/* 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 . SPDX-License-Identifier: AGPL3.0-or-later */ /** * @file reclaim/oidc_helper.c * @brief helper library for OIDC related functions * @author Martin Schanzenbach */ #include "platform.h" #include #include #include "gnunet_util_lib.h" #include "gnunet_reclaim_lib.h" #include "gnunet_reclaim_service.h" #include "gnunet_signatures.h" #include "oidc_helper.h" // #include "benchmark.h" #include GNUNET_NETWORK_STRUCT_BEGIN /** * The signature used to generate the authorization code */ struct OIDC_Parameters { /** * The reclaim ticket */ struct GNUNET_RECLAIM_Ticket ticket; /** * The nonce length */ uint32_t nonce_len GNUNET_PACKED; /** * The length of the PKCE code_challenge */ uint32_t code_challenge_len GNUNET_PACKED; /** * The length of the attributes list */ uint32_t attr_list_len GNUNET_PACKED; /** * The length of the presentation list */ uint32_t pres_list_len GNUNET_PACKED; }; GNUNET_NETWORK_STRUCT_END /** * Standard claims represented by the "profile" scope in OIDC */ static char OIDC_profile_claims[14][32] = { "name", "family_name", "given_name", "middle_name", "nickname", "preferred_username", "profile", "picture", "website", "gender", "birthdate", "zoneinfo", "locale", "updated_at" }; /** * Standard claims represented by the "email" scope in OIDC */ static char OIDC_email_claims[2][16] = { "email", "email_verified" }; /** * Standard claims represented by the "phone" scope in OIDC */ static char OIDC_phone_claims[2][32] = { "phone_number", "phone_number_verified" }; /** * Standard claims represented by the "address" scope in OIDC */ static char OIDC_address_claims[5][32] = { "street_address", "locality", "region", "postal_code", "country" }; static enum GNUNET_GenericReturnValue is_claim_in_address_scope (const char *claim) { int i; for (i = 0; i < 5; i++) { if (0 == strcmp (claim, OIDC_address_claims[i])) { return GNUNET_YES; } } return GNUNET_NO; } static char * create_jwt_header (void) { json_t *root; char *json_str; root = json_object (); json_object_set_new (root, JWT_ALG, json_string (JWT_ALG_VALUE)); json_object_set_new (root, JWT_TYP, json_string (JWT_TYP_VALUE)); json_str = json_dumps (root, JSON_INDENT (0) | JSON_COMPACT); json_decref (root); return json_str; } static void replace_char (char *str, char find, char replace) { char *current_pos = strchr (str, find); while (current_pos) { *current_pos = replace; current_pos = strchr (current_pos, find); } } // RFC4648 static void fix_base64 (char *str) { // Replace + with - replace_char (str, '+', '-'); // Replace / with _ replace_char (str, '/', '_'); } static json_t* generate_userinfo_json(const struct GNUNET_IDENTITY_PublicKey *sub_key, const struct GNUNET_RECLAIM_AttributeList *attrs, const struct GNUNET_RECLAIM_PresentationList *presentations) { struct GNUNET_RECLAIM_AttributeListEntry *le; struct GNUNET_RECLAIM_PresentationListEntry *ple; char *subject; char *source_name; char *attr_val_str; char *pres_val_str; json_t *body; json_t *aggr_names; json_t *aggr_sources; json_t *aggr_sources_jwt; json_t *addr_claim = NULL; int num_presentations = 0; for (le = attrs->list_head; NULL != le; le = le->next) { if (GNUNET_NO == GNUNET_RECLAIM_id_is_zero (&le->attribute->credential)) num_presentations++; } subject = GNUNET_STRINGS_data_to_string_alloc (sub_key, sizeof(struct GNUNET_IDENTITY_PublicKey)); body = json_object (); aggr_names = json_object (); aggr_sources = json_object (); // iss REQUIRED case sensitive server uri with https // The issuer is the local reclaim instance (e.g. // https://reclaim.id/api/openid) json_object_set_new (body, "iss", json_string (SERVER_ADDRESS)); // sub REQUIRED public key identity, not exceed 255 ASCII length json_object_set_new (body, "sub", json_string (subject)); pres_val_str = NULL; source_name = NULL; int i = 0; for (ple = presentations->list_head; NULL != ple; ple = ple->next) { // New presentation GNUNET_asprintf (&source_name, "src%d", i); aggr_sources_jwt = json_object (); pres_val_str = GNUNET_RECLAIM_presentation_value_to_string (ple->presentation->type, ple->presentation->data, ple->presentation->data_size); json_object_set_new (aggr_sources_jwt, GNUNET_RECLAIM_presentation_number_to_typename (ple->presentation->type), json_string (pres_val_str) ); json_object_set_new (aggr_sources, source_name, aggr_sources_jwt); GNUNET_free (pres_val_str); GNUNET_free (source_name); source_name = NULL; i++; } for (le = attrs->list_head; NULL != le; le = le->next) { if (GNUNET_YES == GNUNET_RECLAIM_id_is_zero (&le->attribute->credential)) { attr_val_str = GNUNET_RECLAIM_attribute_value_to_string (le->attribute->type, le->attribute->data, le->attribute->data_size); /** * There is this wierd quirk that the individual address claim(s) must be * inside a JSON object of the "address" claim. * FIXME: Possibly include formatted claim here */ if (GNUNET_YES == is_claim_in_address_scope (le->attribute->name)) { if (NULL == addr_claim) { addr_claim = json_object (); } json_object_set_new (addr_claim, le->attribute->name, json_string (attr_val_str)); } else { json_object_set_new (body, le->attribute->name, json_string (attr_val_str)); } GNUNET_free (attr_val_str); } else { // Check if presentation is there int j = 0; for (ple = presentations->list_head; NULL != ple; ple = ple->next) { if (GNUNET_YES == GNUNET_RECLAIM_id_is_equal (&ple->presentation->credential_id, &le->attribute->credential)) break; j++; } if (NULL == ple) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Presentation for `%s' missing...\n", le->attribute->name); continue; } // Presentation exists, hence take the respective source str GNUNET_asprintf (&source_name, "src%d", j); json_object_set_new (aggr_names, le->attribute->data, json_string (source_name)); GNUNET_free (source_name); } } if (NULL != addr_claim) json_object_set_new (body, "address", addr_claim); if (0 != i) { json_object_set_new (body, "_claim_names", aggr_names); json_object_set_new (body, "_claim_sources", aggr_sources); } return body; } /** * Generate userinfo JSON as string * * @param sub_key the subject (user) * @param attrs user attribute list * @param presentations credential presentation list (may be empty) * @return Userinfo JSON */ char * OIDC_generate_userinfo (const struct GNUNET_IDENTITY_PublicKey *sub_key, const struct GNUNET_RECLAIM_AttributeList *attrs, const struct GNUNET_RECLAIM_PresentationList *presentations) { char *body_str; json_t* body = generate_userinfo_json (sub_key, attrs, presentations); body_str = json_dumps (body, JSON_INDENT (0) | JSON_COMPACT); json_decref (body); return body_str; } /** * Create a JWT from attributes * * @param aud_key the public of the audience * @param sub_key the public key of the subject * @param attrs the attribute list * @param presentations credential presentation list (may be empty) * @param expiration_time the validity of the token * @param secret_key the key used to sign the JWT * @return a new base64-encoded JWT string. */ char * OIDC_generate_id_token (const struct GNUNET_IDENTITY_PublicKey *aud_key, const struct GNUNET_IDENTITY_PublicKey *sub_key, const struct GNUNET_RECLAIM_AttributeList *attrs, const struct GNUNET_RECLAIM_PresentationList *presentations, const struct GNUNET_TIME_Relative *expiration_time, const char *nonce, const char *secret_key) { struct GNUNET_HashCode signature; struct GNUNET_TIME_Absolute exp_time; struct GNUNET_TIME_Absolute time_now; char *audience; char *subject; char *header; char *body_str; char *result; char *header_base64; char *body_base64; char *signature_target; char *signature_base64; json_t *body; body = generate_userinfo_json (sub_key, attrs, presentations); // iat REQUIRED time now time_now = GNUNET_TIME_absolute_get (); // exp REQUIRED time expired from config exp_time = GNUNET_TIME_absolute_add (time_now, *expiration_time); // auth_time only if max_age // nonce only if nonce // OPTIONAL acr,amr,azp subject = GNUNET_STRINGS_data_to_string_alloc (sub_key, sizeof(struct GNUNET_IDENTITY_PublicKey)); audience = GNUNET_STRINGS_data_to_string_alloc (aud_key, sizeof(struct GNUNET_IDENTITY_PublicKey)); header = create_jwt_header (); // aud REQUIRED public key client_id must be there json_object_set_new (body, "aud", json_string (audience)); // iat json_object_set_new (body, "iat", json_integer (time_now.abs_value_us / (1000 * 1000))); // exp json_object_set_new (body, "exp", json_integer (exp_time.abs_value_us / (1000 * 1000))); // nbf json_object_set_new (body, "nbf", json_integer (time_now.abs_value_us / (1000 * 1000))); // nonce if (NULL != nonce) json_object_set_new (body, "nonce", json_string (nonce)); body_str = json_dumps (body, JSON_INDENT (0) | JSON_COMPACT); json_decref (body); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,"ID-Token: %s\n", body_str); GNUNET_STRINGS_base64url_encode (header, strlen (header), &header_base64); fix_base64 (header_base64); GNUNET_STRINGS_base64url_encode (body_str, strlen (body_str), &body_base64); fix_base64 (body_base64); GNUNET_free (subject); GNUNET_free (audience); /** * Creating the JWT signature. This might not be * standards compliant, check. */ GNUNET_asprintf (&signature_target, "%s.