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Diffstat (limited to 'modules/encryption/enc_sha256.cpp')
| -rw-r--r-- | modules/encryption/enc_sha256.cpp | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/modules/encryption/enc_sha256.cpp b/modules/encryption/enc_sha256.cpp new file mode 100644 index 000000000..3034f3731 --- /dev/null +++ b/modules/encryption/enc_sha256.cpp @@ -0,0 +1,314 @@ +/* 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) 2003-2011 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 <olivier.gay@a3.epfl.ch> + * 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" + +static const unsigned SHA256_DIGEST_SIZE = 256 / 8; +static const unsigned SHA256_BLOCK_SIZE = 512 / 8; + +/** An sha256 context + */ +class SHA256Context +{ + public: + unsigned tot_len; + unsigned len; + unsigned char block[2 * SHA256_BLOCK_SIZE]; + uint32 h[8]; +}; + +inline static uint32 SHFR(uint32 x, uint32 n) { return x >> n; } +inline static uint32 ROTR(uint32 x, uint32 n) { return (x >> n) | (x << ((sizeof(x) << 3) - n)); } +inline static uint32 ROTL(uint32 x, uint32 n) { return (x << n) | (x >> ((sizeof(x) << 3) - n)); } +inline static uint32 CH(uint32 x, uint32 y, uint32 z) { return (x & y) ^ (~x & z); } +inline static uint32 MAJ(uint32 x, uint32 y, uint32 z) { return (x & y) ^ (x & z) ^ (y & z); } + +inline static uint32 SHA256_F1(uint32 x) { return ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22); } +inline static uint32 SHA256_F2(uint32 x) { return ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25); } +inline static uint32 SHA256_F3(uint32 x) { return ROTR(x, 7) ^ ROTR(x, 18) ^ SHFR(x, 3); } +inline static uint32 SHA256_F4(uint32 x) { return ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10); } + +inline static void UNPACK32(unsigned x, unsigned char *str) +{ + str[3] = static_cast<uint8>(x); + str[2] = static_cast<uint8>(x >> 8); + str[1] = static_cast<uint8>(x >> 16); + str[0] = static_cast<uint8>(x >> 24); +} + +inline static void PACK32(unsigned char *str, uint32 &x) +{ + x = static_cast<uint32>(str[3]) | static_cast<uint32>(str[2]) << 8 | static_cast<uint32>(str[1]) << 16 | static_cast<uint32>(str[0]) << 24; +} + +/* Macros used for loops unrolling */ + +inline static void SHA256_SCR(uint32 w[64], int i) +{ + w[i] = SHA256_F4(w[i - 2]) + w[i - 7] + SHA256_F3(w[i - 15]) + w[i - 16]; +} + +uint32 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 iv[8]; + bool use_iv; + + /* initializes the IV with a new random value */ + void NewRandomIV() + { + for (int i = 0; i < 8; ++i) + iv[i] = getrandom32(); + } + + /* returns the IV as base64-encrypted string */ + Anope::string GetIVString() + { + char buf[33]; + for (int i = 0; i < 8; ++i) + UNPACK32(iv[i], reinterpret_cast<unsigned char *>(&buf[i << 2])); + buf[32] = '\0'; + return Anope::Hex(buf, 32); + } + + /* splits the appended IV from the password string so it can be used for the next encryption */ + /* password format: <hashmethod>:<password_b64>:<iv_b64> */ + void GetIVFromPass(const Anope::string &password) + { + size_t pos = password.find(':'); + Anope::string buf = password.substr(password.find(':', pos + 1) + 1, password.length()); + char buf2[33]; + Anope::Unhex(buf, buf2); + for (int i = 0 ; i < 8; ++i) + PACK32(reinterpret_cast<unsigned char *>(&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 block_nb) + { + uint32 w[64], wv[8]; + unsigned char *sub_block; + for (unsigned 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(w, j); + for (j = 0; j < 8; ++j) + wv[j] = ctx->h[j]; + for (j = 0; j < 64; ++j) + { + uint32 t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6]) + sha256_k[j] + w[j]; + uint32 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, const unsigned char *message, unsigned 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 rem_len = SHA256_BLOCK_SIZE - ctx->len; + * + * instead of the reference's version of: + * + * unsigned tmp_len = SHA256_BLOCK_SIZE - ctx->len; + * unsigned 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 tmp_len = SHA256_BLOCK_SIZE - ctx->len, 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 new_len = len - rem_len, block_nb = new_len / SHA256_BLOCK_SIZE; + unsigned char *shifted_message = new unsigned char[len - rem_len]; + memcpy(shifted_message, message + rem_len, len - 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); + delete [] shifted_message; + ctx->len = rem_len; + ctx->tot_len += (block_nb + 1) << 6; + } + + void SHA256Final(SHA256Context *ctx, unsigned char *digest) + { + unsigned block_nb = 1 + ((SHA256_BLOCK_SIZE - 9) < (ctx->len % SHA256_BLOCK_SIZE)); + unsigned len_b = (ctx->tot_len + ctx->len) << 3; + unsigned 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 Anope::string &modname, const Anope::string &creator) : Module(modname, creator, ENCRYPTION) + { + this->SetAuthor("Anope"); + + Implementation i[] = { I_OnEncrypt, I_OnCheckAuthentication }; + ModuleManager::Attach(i, this, sizeof(i) / sizeof(Implementation)); + + use_iv = false; + } + + EventReturn OnEncrypt(const Anope::string &src, Anope::string &dest) + { + char digest[SHA256_DIGEST_SIZE + 1]; + SHA256Context ctx; + std::stringstream buf; + + if (!use_iv) + NewRandomIV(); + else + use_iv = false; + + SHA256Init(&ctx); + SHA256Update(&ctx, reinterpret_cast<const unsigned char *>(src.c_str()), src.length()); + SHA256Final(&ctx, reinterpret_cast<unsigned char *>(digest)); + digest[SHA256_DIGEST_SIZE] = '\0'; + buf << "sha256:" << Anope::Hex(digest, SHA256_DIGEST_SIZE) << ":" << GetIVString(); + Log(LOG_DEBUG_2) << "(enc_sha256) hashed password from [" << src << "] to [" << buf.str() << " ]"; + dest = buf.str(); + return EVENT_ALLOW; + } + + EventReturn OnCheckAuthentication(Command *c, CommandSource *source, const std::vector<Anope::string> ¶ms, const Anope::string &account, const Anope::string &password) + { + NickAlias *na = findnick(account); + NickCore *nc = na ? na->nc : NULL; + if (na == NULL) + return EVENT_CONTINUE; + + size_t pos = nc->pass.find(':'); + if (pos == Anope::string::npos) + return EVENT_CONTINUE; + Anope::string hash_method(nc->pass.begin(), nc->pass.begin() + pos); + if (!hash_method.equals_cs("sha256")) + return EVENT_CONTINUE; + + GetIVFromPass(nc->pass); + use_iv = true; + Anope::string buf; + this->OnEncrypt(password, buf); + + if (nc->pass.equals_cs(buf)) + { + /* if we are NOT the first module in the list, + * we want to re-encrypt the pass with the new encryption + */ + if (ModuleManager::FindFirstOf(ENCRYPTION) != this) + enc_encrypt(password, nc->pass); + return EVENT_ALLOW; + } + + return EVENT_CONTINUE; + } +}; + +MODULE_INIT(ESHA256) |