0xf6e8def7u,
    0xe3fe501au, 0xb6794c3bu, 0x976ce0bdu, 0x04c006bau,
    0xc1a94fb6u, 0x409f60c4u, 0x5e5c9ec2u, 0x196a2463u,
    0x68fb6fafu, 0x3e6c53b5u, 0x1339b2ebu, 0x3b52ec6fu,
    0x6dfc511fu, 0x9b30952cu, 0xcc814544u, 0xaf5ebd09u,
    0xbee3d004u, 0xde334afdu, 0x660f2807u, 0x192e4bb3u,
    0xc0cba857u, 0x45c8740fu, 0xd20b5f39u, 0xb9d3fbdbu,
    0x5579c0bdu, 0x1a60320au, 0xd6a100c6u, 0x402c7279u,
    0x679f25feu, 0xfb1fa3ccu, 0x8ea5e9f8u, 0xdb3222f8u,
    0x3c7516dfu, 0xfd616b15u, 0x2f501ec8u, 0xad0552abu,
    0x323db5fau, 0xfd238760u, 0x53317b48u, 0x3e00df82u,
    0x9e5c57bbu, 0xca6f8ca0u, 0x1a87562eu, 0xdf1769dbu,
    0xd542a8f6u, 0x287effc3u, 0xac6732c6u, 0x8c4f5573u,
    0x695b27b0u, 0xbbca58c8u, 0xe1ffa35du, 0xb8f011a0u,
    0x10fa3d98u, 0xfd2183b8u, 0x4afcb56cu, 0x2dd1d35bu,
    0x9a53e479u, 0xb6f84565u, 0xd28e49bcu, 0x4bfb9790u,
    0xe1ddf2dau, 0xa4cb7e33u, 0x62fb1341u, 0xcee4c6e8u,
    0xef20cadau, 0x36774c01u, 0xd07e9efeu, 0x2bf11fb4u,
    0x95dbda4du, 0xae909198u, 0xeaad8e71u, 0x6b93d5a0u,
    0xd08ed1d0u, 0xafc725e0u, 0x8e3c5b2fu, 0x8e7594b7u,
    0x8ff6e2fbu, 0xf2122b64u, 0x8888b812u, 0x900df01cu,
    0x4fad5ea0u, 0x688fc31cu, 0xd1cff191u, 0xb3a8c1adu,
    0x2f2f2218u, 0xbe0e1777u, 0xea752dfeu, 0x8b021fa1u,
    0xe5a0cc0fu, 0xb56f74e8u, 0x18acf3d6u, 0xce89e299u,
    0xb4a84fe0u, 0xfd13e0b7u, 0x7cc43b81u, 0xd2ada8d9u,
    0x165fa266u, 0x80957705u, 0x93cc7314u, 0x211a1477u,
    0xe6ad2065u, 0x77b5fa86u, 0xc75442f5u, 0xfb9d35cfu,
    0xebcdaf0cu, 0x7b3e89a0u, 0xd6411bd3u, 0xae1e7e49u,
    0x00250e2du, 0x2071b35eu, 0x226800bbu, 0x57b8e0afu,
    0x2464369bu, 0xf009b91eu, 0x5563911du, 0x59dfa6aau,
    0x78c14389u, 0xd95a537fu, 0x207d5ba2u, 0x02e5b9c5u,
    0x83260376u, 0x6295cfa9u, 0x11c81968u, 0x4e734a41u,
    0xb3472dcau, 0x7b14a94au, 0x1b510052u, 0x9a532915u,
    0xd60f573fu, 0xbc9bc6e4u, 0x2b60a476u, 0x81e67400u,
    0x08ba6fb5u, 0x571be91fu, 0xf296ec6bu, 0x2a0dd915u,
    0xb6636521u, 0xe7b9f9b6u, 0xff34052eu, 0xc5855664u,
    0x53b02d5du, 0xa99f8fa1u, 0x08ba4799u, 0x6e85076au},
   {0x4b7a70e9u, 0xb5b32944u, 0xdb75092eu, 0xc4192623u,
    0xad6ea6b0u, 0x49a7df7du, 0x9cee60b8u, 0x8fedb266u,
    0xecaa8c71u, 0x699a17ffu, 0x5664526cu, 0xc2b19ee1u,
    0x193602a5u, 0x75094c29u, 0xa0591340u, 0xe4183a3eu,
    0x3f54989au, 0x5b429d65u, 0x6b8fe4d6u, 0x99f73fd6u,
    0xa1d29c07u, 0xefe830f5u, 0x4d2d38e6u, 0xf0255dc1u,
    0x4cdd2086u, 0x8470eb26u, 0x6382e9c6u, 0x021ecc5eu,
    0x09686b3fu, 0x3ebaefc9u, 0x3c971814u, 0x6b6a70a1u,
    0x687f3584u, 0x52a0e286u, 0xb79c5305u, 0xaa500737u,
