crypto: Simplify asymetric key handling.

get_asymmetric_key() and free_asymmetric_key() are public because
para_server maintains a copy to the public key of each user so that
the keys need to be loaded only once. On the other hand, for private
keys (used in para_client) key allocation and freeing is performed
implicitly in priv_decrypt(), and no reference to the key is ever
returned. So the crypto API can be simplified by exposing the interface
only for public keys.

Hence this patch renames get_asymmetric_key() to get_public_key()
and drops the "private" argument. Similarly, free_asymmetric_key()
is renamed to free_public_key().

diff --git a/crypt.c b/crypt.c
index 085c0563d0afb2eb23669d4084e4f83c92ff5540..c15768a3d954c6e0489b0527bd9415432c4517aa 100644 (file)
--- a/crypt.c
+++ b/crypt.c
@@ -155,8 +155,7 @@ fail:
        return ret;
 }
 
-int get_asymmetric_key(const char *key_file, int private,
-               struct asymmetric_key **result)
+int get_public_key(const char *key_file, struct asymmetric_key **result)
 {
        struct asymmetric_key *key = NULL;
        void *map = NULL;
@@ -166,10 +165,6 @@ int get_asymmetric_key(const char *key_file, int private,
        char *cp;
 
        key = para_malloc(sizeof(*key));
-       if (private) {
-               ret = get_openssl_key(key_file, &key->rsa, LOAD_PRIVATE_KEY);
-               goto out;
-       }
        ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
        if (ret < 0)
                goto out;
@@ -210,7 +205,7 @@ out:
        return ret;
 }
 
-void free_asymmetric_key(struct asymmetric_key *key)
+void free_public_key(struct asymmetric_key *key)
 {
        if (!key)
                return;
@@ -229,9 +224,12 @@ int priv_decrypt(const char *key_file, unsigned char *outbuf,
                return ret;
        if (inlen < 0)
                return -E_RSA;
-       ret = get_asymmetric_key(key_file, LOAD_PRIVATE_KEY, &priv);
-       if (ret < 0)
+       priv = para_malloc(sizeof(*priv));
+       ret = get_openssl_key(key_file, &priv->rsa, LOAD_PRIVATE_KEY);
+       if (ret < 0) {
+               free(priv);
                return ret;
+       }
        /*
         * RSA is vulnerable to timing attacks. Generate a random blinding
         * factor to protect against this kind of attack.
@@ -245,7 +243,8 @@ int priv_decrypt(const char *key_file, unsigned char *outbuf,
        if (ret <= 0)
                ret = -E_DECRYPT;
 out:
-       free_asymmetric_key(priv);
+       RSA_free(priv->rsa);
+       free(priv);
        return ret;
 }
 

diff --git a/crypt.h b/crypt.h
index 9be7a23e6da4d6d1796d4d98da7d8280152c6c2a..6f3befdb0c637cdfa706346e5e1adff59f2bcb9f 100644 (file)
--- a/crypt.h
+++ b/crypt.h
@@ -51,22 +51,21 @@ int priv_decrypt(const char *key_file, unsigned char *outbuf,
  * Read an asymmetric key from a file.
  *
  * \param key_file The file containing the key.
- * \param private if non-zero, read the private key, otherwise the public key.
  * \param result The key structure is returned here.
  *
  * \return The size of the key on success, negative on errors.
  */
-int get_asymmetric_key(const char *key_file, int private,
-               struct asymmetric_key **result);
+int get_public_key(const char *key_file, struct asymmetric_key **result);
 
 /**
- * Deallocate an asymmetric key structure.
+ * Deallocate a public key.
  *
  * \param key Pointer to the key structure to free.
  *
- * This must be called for any key obtained by get_asymmetric_key().
+ * This should be called for keys obtained by get_public_key() if the key is no
+ * longer needed.
  */
-void free_asymmetric_key(struct asymmetric_key *key);
+void free_public_key(struct asymmetric_key *key);
 
 
 /**

diff --git a/gcrypt.c b/gcrypt.c
index ba8aadc68e6ce7f7faf4822f186c6c5d22d1718c..8bbc82f3595c5da93c37bb44e72c09080d6f27db 100644 (file)
--- a/gcrypt.c
+++ b/gcrypt.c
@@ -659,8 +659,7 @@ free_blob:
        return ret;
 }
 
-int get_asymmetric_key(const char *key_file, int private,
-               struct asymmetric_key **result)
+int get_public_key(const char *key_file, struct asymmetric_key **result)
 {
        int ret, ret2;
        void *map;
@@ -669,8 +668,6 @@ int get_asymmetric_key(const char *key_file, int private,
        gcry_sexp_t sexp;
        struct asymmetric_key *key;
 
-       if (private)
-               return get_private_key(key_file, result);
        ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
        if (ret < 0)
                return ret;
@@ -700,7 +697,7 @@ unmap:
        return ret;
 }
 
-void free_asymmetric_key(struct asymmetric_key *key)
+void free_public_key(struct asymmetric_key *key)
 {
        if (!key)
                return;
@@ -832,7 +829,8 @@ in_mpi_release:
 key_release:
        gcry_sexp_release(priv_key);
 free_key:
-       free_asymmetric_key(priv);
+       gcry_sexp_release(priv->sexp);
+       free(priv);
        return ret;
 }
 

diff --git a/user_list.c b/user_list.c
index 9c751244339c34197d52229b75b4d55e5a58a43f..23fe086f189e89b3a729aa5afe145006446371bb 100644 (file)
--- a/user_list.c
+++ b/user_list.c
@@ -48,7 +48,7 @@ static void populate_user_list(char *user_list_file)
                if (strcmp(w, "user"))
                        continue;
                PARA_DEBUG_LOG("found entry for user %s\n", n);
-               ret = get_asymmetric_key(k, LOAD_PUBLIC_KEY, &pubkey);
+               ret = get_public_key(k, &pubkey);
                if (ret < 0) {
                        PARA_NOTICE_LOG("skipping entry for user %s: %s\n", n,
                                para_strerror(-ret));
@@ -63,7 +63,7 @@ static void populate_user_list(char *user_list_file)
                if (ret <= CHALLENGE_SIZE + 2 * SESSION_KEY_LEN + 41) {
                        PARA_WARNING_LOG("public key %s too short (%d)\n",
                                k, ret);
-                       free_asymmetric_key(pubkey);
+                       free_public_key(pubkey);
                        continue;
                }
                u = para_malloc(sizeof(*u));
@@ -114,7 +114,7 @@ void init_user_list(char *user_list_file)
                list_for_each_entry_safe(u, tmp, &user_list, node) {
                        list_del(&u->node);
                        free(u->name);
-                       free_asymmetric_key(u->pubkey);
+                       free_public_key(u->pubkey);
                        free(u);
                }
        } else