/*************************************************************************** * NEPContext.cc -- * * * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2012 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 with the clarifications and exceptions described * * below. 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@insecure.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 "derived 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: * * o Integrates source code from Nmap * * o Reads or includes Nmap copyrighted data files, such as * * nmap-os-db or nmap-service-probes. * * o Executes Nmap and parses the results (as opposed to typical shell or * * execution-menu apps, which simply display raw Nmap output and so are * * not derivative works.) * * o Integrates/includes/aggregates Nmap into a proprietary executable * * installer, such as those produced by InstallShield. * * o Links to a library or executes a program that does any of the above * * * * The term "Nmap" should be taken to also include any portions or derived * * works of Nmap, as well as other software we distribute under this * * license such as Zenmap, Ncat, and Nping. This list is not exclusive, * * but is meant to clarify our interpretation of derived works with some * * common examples. 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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 GNU * * General Public License v2.0 for more details at * * http://www.gnu.org/licenses/gpl-2.0.html , or in the COPYING file * * included with Nmap. * * * ***************************************************************************/ #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() */