    0x3e07841cu, 0x7fdeae5cu, 0x8e7d44ecu, 0x5716f2b8u,
    0xb03ada37u, 0xf0500c0du, 0xf01c1f04u, 0x0200b3ffu,
    0xae0cf51au, 0x3cb574b2u, 0x25837a58u, 0xdc0921bdu,
    0xd19113f9u, 0x7ca92ff6u, 0x94324773u, 0x22f54701u,
    0x3ae5e581u, 0x37c2dadcu, 0xc8b57634u, 0x9af3dda7u,
    0xa9446146u, 0x0fd0030eu, 0xecc8c73eu, 0xa4751e41u,
    0xe238cd99u, 0x3bea0e2fu, 0x3280bba1u, 0x183eb331u,
    0x4e548b38u, 0x4f6db908u, 0x6f420d03u, 0xf60a04bfu,
    0x2cb81290u, 0x24977c79u, 0x5679b072u, 0xbcaf89afu,
    0xde9a771fu, 0xd9930810u, 0xb38bae12u, 0xdccf3f2eu,
    0x5512721fu, 0x2e6b7124u, 0x501adde6u, 0x9f84cd87u,
    0x7a584718u, 0x7408da17u, 0xbc9f9abcu, 0xe94b7d8cu,
    0xec7aec3au, 0xdb851dfau, 0x63094366u, 0xc464c3d2u,
    0xef1c1847u, 0x3215d908u, 0xdd433b37u, 0x24c2ba16u,
    0x12a14d43u, 0x2a65c451u, 0x50940002u, 0x133ae4ddu,
    0x71dff89eu, 0x10314e55u, 0x81ac77d6u, 0x5f11199bu,
    0x043556f1u, 0xd7a3c76bu, 0x3c11183bu, 0x5924a509u,
    0xf28fe6edu, 0x97f1fbfau, 0x9ebabf2cu, 0x1e153c6eu,
    0x86e34570u, 0xeae96fb1u, 0x860e5e0au, 0x5a3e2ab3u,
    0x771fe71cu, 0x4e3d06fau, 0x2965dcb9u, 0x99e71d0fu,
    0x803e89d6u, 0x5266c825u, 0x2e4cc978u, 0x9c10b36au,
    0xc6150ebau, 0x94e2ea78u, 0xa5fc3c53u, 0x1e0a2df4u,
    0xf2f74ea7u, 0x361d2b3du, 0x1939260fu, 0x19c27960u,
    0x5223a708u, 0xf71312b6u, 0xebadfe6eu, 0xeac31f66u,
    0xe3bc4595u, 0xa67bc883u, 0xb17f37d1u, 0x018cff28u,
    0xc332ddefu, 0xbe6c5aa5u, 0x65582185u, 0x68ab9802u,
    0xeecea50fu, 0xdb2f953bu, 0x2aef7dadu, 0x5b6e2f84u,
    0x1521b628u, 0x29076170u, 0xecdd4775u, 0x619f1510u,
    0x13cca830u, 0xeb61bd96u, 0x0334fe1eu, 0xaa0363cfu,
    0xb5735c90u, 0x4c70a239u, 0xd59e9e0bu, 0xcbaade14u,
    0xeecc86bcu, 0x60622ca7u, 0x9cab5cabu, 0xb2f3846eu,
    0x648b1eafu, 0x19bdf0cau, 0xa02369b9u, 0x655abb50u,
    0x40685a32u, 0x3c2ab4b3u, 0x319ee9d5u, 0xc021b8f7u,
    0x9b540b19u, 0x875fa099u, 0x95f7997eu, 0x623d7da8u,
    0xf837889au, 0x97e32d77u, 0x11ed935fu, 0x16681281u,
    0x0e358829u, 0xc7e61fd6u, 0x96dedfa1u, 0x7858ba99u,
    0x57f584a5u, 0x1b227263u, 0x9b83c3ffu, 0x1ac24696u,
    0xcdb30aebu, 0x532e3054u, 0x8fd948e4u, 0x6dbc3128u,
    0x58ebf2efu, 0x34c6ffeau, 0xfe28ed61u, 0xee7c3c73u,
    0x5d4a14d9u, 0xe864b7e3u, 0x42105d14u, 0x203e13e0u,
    0x45eee2b6u, 0xa3aaabeau, 0xdb6c4f15u, 0xfacb4fd0u,
    0xc742f442u, 0xef6abbb5u, 0x654f3b1du, 0x41cd2105u,
    0xd81e799eu, 0x86854dc7u, 0xe44b476au, 0x3d816250u,
    0xcf62a1f2u, 0x5b8d2646u, 0xfc8883a0u, 0xc1c7b6a3u,
    0x7f1524c3u, 0x69cb7492u, 0x47848a0bu, 0x5692b285u,
    0x095bbf00u, 0xad19489du, 0x1462b174u, 0x23820e00u,