%s", header_base64, body_base64); GNUNET_CRYPTO_hmac_raw (secret_key, strlen (secret_key), signature_target, strlen (signature_target), &signature); GNUNET_STRINGS_base64url_encode ((const char *) &signature, sizeof(struct GNUNET_HashCode), &signature_base64); fix_base64 (signature_base64); GNUNET_asprintf (&result, "%s.%s.%s", header_base64, body_base64, signature_base64); GNUNET_free (signature_target); GNUNET_free (header); GNUNET_free (body_str); GNUNET_free (signature_base64); GNUNET_free (body_base64); GNUNET_free (header_base64); return result; } /** * Builds an OIDC authorization code including * a reclaim ticket and nonce * * @param issuer the issuer of the ticket, used to sign the ticket and nonce * @param ticket the ticket to include in the code * @param attrs list of attributes which are shared * @param presentations credential presentation list (may be empty) * @param nonce the nonce to include in the code * @param code_challenge PKCE code challenge * @return a new authorization code (caller must free) */ char * OIDC_build_authz_code (const struct GNUNET_IDENTITY_PrivateKey *issuer, const struct GNUNET_RECLAIM_Ticket *ticket, const struct GNUNET_RECLAIM_AttributeList *attrs, const struct GNUNET_RECLAIM_PresentationList *presentations, const char *nonce_str, const char *code_challenge) { struct OIDC_Parameters params; char *code_payload; char *payload; char *tmp; char *code_str; char *buf_ptr = NULL; size_t payload_len; size_t code_payload_len; size_t attr_list_len = 0; size_t pres_list_len = 0; size_t code_challenge_len = 0; uint32_t nonce_len = 0; struct GNUNET_CRYPTO_EccSignaturePurpose *purpose; /** PLAINTEXT **/ // Assign ticket memset (¶ms, 0, sizeof(params)); params.ticket = *ticket; // Assign nonce payload_len = sizeof(struct OIDC_Parameters); if ((NULL != nonce_str) && (strcmp ("", nonce_str) != 0)) { nonce_len = strlen (nonce_str); payload_len += nonce_len; } params.nonce_len = htonl (nonce_len); // Assign code challenge if (NULL != code_challenge) code_challenge_len = strlen (code_challenge); payload_len += code_challenge_len; params.code_challenge_len = htonl (code_challenge_len); // Assign attributes if (NULL != attrs) { // Get length attr_list_len = GNUNET_RECLAIM_attribute_list_serialize_get_size (attrs); params.attr_list_len = htonl (attr_list_len); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Length of serialized attributes: %lu\n", attr_list_len); // Get serialized attributes payload_len += attr_list_len; } if (NULL != presentations) { // Get length pres_list_len = GNUNET_RECLAIM_presentation_list_serialize_get_size (presentations); params.pres_list_len = htonl (pres_list_len); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Length of serialized presentations: %lu\n", pres_list_len); // Get serialized attributes payload_len += pres_list_len; } // Get plaintext length payload = GNUNET_malloc (payload_len); memcpy (payload, ¶ms, sizeof(params)); tmp = payload + sizeof(params); if (0 < code_challenge_len) { memcpy (tmp, code_challenge, code_challenge_len); tmp += code_challenge_len; } if (0 < nonce_len) { memcpy (tmp, nonce_str, nonce_len); tmp += nonce_len; } if (0 < attr_list_len) GNUNET_RECLAIM_attribute_list_serialize (attrs, tmp); if (0 < pres_list_len) GNUNET_RECLAIM_presentation_list_serialize (presentations, tmp); /** END **/ // Get length code_payload_len = sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose) + payload_len + sizeof(struct GNUNET_CRYPTO_EcdsaSignature); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Length of data to encode: %lu\n", code_payload_len); // Initialize code payload code_payload = GNUNET_malloc (code_payload_len); GNUNET_assert (NULL != code_payload); purpose = (struct GNUNET_CRYPTO_EccSignaturePurpose *) code_payload; purpose->size = htonl (sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose) + payload_len); purpose->purpose = htonl (GNUNET_SIGNATURE_PURPOSE_RECLAIM_CODE_SIGN); // Store pubkey buf_ptr = (char *) &purpose[1]; memcpy (buf_ptr, payload, payload_len); GNUNET_free (payload); buf_ptr += payload_len; // Sign and store signature if (GNUNET_SYSERR == GNUNET_CRYPTO_ecdsa_sign_ (&issuer->ecdsa_key, purpose, (struct GNUNET_CRYPTO_EcdsaSignature *) buf_ptr)) { GNUNET_break (0); GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Unable to sign code\n"); GNUNET_free (code_payload); return NULL; } GNUNET_STRINGS_base64url_encode (code_payload, code_payload_len, &code_str); GNUNET_free (code_payload); return code_str; } /** * Parse reclaim ticket and nonce from * authorization code. * This also verifies the signature in the code. * * @param audience the expected audience of the code * @param code the string representation of the code * @param code_verfier PKCE code verifier. Optional, must be provided * if used in request. * @param ticket where to store the ticket * @param attrs the attributes in the code * @param presentations credential presentation list * @param nonce_str where to store the nonce (if contained) * @return GNUNET_OK if successful, else GNUNET_SYSERR */ int OIDC_parse_authz_code (const struct GNUNET_IDENTITY_PublicKey *audience, const char *code, const char *code_verifier, struct GNUNET_RECLAIM_Ticket *ticket, struct GNUNET_RECLAIM_AttributeList **attrs, struct GNUNET_RECLAIM_PresentationList **presentations, char **nonce_str) { char *code_payload; char *ptr; char *plaintext; char *attrs_ser; char *presentations_ser; char *expected_code_challenge; char *code_challenge; char *code_verifier_hash; struct GNUNET_CRYPTO_EccSignaturePurpose *purpose; struct GNUNET_CRYPTO_EcdsaSignature *signature; uint32_t code_challenge_len; uint32_t attrs_ser_len; uint32_t pres_ser_len; size_t plaintext_len; size_t code_payload_len; uint32_t nonce_len = 0; struct OIDC_Parameters *params; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Trying to decode `%s'\n", code); code_payload = NULL; code_payload_len = GNUNET_STRINGS_base64url_decode (code, strlen (code), (void **) &code_payload); if (code_payload_len < sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose) + sizeof(struct OIDC_Parameters) + sizeof(struct GNUNET_CRYPTO_EcdsaSignature)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Authorization code malformed\n"); GNUNET_free (code_payload); return GNUNET_SYSERR; } purpose = (struct GNUNET_CRYPTO_EccSignaturePurpose *) code_payload; plaintext_len = code_payload_len; plaintext_len -= sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose); ptr = (char *) &purpose[1]; plaintext_len -= sizeof(struct GNUNET_CRYPTO_EcdsaSignature); plaintext = ptr; ptr += plaintext_len; signature = (struct GNUNET_CRYPTO_EcdsaSignature *) ptr; params = (struct OIDC_Parameters *) plaintext; // cmp code_challenge code_verifier code_challenge_len = ntohl (params->code_challenge_len); code_challenge = ((char *) ¶ms[1]); if (0 != code_challenge_len) /* Only check if this code requires a CV */ { if (NULL == code_verifier) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Expected code verifier!\n"); GNUNET_free (code_payload); return GNUNET_SYSERR; } code_verifier_hash = GNUNET_malloc (256 / 8); // hash code verifier gcry_md_hash_buffer (GCRY_MD_SHA256, code_verifier_hash, code_verifier, strlen (code_verifier)); // encode code verifier GNUNET_STRINGS_base64url_encode (code_verifier_hash, 256 / 8, &expected_code_challenge); GNUNET_free (code_verifier_hash); if (0 != strncmp (expected_code_challenge, code_challenge, code_challenge_len)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Invalid code verifier! Expected: %s, Got: %.*s\n", expected_code_challenge, code_challenge_len, code_challenge); GNUNET_free (code_payload); GNUNET_free (expected_code_challenge); return GNUNET_SYSERR; } GNUNET_free (expected_code_challenge); } nonce_len = ntohl (params->nonce_len); if (0 != nonce_len) { *nonce_str = GNUNET_strndup (code_challenge + code_challenge_len, nonce_len); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Got nonce: %s\n", *nonce_str); } // Ticket memcpy (ticket, ¶ms->ticket, sizeof(params->ticket)); // Signature // GNUNET_CRYPTO_ecdsa_key_get_public (ecdsa_priv, &ecdsa_pub); if (0 != GNUNET_memcmp (audience, &ticket->audience)) { GNUNET_free (code_payload); if (NULL != *nonce_str) GNUNET_free (*nonce_str); GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Audience in ticket does not match client!