site.c, magic.h, NOTES: Make early capabilities be dynamic.

[secnet.git] / site.c

diff --git a/site.c b/site.c
index c702c7885095b009ca5bea65d259f9d778964823..3b8f34d47c8ff455a0d69bf931598093cacc6a25 100644 (file)
--- a/site.c
+++ b/site.c
@@ -318,6 +318,7 @@ struct site {
     struct hash_if *hash;
 
     uint32_t index; /* Index of this site */
+    uint32_t early_capabilities;
     uint32_t local_capabilities;
     int32_t setup_retries; /* How many times to send setup packets */
     int32_t setup_retry_interval; /* Initial timeout for setup packets */
@@ -575,7 +576,7 @@ static _Bool set_new_transform(struct site *st, char *pk)
 
     slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
         " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
-        st->chosen_transform->capab_transformnum,
+        st->chosen_transform->capab_bit,
         st->local_capabilities, st->remote_capabilities);
     return True;
 }
@@ -626,7 +627,8 @@ static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
 
     struct xinfoadd xia;
     append_string_xinfo_start(&st->buffer,&xia,st->localname);
-    if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
+    if ((st->local_capabilities & st->early_capabilities) ||
+       (type != LABEL_MSG1)) {
        buf_append_uint32(&st->buffer,st->local_capabilities);
     }
     if (type_is_msg34(type)) {
@@ -643,7 +645,7 @@ static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
     if (hacky_par_mid_failnow()) return False;
 
     if (type==LABEL_MSG3BIS)
-       buf_append_uint8(&st->buffer,st->chosen_transform->capab_transformnum);
+       buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
 
     dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
     buf_append_string(&st->buffer,dhpub);
@@ -717,7 +719,7 @@ static bool_t unpick_msg(struct site *st, uint32_t type,
        CHECK_AVAIL(msg,1);
        m->capab_transformnum = buf_unprepend_uint8(msg);
     } else {
-       m->capab_transformnum = CAPAB_TRANSFORMNUM_ANCIENT;
+       m->capab_transformnum = CAPAB_BIT_ANCIENTTRANSFORM;
     }
     CHECK_AVAIL(msg,2);
     m->pklen=buf_unprepend_uint16(msg);
@@ -767,7 +769,7 @@ static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
        return False;
     }
     if (type==LABEL_MSG2) return True;
-    if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
+    if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
        *error="wrong remotely-generated nonce";
        return False;
     }
@@ -824,25 +826,32 @@ static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
 
     /* Select the transform to use */
 
-    uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
-    if (!remote_transforms)
+    uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
+    if (!remote_crypto_caps)
        /* old secnets only had this one transform */
-       remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
+       remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
+
+#define CHOOSE_CRYPTO(kind, whats) do {                                        \
+    struct kind##_if *iface;                                           \
+    uint32_t bit, ours = 0;                                            \
+    int i;                                                             \
+    for (i= 0; i < st->n##kind##s; i++) {                              \
+       iface=st->kind##s[i];                                           \
+       bit = 1UL << iface->capab_bit;                                  \
+       if (bit & remote_crypto_caps) goto kind##_found;                \
+       ours |= bit;                                                    \
+    }                                                                  \
+    slog(st,LOG_ERROR,"no " whats " in common"                         \
+        " (us %#"PRIx32"; them: %#"PRIx32")",                          \
+        st->local_capabilities & ours, remote_crypto_caps);            \
+    return False;                                                      \
+kind##_found:                                                          \
+    st->chosen_##kind = iface;                                         \
+} while (0)
 
