1 files changed, 203 insertions, 0 deletions

diff --git a/src/service/reclaim/did_helper.c b/src/service/reclaim/did_helper.c
new file mode 100644
index 000000000..3aac027ee
--- /dev/null
+++ b/src/service/reclaim/did_helper.c
@@ -0,0 +1,203 @@
+/*
+   This file is part of GNUnet
+   Copyright (C) 2010-2015 GNUnet e.V.
+
+   GNUnet is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Affero General Public License as published
+   by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   GNUnet is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+   SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+/**
+ * @file reclaim/did_helper.c
+ * @brief helper library for DID related functions
+ * @author Tristan Schwieren
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_namestore_service.h"
+#include "gnunet_gns_service.h"
+#include "gnunet_gnsrecord_lib.h"
+#include "did_helper.h"
+#include "jansson.h"
+
+#define STR_INDIR(x) #x
+#define STR(x) STR_INDIR (x)
+
+/**
+ * @brief Generate a DID for a given GNUNET public key
+ *
+ * @param pkey
+ * @return char* Returns the DID. Caller must free
+ * TODO: Check if EdDSA
+ */
+char*
+DID_pkey_to_did (struct GNUNET_CRYPTO_PublicKey *pkey)
+{
+  char *pkey_str;
+  char *did_str;
+
+  pkey_str = GNUNET_CRYPTO_public_key_to_string (pkey);
+  GNUNET_asprintf (&did_str, "%s%s",
+                   GNUNET_DID_METHOD_PREFIX,
+                   pkey_str);
+
+  GNUNET_free (pkey_str);
+  return did_str;
+}
+
+/**
+ * @brief Generate a DID for a given gnunet EGO.
+ * Wrapper around GNUNET_DID_pkey_to_did
+ *
+ * @param ego
+ * @return char* Returns the DID. Caller must free
+ */
+char*
+DID_identity_to_did (struct GNUNET_IDENTITY_Ego *ego)
+{
+  struct GNUNET_CRYPTO_PublicKey pkey;
+
+  GNUNET_IDENTITY_ego_get_public_key (ego, &pkey);
+  return DID_pkey_to_did (&pkey);
+}
+
+/**
+ * @brief Return the public key of a DID
+ */
+enum GNUNET_GenericReturnValue
+DID_did_to_pkey (const char *did, struct GNUNET_CRYPTO_PublicKey *pkey)
+{
+  char pkey_str[MAX_DID_SPECIFIC_IDENTIFIER_LENGTH + 1]; /* 0-term */
+
+  if ((1 != (sscanf (did,
+                     GNUNET_DID_METHOD_PREFIX "%"
+                     STR (MAX_DID_SPECIFIC_IDENTIFIER_LENGTH)
+                     "s", pkey_str))) ||
+      (GNUNET_OK != GNUNET_CRYPTO_public_key_from_string (pkey_str, pkey)))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Could not decode given DID: %s\n",
+                did);
+    return GNUNET_NO;
+  }
+
+  return GNUNET_OK;
+}
+
+/**
+ * @brief Convert a base 64 encoded public key to a GNUNET key
+ */
+struct GNUNET_CRYPTO_PublicKey *
+GNUNET_DID_key_convert_multibase_base64_to_gnunet (char *pkey_str)
+{
+  return NULL;
+}
+
+/**
+ * @brief Convert GNUNET key to a base 64 encoded public key
+ */
+char *
+DID_key_convert_gnunet_to_multibase_base64 (struct
+                                           GNUNET_CRYPTO_PublicKey *
+                                           pkey)
+{
+  struct GNUNET_CRYPTO_EddsaPublicKey pubkey = pkey->eddsa_key;
+
+  // This is how to convert out pubkeys to W3c Ed25519-2020 multibase (base64url no padding)
+  char *pkey_base_64;
+  char *pkey_multibase;
+  char pkx[34];
+
+  pkx[0] = 0xed;
+  pkx[1] = 0x01;
+  memcpy (pkx + 2, &pubkey, sizeof (pubkey));
+  GNUNET_STRINGS_base64url_encode (pkx, sizeof (pkx), &pkey_base_64);
+  GNUNET_asprintf (&pkey_multibase, "u%s", pkey_base_64);
+
+  GNUNET_free (pkey_base_64);
+  return pkey_multibase;
+}
+
+/**
+ * @brief Create a did generate did object
+ *
+ * @param pkey
+ * @return void* Return pointer to the DID Document
+ */
+char *
+DID_pkey_to_did_document (struct GNUNET_CRYPTO_PublicKey *pkey)
+{
+
+  /* FIXME-MSC: This is effectively creating a DID Document default template for
+   * the initial document.
+   * Maybe this can be refactored to generate such a template for an identity?
+   * Even if higher layers add/modify it, there should probably still be a
+   * GNUNET_DID_document_template_from_identity()
+   */
+
+  char *did_str;
+  char *verify_id_str;
+  char *pkey_multibase_str;
+  char *didd_str;
+  json_t *didd_json;
+
+  did_str = DID_pkey_to_did (pkey);
+  GNUNET_asprintf (&verify_id_str, "%s#key-1", did_str);
+
+  pkey_multibase_str = DID_key_convert_gnunet_to_multibase_base64 (pkey);
+
+  didd_json = json_pack (
+    "{s:[ss], s:s, s:[{s:s, s:s, s:s, s:s}], s:[s], s:[s]}",
+    "@context",
+    "https://www.w3.org/ns/did/v1",
+    "https://w3id.org/security/suites/ed25519-2020/v1",
+    "id",
+    did_str,
+    "verificationMethod",
+    "id",
+    verify_id_str,
+    "type",
+    "Ed25519VerificationKey2020",
+    "controller",
+    did_str,
+    "publicKeyMultibase",
+    pkey_multibase_str,
+    "authentication",
+    "#key-1",
+    "assertionMethod",
+    "#key-1");
+
+  // Encode DID Document as JSON string
+  didd_str = json_dumps (didd_json, JSON_INDENT (2));
+
+  // Free
+  GNUNET_free (did_str);
+  GNUNET_free (verify_id_str);
+  GNUNET_free (pkey_multibase_str);
+  json_decref (didd_json);
+
+  return didd_str;
+}
+
+/**
+ * @brief Generate the default DID document for a GNUNET ego
+ * Wrapper around GNUNET_DID_pkey_to_did_document
+ */
+char *
+DID_identity_to_did_document (struct GNUNET_IDENTITY_Ego *ego)
+{
+  struct GNUNET_CRYPTO_PublicKey pkey;
+
+  GNUNET_IDENTITY_ego_get_public_key (ego, &pkey);
+  return DID_pkey_to_did (&pkey);
+}
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