X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/e4a509b8174c8b2cfc0a084b78c9c7b7d08b624b..ef13e9a46baaa347014ac236f36a2536f055b108:/key-data.c

diff --git a/key-data.c b/key-data.c
index 8bb9099..a0644a1 100644
--- a/key-data.c
+++ b/key-data.c
@@ -43,114 +43,231 @@
 #include "mp.h"
 #include "mptext.h"
 
+/*----- Reference counting stuff ------------------------------------------*/
+
+/* --- @key_incref@ --- *
+ *
+ * Arguments:	@key_data *k@ = pointer to key data
+ *
+ * Returns:	---
+ *
+ * Use:		Increments the refcount on a key data block.
+ */
+
+void key_incref(key_data *k) { KEY_INCREF(k); }
+
+/* --- @key_destroy@ --- *
+ *
+ * Arguments:	@key_data *k@ = pointer to key data to destroy
+ *
+ * Returns:	---
+ *
+ * Use:		Destroys a block of key data, regardless of reference count.
+ *		Don't use this unless you know what you're doing.
+ */
+
+void key_destroy(key_data *k)
+{
+  switch (k->e & KF_ENCMASK) {
+    case KENC_BINARY:
+    case KENC_ENCRYPT:
+      if (k->u.k.k) {
+	if (k->e & KF_BURN)
+	  memset(k->u.k.k, 0, k->u.k.sz);
+	sub_free(k->u.k.k, k->u.k.sz);
+      }
+      break;
+    case KENC_MP:
+      mp_drop(k->u.m);
+      break;
+    case KENC_STRING:
+      xfree(k->u.p);
+      break;
+    case KENC_EC:
+      EC_DESTROY(&k->u.e);
+      break;
+    case KENC_STRUCT: {
+      key_data *kd;
+      key_subkeyiter i;
+
+      for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, 0, &kd); )
+	KEY_DROP(kd);
+      sym_destroy(&k->u.s);
+    } break;
+    default:
+      abort();
+  }
+  DESTROY(k);
+}
+
+/* --- @key_drop@ --- *
+ *
+ * Arguments:	@key_data *k@ = pointer to key data to destroy
+ *
+ * Returns:	---
+ *
+ * Use:		Drops a reference to key data, destroying it if necessary.
+ */
+
+void key_drop(key_data *k) { KEY_DROP(k); }
+
+/* --- @key_split@ --- *
+ *
+ * Arguments:	@key_data **kk@ = address of pointer to key data block
+ *
+ * Returns:	---
+ *
+ * Use:		Replaces @*kk@ with a pointer to the same key data, but with
+ *		just one reference.
+ */
+
+void key_split(key_data **kk)
+{
+  key_data *k = *kk;
+  
+  if (k->ref == 1)
+    return;
+  switch (k->e & KF_ENCMASK) {
+    case KENC_BINARY:
+      *kk = key_newbinary(k->e, k->u.k.k, k->u.k.sz);
+      break;
+    case KENC_ENCRYPT:
+      *kk = key_newencrypted(k->e, k->u.k.k, k->u.k.sz);
+      break;
+    case KENC_MP:
+      *kk = key_newmp(k->e, k->u.m);
+      break;
+    case KENC_STRING:
+      *kk = key_newstring(k->e, k->u.p);
+      break;
+    case KENC_EC:
+      *kk = key_newec(k->e, &k->u.e);
+      break;
+    case KENC_STRUCT: {
+      key_subkeyiter i;
+      const char *tag;
+      key_data *kd;
+
+      *kk = key_newstruct();
+      for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &kd); )
+	key_structset(*kk, tag, kd);
+    } break;
+    default:
+      abort();
+  }
+}
+
 /*----- Setting new values ------------------------------------------------*/
 
-/* --- @key_binary@ --- *
+/* --- @key_newraw@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
+ * Arguments:	@unsigned e@ = encoding type to set
+ *
+ * Returns:	New key block, not filled in.
+ */
+
+key_data *key_newraw(unsigned e)
+{
+  key_data *k = CREATE(key_data);
+  k->e = e;
+  k->ref = 1;
+  return (k);
+}
+
+/* --- @key_newbinary@ --- *
+ *
+ * Arguments:	@unsigned e@ = other encoding flags
  *		@const void *p@ = pointer to key data
  *		@size_t sz@ = size of the key data
  *
- * Returns:	---
- *
- * Use:		Sets a binary key in a key data block.
+ * Returns:	New key data object.
  */
 
