Add support for diffie-hellman-group-exchange-sha256. Tested against a

[u/mdw/putty] / ssh.c

diff --git a/ssh.c b/ssh.c
index 22cea9f..75610c6 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -705,7 +705,7 @@ struct ssh_tag {
     void *cs_comp_ctx, *sc_comp_ctx;
     const struct ssh_kex *kex;
     const struct ssh_signkey *hostkey;
-    unsigned char v2_session_id[20];
+    unsigned char v2_session_id[32];
     int v2_session_id_len;
     void *kex_ctx;
 
@@ -4994,9 +4994,9 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
        char *hostkeydata, *sigdata, *keystr, *fingerprint;
        int hostkeylen, siglen;
        void *hkey;                    /* actual host key */
-       unsigned char exchange_hash[20];
+       unsigned char exchange_hash[32];
        int n_preferred_kex;
-       const struct ssh_kex *preferred_kex[KEX_MAX];
+       const struct ssh_kexes *preferred_kex[KEX_MAX];
        int n_preferred_ciphers;
        const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
        const struct ssh_compress *preferred_comp;
@@ -5119,12 +5119,14 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
        ssh2_pkt_addstring_start(s->pktout);
        commalist_started = 0;
        for (i = 0; i < s->n_preferred_kex; i++) {
-           const struct ssh_kex *k = s->preferred_kex[i];
+           const struct ssh_kexes *k = s->preferred_kex[i];
            if (!k) continue;          /* warning flag */
-           if (commalist_started)
-               ssh2_pkt_addstring_str(s->pktout, ",");
-           ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
-           commalist_started = 1;
+           for (j = 0; j < k->nkexes; j++) {
+               if (commalist_started)
+                   ssh2_pkt_addstring_str(s->pktout, ",");
+               ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
+               commalist_started = 1;
+           }
        }
        /* List server host key algorithms. */
        ssh2_pkt_addstring_start(s->pktout);
@@ -5241,13 +5243,17 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 
        preferred = NULL;
        for (i = 0; i < s->n_preferred_kex; i++) {
-           const struct ssh_kex *k = s->preferred_kex[i];
+           const struct ssh_kexes *k = s->preferred_kex[i];
            if (!k) {
                s->warn_kex = TRUE;
            } else {
-               if (!preferred) preferred = k->name;
-               if (in_commasep_string(k->name, str, len))
-                   ssh->kex = k;
+               for (j = 0; j < k->nkexes; j++) {
+                   if (!preferred) preferred = k->list[j]->name;
+                   if (in_commasep_string(k->list[j]->name, str, len)) {
+                       ssh->kex = k->list[j];
+                       break;
+                   }
+               }
            }
            if (ssh->kex)
                break;
@@ -5528,7 +5534,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
     set_busy_status(ssh->frontend, BUSY_NOT);
 
     hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
-    if (ssh->kex == &ssh_diffiehellman_gex) {
+    if (!ssh->kex->pdata) {
        hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
        hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
        hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
@@ -5602,8 +5608,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
        assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
        memcpy(ssh->v2_session_id, s->exchange_hash,
               sizeof(s->exchange_hash));
-       assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
        ssh->v2_session_id_len = ssh->kex->hash->hlen;
+       assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
        s->got_session_id = TRUE;
     }
 
@@ -5717,7 +5723,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
      */
     freebn(s->f);
     freebn(s->K);
-    if (ssh->kex == &ssh_diffiehellman_gex) {
+    if (!ssh->kex->pdata) {
        freebn(s->g);
        freebn(s->p);
     }