/*************************************************************************** * NEPContext.cc -- * * * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2016 Insecure.Com LLC. Nmap is * * also a registered trademark of Insecure.Com LLC. This program is free * * software; you may redistribute and/or modify it under the terms of the * * GNU General Public License as published by the Free Software * * Foundation; Version 2 ("GPL"), BUT ONLY WITH ALL OF THE CLARIFICATIONS * * AND EXCEPTIONS DESCRIBED HEREIN. This guarantees your right to use, * * modify, and redistribute this software under certain conditions. If * * you wish to embed Nmap technology into proprietary software, we sell * * alternative licenses (contact sales@nmap.com). Dozens of software * * vendors already license Nmap technology such as host discovery, port * * scanning, OS detection, version detection, and the Nmap Scripting * * Engine. * * * * Note that the GPL places important restrictions on "derivative works", * * yet it does not provide a detailed definition of that term. To avoid * * misunderstandings, we interpret that term as broadly as copyright law * * allows. For example, we consider an application to constitute a * * derivative work for the purpose of this license if it does any of the * * following with any software or content covered by this license * * ("Covered Software"): * * * * o Integrates source code from Covered Software. * * * * o Reads or includes copyrighted data files, such as Nmap's nmap-os-db * * or nmap-service-probes. * * * * o Is designed specifically to execute Covered Software and parse the * * results (as opposed to typical shell or execution-menu apps, which will * * execute anything you tell them to). * * * * o Includes Covered Software in a proprietary executable installer. The * * installers produced by InstallShield are an example of this. Including * * Nmap with other software in compressed or archival form does not * * trigger this provision, provided appropriate open source decompression * * or de-archiving software is widely available for no charge. For the * * purposes of this license, an installer is considered to include Covered * * Software even if it actually retrieves a copy of Covered Software from * * another source during runtime (such as by downloading it from the * * Internet). * * * * o Links (statically or dynamically) to a library which does any of the * * above. * * * * o Executes a helper program, module, or script to do any of the above. * * * * This list is not exclusive, but is meant to clarify our interpretation * * of derived works with some common examples. Other people may interpret * * the plain GPL differently, so we consider this a special exception to * * the GPL that we apply to Covered Software. Works which meet any of * * these conditions must conform to all of the terms of this license, * * particularly including the GPL Section 3 requirements of providing * * source code and allowing free redistribution of the work as a whole. * * * * As another special exception to the GPL terms, Insecure.Com LLC grants * * permission to link the code of this program with any version of the * * OpenSSL library which is distributed under a license identical to that * * listed in the included docs/licenses/OpenSSL.txt file, and distribute * * linked combinations including the two. * * * * Any redistribution of Covered Software, including any derived works, * * must obey and carry forward all of the terms of this license, including * * obeying all GPL rules and restrictions. For example, source code of * * the whole work must be provided and free redistribution must be * * allowed. All GPL references to "this License", are to be treated as * * including the terms and conditions of this license text as well. * * * * Because this license imposes special exceptions to the GPL, Covered * * Work may not be combined (even as part of a larger work) with plain GPL * * software. The terms, conditions, and exceptions of this license must * * be included as well. This license is incompatible with some other open * * source licenses as well. In some cases we can relicense portions of * * Nmap or grant special permissions to use it in other open source * * software. Please contact fyodor@nmap.org with any such requests. * * Similarly, we don't incorporate incompatible open source software into * * Covered Software without special permission from the copyright holders. * * * * If you have any questions about the licensing restrictions on using * * Nmap in other works, are happy to help. As mentioned above, we also * * offer alternative license to integrate Nmap into proprietary * * applications and appliances. These contracts have been sold to dozens * * of software vendors, and generally include a perpetual license as well * * as providing for priority support and updates. They also fund the * * continued development of Nmap. Please email sales@nmap.com for further * * information. * * * * If you have received a written license agreement or contract for * * Covered Software stating terms other than these, you may choose to use * * and redistribute Covered Software under those terms instead of these. * * * * Source is provided to this software because we believe users have a * * right to know exactly what a program is going to do before they run it. * * This also allows you to audit the software for security holes. * * * * Source code also allows you to port Nmap to new platforms, fix bugs, * * and add new features. You are highly encouraged to send your changes * * to the dev@nmap.org mailing list for possible incorporation into the * * main distribution. By sending these changes to Fyodor or one of the * * Insecure.Org development mailing lists, or checking them into the Nmap * * source code repository, it is understood (unless you specify otherwise) * * that you are offering the Nmap Project (Insecure.Com LLC) the * * unlimited, non-exclusive right to reuse, modify, and relicense the * * code. Nmap will always be available Open Source, but this is important * * because the inability to relicense code has caused devastating problems * * for other Free Software projects (such as KDE and NASM). We also * * occasionally relicense the code to third parties as discussed above. * * If you wish to specify special license conditions of your * * contributions, just say so when you send them. * * * * This program is distributed in the hope that it will be useful, but * * WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Nmap * * license file for more details (it's in a COPYING file included with * * Nmap, and also available from https://svn.nmap.org/nmap/COPYING) * * * ***************************************************************************/ #include "nping.h" #include "NEPContext.h" #include "Crypto.h" #include "EchoHeader.h" #include "nbase.h" #include "NpingOps.h" extern NpingOps o; NEPContext::NEPContext() { this->reset(); } /* End of NEPContext constructor */ NEPContext::~NEPContext() { } /* End of NEPContext destructor */ /** Sets every attribute to its default value- */ void NEPContext::reset() { this->id=CLIENT_NOT_FOUND; this->nsi=NULL; this->state=STATE_LISTEN; this->last_seq_client=0; this->last_seq_server=0; memset(this->next_iv_enc, 0, CIPHER_BLOCK_SIZE); memset(this->next_iv_dec, 0, CIPHER_BLOCK_SIZE); memset(this->nep_key_mac_c2s, 0, MAC_KEY_LEN); memset(this->nep_key_mac_s2c, 0, MAC_KEY_LEN); memset(this->nep_key_ciphertext_c2s, 0, CIPHER_KEY_LEN); memset(this->nep_key_ciphertext_s2c, 0, CIPHER_KEY_LEN); memset(this->server_nonce, 0, NONCE_LEN); memset(this->client_nonce, 0, NONCE_LEN); memset(&this->clnt_addr, 0, sizeof(struct sockaddr_storage )); server_nonce_set=false; client_nonce_set=false; } /* End