site.c: Abstract out the various parts of capability handling.

[secnet] / site.c

diff --git a/site.c b/site.c
index d0dd909..9e877c7 100644 (file)
--- a/site.c
+++ b/site.c
@@ -575,7 +575,7 @@ 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;
 }
@@ -643,7 +643,7 @@ 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 +717,7 @@ 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);
@@ -824,25 +824,32 @@ 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;
@@ -906,18 +913,24 @@ 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;
@@ -2228,14 +2241,18 @@ 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;