lib-dcrypt: Implement dcrypt_key_get_curve_public using openssl

diff --git a/src/lib-dcrypt/dcrypt-openssl.c b/src/lib-dcrypt/dcrypt-openssl.c
index fea216fd0580339165f18611e396294f4330db6c..73981ce46496097a4fa4d2ce95be259faccb2b27 100644 (file)
--- a/src/lib-dcrypt/dcrypt-openssl.c
+++ b/src/lib-dcrypt/dcrypt-openssl.c
@@ -2715,6 +2715,35 @@ dcrypt_openssl_key_load_public_raw(struct dcrypt_public_key **key_r,
        return FALSE;
 }
 
+static bool
+dcrypt_openssl_key_get_curve_public(struct dcrypt_public_key *key,
+                                   const char **curve_r, const char **error_r)
+{
+       EVP_PKEY *pkey = key->key;
+       char objtxt[OID_TEXT_MAX_LEN];
+
+       if (EVP_PKEY_base_id(pkey) != EVP_PKEY_EC) {
+               *error_r = "Unsupported key type";
+               return FALSE;
+       }
+
+       ASN1_OBJECT *obj = OBJ_nid2obj(EC_GROUP_get_curve_name(
+                               EC_KEY_get0_group(EVP_PKEY_get0_EC_KEY(pkey))));
+
+       int len = OBJ_obj2txt(objtxt, sizeof(objtxt), obj, 1);
+       ASN1_OBJECT_free(obj);
+
+       if (len < 1) {
+               return dcrypt_openssl_error(error_r);
+       } else if ((unsigned int)len > sizeof(objtxt)) {
+               *error_r = "Object name too long";
+               return FALSE;
+       }
+
+       *curve_r = t_strndup(objtxt, len);
+       return TRUE;
+}
+
 static struct dcrypt_vfs dcrypt_openssl_vfs = {
        .initialize = dcrypt_openssl_initialize,
        .ctx_sym_create = dcrypt_openssl_ctx_sym_create,
@@ -2773,6 +2802,7 @@ static struct dcrypt_vfs dcrypt_openssl_vfs = {
        .key_store_public_raw = dcrypt_openssl_key_store_public_raw,
        .key_load_private_raw = dcrypt_openssl_key_load_private_raw,
        .key_load_public_raw = dcrypt_openssl_key_load_public_raw,
+       .key_get_curve_public = dcrypt_openssl_key_get_curve_public,
 };
 
 void dcrypt_openssl_init(struct module *module ATTR_UNUSED)