of reset() */ clientid_t NEPContext::getIdentifier(){ return this->id; } /* End of getIdentifier() */ int NEPContext::setIdentifier(clientid_t clnt){ this->id=clnt; return OP_SUCCESS; } /* End of setIdentifier() */ struct sockaddr_storage NEPContext::getAddress(){ return this->clnt_addr; } /* End of getAddress() */ int NEPContext::setAddress(struct sockaddr_storage a){ this->clnt_addr=a; return OP_SUCCESS; } /* End of setAddress() */ nsock_iod NEPContext::getNsockIOD(){ return this->nsi; } /* End of getNsockIOD() */ int NEPContext::setNsockIOD(nsock_iod iod){ this->nsi=iod; return OP_SUCCESS; } /* End of setNsockIOD() */ bool NEPContext::ready(){ return (this->state==STATE_READY_SENT); } int NEPContext::setState(int st){ this->state=st; return OP_SUCCESS; } /* End of setState() */ int NEPContext::getState(){ return this->state; } /* End of getState() */ int NEPContext::setNextEncryptionIV(u8 *block){ if(block==NULL) return OP_FAILURE; else{ memcpy(this->next_iv_enc, block, CIPHER_BLOCK_SIZE); return OP_SUCCESS; } } /* End of setLastBlock4Encryption() */ u8 *NEPContext::getNextEncryptionIV(size_t *final_len){ if(final_len!=NULL) *final_len=CIPHER_BLOCK_SIZE; return this->next_iv_enc; } /* End of getLastBlock4Encryption() */ u8 *NEPContext::getNextEncryptionIV(){ return this->getNextEncryptionIV(NULL); } /* End of getLastBlock4Encryption() */ int NEPContext::setNextDecryptionIV(u8 *block){ if(block==NULL) return OP_FAILURE; else{ memcpy(this->next_iv_dec, block, CIPHER_BLOCK_SIZE); return OP_SUCCESS; } } /* End of setLastBlock4Decryption() */ u8 *NEPContext::getNextDecryptionIV(size_t *final_len){ if(final_len!=NULL) *final_len=CIPHER_BLOCK_SIZE; return this->next_iv_dec; } /* End of getLastBlock4Decryption() */ u8 *NEPContext::getNextDecryptionIV(){ return this->getNextDecryptionIV(NULL); } /* End of getLastBlock4Decryption() */ int NEPContext::setLastServerSequence(u32 seq){ this->last_seq_server=seq; return OP_SUCCESS; } /* End of setLastServerSequence() */ u32 NEPContext::getLastServerSequence(){ return this->last_seq_server; } /* End of getLastServerSequence() */ /** Increments current server sequence number by one and returns it. * @warning this function changes object's internal state. It should be * called only when the caller wants to increment the internal last_seq_client * attribute. */ u32 NEPContext::getNextServerSequence(){ if( this->last_seq_server==0xFFFFFFFF) this->last_seq_server=0; /* Wrap back to zero */ else this->last_seq_server++; return this->last_seq_server; } /* End of getNextServerSequence() */ int NEPContext::setLastClientSequence(u32 seq){ this->last_seq_client=seq; return OP_SUCCESS; } /* End of setLastClientSequence() */ u32 NEPContext::getLastClientSequence(){ return this->last_seq_client; } /* End of getLastClientSequence() */ /** Increments current client sequence number by one and returns it. * @warning this function changes object's internal state. It should be * called only when the caller wants to increment the internal last_seq_client * attribute. */ u32 NEPContext::getNextClientSequence(){ if( this->last_seq_client==0xFFFFFFFF) this->last_seq_client=0; /* Wrap back to zero */ else this->last_seq_client++; return this->last_seq_client; } /* End of getNextClientSequence() */ int NEPContext::generateInitialServerSequence(){ return Crypto::generateNonce((u8 *)&(this->last_seq_server), sizeof(u32)); } /* End of generateInitialServerSequence() */ int NEPContext::generateInitialClientSequence(){ return Crypto::generateNonce((u8 *)&(this->last_seq_client), sizeof(u32)); } /* End of generateInitialClientSequence() */ u8 *NEPContext::generateKey(int key_type, size_t *final_len){ u8 data[1024]; char key_type_id[128+1]; size_t len=0; /* Copy the passphrase */ char *passphrase=o.getEchoPassphrase(); size_t plen=strlen(passphrase); memcpy(data, passphrase, plen); len+=plen; /* Copy