Move CMAC functionality to a new file

1 files changed, 50 insertions, 0 deletions

diff --git a/lib/crypto/c_src/cmac.c b/lib/crypto/c_src/cmac.c
new file mode 100644
index 0000000000..8a9d677f58
--- /dev/null
+++ b/lib/crypto/c_src/cmac.c
@@ -0,0 +1,50 @@
+#include "cmac.h"
+#include "cipher.h"
+
+ERL_NIF_TERM cmac_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{/* (Type, Key, Data) */
+#if defined(HAVE_CMAC)
+    struct cipher_type_t *cipherp = NULL;
+    const EVP_CIPHER     *cipher;
+    CMAC_CTX             *ctx;
+    ErlNifBinary         key;
+    ErlNifBinary         data;
+    ERL_NIF_TERM         ret;
+    size_t               ret_size;
+
+    if (!enif_inspect_iolist_as_binary(env, argv[1], &key)
+        || !(cipherp = get_cipher_type(argv[0], key.size))
+        || !enif_inspect_iolist_as_binary(env, argv[2], &data)) {
+        return enif_make_badarg(env);
+    }
+    cipher = cipherp->cipher.p;
+    if (!cipher) {
+        return enif_raise_exception(env, atom_notsup);
+    }
+
+    ctx = CMAC_CTX_new();
+    if (!CMAC_Init(ctx, key.data, key.size, cipher, NULL)) {
+        CMAC_CTX_free(ctx);
+        return atom_notsup;
+    }
+
+    if (!CMAC_Update(ctx, data.data, data.size) ||
+        !CMAC_Final(ctx,
+                    enif_make_new_binary(env, EVP_CIPHER_block_size(cipher), &ret),
+                    &ret_size)) {
+        CMAC_CTX_free(ctx);
+        return atom_notsup;
+    }
+    ASSERT(ret_size == (unsigned)EVP_CIPHER_block_size(cipher));
+
+    CMAC_CTX_free(ctx);
+    CONSUME_REDS(env, data);
+    return ret;
+#else
+    /* The CMAC functionality was introduced in OpenSSL 1.0.1
+     * Although OTP requires at least version 0.9.8, the versions 0.9.8 and 1.0.0 are
+     * no longer maintained. */
+    return atom_notsup;
+#endif
+}
+