-void key_binary(key_data *k, const void *p, size_t sz)
+key_data *key_newbinary(unsigned e, const void *p, size_t sz)
 {
-  key_destroy(k);
-  k->e |= KENC_BINARY;
+  key_data *k = key_newraw(KENC_BINARY | e);
   k->u.k.k = sub_alloc(sz);
   memcpy(k->u.k.k, p, sz);
   k->u.k.sz = sz;
+  return (k);
 }
 
-/* --- @key_encrypted@ --- *
+/* --- @key_newencrypted@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
+ * Arguments:	@unsigned e@ = other encoding flags
  *		@const void *p@ = pointer to key data
  *		@size_t sz@ = size of the key data
  *
- * Returns:	---
- *
- * Use:		Sets an encrypted key in a key data block.
+ * Returns:	New key data object.
  */
 
-void key_encrypted(key_data *k, const void *p, size_t sz)
+key_data *key_newencrypted(unsigned e, const void *p, size_t sz)
 {
-  key_destroy(k);
-  k->e |= KENC_ENCRYPT;
+  key_data *k = key_newraw(KENC_ENCRYPT | e);
   k->u.k.k = sub_alloc(sz);
   memcpy(k->u.k.k, p, sz);
   k->u.k.sz = sz;
+  return (k);
 }
 
-/* --- @key_mp@ --- *
+/* --- @key_mewmp@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
+ * Arguments:	@unsigned e@ = other encoding flags
  *		@mp *m@ = pointer to the value to set
  *
- * Returns:	---
- *
- * Use:		Sets a multiprecision integer key in a key block.
+ * Returns:	New key data object.
  */
 
-void key_mp(key_data *k, mp *m)
+key_data *key_newmp(unsigned e, mp *m)
 {
-  key_destroy(k);
-  k->e |= KENC_MP;
+  key_data *k = key_newraw(KENC_MP | e);
   k->u.m = MP_COPY(m);
+  return (k);
 }
 
-/* --- @key_string@ --- *
+/* --- @key_newstring@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
+ * Arguments:	@unsigned e@ = other encoding flags
  *		@const char *p@ = pointer to the value to set
  *
- * Returns:	---
- *
- * Use:		Sets a plain string in a key block.
+ * Returns:	New key data object.
  */
 
-void key_string(key_data *k, const char *p)
+key_data *key_newstring(unsigned e, const char *p)
 {
-  key_destroy(k);
-  k->e |= KENC_STRING;
+  key_data *k = key_newraw(KENC_STRING | e);
   k->u.p = xstrdup(p);
+  return (k);
 }
 
-/* --- @key_ec@ --- *
+/* --- @key_newec@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
- *		@const ec *e@ = pointer to the value to set
+ * Arguments:	@unsigned e@ = other encoding flags
+ *		@const ec *pt@ = pointer to the value to set
  *
- * Returns:	---
- *
- * Use:		Sets an elliptic curve point in a key block.
+ * Returns:	New key data object.
  */
 
-void key_ec(key_data *k, const ec *e)
-{ 
-  key_destroy(k);
-  k->e |= KENC_EC;
+key_data *key_newec(unsigned e, const ec *pt)
+{
+  key_data *k = key_newraw(KENC_EC | e);
   EC_CREATE(&k->u.e);
-  EC_COPY(&k->u.e, e);
+  EC_COPY(&k->u.e, pt);
+  return (k);
 }
 
-/* --- @key_structure@ --- *
+/* --- @key_newstruct@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
- *
- * Returns:	---
+ * Arguments:	---
  *
- * Use:		Initializes a structured key type.
+ * Returns:	New key data object.
  */
 
-void key_structure(key_data *k)
+key_data *key_newstruct(void)
 {
-  key_destroy(k);
-  k->e |= KENC_STRUCT;
+  key_data *k = key_newraw(KENC_STRUCT);
   sym_create(&k->u.s);
+  return (k);
 }
 
