// Copyright (c) 2012, Outercurve Foundation. // All rights reserved. // // Redistribution and use in source and binary forms, with or without modification, // are permitted provided that the following conditions are met: // // - Redistributions of source code must retain the above copyright notice, this // list of conditions and the following disclaimer. // // - 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. // // - Neither the name of the Outercurve Foundation nor the names of its // contributors may be used to endorse or promote products derived from this // software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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. using System; using System.Collections.Generic; using System.Text; namespace WebsitePanel.Server.Utils { /* * FreeSec: libcrypt for NetBSD * * Copyright (c) 1994 David Burren * All rights reserved. * * Adapted for FreeBSD-2.0 by Geoffrey M. Rehmet * this file should now *only* export crypt(), in order to make * binaries of libcrypt exportable from the USA * * Adapted for FreeBSD-4.0 by Mark R V Murray * this file should now *only* export crypt_des(), in order to make * a module that can be optionally included in libcrypt. * * 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. * 3. Neither the name of the author nor the names of other contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * 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. */ public class BsdDES { byte[] IP = new byte[64] { 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 }; byte[] inv_key_perm = new byte[64]; byte[] key_perm = new byte[56] { 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4 }; byte[] key_shifts = new byte[16] { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 }; byte[] inv_comp_perm = new byte[56]; byte[] comp_perm = new byte[48] { 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 }; /* * No E box is used, as it's replaced by some ANDs, shifts, and ORs. */ byte[,] u_sbox = new byte[8, 64]; byte[,] sbox = new byte[8, 64] { { 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7, 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8, 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0, 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 }, { 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10, 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5, 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15, 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 }, { 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8, 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1, 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7, 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 }, { 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15, 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9, 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4, 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 }, { 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9, 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6, 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14, 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 }, { 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11, 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8, 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6, 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 }, { 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1, 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6, 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2, 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 }, { 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7, 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2, 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8, 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 } }; byte[] un_pbox = new byte[32]; byte[] pbox = new byte[32] { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; uint[] bits32 = new uint[32] { 0x80000000, 0x40000000, 0x20000000, 0x10000000, 0x08000000, 0x04000000, 0x02000000, 0x01000000, 0x00800000, 0x00400000, 0x00200000, 0x00100000, 0x00080000, 0x00040000, 0x00020000, 0x00010000, 0x00008000, 0x00004000, 0x00002000, 0x00001000, 0x00000800, 0x00000400, 0x00000200, 0x00000100, 0x00000080, 0x00000040, 0x00000020, 0x00000010, 0x00000008, 0x00000004, 0x00000002, 0x00000001 }; byte[] bits8 = new byte[8] { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 }; byte[] ascii64 = System.Text.ASCIIEncoding.ASCII.GetBytes( "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"); /* 0000000000111111111122222222223333333333444444444455555555556666 */ /* 0123456789012345678901234567890123456789012345678901234567890123 */ bool des_initialised = false; uint saltbits; uint old_salt; byte[] init_perm = new byte[64], final_perm = new byte[64]; uint[] en_keysl = new uint[16], en_keysr = new uint[16]; uint[] de_keysl = new uint[16], de_keysr = new uint[16]; byte[,] m_sbox = new byte[4, 4096]; uint[,] psbox = new uint[4, 256]; uint[,] ip_maskl = new uint[8, 256], ip_maskr = new uint[8, 256]; uint[,] fp_maskl = new uint[8, 256], fp_maskr = new uint[8, 256]; uint[,] key_perm_maskl = new uint[8, 128], key_perm_maskr = new uint[8, 128]; uint[,] comp_maskl = new uint[8, 128], comp_maskr = new uint[8, 128]; uint old_rawkey0, old_rawkey1; uint AsciiToBin(char ch) { if (ch > 'z') return 0; if (ch >= 'a') return (uint)(ch - 'a' + 38); if (ch > 'Z') return 0; if (ch >= 'A') return (uint)(ch - 'A' + 12); if (ch > '9') return (0); if (ch >= '.') return (uint)(ch - '.'); return 0; } void Init() { int inbit, obit; old_rawkey0 = old_rawkey1 = 0; saltbits = 0; old_salt = 0; const int bits28 = 4; const int bits24 = 8; /* * Invert the S-boxes, reordering the input bits. */ for (int i = 0; i < 8; i++) for (int j = 0; j < 64; j++) { int b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf); u_sbox[i, j] = sbox[i, b]; } /* * Convert the inverted S-boxes into 4 arrays of 8 bits. * Each will handle 12 bits of the S-box input. */ for (int b = 0; b < 4; b++) for (int i = 0; i < 64; i++) for (int j = 0; j < 64; j++) m_sbox[b, (i << 6) | j] = (byte)((u_sbox[(b << 1), i] << 4) | u_sbox[(b << 1) + 1, j]); /* * Set up the initial & final permutations into a useful form, and * initialise the inverted key permutation. */ for (int i = 0; i < 64; i++) { init_perm[final_perm[i] = (byte)(IP[i] - 1)] = (byte)i; inv_key_perm[i] = 255; } /* * Invert the key permutation and initialise the inverted key * compression permutation. */ for (int i = 0; i < 56; i++) { inv_key_perm[key_perm[i] - 1] = (byte)i; inv_comp_perm[i] = 255; } /* * Invert the key compression permutation. */ for (int i = 0; i < 48; i++) { inv_comp_perm[comp_perm[i] - 1] = (byte)i; } /* * Set up the OR-mask arrays for the initial and final permutations, * and for the key initial and compression permutations. */ for (int k = 0; k < 8; k++) { for (int i = 0; i < 256; i++) { ip_maskl[k, i] = 0; ip_maskr[k, i] = 0; fp_maskl[k, i] = 0; fp_maskr[k, i] = 0; for (int j = 0; j < 8; j++) { inbit = 8 * k + j; if ((i & bits8[j]) > 0) { if ((obit = init_perm[inbit]) < 32) ip_maskl[k, i] |= bits32[obit]; else ip_maskr[k, i] |= bits32[obit - 32]; if ((obit = final_perm[inbit]) < 32) fp_maskl[k, i] |= bits32[obit]; else fp_maskr[k, i] |= bits32[obit - 32]; } } } for (int i = 0; i < 128; i++) { key_perm_maskl[k, i] = 0; key_perm_maskr[k, i] = 0; for (int j = 0; j < 7; j++) { inbit = 8 * k + j; if ((i & bits8[j + 1]) > 0) { if ((obit = inv_key_perm[inbit]) == 255) continue; if (obit < 28) key_perm_maskl[k, i] |= bits32[obit + bits28]; else key_perm_maskr[k, i] |= bits32[obit - 28 + bits28]; } } comp_maskl[k, i] = 