/***************************************************************************
* NEPContext.cc -- *
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#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() */