Revamp chacha20_stream_crypt()

* Check return values on all OpenSSL and Erlang calls.
* Remove trailing semicolon after function definition.

1 files changed, 33 insertions, 12 deletions

diff --git a/lib/crypto/c_src/chacha20.c b/lib/crypto/c_src/chacha20.c
index 587c0cea53..03b8589524 100644
--- a/lib/crypto/c_src/chacha20.c
+++ b/lib/crypto/c_src/chacha20.c
@@ -74,28 +74,49 @@ ERL_NIF_TERM chacha20_stream_init(ErlNifEnv* env, int argc, const ERL_NIF_TERM a
 ERL_NIF_TERM chacha20_stream_crypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {/* (State, Data) */
 #if defined(HAVE_CHACHA20)
-    struct evp_cipher_ctx *ctx, *new_ctx;
+    struct evp_cipher_ctx *ctx = NULL, *new_ctx = NULL;
     ErlNifBinary   data_bin;
     ERL_NIF_TERM   ret, cipher_term;
     unsigned char  *out;
     int            outl = 0;
 
-    if (!enif_get_resource(env, argv[0], evp_cipher_ctx_rtype, (void**)&ctx)
-        || !enif_inspect_iolist_as_binary(env, argv[1], &data_bin)) {
-        return enif_make_badarg(env);
-    }
-    new_ctx = enif_alloc_resource(evp_cipher_ctx_rtype, sizeof(struct evp_cipher_ctx));
-    new_ctx->ctx = EVP_CIPHER_CTX_new();
-    EVP_CIPHER_CTX_copy(new_ctx->ctx, ctx->ctx);
-    out = enif_make_new_binary(env, data_bin.size, &cipher_term);
-    EVP_CipherUpdate(new_ctx->ctx, out, &outl, data_bin.data, data_bin.size);
+    if (argc != 2)
+        goto bad_arg;
+    if (!enif_get_resource(env, argv[0], evp_cipher_ctx_rtype, (void**)&ctx))
+        goto bad_arg;
+    if (!enif_inspect_iolist_as_binary(env, argv[1], &data_bin))
+        goto bad_arg;
+    if (data_bin.size > INT_MAX)
+        goto bad_arg;
+
+    if ((new_ctx = enif_alloc_resource(evp_cipher_ctx_rtype, sizeof(struct evp_cipher_ctx))) == NULL)
+        goto err;
+    if ((new_ctx->ctx = EVP_CIPHER_CTX_new()) == NULL)
+        goto err;
+
+    if (EVP_CIPHER_CTX_copy(new_ctx->ctx, ctx->ctx) != 1)
+        goto err;
+    if ((out = enif_make_new_binary(env, data_bin.size, &cipher_term)) == NULL)
+        goto err;
+    if (EVP_CipherUpdate(new_ctx->ctx, out, &outl, data_bin.data, (int)data_bin.size) != 1)
+        goto err;
     ASSERT(outl == data_bin.size);
 
     ret = enif_make_tuple2(env, enif_make_resource(env, new_ctx), cipher_term);
+    CONSUME_REDS(env, data_bin);
+    goto done;
+
+ bad_arg:
+    return enif_make_badarg(env);
+
+ err:
+    ret = enif_make_badarg(env);
+
+ done:
     enif_release_resource(new_ctx);
-    CONSUME_REDS(env,data_bin);
     return ret;
+
 #else
     return enif_raise_exception(env, atom_notsup);
 #endif
-};
+}