    0x58428d2au, 0x0c55f5eau, 0x1dadf43eu, 0x233f7061u,
    0x3372f092u, 0x8d937e41u, 0xd65fecf1u, 0x6c223bdbu,
    0x7cde3759u, 0xcbee7460u, 0x4085f2a7u, 0xce77326eu,
    0xa6078084u, 0x19f8509eu, 0xe8efd855u, 0x61d99735u,
    0xa969a7aau, 0xc50c06c2u, 0x5a04abfcu, 0x800bcadcu,
    0x9e447a2eu, 0xc3453484u, 0xfdd56705u, 0x0e1e9ec9u,
    0xdb73dbd3u, 0x105588cdu, 0x675fda79u, 0xe3674340u,
    0xc5c43465u, 0x713e38d8u, 0x3d28f89eu, 0xf16dff20u,
    0x153e21e7u, 0x8fb03d4au, 0xe6e39f2bu, 0xdb83adf7u},
   {0xe93d5a68u, 0x948140f7u, 0xf64c261cu, 0x94692934u,
    0x411520f7u, 0x7602d4f7u, 0xbcf46b2eu, 0xd4a20068u,
    0xd4082471u, 0x3320f46au, 0x43b7d4b7u, 0x500061afu,
    0x1e39f62eu, 0x97244546u, 0x14214f74u, 0xbf8b8840u,
    0x4d95fc1du, 0x96b591afu, 0x70f4ddd3u, 0x66a02f45u,
    0xbfbc09ecu, 0x03bd9785u, 0x7fac6dd0u, 0x31cb8504u,
    0x96eb27b3u, 0x55fd3941u, 0xda2547e6u, 0xabca0a9au,
    0x28507825u, 0x530429f4u, 0x0a2c86dau, 0xe9b66dfbu,
    0x68dc1462u, 0xd7486900u, 0x680ec0a4u, 0x27a18deeu,
    0x4f3ffea2u, 0xe887ad8cu, 0xb58ce006u, 0x7af4d6b6u,
    0xaace1e7cu, 0xd3375fecu, 0xce78a399u, 0x406b2a42u,
    0x20fe9e35u, 0xd9f385b9u, 0xee39d7abu, 0x3b124e8bu,
    0x1dc9faf7u, 0x4b6d1856u, 0x26a36631u, 0xeae397b2u,
    0x3a6efa74u, 0xdd5b4332u, 0x6841e7f7u, 0xca7820fbu,
    0xfb0af54eu, 0xd8feb397u, 0x454056acu, 0xba489527u,
    0x55533a3au, 0x20838d87u, 0xfe6ba9b7u, 0xd096954bu,
    0x55a867bcu, 0xa1159a58u, 0xcca92963u, 0x99e1db33u,
    0xa62a4a56u, 0x3f3125f9u, 0x5ef47e1cu, 0x9029317cu,
    0xfdf8e802u, 0x04272f70u, 0x80bb155cu, 0x05282ce3u,
    0x95c11548u, 0xe4c66d22u, 0x48c1133fu, 0xc70f86dcu,
    0x07f9c9eeu, 0x41041f0fu, 0x404779a4u, 0x5d886e17u,
    0x325f51ebu, 0xd59bc0d1u, 0xf2bcc18fu, 0x41113564u,
    0x257b7834u, 0x602a9c60u, 0xdff8e8a3u, 0x1f636c1bu,
    0x0e12b4c2u, 0x02e1329eu, 0xaf664fd1u, 0xcad18115u,
    0x6b2395e0u, 0x333e92e1u, 0x3b240b62u, 0xeebeb922u,
    0x85b2a20eu, 0xe6ba0d99u, 0xde720c8cu, 0x2da2f728u,
    0xd0127845u, 0x95b794fdu, 0x647d0862u, 0xe7ccf5f0u,
    0x5449a36fu, 0x877d48fau, 0xc39dfd27u, 0xf33e8d1eu,
    0x0a476341u, 0x992eff74u, 0x3a6f6eabu, 0xf4f8fd37u,
    0xa812dc60u, 0xa1ebddf8u, 0x991be14cu, 0xdb6e6b0du,
    0xc67b5510u, 0x6d672c37u, 0x2765d43bu, 0xdcd0e804u,
    0xf1290dc7u, 0xcc00ffa3u, 0xb5390f92u, 0x690fed0bu,
    0x667b9ffbu, 0xcedb7d9cu, 0xa091cf0bu, 0xd9155ea3u,
    0xbb132f88u, 0x515bad24u, 0x7b9479bfu, 0x763bd6ebu,
    0x37392eb3u, 0xcc115979u, 0x8026e297u, 0xf42e312du,
    0x6842ada7u, 0xc66a2b3bu, 0x12754cccu, 0x782ef11cu,
    0x6a124237u, 0xb79251e7u, 0x06a1bbe6u, 0x4bfb6350u,
