Fix EC_KEY initialization race.

Submitted by: Adam Langley

diff --git a/crypto/ec/ec.h b/crypto/ec/ec.h
index 8bc2a235b1a7576bf0cec79362b618599fab8f31..367307f9fda6c457f2eb370eed1790aabc5a92f9 100644 (file)
--- a/crypto/ec/ec.h
+++ b/crypto/ec/ec.h
@@ -321,7 +321,15 @@ void EC_KEY_set_conv_form(EC_KEY *, point_conversion_form_t);
 /* functions to set/get method specific data  */
 void *EC_KEY_get_key_method_data(EC_KEY *, 
        void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *));
-void EC_KEY_insert_key_method_data(EC_KEY *, void *data,
+/** Sets the key method data of an EC_KEY object, if none has yet been set.
+ *  \param  key              EC_KEY object
+ *  \param  data             opaque data to install.
+ *  \param  dup_func         a function that duplicates |data|.
+ *  \param  free_func        a function that frees |data|.
+ *  \param  clear_free_func  a function that wipes and frees |data|.
+ *  \return the previously set data pointer, or NULL if |data| was inserted.
+ */
+void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
        void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *));
 /* wrapper functions for the underlying EC_GROUP object */
 void EC_KEY_set_asn1_flag(EC_KEY *, int);

diff --git a/crypto/ec/ec_key.c b/crypto/ec/ec_key.c
index 522802c07ae13c3c34bb31185da508cf20077233..6c933d22ed545ae05803d338853e5fcc7aa3c659 100644 (file)
--- a/crypto/ec/ec_key.c
+++ b/crypto/ec/ec_key.c
@@ -435,18 +435,27 @@ void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 void *EC_KEY_get_key_method_data(EC_KEY *key,
        void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
        {
-       return EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
+       void *ret;
+
+       CRYPTO_r_lock(CRYPTO_LOCK_EC);
+       ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
+       CRYPTO_r_unlock(CRYPTO_LOCK_EC);
+
+       return ret;
        }
 
-void EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
+void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
        void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
        {
        EC_EXTRA_DATA *ex_data;
+
        CRYPTO_w_lock(CRYPTO_LOCK_EC);
        ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
        if (ex_data == NULL)
                EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);
        CRYPTO_w_unlock(CRYPTO_LOCK_EC);
+
+       return ex_data;
        }
 
 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)

diff --git a/crypto/ecdh/ech_lib.c b/crypto/ecdh/ech_lib.c
index bf22234778520810da9b47cf6f18246ed415d5ae..f9ba5fb57c5b5f863295927a323c11a594af146b 100644 (file)
--- a/crypto/ecdh/ech_lib.c
+++ b/crypto/ecdh/ech_lib.c
@@ -205,8 +205,15 @@ ECDH_DATA *ecdh_check(EC_KEY *key)
                ecdh_data = (ECDH_DATA *)ecdh_data_new();
                if (ecdh_data == NULL)
                        return NULL;
-               EC_KEY_insert_key_method_data(key, (void *)ecdh_data,
-                       ecdh_data_dup, ecdh_data_free, ecdh_data_free);
+               data = EC_KEY_insert_key_method_data(key, (void *)ecdh_data,
+                          ecdh_data_dup, ecdh_data_free, ecdh_data_free);
+               if (data != NULL)
+                       {
+                       /* Another thread raced us to install the key_method
+                        * data and won. */
+                       ecdh_data_free(ecdh_data);
+                       ecdh_data = (ECDH_DATA *)data;
+                       }
        }
        else
                ecdh_data = (ECDH_DATA *)data;

diff --git a/crypto/ecdsa/ecs_lib.c b/crypto/ecdsa/ecs_lib.c
index 2ebae3aa27d7fe7b563c5c41b20a0bdf3dfc7e20..81082c972726bbaafb8b3504d90ffa5feb92e295 100644 (file)
--- a/crypto/ecdsa/ecs_lib.c
+++ b/crypto/ecdsa/ecs_lib.c
@@ -188,8 +188,15 @@ ECDSA_DATA *ecdsa_check(EC_KEY *key)
                ecdsa_data = (ECDSA_DATA *)ecdsa_data_new();
                if (ecdsa_data == NULL)
                        return NULL;
-               EC_KEY_insert_key_method_data(key, (void *)ecdsa_data,
-                       ecdsa_data_dup, ecdsa_data_free, ecdsa_data_free);
+               data = EC_KEY_insert_key_method_data(key, (void *)ecdsa_data,
+                          ecdsa_data_dup, ecdsa_data_free, ecdsa_data_free);
+               if (data != NULL)
+                       {
+                       /* Another thread raced us to install the key_method
+                        * data and won. */
+                       ecdsa_data_free(ecdsa_data);
+                       ecdsa_data = (ECDSA_DATA *)data;
+                       }
        }
        else
                ecdsa_data = (ECDSA_DATA *)data;