Move EVP functionality to a new file

1 files changed, 104 insertions, 0 deletions

diff --git a/lib/crypto/c_src/evp.c b/lib/crypto/c_src/evp.c
new file mode 100644
index 0000000000..d06521c121
--- /dev/null
+++ b/lib/crypto/c_src/evp.c
@@ -0,0 +1,104 @@
+#include "evp.h"
+
+ERL_NIF_TERM evp_compute_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+    /*    (Curve, PeerBin, MyBin) */
+{
+#ifdef HAVE_ED_CURVE_DH
+    int type;
+    EVP_PKEY_CTX *ctx = NULL;
+    ErlNifBinary peer_bin, my_bin, key_bin;
+    EVP_PKEY *peer_key = NULL, *my_key = NULL;
+    size_t max_size;
+
+    if (argv[0] == atom_x25519) type = EVP_PKEY_X25519;
+    else if (argv[0] == atom_x448) type = EVP_PKEY_X448;
+    else return enif_make_badarg(env);
+
+    if (!enif_inspect_binary(env, argv[1], &peer_bin) ||
+        !enif_inspect_binary(env, argv[2], &my_bin)) 
+        goto return_badarg;
+
+    if (!(my_key = EVP_PKEY_new_raw_private_key(type, NULL, my_bin.data, my_bin.size)) ||
+        !(ctx = EVP_PKEY_CTX_new(my_key, NULL))) 
+        goto return_badarg;
+
+    if (!EVP_PKEY_derive_init(ctx)) 
+        goto return_badarg;
+
+    if (!(peer_key = EVP_PKEY_new_raw_public_key(type, NULL, peer_bin.data, peer_bin.size)) ||
+        !EVP_PKEY_derive_set_peer(ctx, peer_key)) 
+        goto return_badarg;
+
+    if (!EVP_PKEY_derive(ctx, NULL, &max_size)) 
+        goto return_badarg;
+
+    if (!enif_alloc_binary(max_size, &key_bin) ||
+        !EVP_PKEY_derive(ctx, key_bin.data, &key_bin.size)) 
+        goto return_badarg;
+
+    if (key_bin.size < max_size) {
+        size_t actual_size = key_bin.size;
+        if (!enif_realloc_binary(&key_bin, actual_size)) 
+            goto return_badarg;
+    }
+
+    EVP_PKEY_free(my_key);
+    EVP_PKEY_free(peer_key);
+    EVP_PKEY_CTX_free(ctx);
+    return enif_make_binary(env, &key_bin);
+
+return_badarg:
+    if (my_key)   EVP_PKEY_free(my_key);
+    if (peer_key) EVP_PKEY_free(peer_key);
+    if (ctx)      EVP_PKEY_CTX_free(ctx);
+    return enif_make_badarg(env);
+#else
+    return atom_notsup;
+#endif
+}
+
+ERL_NIF_TERM evp_generate_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+/* (Curve) */
+{
+#ifdef HAVE_ED_CURVE_DH
+    int type;
+    EVP_PKEY_CTX *ctx = NULL;
+    EVP_PKEY *pkey = NULL;
+    ERL_NIF_TERM ret_pub, ret_prv;
+    size_t key_len;
+
+    if (argv[0] == atom_x25519) type = EVP_PKEY_X25519;
+    else if (argv[0] == atom_x448) type = EVP_PKEY_X448;
+    else return enif_make_badarg(env);
+
+    if (!(ctx = EVP_PKEY_CTX_new_id(type, NULL))) return enif_make_badarg(env);
+
+    if (!EVP_PKEY_keygen_init(ctx)) goto return_error;
+    if (!EVP_PKEY_keygen(ctx, &pkey)) goto return_error;
+
+    if (!EVP_PKEY_get_raw_public_key(pkey, NULL, &key_len)) goto return_error;
+    if (!EVP_PKEY_get_raw_public_key(pkey,
+                                     enif_make_new_binary(env, key_len, &ret_pub),
+                                     &key_len))
+        goto return_error;
+
+    if (!EVP_PKEY_get_raw_private_key(pkey, NULL, &key_len)) goto return_error;
+    if (!EVP_PKEY_get_raw_private_key(pkey,
+                                      enif_make_new_binary(env, key_len, &ret_prv),
+                                      &key_len))
+        goto return_error;
+
+    EVP_PKEY_free(pkey);
+    EVP_PKEY_CTX_free(ctx);
+    return enif_make_tuple2(env, ret_pub, ret_prv);
+
+return_error:
+    if (pkey) EVP_PKEY_free(pkey);
+    if (ctx)  EVP_PKEY_CTX_free(ctx);
+    return atom_error;
+
+#else
+    return atom_notsup;
+#endif
+}
+