diff options
Diffstat (limited to 'ct_servmgmt.c')
| -rw-r--r-- | ct_servmgmt.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/ct_servmgmt.c b/ct_servmgmt.c new file mode 100644 index 0000000..a63eb57 --- /dev/null +++ b/ct_servmgmt.c @@ -0,0 +1,278 @@ +/* + * netsniff-ng - the packet sniffing beast + * Copyright 2011 Daniel Borkmann. + * Subject to the GPL, version 2. + */ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <limits.h> +#include <syslog.h> + +#include "die.h" +#include "built_in.h" +#include "locking.h" +#include "xmalloc.h" +#include "curvetun.h" +#include "xutils.h" +#include "curve.h" +#include "ct_servmgmt.h" +#include "crypto_box_curve25519xsalsa20poly1305.h" +#include "crypto_auth_hmacsha512256.h" + +#define crypto_box_pub_key_size crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES + +/* Config line format: alias;serverip|servername;port;udp|tcp;pubkey\n */ + +struct server_store { + int udp; + char alias[256]; + char host[256]; + char port[6]; /* 5 + \0 */ + unsigned char publickey[crypto_box_pub_key_size]; + struct curve25519_proto proto_inf; + unsigned char auth_token[crypto_auth_hmacsha512256_KEYBYTES]; + struct server_store *next; +}; + +static struct server_store *store = NULL; +static struct server_store *selected = NULL; +static struct rwlock store_lock; + +static struct server_store *server_store_alloc(void) +{ + return xzmalloc(sizeof(struct server_store)); +} + +static void server_store_free(struct server_store *ss) +{ + if (!ss) + return; + memset(ss, 0, sizeof(struct server_store)); + xfree(ss); +} + +enum parse_states { + PARSE_ALIAS, + PARSE_SERVER, + PARSE_PORT, + PARSE_CARRIER, + PARSE_PUBKEY, + PARSE_DONE, +}; + +static int parse_line(char *line, char *homedir) +{ + int ret; + char *str; + enum parse_states s = PARSE_ALIAS; + struct server_store *elem; + unsigned char pkey[crypto_box_pub_key_size]; + + elem = server_store_alloc(); + elem->next = store; + + str = strtok(line, ";"); + for (; str != NULL;) { + switch (s) { + case PARSE_ALIAS: + strlcpy(elem->alias, str, sizeof(elem->alias)); + s = PARSE_SERVER; + break; + case PARSE_SERVER: + strlcpy(elem->host, str, sizeof(elem->host)); + s = PARSE_PORT; + break; + case PARSE_PORT: + strlcpy(elem->port, str, sizeof(elem->port)); + s = PARSE_CARRIER; + break; + case PARSE_CARRIER: + if (!strncmp("udp", str, strlen("udp"))) + elem->udp = 1; + else if (!strncmp("tcp", str, strlen("tcp"))) + elem->udp = 0; + else { + syslog(LOG_ERR, "Incorrect carrier type !(udp|tcp) in server spec.\n"); + return -EIO; + } + s = PARSE_PUBKEY; + break; + case PARSE_PUBKEY: + if (!curve25519_pubkey_hexparse_32(pkey, sizeof(pkey), + str, strlen(str))) + return -EINVAL; + memcpy(elem->publickey, pkey, sizeof(elem->publickey)); + memcpy(elem->auth_token, pkey, sizeof(elem->auth_token)); + ret = curve25519_proto_init(&elem->proto_inf, + elem->publickey, + sizeof(elem->publickey), + homedir, 1); + if (ret) + return -EIO; + s = PARSE_DONE; + break; + case PARSE_DONE: + break; + default: + return -EIO; + } + + str = strtok(NULL, ";"); + } + + store = elem; + return s == PARSE_DONE ? 0 : -EIO; +} + +void parse_userfile_and_generate_serv_store_or_die(char *homedir) +{ + FILE *fp; + char path[PATH_MAX], buff[1024]; + int line = 1, ret; + + memset(path, 0, sizeof(path)); + slprintf(path, sizeof(path), "%s/%s", homedir, FILE_SERVERS); + + rwlock_init(&store_lock); + rwlock_wr_lock(&store_lock); + + fp = fopen(path, "r"); + if (!fp) + panic("Cannot open server file!\n"); + + memset(buff, 0, sizeof(buff)); + while (fgets(buff, sizeof(buff), fp) != NULL) { + buff[sizeof(buff) - 1] = 0; + /* A comment. Skip this line */ + if (buff[0] == '#' || buff[0] == '\n') { + memset(buff, 0, sizeof(buff)); + line++; + continue; + } + + ret = parse_line(buff, homedir); + if (ret < 0) + panic("Cannot parse line %d from clients!\n", line); + line++; + memset(buff, 0, sizeof(buff)); + } + + fclose(fp); + + if (store == NULL) + panic("No registered servers found!\n"); + + rwlock_unlock(&store_lock); +} + +void dump_serv_store(void) +{ + int i; + struct server_store *elem; + + rwlock_rd_lock(&store_lock); + elem = store; + while (elem) { + printf("[%s] -> %s:%s via %s -> ", elem->alias, + elem->host, elem->port, + elem->udp ? "udp" : "tcp"); + for (i = 0; i < sizeof(elem->publickey); ++i) + if (i == (sizeof(elem->publickey) - 1)) + printf("%02x\n", (unsigned char) + elem->publickey[i]); + else + printf("%02x:", (unsigned char) + elem->publickey[i]); + elem = elem->next; + } + rwlock_unlock(&store_lock); +} + +void destroy_serv_store(void) +{ + struct server_store *elem, *nelem = NULL; + + rwlock_wr_lock(&store_lock); + selected = NULL; + elem = store; + while (elem) { + nelem = elem->next; + elem->next = NULL; + server_store_free(elem); + elem = nelem; + } + rwlock_unlock(&store_lock); + rwlock_destroy(&store_lock); +} + +void get_serv_store_entry_by_alias(char *alias, size_t len, + char **host, char **port, int *udp) +{ + struct server_store *elem; + + rwlock_rd_lock(&store_lock); + elem = store; + if (!alias) { + while (elem && elem->next) + elem = elem->next; + if (elem) { + (*host) = elem->host; + (*port) = elem->port; + (*udp) = elem->udp; + selected = elem; + } else { + rwlock_unlock(&store_lock); + goto nothing; + } + } else { + while (elem) { + if (!strncmp(elem->alias, alias, + min(len, strlen(elem->alias) + 1))) + break; + elem = elem->next; + } + if (elem) { + (*host) = elem->host; + (*port) = elem->port; + (*udp) = elem->udp; + selected = elem; + } else { + rwlock_unlock(&store_lock); + goto nothing; + } + } + rwlock_unlock(&store_lock); + + return; +nothing: + (*host) = NULL; + (*port) = NULL; + (*udp) = -1; +} + +struct curve25519_proto *get_serv_store_entry_proto_inf(void) +{ + struct curve25519_proto *ret = NULL; + + rwlock_rd_lock(&store_lock); + if (selected) + ret = &selected->proto_inf; + rwlock_unlock(&store_lock); + + return ret; +} + +unsigned char *get_serv_store_entry_auth_token(void) +{ + unsigned char *ret = NULL; + + rwlock_rd_lock(&store_lock); + if (selected) + ret = selected->auth_token; + rwlock_unlock(&store_lock); + + return ret; +} |