 /* --- @key_structfind@ --- *
@@ -171,79 +288,86 @@ key_data *key_structfind(key_data *k, const char *tag)
   ks = sym_find(&k->u.s, tag, -1, 0, 0);
   if (!ks)
     return (0);
-  return (&ks->k);
+  return (ks->k);
 }
 
-/* --- @key_structcreate@ --- *
+/* --- @key_mksubkeyiter@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data block
- *		@const char *tag@ = pointer to tag string
+ * Arguments:	@key_subkeyiter *i@ = pointer to iterator block
+ *		@key_data *k@ = pointer to key data block
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes a subkey iterator.
+ */
+
+void key_mksubkeyiter(key_subkeyiter *i, key_data *k)
+{
+  assert(((void)"Key is not structured",
+	  (k->e & KF_ENCMASK) == KENC_STRUCT));
+  sym_mkiter(&i->i, &k->u.s);
+}
+
+/* --- @key_nextsubkey@ --- *
  *
- * Returns:	Pointer to newly created key data.
+ * Arguments:	@key_structiter *i@ = pointer to iterator block
+ *		@const char **tag@ = where to put the tag pointer, or null
+ *		@key_data **kd@ = where to put the key data pointer, or null
  *
- * Use:		Creates a new uninitialized subkey.
+ * Returns:	Nonzero if there was another item, zero if we hit the
+ *		end-stop.
+ *
+ * Use:		Collects the next subkey of a structured key.
  */
 
-key_data *key_structcreate(key_data *k, const char *tag)
+int key_nextsubkey(key_subkeyiter *i, const char **tag, key_data **kd)
 {
   key_struct *ks;
-  unsigned f;
 
-  assert(((void)"Key is not structured", k->e == KENC_STRUCT));
-  ks = sym_find(&k->u.s, tag, -1, sizeof(*ks), &f);
-  if (f)
-    key_destroy(&ks->k);
-  ks->k.e = 0;
-  ks->k.u.k.k = 0;
-  ks->k.u.k.sz = 0;
-  return (&ks->k);
+  if ((ks = sym_next(&i->i)) == 0)
+    return (0);
+  if (tag) *tag = SYM_NAME(ks);
+  if (kd) *kd = ks->k;
 }
 
-/*----- Miscellaneous operations ------------------------------------------*/
-
-/* --- @key_destroy@ --- *
+/* --- @key_structset@, @key_structsteal@ --- *
  *
- * Arguments:	@key_data *k@ = pointer to key data to destroy
+ * Arguments:	@key_data *k@ = pointer to key data block
+ *		@const char *tag@ = pointer to tag string
+ *		@key_data *kd@ = new key data to store
  *
  * Returns:	---
  *
- * Use:		Destroys a lump of key data.
+ * Use:		Creates a new subkey.  Stealing doesn't affect @kd@'s
+ *		refcount.  If @kd@ is null, the subkey is deleted.
  */
 
-void key_destroy(key_data *k)
+static void structset(key_data *k, int stealp,
+		      const char *tag, key_data *kd)
 {
-  switch (k->e & KF_ENCMASK) {
-    case KENC_BINARY:
-    case KENC_ENCRYPT:
-      if (k->u.k.k) {
-	if (k->e & KF_BURN)
-	  memset(k->u.k.k, 0, k->u.k.sz);
-	sub_free(k->u.k.k, k->u.k.sz);
-      }
-      break;
-    case KENC_MP:
-      mp_drop(k->u.m);
-      break;
-    case KENC_STRING:
-      xfree(k->u.p);
-      break;
-    case KENC_EC:
-      EC_DESTROY(&k->u.e);
-      break;
-    case KENC_STRUCT: {
-      sym_iter i;
-      key_struct *ks;
+  key_struct *ks;
+  unsigned f;
 
