123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319 |
- #include "or.h"
- /********* START VARIABLES **********/
- circuit_t *global_circuitlist=NULL;
- /********* END VARIABLES ************/
- void circuit_add(circuit_t *circ) {
- if(!global_circuitlist) { /* first one */
- global_circuitlist = circ;
- circ->next = NULL;
- } else {
- circ->next = global_circuitlist;
- global_circuitlist = circ;
- }
- }
- void circuit_remove(circuit_t *circ) {
- circuit_t *tmpcirc;
- if(!circ || !global_circuitlist)
- return;
- if(global_circuitlist == circ) {
- global_circuitlist = global_circuitlist->next;
- return;
- }
- for(tmpcirc = global_circuitlist;tmpcirc->next;tmpcirc = tmpcirc->next) {
- if(tmpcirc->next == circ) {
- tmpcirc->next = circ->next;
- return;
- }
- }
- }
- circuit_t *circuit_new(aci_t p_aci, connection_t *p_conn) {
- circuit_t *circ;
- circ = (circuit_t *)malloc(sizeof(circuit_t));
- if(!circ)
- return NULL;
- memset(circ,0,sizeof(circuit_t)); /* zero it out */
- circ->p_aci = p_aci;
- circ->p_conn = p_conn;
- circ->state = CIRCUIT_STATE_OPEN_WAIT;
- circ->onion = NULL;
- circ->onionlen=0;
- circ->recvlen=0;
- /* ACIs */
- circ->p_aci = p_aci;
- circ->n_aci = 0; /* we need to have identified the next hop to choose a correct ACI */
- circuit_add(circ);
- return circ;
- }
- void circuit_free(circuit_t *circ) {
- EVP_CIPHER_CTX_cleanup(&circ->n_ctx);
- EVP_CIPHER_CTX_cleanup(&circ->p_ctx);
- if(circ->onion)
- free(circ->onion);
- free(circ);
- }
- aci_t get_unique_aci_by_addr_port(uint32_t addr, uint16_t port, int aci_type) {
- aci_t test_aci;
- connection_t *conn;
- log(LOG_DEBUG,"get_unique_aci_by_addr_port() trying to get a unique aci");
- RAND_pseudo_bytes((unsigned char *)&test_aci, 2);
- if(aci_type == ACI_TYPE_LOWER)
- test_aci &= htons(0x00FF);
- if(aci_type == ACI_TYPE_HIGHER)
- test_aci &= htons(0xFF00);
- if(test_aci == 0)
- return get_unique_aci_by_addr_port(addr, port, aci_type); /* try again */
- conn = connection_get_by_addr_port(addr,port);
- if(!conn) /* there can't be a conflict -- no connection of that sort yet */
- return test_aci;
- if(circuit_get_by_aci_conn(test_aci, conn))
- return get_unique_aci_by_addr_port(addr, port, aci_type); /* try again */
- return test_aci;
-
- }
- int circuit_init(circuit_t *circ, int aci_type) {
- onion_layer_t *ol;
- int retval = 0;
- unsigned char digest1[20];
- unsigned char digest2[20];
- if (!circ)
- return -1;
- ol = (onion_layer_t *)circ->onion;
- if (!ol)
- return -1;
- log(LOG_DEBUG,"circuit_init(): starting");
- circ->n_addr = ol->addr;
- circ->n_port = ol->port;
- log(LOG_DEBUG,"circuit_init(): Set port to %u.",ntohs(ol->port));
- circ->p_f = ol->backf;
- log(LOG_DEBUG,"circuit_init(): Set BACKF to %u.",ol->backf);
- circ->n_f = ol->forwf;
- log(LOG_DEBUG,"circuit_init(): Set FORWF to %u.",ol->forwf);
- circ->state = CIRCUIT_STATE_OPEN;
- log(LOG_DEBUG,"circuit_init(): aci_type = %u.",aci_type);
- circ->n_aci = get_unique_aci_by_addr_port(circ->n_addr, circ->n_port, aci_type);
- log(LOG_DEBUG,"circuit_init(): Chosen ACI %u.",circ->n_aci);
- /* keys */
- SHA1(ol->keyseed,16,digest1);
- SHA1(digest1,20,digest2);
- SHA1(digest2,20,digest1);
- memcpy(circ->p_key,digest2,16);
- memcpy(circ->n_key,digest1,16);
- log(LOG_DEBUG,"circuit_init(): Computed keys.");
- /* set IVs to zero */
- memset(circ->n_iv,0,16);
- memset(circ->p_iv,0,16);
- /* initialize cipher context */
- EVP_CIPHER_CTX_init(&circ->n_ctx);
- EVP_CIPHER_CTX_init(&circ->p_ctx);
- /* initialize crypto engines */
- switch(circ->p_f)
- {
- case ONION_CIPHER_DES :
- retval = EVP_EncryptInit(&circ->p_ctx, EVP_des_ofb(), circ->p_key, circ->p_iv);
- break;
- case ONION_CIPHER_RC4 :
- retval = EVP_EncryptInit(&circ->p_ctx, EVP_rc4(), circ->p_key,circ->p_iv);
- break;
- case ONION_CIPHER_IDENTITY :
- retval = EVP_EncryptInit(&circ->p_ctx, EVP_enc_null(), circ->p_key, circ->p_iv);
- break;
- default :
- log(LOG_ERR,"Onion contains unrecognized cipher(%u) for ACI : %u.",circ->p_f,circ->n_aci);
- return -1;
- break;
- }
- if (!retval) /* EVP_EncryptInit() error */
- {
- log(LOG_ERR,"Cipher initialization failed (ACI %u).",circ->n_aci);