    0x1a6b1018u, 0x11caedfau, 0x3d25bdd8u, 0xe2e1c3c9u,
    0x44421659u, 0x0a121386u, 0xd90cec6eu, 0xd5abea2au,
    0x64af674eu, 0xda86a85fu, 0xbebfe988u, 0x64e4c3feu,
    0x9dbc8057u, 0xf0f7c086u, 0x60787bf8u, 0x6003604du,
    0xd1fd8346u, 0xf6381fb0u, 0x7745ae04u, 0xd736fcccu,
    0x83426b33u, 0xf01eab71u, 0xb0804187u, 0x3c005e5fu,
    0x77a057beu, 0xbde8ae24u, 0x55464299u, 0xbf582e61u,
    0x4e58f48fu, 0xf2ddfda2u, 0xf474ef38u, 0x8789bdc2u,
    0x5366f9c3u, 0xc8b38e74u, 0xb475f255u, 0x46fcd9b9u,
    0x7aeb2661u, 0x8b1ddf84u, 0x846a0e79u, 0x915f95e2u,
    0x466e598eu, 0x20b45770u, 0x8cd55591u, 0xc902de4cu,
    0xb90bace1u, 0xbb8205d0u, 0x11a86248u, 0x7574a99eu,
    0xb77f19b6u, 0xe0a9dc09u, 0x662d09a1u, 0xc4324633u,
    0xe85a1f02u, 0x09f0be8cu, 0x4a99a025u, 0x1d6efe10u,
    0x1ab93d1du, 0x0ba5a4dfu, 0xa186f20fu, 0x2868f169u,
    0xdcb7da83u, 0x573906feu, 0xa1e2ce9bu, 0x4fcd7f52u,
    0x50115e01u, 0xa70683fau, 0xa002b5c4u, 0x0de6d027u,
    0x9af88c27u, 0x773f8641u, 0xc3604c06u, 0x61a806b5u,
    0xf0177a28u, 0xc0f586e0u, 0x006058aau, 0x30dc7d62u,
    0x11e69ed7u, 0x2338ea63u, 0x53c2dd94u, 0xc2c21634u,
    0xbbcbee56u, 0x90bcb6deu, 0xebfc7da1u, 0xce591d76u,
    0x6f05e409u, 0x4b7c0188u, 0x39720a3du, 0x7c927c24u,
    0x86e3725fu, 0x724d9db9u, 0x1ac15bb4u, 0xd39eb8fcu,
    0xed545578u, 0x08fca5b5u, 0xd83d7cd3u, 0x4dad0fc4u,
    0x1e50ef5eu, 0xb161e6f8u, 0xa28514d9u, 0x6c51133cu,
    0x6fd5c7e7u, 0x56e14ec4u, 0x362abfceu, 0xddc6c837u,
    0xd79a3234u, 0x92638212u, 0x670efa8eu, 0x406000e0u},
   {0x3a39ce37u, 0xd3faf5cfu, 0xabc27737u, 0x5ac52d1bu,
    0x5cb0679eu, 0x4fa33742u, 0xd3822740u, 0x99bc9bbeu,
    0xd5118e9du, 0xbf0f7315u, 0xd62d1c7eu, 0xc700c47bu,
    0xb78c1b6bu, 0x21a19045u, 0xb26eb1beu, 0x6a366eb4u,
    0x5748ab2fu, 0xbc946e79u, 0xc6a376d2u, 0x6549c2c8u,
    0x530ff8eeu, 0x468dde7du, 0xd5730a1du, 0x4cd04dc6u,
    0x2939bbdbu, 0xa9ba4650u, 0xac9526e8u, 0xbe5ee304u,
    0xa1fad5f0u, 0x6a2d519au, 0x63ef8ce2u, 0x9a86ee22u,
    0xc089c2b8u, 0x43242ef6u, 0xa51e03aau, 0x9cf2d0a4u,
    0x83c061bau, 0x9be96a4du, 0x8fe51550u, 0xba645bd6u,
    0x2826a2f9u, 0xa73a3ae1u, 0x4ba99586u, 0xef5562e9u,
    0xc72fefd3u, 0xf752f7dau, 0x3f046f69u, 0x77fa0a59u,
    0x80e4a915u, 0x87b08601u, 0x9b09e6adu, 0x3b3ee593u,
    0xe990fd5au, 0x9e34d797u, 0x2cf0b7d9u, 0x022b8b51u,
    0x96d5ac3au, 0x017da67du, 0xd1cf3ed6u, 0x7c7d2d28u,
    0x1f9f25cfu, 0xadf2b89bu, 0x5ad6b472u, 0x5a88f54cu,
    0xe029ac71u, 0xe019a5e6u, 0x47b0acfdu, 0xed93fa9bu,
    0xe8d3c48du, 0x283b57ccu, 0xf8d56629u, 0x79132e28u,