\n"); return GNUNET_SYSERR; } if (GNUNET_OK != GNUNET_CRYPTO_ecdsa_verify_ (GNUNET_SIGNATURE_PURPOSE_RECLAIM_CODE_SIGN, purpose, signature, &ticket->identity.ecdsa_key)) { GNUNET_free (code_payload); if (NULL != *nonce_str) GNUNET_free (*nonce_str); GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Signature of AuthZ code invalid!\n"); return GNUNET_SYSERR; } // Attributes attrs_ser = ((char *) ¶ms[1]) + code_challenge_len + nonce_len; attrs_ser_len = ntohl (params->attr_list_len); *attrs = GNUNET_RECLAIM_attribute_list_deserialize (attrs_ser, attrs_ser_len); presentations_ser = ((char*) attrs_ser) + attrs_ser_len; pres_ser_len = ntohl (params->pres_list_len); *presentations = GNUNET_RECLAIM_presentation_list_deserialize (presentations_ser, pres_ser_len); GNUNET_free (code_payload); return GNUNET_OK; } /** * Build a token response for a token request * TODO: Maybe we should add the scope here? * * @param access_token the access token to include * @param id_token the id_token to include * @param expiration_time the expiration time of the token(s) * @param token_response where to store the response */ void OIDC_build_token_response (const char *access_token, const char *id_token, const struct GNUNET_TIME_Relative *expiration_time, char **token_response) { json_t *root_json; root_json = json_object (); GNUNET_assert (NULL != access_token); GNUNET_assert (NULL != id_token); GNUNET_assert (NULL != expiration_time); json_object_set_new (root_json, "access_token", json_string (access_token)); json_object_set_new (root_json, "token_type", json_string ("Bearer")); json_object_set_new (root_json, "expires_in", json_integer (expiration_time->rel_value_us / (1000 * 1000))); json_object_set_new (root_json, "id_token", json_string (id_token)); *token_response = json_dumps (root_json, JSON_INDENT (0) | JSON_COMPACT); json_decref (root_json); } /** * Generate a new access token */ char * OIDC_access_token_new (const struct GNUNET_RECLAIM_Ticket *ticket) { char *access_token; GNUNET_STRINGS_base64_encode (ticket, sizeof(*ticket), &access_token); return access_token; } /** * Parse an access token */ int OIDC_access_token_parse (const char *token, struct GNUNET_RECLAIM_Ticket **ticket) { if (sizeof (struct GNUNET_RECLAIM_Ticket) != GNUNET_STRINGS_base64_decode (token, strlen (token), (void**) ticket)) return GNUNET_SYSERR; return GNUNET_OK; } /** * Checks if a claim is implicitly requested through standard * scope(s) or explicitly through non-standard scope. * * @param scopes the scopes which have been requested * @param attr the attribute name to check * @return GNUNET_YES if attribute is implcitly requested */ enum GNUNET_GenericReturnValue OIDC_check_scopes_for_claim_request (const char*scopes, const char*attr) { char *scope_variables; char *scope_variable; char delimiter[] = " "; int i; scope_variables = GNUNET_strdup (scopes); scope_variable = strtok (scope_variables, delimiter); while (NULL != scope_variable) { if (0 == strcmp ("profile", scope_variable)) { for (i = 0; i < 14; i++) { if (0 == strcmp (attr, OIDC_profile_claims[i])) { GNUNET_free (scope_variables); return GNUNET_YES; } } } else if (0 == strcmp ("address", scope_variable)) { for (i = 0; i < 5; i++) { if (0 == strcmp (attr, OIDC_address_claims[i])) { GNUNET_free (scope_variables); return GNUNET_YES; } } } else if (0 == strcmp ("email", scope_variable)) { for (i = 0; i < 2; i++) { if (0 == strcmp (attr, OIDC_email_claims[i])) { GNUNET_free (scope_variables); return GNUNET_YES; } } } else if (0 == strcmp ("phone", scope_variable)) { for (i = 0; i < 2; i++) { if (0 == strcmp (attr, OIDC_phone_claims[i])) { GNUNET_free (scope_variables); return GNUNET_YES; } } } else if (0 == strcmp (attr, scope_variable)) { /** attribute matches requested scope **/ GNUNET_free (scope_variables); return GNUNET_YES; } scope_variable = strtok (NULL, delimiter); } GNUNET_free (scope_variables); return GNUNET_NO; }