/* This module generates and compares password hashes using SHA256 algorithms. * To help reduce the risk of dictionary attacks, the code appends random bytes * (so-called "salt") to the original plain text before generating hashes and * stores this salt appended to the result. To verify another plain text value * against the given hash, this module will retrieve the salt value from the * password string and use it when computing a new hash of the plain text. * * If an intruder gets access to your system or uses a brute force attack, * salt will not provide much value. * IMPORTANT: DATA HASHES CANNOT BE "DECRYPTED" BACK TO PLAIN TEXT. * * Modified for Anope. * (C) 2003-2010 Anope Team * Contact us at team@anope.org * * Taken from InspIRCd ( www.inspircd.org ) * see http://wiki.inspircd.org/Credits * * This program is free but copyrighted software; see * the file COPYING for details. */ /* FIPS 180-2 SHA-224/256/384/512 implementation * Last update: 05/23/2005 * Issue date: 04/30/2005 * * Copyright (C) 2005 Olivier Gay * All rights reserved. * * 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 project 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 PROJECT 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 PROJECT 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. */ #include "module.h" #define SHA256_DIGEST_SIZE (256 / 8) #define SHA256_BLOCK_SIZE (512 / 8) #ifndef HAS_STDINT typedef unsigned int uint32_t; #endif /** An sha256 context */ class SHA256Context { public: unsigned int tot_len; unsigned int len; unsigned char block[2 * SHA256_BLOCK_SIZE]; uint32_t h[8]; }; #define SHFR(x, n) (x >> n) #define ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n))) #define ROTL(x, n) ((x << n) | (x >> ((sizeof(x) << 3) - n))) #define CH(x, y, z) ((x & y) ^ (~x & z)) #define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z)) #define SHA256_F1(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) #define SHA256_F2(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) #define SHA256_F3(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHFR(x, 3)) #define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10)) #define UNPACK32(x, str) \ { \ *((str) + 3) = (uint8) ((x) ); \ *((str) + 2) = (uint8) ((x) >> 8); \ *((str) + 1) = (uint8) ((x) >> 16); \ *((str) + 0) = (uint8) ((x) >> 24); \ } #define PACK32(str, x) \ { \ *(x) = ((uint32_t) *((str) + 3) ) \ | ((uint32_t) *((str) + 2) << 8) \ | ((uint32_t) *((str) + 1) << 16) \ | ((uint32_t) *((str) + 0) << 24); \ } /* Macros used for loops unrolling */ #define SHA256_SCR(i) \ { \ w[i] = SHA256_F4(w[i - 2]) + w[i - 7] \ + SHA256_F3(w[i - 15]) + w[i - 16]; \ } uint32_t sha256_k[64] = { 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 }; class ESHA256 : public Module { unsigned int iv[8]; bool use_iv; /* initializes the IV with a new random value */ void NewRandomIV() { srand(time(NULL)); for (int i = 0; i < 8; i++) { iv[i] = getrandom32(); } } /* returns the IV as base64-encrypted string */ std::string GetIVString() { unsigned char buf[33]; char buf2[512]; for (int i = 0; i < 8; i++) { UNPACK32(iv[i], &buf[i << 2]); } b64_encode(reinterpret_cast(buf), 32, buf2, 512); return buf2; } /* splits the appended IV from the password string so it can be used for the next encryption */ /* password format: :: */ void GetIVFromPass(std::string &password) { size_t pos; pos = password.find(":"); std::string buf(password, password.find(":", pos+1)+1, password.size()); unsigned char buf2[33]; b64_decode(buf.c_str(), reinterpret_cast(buf2), 33); for (int i = 0 ; i < 8; i++) { PACK32(&buf2[i<<2], &iv[i]); } } void SHA256Init(SHA256Context *ctx) { for (int i = 0; i < 8; i++) ctx->h[i] = iv[i]; ctx->len = 0; ctx->tot_len = 0; } void SHA256Transform(SHA256Context *ctx, unsigned char *message, unsigned int block_nb) { uint32_t w[64]; uint32_t wv[8]; unsigned char *sub_block; for (unsigned int i = 1; i <= block_nb; i++) { int j; sub_block = message + ((i - 1) << 6); for (j = 