-    struct transform_if *ti;
-    int i;
-    for (i=0; i<st->ntransforms; i++) {
-       ti=st->transforms[i];
-       if ((1UL << ti->capab_transformnum) & remote_transforms)
-           goto transform_found;
-    }
-    slog(st,LOG_ERROR,"no transforms in common"
-        " (us %#"PRIx32"; them: %#"PRIx32")",
-        st->local_capabilities & CAPAB_TRANSFORM_MASK,
-        remote_transforms);
-    return False;
- transform_found:
-    st->chosen_transform=ti;
+    CHOOSE_CRYPTO(transform, "transforms");
+
+#undef CHOOSE_CRYPTO
 
     memcpy(st->remoteN,m.nR,NONCELEN);
     return True;
@@ -897,7 +906,7 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
        return False;
     }
     uint32_t capab_adv_late = m.remote_capabilities
-       & ~st->remote_capabilities & CAPAB_EARLY;
+       & ~st->remote_capabilities & st->early_capabilities;
     if (capab_adv_late) {
        slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
             " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
@@ -906,18 +915,24 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
     }
     st->remote_capabilities|=m.remote_capabilities;
 
-    struct transform_if *ti;
-    int i;
-    for (i=0; i<st->ntransforms; i++) {
-       ti=st->transforms[i];
-       if (ti->capab_transformnum == m.capab_transformnum)
-           goto transform_found;
-    }
-    slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
-        m.capab_transformnum);
-    return False;
- transform_found:
-    st->chosen_transform=ti;
+#define CHOSE_CRYPTO(kind, what) do {                                  \
+    struct kind##_if *iface;                                           \
+    int i;                                                             \
+    for (i=0; i<st->n##kind##s; i++) {                                 \
+       iface=st->kind##s[i];                                           \
+       if (iface->capab_bit == m.capab_##kind##num)                    \
+           goto kind##_found;                                          \
+    }                                                                  \
+    slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!",           \
+        m.capab_##kind##num);                                                  \
+    return False;                                                      \
+kind##_found:                                                          \
+    st->chosen_##kind=iface;                                           \
+} while (0)
+
+    CHOSE_CRYPTO(transform, "transform");
+
+#undef CHOSE_CRYPTO
 
     if (!process_msg3_msg4(st,&m))
        return False;
@@ -1781,8 +1796,8 @@ static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
 }
 
 static bool_t we_have_priority(struct site *st, const struct msg *m) {
-    if ((st->local_capabilities & m->remote_capabilities)
-       && CAPAB_PRIORITY_MOBILE) {
+    if (st->local_capabilities & m->remote_capabilities &
+       CAPAB_PRIORITY_MOBILE) {
        if (st->local_mobile) return True;
        if (st-> peer_mobile) return False;
     }
@@ -2112,6 +2127,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     assert(index_sequence < 0xffffffffUL);
     st->index = ++index_sequence;
     st->local_capabilities = 0;
+    st->early_capabilities = CAPAB_PRIORITY_MOBILE;
     st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
 
 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{           \
@@ -2228,14 +2244,18 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->sharedsecretlen=st->sharedsecretallocd=0;
     st->sharedsecret=0;
 
-    for (i=0; i<st->ntransforms; i++) {
-       struct transform_if *ti=st->transforms[i];
-       uint32_t capbit = 1UL << ti->capab_transformnum;
-       if (st->local_capabilities & capbit)
-           slog(st,LOG_ERROR,"transformnum capability bit"
-                " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
-       st->local_capabilities |= capbit;
-    }
+#define SET_CAPBIT(bit) do {                                           \
+    uint32_t capflag = 1UL << (bit);                                   \
+    if (st->local_capabilities & capflag)                              \
+       slog(st,LOG_ERROR,"capability bit"                              \
+            " %d (%#"PRIx32") reused", (bit), capflag);                \
+    st->local_capabilities |= capflag;                                 \
+} while (0)
+
+    for (i=0; i<st->ntransforms; i++)
+       SET_CAPBIT(st->transforms[i]->capab_bit);
+
+#undef SET_CAPBIT
 
     if (st->local_mobile || st->peer_mobile)
        st->local_capabilities |= CAPAB_PRIORITY_MOBILE;