    0x785f0191u, 0xed756055u, 0xf7960e44u, 0xe3d35e8cu,
    0x15056dd4u, 0x88f46dbau, 0x03a16125u, 0x0564f0bdu,
    0xc3eb9e15u, 0x3c9057a2u, 0x97271aecu, 0xa93a072au,
    0x1b3f6d9bu, 0x1e6321f5u, 0xf59c66fbu, 0x26dcf319u,
    0x7533d928u, 0xb155fdf5u, 0x03563482u, 0x8aba3cbbu,
    0x28517711u, 0xc20ad9f8u, 0xabcc5167u, 0xccad925fu,
    0x4de81751u, 0x3830dc8eu, 0x379d5862u, 0x9320f991u,
    0xea7a90c2u, 0xfb3e7bceu, 0x5121ce64u, 0x774fbe32u,
    0xa8b6e37eu, 0xc3293d46u, 0x48de5369u, 0x6413e680u,
    0xa2ae0810u, 0xdd6db224u, 0x69852dfdu, 0x09072166u,
    0xb39a460au, 0x6445c0ddu, 0x586cdecfu, 0x1c20c8aeu,
    0x5bbef7ddu, 0x1b588d40u, 0xccd2017fu, 0x6bb4e3bbu,
    0xdda26a7eu, 0x3a59ff45u, 0x3e350a44u, 0xbcb4cdd5u,
    0x72eacea8u, 0xfa6484bbu, 0x8d6612aeu, 0xbf3c6f47u,
    0xd29be463u, 0x542f5d9eu, 0xaec2771bu, 0xf64e6370u,
    0x740e0d8du, 0xe75b1357u, 0xf8721671u, 0xaf537d5du,
    0x4040cb08u, 0x4eb4e2ccu, 0x34d2466au, 0x0115af84u,
    0xe1b00428u, 0x95983a1du, 0x06b89fb4u, 0xce6ea048u,
    0x6f3f3b82u, 0x3520ab82u, 0x011a1d4bu, 0x277227f8u,
    0x611560b1u, 0xe7933fdcu, 0xbb3a792bu, 0x344525bdu,
    0xa08839e1u, 0x51ce794bu, 0x2f32c9b7u, 0xa01fbac9u,
    0xe01cc87eu, 0xbcc7d1f6u, 0xcf0111c3u, 0xa1e8aac7u,
    0x1a908749u, 0xd44fbd9au, 0xd0dadecbu, 0xd50ada38u,
    0x0339c32au, 0xc6913667u, 0x8df9317cu, 0xe0b12b4fu,
    0xf79e59b7u, 0x43f5bb3au, 0xf2d519ffu, 0x27d9459cu,
    0xbf97222cu, 0x15e6fc2au, 0x0f91fc71u, 0x9b941525u,
    0xfae59361u, 0xceb69cebu, 0xc2a86459u, 0x12baa8d1u,
    0xb6c1075eu, 0xe3056a0cu, 0x10d25065u, 0xcb03a442u,
    0xe0ec6e0eu, 0x1698db3bu, 0x4c98a0beu, 0x3278e964u,
    0x9f1f9532u, 0xe0d392dfu, 0xd3a0342bu, 0x8971f21eu,
    0x1b0a7441u, 0x4ba3348cu, 0xc5be7120u, 0xc37632d8u,
    0xdf359f8du, 0x9b992f2eu, 0xe60b6f47u, 0x0fe3f11du,
    0xe54cda54u, 0x1edad891u, 0xce6279cfu, 0xcd3e7e6fu,
    0x1618b166u, 0xfd2c1d05u, 0x848fd2c5u, 0xf6fb2299u,
    0xf523f357u, 0xa6327623u, 0x93a83531u, 0x56cccd02u,
    0xacf08162u, 0x5a75ebb5u, 0x6e163697u, 0x88d273ccu,
    0xde966292u, 0x81b949d0u, 0x4c50901bu, 0x71c65614u,
    0xe6c6c7bdu, 0x327a140au, 0x45e1d006u, 0xc3f27b9au,
    0xc9aa53fdu, 0x62a80f00u, 0xbb25bfe2u, 0x35bdd2f6u,
    0x71126905u, 0xb2040222u, 0xb6cbcf7cu, 0xcd769c2bu,
    0x53113ec0u, 0x1640e3d3u, 0x38abbd60u, 0x2547adf0u,
    0xba38209cu, 0xf746ce76u, 0x77afa1c5u, 0x20756060u,
    0x85cbfe4eu, 0x8ae88dd8u, 0x7aaaf9b0u, 0x4cf9aa7eu,
    0x1948c25cu, 0x02fb8a8cu, 0x01c36ae4u, 0xd6ebe1f9u,
    0x90d4f869u, 0xa65cdea0u, 0x3f09252du, 0xc208e69fu,
    0xb74e6132u, 0xce77e25bu, 0x578fdfe3u, 0x3ac372e6u
 }
};