0; j < 16; j++) PACK32(&sub_block[j << 2], &w[j]); for (j = 16; j < 64; j++) SHA256_SCR(j); for (j = 0; j < 8; j++) wv[j] = ctx->h[j]; for (j = 0; j < 64; j++) { uint32_t t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6]) + sha256_k[j] + w[j]; uint32_t t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]); wv[7] = wv[6]; wv[6] = wv[5]; wv[5] = wv[4]; wv[4] = wv[3] + t1; wv[3] = wv[2]; wv[2] = wv[1]; wv[1] = wv[0]; wv[0] = t1 + t2; } for (j = 0; j < 8; j++) ctx->h[j] += wv[j]; } } void SHA256Update(SHA256Context *ctx, unsigned char *message, unsigned int len) { /* * XXX here be dragons! * After many hours of pouring over this, I think I've found the problem. * When Special created our module from the reference one, he used: * * unsigned int rem_len = SHA256_BLOCK_SIZE - ctx->len; * * instead of the reference's version of: * * unsigned int tmp_len = SHA256_BLOCK_SIZE - ctx->len; * unsigned int rem_len = len < tmp_len ? len : tmp_len; * * I've changed back to the reference version of this code, and it seems to work with no errors. * So I'm inclined to believe this was the problem.. * -- w00t (January 06, 2008) */ unsigned int tmp_len = SHA256_BLOCK_SIZE - ctx->len; unsigned int rem_len = len < tmp_len ? len : tmp_len; memcpy(&ctx->block[ctx->len], message, rem_len); if (ctx->len + len < SHA256_BLOCK_SIZE) { ctx->len += len; return; } unsigned int new_len = len - rem_len; unsigned int block_nb = new_len / SHA256_BLOCK_SIZE; unsigned char *shifted_message = message + rem_len; SHA256Transform(ctx, ctx->block, 1); SHA256Transform(ctx, shifted_message, block_nb); rem_len = new_len % SHA256_BLOCK_SIZE; memcpy(ctx->block, &shifted_message[block_nb << 6],rem_len); ctx->len = rem_len; ctx->tot_len += (block_nb + 1) << 6; } void SHA256Final(SHA256Context *ctx, unsigned char *digest) { unsigned int block_nb = (1 + ((SHA256_BLOCK_SIZE - 9) < (ctx->len % SHA256_BLOCK_SIZE))); unsigned int len_b = (ctx->tot_len + ctx->len) << 3; unsigned int pm_len = block_nb << 6; memset(ctx->block + ctx->len, 0, pm_len - ctx->len); ctx->block[ctx->len] = 0x80; UNPACK32(len_b, ctx->block + pm_len - 4); SHA256Transform(ctx, ctx->block, block_nb); for (int i = 0 ; i < 8; i++) UNPACK32(ctx->h[i], &digest[i << 2]); } /********** ANOPE ******/ public: ESHA256(const std::string &modname, const std::string &creator) : Module(modname, creator) { this->SetAuthor("Anope"); this->SetVersion("$Id$"); this->SetType(ENCRYPTION); ModuleManager::Attach(I_OnEncrypt, this); ModuleManager::Attach(I_OnEncryptInPlace, this); ModuleManager::Attach(I_OnDecrypt, this); ModuleManager::Attach(I_OnCheckPassword, this); use_iv = false; } EventReturn OnEncrypt(const std::string &src, std::string &dest) { char digest[SHA256_DIGEST_SIZE]; char cpass[1000]; SHA256Context ctx; std::stringstream buf; if (!use_iv) NewRandomIV(); else use_iv = false; SHA256Init(&ctx); SHA256Update(&ctx, (unsigned char *)src.c_str(), src.size()); SHA256Final(&ctx, (unsigned char*)digest); b64_encode(digest, SHA256_DIGEST_SIZE, cpass, 1000); buf << "sha256:" << cpass << ":" << GetIVString(); Alog(LOG_DEBUG_2) << "(enc_sha256) hashed password from [" << src << "] to [" << buf.str() << " ]"; dest.assign(buf.str()); return EVENT_ALLOW; } EventReturn OnEncryptInPlace(std::string &buf) { return this->OnEncrypt(buf, buf); } EventReturn OnDecrypt(const std::string &hashm, std::string &src, std::string &dest) { if (hashm != "sha256") return EVENT_CONTINUE; return EVENT_STOP; } EventReturn OnCheckPassword(const std::string &hashm, std::string &plaintext, std::string &password) { if (hashm != "sha256") return EVENT_CONTINUE; std::string buf; GetIVFromPass(password); use_iv = true; this->OnEncrypt(plaintext, buf); if(!password.compare(buf)) { /* if we are NOT the first module in the list, * we want to re-encrypt the pass with the new encryption */ if (Config.EncModuleList.front().compare(this->name)) { enc_encrypt(plaintext, password ); } return EVENT_ALLOW; } return EVENT_STOP; } }; MODULE_INIT(ESHA256)