- EVP_CIPHER_CTX_cleanup(&circ->n_ctx);
- EVP_CIPHER_CTX_cleanup(&circ->p_ctx);
- return -1;
- }
- switch(circ->n_f)
- {
- case ONION_CIPHER_DES :
- retval = EVP_DecryptInit(&circ->n_ctx, EVP_des_ofb(), circ->n_key, circ->n_iv);
- break;
- case ONION_CIPHER_RC4 :
- retval = EVP_DecryptInit(&circ->n_ctx, EVP_rc4(), circ->n_key,circ->n_iv);
- break;
- case ONION_CIPHER_IDENTITY :
- retval = EVP_DecryptInit(&circ->n_ctx, EVP_enc_null(), circ->n_key, circ->n_iv);
- break;
- default :
- log(LOG_ERR,"Onion contains unrecognized cipher for ACI : %u.",circ->n_aci);
- return -1;
- break;
- }
- if (!retval) /* EVP_EncryptInit() error */
- {
- log(LOG_ERR,"Cipher initialization failed (ACI %u).",circ->n_aci);
- EVP_CIPHER_CTX_cleanup(&circ->n_ctx);
- EVP_CIPHER_CTX_cleanup(&circ->p_ctx);
- return -1;
- }
- log(LOG_DEBUG,"circuit_init(): Cipher initialization complete.");
- circ->expire = ol->expire;
- return 0;
- }
- circuit_t *circuit_get_by_aci_conn(aci_t aci, connection_t *conn) {
- circuit_t *circ;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn && circ->p_aci == aci)
- return circ;
- if(circ->n_conn == conn && circ->n_aci == aci)
- return circ;
- }
- return NULL;
- }
- circuit_t *circuit_get_by_conn(connection_t *conn) {
- circuit_t *circ;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn)
- return circ;
- if(circ->n_conn == conn)
- return circ;
- }
- return NULL;
- }
- int circuit_deliver_data_cell(cell_t *cell, circuit_t *circ, connection_t *conn, int crypt_type) {
- /* first decrypt cell->length */
- if(circuit_crypt(circ, &(cell->length), 1, crypt_type) < 0) {
- log(LOG_DEBUG,"circuit_deliver_data_cell(): length decryption failed. Dropping connection.");
- return -1;
- }
- /* then decrypt the payload */
- if(circuit_crypt(circ, (char *)&(cell->payload), CELL_PAYLOAD_SIZE, crypt_type) < 0) {
- log(LOG_DEBUG,"circuit_deliver_data_cell(): payload decryption failed. Dropping connection.");
- return -1;
- }
- if(conn->type == CONN_TYPE_APP) { /* send payload directly */
- log(LOG_DEBUG,"circuit_deliver_data_cell(): Sending to application.");
- if(connection_app_process_data_cell(cell, conn) < 0) {
- return -1;
- }
- } else { /* send it as a cell */
- log(LOG_DEBUG,"circuit_deliver_data_cell(): Sending to connection.");
- if(connection_write_cell_to_buf(cell, conn) < 0) {
- return -1;
- }
- }
- return 0; /* success */
- }
- int circuit_crypt(circuit_t *circ, char *in, size_t inlen, char crypt_type) {
- char *out;
- int outlen;
- if(!circ || !in)
- return -1;
- out = malloc(inlen);
- if(!out)
- return -1;
- if(crypt_type == 'e') {
- log(LOG_DEBUG,"circuit_crypt(): Encrypting %d bytes.",inlen);
- if(!EVP_EncryptUpdate(&circ->p_ctx,out,&outlen,in,inlen)) {
- log(LOG_ERR,"circuit_encrypt(): Encryption failed for ACI : %u (%s).",circ->p_aci, ERR_reason_error_string(ERR_get_error()));
- return -1;
- }
- } else if(crypt_type == 'd') {
- log(LOG_DEBUG,"circuit_crypt(): Decrypting %d bytes.",inlen);
- if(!EVP_DecryptUpdate(&circ->n_ctx,out,&outlen,in,inlen)) {
- log(LOG_ERR,"circuit_crypt(): Decryption failed for ACI : %u (%s).",circ->n_aci, ERR_reason_error_string(ERR_get_error()));
- return -1;
- }
- }
- if(outlen != inlen) {
- log(LOG_DEBUG,"circuit_crypt(): %d bytes crypted to %d bytes. Weird.",inlen,outlen);
- return -1;
- }
-
- memcpy(in,out,inlen);
- free(out);
- return 0;
- }
- void circuit_close(circuit_t *circ) {
- circuit_remove(circ);
- connection_send_destroy(circ->n_aci, circ->n_conn);
- connection_send_destroy(circ->p_aci, circ->p_conn);
- circuit_free(circ);
- }
- void circuit_about_to_close_connection(connection_t *conn) {
- /* send destroys for all circuits using conn */
- /* currently, we assume it's too late to flush conn's buf here.
- * down the road, maybe we'll consider that eof doesn't mean can't-write
- */
- circuit_t *circ;
- while((circ = circuit_get_by_conn(conn))) {
- circuit_remove(circ);
- if(circ->n_conn == conn) /* it's closing in front of us */
- connection_send_destroy(circ->p_aci, circ->p_conn);
- if(circ->p_conn == conn) /* it's closing behind us */
- connection_send_destroy(circ->n_aci, circ->n_conn);
- circuit_free(circ);
- }
- }
|