the nonces */ memcpy(data+len, this->getServerNonce(), NONCE_LEN ); len+=NONCE_LEN; if(key_type==MAC_KEY_S2C_INITIAL){ memset(data+len, 0, NONCE_LEN); /* Empty nonce in this case */ len+=NONCE_LEN; }else{ memcpy(data+len, this->getClientNonce(), NONCE_LEN); len+=NONCE_LEN; } switch(key_type){ case MAC_KEY_S2C_INITIAL: strncpy(key_type_id, "NEPkeyforMACServer2ClientInitial", 128); break; case MAC_KEY_S2C: strncpy(key_type_id, "NEPkeyforMACServer2Client", 128); break; case MAC_KEY_C2S: strncpy(key_type_id, "NEPkeyforMACClient2Server", 128); break; case CIPHER_KEY_C2S: strncpy(key_type_id, "NEPkeyforCiphertextClient2Server", 128); break; case CIPHER_KEY_S2C: strncpy(key_type_id, "NEPkeyforCiphertextServer2Client", 128); break; default: return NULL; break; } /* Copy the id */ memcpy(data+len, key_type_id, strlen(key_type_id)); len+=strlen(key_type_id); return Crypto::deriveKey(data, len, final_len); } /* End of generateKey() */ /** Set key for C->S MAC computation (NEP_KEY_MAC_C2S)*/ int NEPContext::setMacKeyC2S(u8 *key){ if(key==NULL) return OP_FAILURE; else memcpy(this->nep_key_mac_c2s, key, MAC_KEY_LEN); return OP_SUCCESS; } /* End of setMacKeyC2S() */ /** Returns NEP_KEY_MAC_C2S key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getMacKeyC2S(size_t *final_len){ if(final_len!=NULL) *final_len=MAC_KEY_LEN; return this->nep_key_mac_c2s; } /* End of getMacKeyC2S() */ /** Returns NEP_KEY_MAC_C2S key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getMacKeyC2S(){ return this->getMacKeyC2S(NULL); } /* End of getMacKeyC2S() */ int NEPContext::generateMacKeyC2S(){ u8 *key=NULL; size_t len=0; if( (key=this->generateKey(MAC_KEY_C2S, &len))==NULL ) return OP_FAILURE; return this->setMacKeyC2S(key); } /* End of generateMacKeyC2S() */ /** Set key for S->C MAC computation (NEP_KEY_MAC_S2C) */ int NEPContext::setMacKeyS2C(u8 *key){ if(key==NULL) return OP_FAILURE; else memcpy(this->nep_key_mac_s2c, key, MAC_KEY_LEN); return OP_SUCCESS; } /* End of setMacKeyS2C() */ /** Returns NEP_KEY_MAC_S2C key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getMacKeyS2C(size_t *final_len){ if(final_len!=NULL) *final_len=MAC_KEY_LEN; return this->nep_key_mac_s2c; } /* End of getMacKeyS2C() */ /** Returns NEP_KEY_MAC_S2C key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getMacKeyS2C(){ return this->getMacKeyS2C(NULL); } /* End of getMacKeyS2C() */ int NEPContext::generateMacKeyS2C(){ u8 *key=NULL; size_t len=0; if( (key=this->generateKey(MAC_KEY_S2C, &len))==NULL ) return OP_FAILURE; return this->setMacKeyS2C(key); } /* End of generateMacKeyS2C() */ int NEPContext::generateMacKeyS2CInitial(){ u8 *key=NULL; size_t len=0; if( (key=this->generateKey(MAC_KEY_S2C_INITIAL, &len))==NULL ) return OP_FAILURE; return this->setMacKeyS2C(key); } /* End of generateMacKeyS2CInitial() */ /** Set cipher key for C->S ciphertext (NEP_KEY_CIPHERTEXT_C2S) */ int NEPContext::setCipherKeyC2S(u8 *key){ if(key==NULL) return OP_FAILURE; else memcpy(this->nep_key_ciphertext_c2s, key, CIPHER_KEY_LEN); return OP_SUCCESS; } /* End of setCipherKeyC2S() */ /** Returns NEP_KEY_CIPHERTEXT_C2S key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getCipherKeyC2S(size_t *final_len){ if(final_len!=NULL) *final_len=MAC_KEY_LEN; return this->nep_key_ciphertext_c2s; } /* End of getCipherKeyC2S() */ /** Returns NEP_KEY_CIPHERTEXT_C2S key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getCipherKeyC2S(){ return this->getCipherKeyC2S(NULL); } /* End of getCipherKeyC2S() */ int NEPContext::generateCipherKeyC2S(){ u8 *key=NULL; size_t len=0; if( (key=this->generateKey(CIPHER_KEY_C2S, &len))==NULL ) return OP_FAILURE; return this->setCipherKeyC2S(key); } /* End of generateCipherKeyC2S() */ /** Set cipher key for S->C ciphertext (NEP_KEY_CIPHERTEXT_S2C) */ int NEPContext::setCipherKeyS2C(u8 *key){ if(key==NULL) return OP_FAILURE; else memcpy(this->nep_key_ciphertext_s2c, key, CIPHER_KEY_LEN); return OP_SUCCESS; } /* End of setCipherKeyS2C() */ /** Returns NEP_KEY_CIPHERTEXT_S2C key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getCipherKeyS2C(size_t *final_len){ if(final_len!