0; comp_maskr[k, i] = 0; for (int j = 0; j < 7; j++) { inbit = 7 * k + j; if ((i & bits8[j + 1]) > 0) { if ((obit = inv_comp_perm[inbit]) == 255) continue; if (obit < 24) comp_maskl[k, i] |= bits32[obit + bits24]; else comp_maskr[k, i] |= bits32[obit - 24 + bits24]; } } } } /* * Invert the P-box permutation, and convert into OR-masks for * handling the output of the S-box arrays setup above. */ for (int i = 0; i < 32; i++) un_pbox[pbox[i] - 1] = (byte)i; for (int b = 0; b < 4; b++) for (int i = 0; i < 256; i++) { psbox[b, i] = 0; for (int j = 0; j < 8; j++) { if ((i & bits8[j]) > 0) psbox[b, i] |= bits32[un_pbox[8 * b + j]]; } } des_initialised = true; } void SetupSalt(uint salt) { uint obit, saltbit; int i; if (salt == old_salt) return; old_salt = salt; saltbits = 0; saltbit = 1; obit = 0x800000; for (i = 0; i < 24; i++) { if ((salt & saltbit) > 0) saltbits |= obit; saltbit <<= 1; obit >>= 1; } } int SetKey(byte[] key) { if (!des_initialised) Init(); uint rawkey0 = ntohl(BitConverter.ToUInt32(key, 0)); uint rawkey1 = ntohl(BitConverter.ToUInt32(key, 4)); if ((rawkey0 | rawkey1) > 0 && rawkey0 == old_rawkey0 && rawkey1 == old_rawkey1) { /* * Already setup for this key. * This optimisation fails on a zero key (which is weak and * has bad parity anyway) in order to simplify the starting * conditions. */ return 0; } old_rawkey0 = rawkey0; old_rawkey1 = rawkey1; /* * Do key permutation and split into two 28-bit subkeys. */ uint k0 = key_perm_maskl[0, rawkey0 >> 25] | key_perm_maskl[1, (rawkey0 >> 17) & 0x7f] | key_perm_maskl[2, (rawkey0 >> 9) & 0x7f] | key_perm_maskl[3, (rawkey0 >> 1) & 0x7f] | key_perm_maskl[4, rawkey1 >> 25] | key_perm_maskl[5, (rawkey1 >> 17) & 0x7f] | key_perm_maskl[6, (rawkey1 >> 9) & 0x7f] | key_perm_maskl[7, (rawkey1 >> 1) & 0x7f]; uint k1 = key_perm_maskr[0, rawkey0 >> 25] | key_perm_maskr[1, (rawkey0 >> 17) & 0x7f] | key_perm_maskr[2, (rawkey0 >> 9) & 0x7f] | key_perm_maskr[3, (rawkey0 >> 1) & 0x7f] | key_perm_maskr[4, rawkey1 >> 25] | key_perm_maskr[5, (rawkey1 >> 17) & 0x7f] | key_perm_maskr[6, (rawkey1 >> 9) & 0x7f] | key_perm_maskr[7, (rawkey1 >> 1) & 0x7f]; /* * Rotate subkeys and do compression permutation. */ int shifts = 0; for (int round = 0; round < 16; round++) { uint t0, t1; shifts += key_shifts[round]; t0 = (k0 << shifts) | (k0 >> (28 - shifts)); t1 = (k1 << shifts) | (k1 >> (28 - shifts)); de_keysl[15 - round] = en_keysl[round] = comp_maskl[0, (t0 >> 21) & 0x7f] | comp_maskl[1, (t0 >> 14) & 0x7f] | comp_maskl[2, (t0 >> 7) & 0x7f] | comp_maskl[3, t0 & 0x7f] | comp_maskl[4, (t1 >> 21) & 0x7f] | comp_maskl[5, (t1 >> 14) & 0x7f] | comp_maskl[6, (t1 >> 7) & 0x7f] | comp_maskl[7, t1 & 0x7f]; de_keysr[15 - round] = en_keysr[round] = comp_maskr[0, (t0 >> 21) & 0x7f] | comp_maskr[1, (t0 >> 14) & 0x7f] | comp_maskr[2, (t0 >> 7) & 0x7f] | comp_maskr[3, t0 & 0x7f] | comp_maskr[4, (t1 >> 21) & 0x7f] | comp_maskr[5, (t1 >> 14) & 0x7f] | comp_maskr[6, (t1 >> 7) & 0x7f] | comp_maskr[7, t1 & 0x7f]; } return 0; } int DoDes(uint l_in, uint r_in, out uint l_out, out uint r_out, int count) { /* * l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format. */ uint l, r; uint[] kl1, kr1; int kl, kr; uint f, r48l, r48r; int round; f = 0; l_out = r_out = 0; if (count == 0) { return 1; } else if (count > 0) { /* * Encrypting */ kl1 = en_keysl; kr1 = en_keysr; } else { /* * Decrypting */ count = -count; kl1 = de_keysl; kr1 = de_keysr; } /* * Do initial permutation (IP). */ l = ip_maskl[0, l_in >> 24] | ip_maskl[1, (l_in >> 16) & 0xff] | ip_maskl[2, (l_in >> 8) & 0xff] | ip_maskl[3, l_in & 0xff] | ip_maskl[4, r_in >> 24] | ip_maskl[5, (r_in >> 16) & 0xff] | ip_maskl[6, (r_in >> 8) & 0xff] | ip_maskl[7, r_in & 0xff]; r = ip_maskr[0, l_in >> 24] | ip_maskr[1, (l_in >> 16) & 0xff] | ip_maskr[2, (l_in >> 8) & 0xff] | ip_maskr[3, l_in & 0xff] | ip_maskr[4, r_in >> 24] | ip_maskr[5, (r_in >> 16) & 0xff] | ip_maskr[6, (r_in >> 8) & 0xff] | ip_maskr[7, r_in & 0xff]; while (count-- > 0) { /* * Do each round. */ kl = 0; kr = 0; round = 16; while (round-- > 0) { /* * Expand R to 48 bits (simulate the E-box). */ r48l = ((r & 0x00000001) << 23) | ((r & 0xf8000000) >> 9) | ((r & 0x1f800000) >> 11) | ((r & 0x01f80000) >> 13) | ((r & 0x001f8000) >> 15); r48r = ((r & 0x0001f800) << 7) | ((r & 0x00001f80) << 5) | ((r & 0x000001f8) << 3) | ((r & 0x0000001f) << 1) | ((r & 0x80000000) >> 31); /* * Do salting for crypt() and friends, and * XOR with the permuted key. */ f = (r48l ^ r48r) & saltbits; r48l ^= f ^ kl1[kl++]; r48r ^= f ^ kr1[kr++]; /* * Do sbox lookups (which shrink it back to 32 bits) * and do the pbox permutation at the same time. */ f = psbox[0, m_sbox[0, r48l >> 12]] | psbox[1, m_sbox[1, r48l & 0xfff]] | psbox[2, m_sbox[2, r48r >> 12]] | psbox[3, m_sbox[3, r48r & 0xfff]]; /* * Now that we've permuted things, complete f(). */ f ^= l; l = r; r = f; } r = l; l = f; } /* * Do final permutation (inverse of IP). */ l_out = fp_maskl[0, l >> 24] | fp_maskl[1, (l >> 16) & 0xff] | fp_maskl[2, (l >> 8) & 0xff] | fp_maskl[3, l & 0xff] | fp_maskl[4, r >> 24] | fp_maskl[5, (r >> 16) & 0xff] | fp_maskl[6, (r >> 8) & 0xff] | fp_maskl[7, r & 0xff]; r_out = fp_maskr[0, l >> 24] | fp_maskr[1, (l >> 16) & 0xff] | fp_maskr[2, (l >> 8) & 0xff] | fp_maskr[3, l & 0xff] | fp_maskr[4, r >> 24] | fp_maskr[5, (r >> 16) & 0xff] | fp_maskr[6, (r >> 8) & 0xff] | fp_maskr[7, r & 0xff]; return 0; } public string Crypt(string key) { // salt chars string salt_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./"; // generate random salt - 2 symbols StringBuilder salt = new StringBuilder(); Random rnd = new Random(); for (int i = 0; i < 2; i++) salt.Append(salt_chars[rnd.Next(salt_chars.Length - 1)]); // call crypt return Crypt(key, salt.ToString()); } public string Crypt(string key, string setting) { if (String.IsNullOrEmpty(setting) || setting.Length < 2) throw new ArgumentException("Salt must be at least 2 symbols", "setting"); uint salt, l, r0, r1; int count; //u_char *p, *q; //static char output[21]; byte[] output = new byte[13]; if (!des_initialised) Init(); /* * Copy the key, shifting each character up by one bit * and padding with zeros. */ byte[] key_bytes = System.Text.ASCIIEncoding.ASCII.GetBytes(key); byte[] setting_bytes = System.Text.ASCIIEncoding.ASCII.GetBytes(setting); byte[] keybuf = new byte[8]; for (int i = 0; i < keybuf.Length; i++) keybuf[i] = (i < key_bytes.Length) ? (byte)(key_bytes[i] << 1) : (byte)0; if (SetKey(keybuf) != 0) return null; /* * "old"-style: * setting - 2 bytes of salt * key - up to 8 characters */ count = 25; salt = (AsciiToBin(setting[1]) << 6) | AsciiToBin(setting[0]); output[0] = setting_bytes[0]; /* * If the encrypted password that the salt was extracted from * is only 1 character long, the salt will be corrupted. We * need to ensure that the output string doesn't have an extra * NUL in it! */ output[1] = setting_bytes.Length > 1 ? setting_bytes[1] : output[0]; int p = 2; SetupSalt(salt); /* * Do it. */ if (DoDes(0, 0, out r0, out r1, count) != 0) return null; /* * Now encode the result... */ l = (r0 >> 8); output[p++] = ascii64[(l >> 18) & 0x3f]; output[p++] = ascii64[(l >> 12) & 0x3f]; output[p++] = ascii64[(l >> 6) & 0x3f]; output[p++] = ascii64[l & 0x3f]; l = (r0 << 16) | ((r1 >> 16) & 0xffff); output[p++] = ascii64[(l >> 18) & 0x3f]; output[p++] = ascii64[(l >> 12) & 0x3f]; output[p++] = ascii64[(l >> 6) & 0x3f]; output[p++] = ascii64[l & 0x3f]; l = r1 << 2; output[p++] = ascii64[(l >> 12) & 0x3f]; output[p++] = ascii64[(l >> 6) & 0x3f]; output[p++] = ascii64[l & 0x3f]; return System.Text.ASCIIEncoding.ASCII.GetString(output); } uint ntohl(uint n) { return ((n & 0xFF) << 24) | ((n & 0xFF00) << 8) | ((n & 0xFF0000) >> 8) | ((n & 0xFF000000) >> 24); } } }