#define F1(i) \
    xl ^= bfs->pax[i]; \
    xr ^= ((bfs->sbx[0][xl >> 24] + \
    bfs->sbx[1][(xl & 0xFF0000) >> 16]) ^ \
    bfs->sbx[2][(xl & 0xFF00) >> 8]) + \
    bfs->sbx[3][xl & 0xFF];

#define F2(i) \
    xr ^= bfs->pax[i]; \
    xl ^= ((bfs->sbx[0][xr >> 24] + \
    bfs->sbx[1][(xr & 0xFF0000) >> 16]) ^ \
    bfs->sbx[2][(xr & 0xFF00) >> 8]) + \
    bfs->sbx[3][xr & 0xFF];

    static void
bf_e_block(
    bf_state_T *bfs,
    UINT32_T *p_xl,
    UINT32_T *p_xr)
{
    UINT32_T temp;
    UINT32_T xl = *p_xl;
    UINT32_T xr = *p_xr;

    F1(0) F2(1)
    F1(2) F2(3)
    F1(4) F2(5)
    F1(6) F2(7)
    F1(8) F2(9)
    F1(10) F2(11)
    F1(12) F2(13)
    F1(14) F2(15)
    xl ^= bfs->pax[16];
    xr ^= bfs->pax[17];
    temp = xl;
    xl = xr;
    xr = temp;
    *p_xl = xl;
    *p_xr = xr;
}