=NULL) *final_len=CIPHER_KEY_LEN; return this->nep_key_ciphertext_s2c; } /* End of getCipherKeyS2C() */ /** Returns NEP_KEY_CIPHERTEXT_S2C key. If final_len is not NULL, key length * is stored in it. */ u8 *NEPContext::getCipherKeyS2C(){ return this->getCipherKeyS2C(NULL); } /* End of getCipherKeyS2C() */ int NEPContext::generateCipherKeyS2C(){ u8 *key=NULL; size_t len=0; if( (key=this->generateKey(CIPHER_KEY_S2C, &len))==NULL ) return OP_FAILURE; return this->setCipherKeyS2C(key); } /* End of generateCipherKeyS2C() */ /** Generates a random nonce which is, if possible, cryptographically secure. * This method is used by the Echo client to generate its own nonce for the * initial NEP_HANDSHAKE_CLIENT message */ int NEPContext::generateClientNonce(){ return Crypto::generateNonce(this->client_nonce, NONCE_LEN); } /* End of generateClientNonce() */ /** Generates a random nonce which is, if possible, cryptographically secure. * This method is used by the Echo server to generate its own nonce for the * initial NEP_HANDSHAKE_SERVER message */ int NEPContext::generateServerNonce(){ return Crypto::generateNonce(this->server_nonce, NONCE_LEN); } /* End of generateServerNonce() */ /** This method is used by the Echo server to store the initial nonce received * from the client. */ int NEPContext::setClientNonce(u8 *buff){ if(buff==NULL) return OP_FAILURE; else{ memcpy(this->client_nonce, buff, NONCE_LEN); this->client_nonce_set=true; } return OP_SUCCESS; } /* End of setClientNonce() */ /** This method is used by the Echo client to store the initial nonce received * from the server. */ int NEPContext::setServerNonce(u8 *buff){ if(buff==NULL) return OP_FAILURE; else{ memcpy(this->server_nonce, buff, NONCE_LEN); this->server_nonce_set=true; } return OP_SUCCESS; } /* End of setServerNonce() */ u8 *NEPContext::getClientNonce(){ return this->client_nonce; } /* End of getClientNonce() */ u8 *NEPContext::getServerNonce(){ return this->server_nonce; } /* End of getServerNonce() */ /** Adds a field specifier, received from the client in a NEP_PACKET_SPEC * message. */ int NEPContext::addClientFieldSpec(u8 field, u8 len, u8 *value){ fspec_t t; if(value==NULL){ return OP_FAILURE; }else{ t.field=field; t.len=MIN(len, PACKETSPEC_FIELD_LEN); memcpy(t.value, value, t.len); this->fspecs.push_back(t); } return OP_SUCCESS; } /* End of addClientFieldSpec() */ /** Returns a pointer to the N-th client's field specifier. Callers should start * passing 0 and then incrementing the index by one until it returns NULL */ fspec_t *NEPContext::getClientFieldSpec(int index){ if(index<0 || index>=(int)this->fspecs.size() ) return NULL; else return &(this->fspecs[index]); } /* End of getClientFieldSpec() */ /** Returns true if we already have a packet spec of the same type. This * method should be called for EVERY spec in a NEP_PACKET_SPEC message, to * ensure that malicious clients are not supplying the same spec repeatedly * to increase their packet score. */ bool NEPContext::isDuplicateFieldSpec(u8 test_field){ int i=0; fspec_t *spec=NULL; /* Iterate through the list of stored specs and determine if we already have a spec of the same type. */ while( (spec=this->getClientFieldSpec(i++))!=NULL ){ if(spec->field==test_field) return true; } return false; } /* End of isDuplicateFieldSpect() */ /** Deletes all previous field specifiers. This should be used when dealing * with clients that send multiple NEP_PACKET_SPEC messages, so only the last * PacketSpec is taken into account. */ int NEPContext::resetClientFieldSpecs(){ this->fspecs.empty(); return OP_SUCCESS; } /* End of resetClientFieldSpecs() */