diff options
Diffstat (limited to 'kex.c')
| -rw-r--r-- | kex.c | 96 |
1 files changed, 70 insertions, 26 deletions
@@ -28,13 +28,14 @@ */ #include "includes.h" -RCSID("$Id: kex.c,v 1.8 2000/05/09 01:03:01 damien Exp $"); +RCSID("$Id: kex.c,v 1.9 2000/05/30 03:44:53 damien Exp $"); #include "ssh.h" #include "ssh2.h" #include "xmalloc.h" #include "buffer.h" #include "bufaux.h" +#include "packet.h" #include "cipher.h" #include "compat.h" @@ -49,15 +50,17 @@ RCSID("$Id: kex.c,v 1.8 2000/05/09 01:03:01 damien Exp $"); #include "kex.h" +#define KEX_COOKIE_LEN 16 + Buffer * kex_init(char *myproposal[PROPOSAL_MAX]) { - char c = 0; - unsigned char cookie[16]; + int first_kex_packet_follows = 0; + unsigned char cookie[KEX_COOKIE_LEN]; u_int32_t rand = 0; int i; Buffer *ki = xmalloc(sizeof(*ki)); - for (i = 0; i < 16; i++) { + for (i = 0; i < KEX_COOKIE_LEN; i++) { if (i % 4 == 0) rand = arc4random(); cookie[i] = rand & 0xff; @@ -67,11 +70,55 @@ kex_init(char *myproposal[PROPOSAL_MAX]) buffer_append(ki, (char *)cookie, sizeof cookie); for (i = 0; i < PROPOSAL_MAX; i++) buffer_put_cstring(ki, myproposal[i]); - buffer_append(ki, &c, 1); /* boolean first_kex_packet_follows */ - buffer_put_int(ki, 0); /* uint32 0 (reserved for future extension) */ + buffer_put_char(ki, first_kex_packet_follows); + buffer_put_int(ki, 0); /* uint32 reserved */ return ki; } +/* send kexinit, parse and save reply */ +void +kex_exchange_kexinit( + Buffer *my_kexinit, Buffer *peer_kexint, + char *peer_proposal[PROPOSAL_MAX]) +{ + int i; + char *ptr; + int plen; + + debug("send KEXINIT"); + packet_start(SSH2_MSG_KEXINIT); + packet_put_raw(buffer_ptr(my_kexinit), buffer_len(my_kexinit)); + packet_send(); + packet_write_wait(); + debug("done"); + + /* + * read and save raw KEXINIT payload in buffer. this is used during + * computation of the session_id and the session keys. + */ + debug("wait KEXINIT"); + packet_read_expect(&plen, SSH2_MSG_KEXINIT); + ptr = packet_get_raw(&plen); + buffer_append(peer_kexint, ptr, plen); + + /* parse packet and save algorithm proposal */ + /* skip cookie */ + for (i = 0; i < KEX_COOKIE_LEN; i++) + packet_get_char(); + /* extract kex init proposal strings */ + for (i = 0; i < PROPOSAL_MAX; i++) { + peer_proposal[i] = packet_get_string(NULL); + debug("got kexinit: %s", peer_proposal[i]); + } + /* first kex follow / reserved */ + i = packet_get_char(); + debug("first kex follow: %d ", i); + i = packet_get_int(); + debug("reserved: %d ", i); + packet_done(); + debug("done"); +} + /* diffie-hellman-group1-sha1 */ int @@ -134,12 +181,6 @@ dh_new_group1() } void -bignum_print(BIGNUM *b) -{ - BN_print_fp(stderr,b); -} - -void dump_digest(unsigned char *digest, int len) { int i; @@ -246,10 +287,13 @@ char * get_match(char *client, char *server) { char *sproposals[MAX_PROP]; - char *p; + char *c, *s, *p, *ret; int i, j, nproposals; - for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) { + c = xstrdup(client); + s = xstrdup(server); + + for ((p = strtok(s, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) { if (i < MAX_PROP) sproposals[i] = p; else @@ -257,11 +301,18 @@ get_match(char *client, char *server) } nproposals = i; - for ((p = strtok(client, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) { - for (j = 0; j < nproposals; j++) - if (strcmp(p, sproposals[j]) == 0) - return xstrdup(p); + for ((p = strtok(c, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) { + for (j = 0; j < nproposals; j++) { + if (strcmp(p, sproposals[j]) == 0) { + ret = xstrdup(p); + xfree(c); + xfree(s); + return ret; + } + } } + xfree(c); + xfree(s); return NULL; } void @@ -355,7 +406,6 @@ choose_hostkeyalg(Kex *k, char *client, char *server) Kex * kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server) { - int i; int mode; int ctos; /* direction: if true client-to-server */ int need; @@ -383,10 +433,6 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]); choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS], sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]); - for (i = 0; i < PROPOSAL_MAX; i++) { - xfree(cprop[i]); - xfree(sprop[i]); - } need = 0; for (mode = 0; mode < MODE_MAX; mode++) { if (need < k->enc[mode].key_len) @@ -396,9 +442,7 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server if (need < k->mac[mode].key_len) need = k->mac[mode].key_len; } - /* need runden? */ -#define WE_NEED 32 - k->we_need = WE_NEED; + /* XXX need runden? */ k->we_need = need; return k; } |