#ifdef WORDS_BIGENDIAN
# define htonl2(x) \
    x = ((((x) &     0xffL) << 24) | (((x) & 0xff00L)     <<  8) | \
	 (((x) & 0xff0000L) >>  8) | (((x) & 0xff000000L) >> 24))
#else
# define htonl2(x)
#endif

    static void
bf_e_cblock(
    bf_state_T *bfs,
    char_u *block)
{
    block8	bk;

    memcpy(bk.uc, block, 8);
    htonl2(bk.ul[0]);
    htonl2(bk.ul[1]);
    bf_e_block(bfs, &bk.ul[0], &bk.ul[1]);
    htonl2(bk.ul[0]);
    htonl2(bk.ul[1]);
    memcpy(block, bk.uc, 8);
}

/*
 * Initialize the crypt method using "password" as the encryption key and
 * "salt[salt_len]" as the salt.
 */
    static void
bf_key_init(
    bf_state_T	*bfs,
    char_u	*password,
    char_u	*salt,
    int		salt_len)
{
    int      i, j, keypos = 0;
    unsigned u;
    UINT32_T val, data_l, data_r;
    char_u   *key;
    int      keylen;

    // Process the key 1001 times.
    // See http://en.wikipedia.org/wiki/Key_strengthening.
    key = sha256_key(password, salt, salt_len);
    for (i = 0; i < 1000; i++)
	key = sha256_key(key, salt, salt_len);

    // Convert the key from 64 hex chars to 32 binary chars.
    keylen = (int)STRLEN(key) / 2;
    if (keylen == 0)
    {
	iemsg(_("E831: bf_key_init() called with empty password"));
	return;
    }
    for (i = 0; i < keylen; i++)
    {
	sscanf((char *)&key[i * 2], "%2x", &u);
	key[i] = u;
    }

    // Use "key" to initialize the P-array ("pax") and S-boxes ("sbx") of
    // Blowfish.
    mch_memmove(bfs->sbx, sbx_init, 4 * 4 * 256);

    for (i = 0; i < 18; ++i)
    {
	val = 0;
	for (j = 0; j < 4; ++j)
	    val = (val << 8) | key[keypos++ % keylen];
	bfs->pax[i] = pax_init[i] ^ val;
    }

    data_l = data_r = 0;
    for (i = 0; i < 18; i += 2)
    {
	bf_e_block(bfs, &data_l, &data_r);
	bfs->pax[i + 0] = data_l;
	bfs->pax[i + 1] = data_r;
    }

    for (i = 0; i < 4; ++i)
    {
	for (j = 0; j < 256; j += 2)
	{
	    bf_e_block(bfs, &data_l, &data_r);
	    bfs->sbx[i][j + 0] = data_l;
	    bfs->sbx[i][j + 1] = data_r;
	}
    }
}

/*
 * Blowfish self-test for corrupted tables or instructions.
 */
    static int
bf_check_tables(
    UINT32_T pax[18],
    UINT32_T sbx[4][256],
    UINT32_T val)
{
    int i, j;
    UINT32_T c = 0;

    for (i = 0; i < 18; i++)
	c ^= pax[i];
    for (i = 0; i < 4; i++)
	for (j = 0; j < 256; j++)
	    c ^= sbx[i][j];
    return c == val;
}

typedef struct {
    char_u   password[64];
    char_u   salt[9];
    char_u   plaintxt[9];
    char_u   cryptxt[9];
    char_u   badcryptxt[9]; // cryptxt when big/little endian is wrong
    UINT32_T keysum;
} struct_bf_test_data;

/*
 * Assert bf(password, plaintxt) is cryptxt.
 * Assert csum(pax sbx(password)) is keysum.
 */
static struct_bf_test_data bf_test_data[] = {
  {
      "password",
      "salt",
      "plaintxt",
      "\xad\x3d\xfa\x7f\xe8\xea\x40\xf6", // cryptxt
      "\x72\x50\x3b\x38\x10\x60\x22\xa7", // badcryptxt
      0x56701b5du // keysum
  },
};

/*
 * Return FAIL when there is something wrong with blowfish encryption.
 */
    static int
bf_self_test(void)
{
    int    i, bn;
    int    err = 0;
    block8 bk;
    UINT32_T ui = 0xffffffffUL;
    bf_state_T state;

    vim_memset(&state, 0, sizeof(bf_state_T));
    state.cfb_len = BF_MAX_CFB_LEN;

    // We can't simply use sizeof(UINT32_T), it would generate a compiler
    // warning.
    if (ui != 0xffffffffUL || ui + 1 != 0) {
	err++;
	emsg(_("E820: sizeof(uint32_t) != 4"));
    }

    if (!bf_check_tables(pax_init, sbx_init, 0x6ffa520a))
	err++;

    bn = ARRAY_LENGTH(bf_test_data);
    for (i = 0; i < bn; i++)
    {
	bf_key_init(&state, (char_u *)(bf_test_data[i].password),
		    bf_test_data[i].salt,
		    (int)STRLEN(bf_test_data[i].salt));
	if (!bf_check_tables(state.pax, state.sbx, bf_test_data[i].keysum))
	    err++;