-      for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; )
-	key_destroy(&ks->k);
-      sym_destroy(&k->u.s);
-    } break;
-  }
-  k->e = (k->e & ~KF_ENCMASK);
-  k->u.k.k = 0;
-  k->u.k.sz = 0;
+  assert(((void)"Key is not structured", k->e == KENC_STRUCT));
+  if (!kd) {
+    ks = sym_find(&k->u.s, tag, -1, 0, 0);
+    if (ks) sym_remove(&k->u.s, ks);
+  } else {
+    ks = sym_find(&k->u.s, tag, -1, sizeof(*ks), &f);
+    if (f)
+      key_drop(ks->k);
+    if (!stealp) KEY_INCREF(kd);
+    ks->k = kd;
+  }  
 }
 
+void key_structset(key_data *k, const char *tag, key_data *kd)
+  { structset(k, 0, tag, kd); }
+void key_structsteal(key_data *k, const char *tag, key_data *kd)
+  { structset(k, 1, tag, kd); }
+
+/*----- Miscellaneous operations ------------------------------------------*/
+
 /* --- @key_do@ --- *
  *
  * Arguments:	@key_data *k@ = pointer to key data block
@@ -266,101 +390,23 @@ int key_do(key_data *k, const key_filter *kf, dstr *d,
   if ((k->e & KF_ENCMASK) != KENC_STRUCT)
     return (func(k, d, p));
   else {
-    sym_iter i;
-    key_struct *ks;
+    key_subkeyiter i;
+    const char *tag;
     size_t n = 0;
     int rc;
 
     if (d)
       n = d->len;
-    for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
+    for (key_mksubkeyiter(&i, k); key_nextsubkey(&i, &tag, &k); ) {
       if (d) {
 	d->len = n;
-	dstr_putf(d, ".%s", SYM_NAME(ks));
+	dstr_putf(d, ".%s", tag);
       }
-      if ((rc = key_do(&ks->k, kf, d, func, p)) != 0)
+      if ((rc = key_do(k, kf, d, func, p)) != 0)
 	return (rc);
     }
     return (0);
   }
 }
 
-/* --- @key_copy@ --- *
- *
- * Arguments:	@key_data *kd@ = pointer to destination data block
- *		@key_data *k@ = pointer to source data block
- *		@const key_filter *kf@ = pointer to filter block
- *
- * Returns:	Nonzero if an item was actually copied.
- *
- * Use:		Copies a chunk of key data from one place to another.
- */
-
-int key_copy(key_data *kd, key_data *k, const key_filter *kf)
-{
-  kd->e = k->e;
-
-  if (!KEY_MATCH(kd, kf))
-    return (0);
-  switch (k->e & KF_ENCMASK) {
-
-    /* --- Plain binary data --- */
-
-    case KENC_BINARY:
-    case KENC_ENCRYPT:
-      if (!k->u.k.k)
-	kd->u.k.k = 0;
-      else {
-	kd->u.k.k = sub_alloc(k->u.k.sz);
-	memcpy(kd->u.k.k, k->u.k.k, k->u.k.sz);
-      }
-      kd->u.k.sz = k->u.k.sz;
-      break;
-
-    /* --- Multiprecision integers --- */
-
-    case KENC_MP:
-      kd->u.m = MP_COPY(k->u.m);
-      break;
-
-    /* --- Strings --- */
-
-    case KENC_STRING:
-      kd->u.p = xstrdup(k->u.p);
-      break;
-
-    /* --- Elliptic curve points --- */
-
-    case KENC_EC:
-      EC_CREATE(&kd->u.e);
-      EC_COPY(&kd->u.e, &k->u.e);
-      break;
-
-    /* --- Structured key data --- */
-
-    case KENC_STRUCT: {
-      sym_iter i;
-      key_struct *ks;
-      int rc = 0;
-
-      sym_create(&kd->u.s);
-      for (sym_mkiter(&i, &k->u.s); (ks = sym_next(&i)) != 0; ) {
-	unsigned f;
-	key_struct *kks = sym_find(&kd->u.s, SYM_NAME(ks), -1,
-				   sizeof(*kks), &f);
-	assert(((void)"Duplicate subkey tags", !f));
-	if (key_copy(&kks->k, &ks->k, kf))
-	  rc = 1;
-	else
-	  sym_remove(&kd->u.s, kks);
-      }
-      if (!rc) {
-	sym_destroy(&kd->u.s);
-	return (0);
-      }
-    } break;
-  }
-  return (1);
-}
-
 /*----- That's all, folks -------------------------------------------------*/