MONGOCRYPT-743 implement token _new_from_buffer_copy (#914)

* implement new_from_buffer_copy

* add test

* initialize data buffer

* initialize buffer in test

* fix formatting error

* remove original_test_input

Author: joshbsiegel

src/mc-tokens-private.h

@@ -89,8 +89,10 @@
     extern const _mongocrypt_buffer_t *BSON_CONCAT(Prefix, _get)(const T *t);                                          \
     /* Destructor */                                                                                                   \
     extern void BSON_CONCAT(Prefix, _destroy)(T * t);                                                                  \
-    /* Constructor for server to create tokens from raw buffer */                                                      \
+    /* Constructor for server to shallow copy tokens from raw buffer */                                                \
     extern T *BSON_CONCAT(Prefix, _new_from_buffer)(_mongocrypt_buffer_t * buf);                                       \
+    /* Constructor for server to deep copy tokens from raw buffer */                                                   \
+    extern T *BSON_CONCAT(Prefix, _new_from_buffer_copy)(_mongocrypt_buffer_t * buf);                                  \
     /* Constructor. Parameter list given as variadic args */                                                           \
     extern T *BSON_CONCAT(Prefix, _new)(_mongocrypt_crypto_t * crypto, __VA_ARGS__, mongocrypt_status_t * status)
 

src/mc-tokens.c

@@ -38,13 +38,21 @@
         _mongocrypt_buffer_cleanup(&self->data);                                                                       \
         bson_free(self);                                                                                               \
     }                                                                                                                  \
-    /* Constructor. From raw buffer */                                                                                 \
+    /* Constructor. Shallow copy from raw buffer */                                                                    \
     T *BSON_CONCAT(Prefix, _new_from_buffer)(_mongocrypt_buffer_t * buf) {                                             \
         BSON_ASSERT(buf->len == MONGOCRYPT_HMAC_SHA256_LEN);                                                           \
         T *t = bson_malloc(sizeof(T));                                                                                 \
         _mongocrypt_buffer_set_to(buf, &t->data);                                                                      \
         return t;                                                                                                      \
     }                                                                                                                  \
+    /* Constructor. Deep copy from raw buffer */                                                                       \
+    T *BSON_CONCAT(Prefix, _new_from_buffer_copy)(_mongocrypt_buffer_t * buf) {                                        \
+        BSON_ASSERT(buf->len == MONGOCRYPT_HMAC_SHA256_LEN);                                                           \
+        T *t = bson_malloc(sizeof(T));                                                                                 \
+        _mongocrypt_buffer_init(&t->data);                                                                             \
+        _mongocrypt_buffer_copy_to(buf, &t->data);                                                                     \
+        return t;                                                                                                      \
+    }                                                                                                                  \
     /* Constructor. Parameter list given as variadic args. */                                                          \
     T *BSON_CONCAT(Prefix, _new)(_mongocrypt_crypto_t * crypto, __VA_ARGS__, mongocrypt_status_t * status)
 

test/test-mc-tokens.c

@@ -259,31 +259,38 @@ static void _test_mc_tokens_error(_mongocrypt_tester_t *tester) {
 }
 
 static void _test_mc_tokens_raw_buffer(_mongocrypt_tester_t *tester) {
-    mc_ServerDataEncryptionLevel1Token_t *token;
+    mc_ServerDataEncryptionLevel1Token_t *token1;
+    mc_ServerDataEncryptionLevel1Token_t *token2;
     _mongocrypt_buffer_t test_input;
     _mongocrypt_buffer_t expected;
 
     _mongocrypt_buffer_copy_from_hex(&test_input, "6c6a349956c19f9c5e638e612011a71fbb71921edb540310c17cd0208b7f548b");
 
     /* Make a token from a raw buffer */
-    token = mc_ServerDataEncryptionLevel1Token_new_from_buffer(&test_input);
+    token1 = mc_ServerDataEncryptionLevel1Token_new_from_buffer(&test_input);
+    token2 = mc_ServerDataEncryptionLevel1Token_new_from_buffer_copy(&test_input);
 
     /* Assert new_from_buffer did not steal ownership. */
     ASSERT(test_input.owned);
     ASSERT(test_input.len == MONGOCRYPT_HMAC_SHA256_LEN);
 
     _mongocrypt_buffer_copy_from_hex(&expected, "6c6a349956c19f9c5e638e612011a71fbb71921edb540310c17cd0208b7f548b");
 
-    ASSERT_CMPBUF(*mc_ServerDataEncryptionLevel1Token_get(token), expected);
+    ASSERT_CMPBUF(*mc_ServerDataEncryptionLevel1Token_get(token1), expected);
+    ASSERT_CMPBUF(*mc_ServerDataEncryptionLevel1Token_get(token2), expected);
 
     /* Assert new_from_buffer references original buffer instead of a copy. */
     test_input.data[0] = '0';
     expected.data[0] = '0';
-    ASSERT_CMPBUF(*mc_ServerDataEncryptionLevel1Token_get(token), expected);
+    ASSERT_CMPBUF(*mc_ServerDataEncryptionLevel1Token_get(token1), expected);
+
+    // Assert new_from_buffer_copy references a new buffer.
+    ASSERT_CMPUINT8(mc_ServerDataEncryptionLevel1Token_get(token2)->data[0], !=, expected.data[0]);
 
     _mongocrypt_buffer_cleanup(&test_input);
     _mongocrypt_buffer_cleanup(&expected);
-    mc_ServerDataEncryptionLevel1Token_destroy(token);
+    mc_ServerDataEncryptionLevel1Token_destroy(token1);
+    mc_ServerDataEncryptionLevel1Token_destroy(token2);
 }
 
 void _mongocrypt_tester_install_mc_tokens(_mongocrypt_tester_t *tester) {