	// Don't modify bf_test_data[i].plaintxt, self test is idempotent.
	memcpy(bk.uc, bf_test_data[i].plaintxt, 8);
	bf_e_cblock(&state, bk.uc);
	if (memcmp(bk.uc, bf_test_data[i].cryptxt, 8) != 0)
	{
	    if (err == 0 && memcmp(bk.uc, bf_test_data[i].badcryptxt, 8) == 0)
		emsg(_("E817: Blowfish big/little endian use wrong"));
	    err++;
	}
    }

    return err > 0 ? FAIL : OK;
}

/*
 * CFB: Cipher Feedback Mode.
 */

/*
 * Initialize with seed "seed[seed_len]".
 */
    static void
bf_cfb_init(
    bf_state_T	*bfs,
    char_u	*seed,
    int		seed_len)
{
    int i, mi;

    bfs->randbyte_offset = bfs->update_offset = 0;
    vim_memset(bfs->cfb_buffer, 0, bfs->cfb_len);
    if (seed_len > 0)
    {
	mi = seed_len > bfs->cfb_len ? seed_len : bfs->cfb_len;
	for (i = 0; i < mi; i++)
	    bfs->cfb_buffer[i % bfs->cfb_len] ^= seed[i % seed_len];
    }
}

#define BF_CFB_UPDATE(bfs, c) { \
    bfs->cfb_buffer[bfs->update_offset] ^= (char_u)c; \
    if (++bfs->update_offset == bfs->cfb_len) \
	bfs->update_offset = 0; \
}

#define BF_RANBYTE(bfs, t) { \
    if ((bfs->randbyte_offset & BF_BLOCK_MASK) == 0) \
	bf_e_cblock(bfs, &(bfs->cfb_buffer[bfs->randbyte_offset])); \
    t = bfs->cfb_buffer[bfs->randbyte_offset]; \
    if (++bfs->randbyte_offset == bfs->cfb_len) \
	bfs->randbyte_offset = 0; \
}

/*
 * Encrypt "from[len]" into "to[len]".
 * "from" and "to" can be equal to encrypt in place.
 */
    void
crypt_blowfish_encode(
    cryptstate_T *state,
    char_u	*from,
    size_t	len,
    char_u	*to)
{
    bf_state_T *bfs = state->method_state;
    size_t	i;
    int		ztemp, t;

    for (i = 0; i < len; ++i)
    {
	ztemp = from[i];
	BF_RANBYTE(bfs, t);
	BF_CFB_UPDATE(bfs, ztemp);
	to[i] = t ^ ztemp;
    }
}

/*
 * Decrypt "from[len]" into "to[len]".
 */
    void
crypt_blowfish_decode(
    cryptstate_T *state,
    char_u	*from,
    size_t	len,
    char_u	*to)
{
    bf_state_T *bfs = state->method_state;
    size_t	i;
    int		t;

    for (i = 0; i < len; ++i)
    {
	BF_RANBYTE(bfs, t);
	to[i] = from[i] ^ t;
	BF_CFB_UPDATE(bfs, to[i]);
    }
}

    int
crypt_blowfish_init(
    cryptstate_T	*state,
    char_u*		key,
    char_u*		salt,
    int			salt_len,
    char_u*		seed,
    int			seed_len)
{
    bf_state_T	*bfs = ALLOC_CLEAR_ONE(bf_state_T);

    if (bfs == NULL)
	return FAIL;
    state->method_state = bfs;

    // "blowfish" uses a 64 byte buffer, causing it to repeat 8 byte groups 8
    // times.  "blowfish2" uses a 8 byte buffer to avoid repeating.
    bfs->cfb_len = state->method_nr == CRYPT_M_BF ? BF_MAX_CFB_LEN : BF_BLOCK;

    if (blowfish_self_test() == FAIL)
	return FAIL;

    bf_key_init(bfs, key, salt, salt_len);
    bf_cfb_init(bfs, seed, seed_len);

    return OK;
}

/*
 * Run a test to check if the encryption works as expected.
 * Give an error and return FAIL when not.
 */
    int
blowfish_self_test(void)
{
    if (sha256_self_test() == FAIL)
    {
	emsg(_("E818: sha256 test failed"));
	return FAIL;
    }
    if (bf_self_test() == FAIL)
    {
	emsg(_("E819: Blowfish test failed"));
	return FAIL;
    }
    return OK;
}

#endif // FEAT_CRYPT