Initial checkin of gRPC to third_party/

third_party/grpc/src/core/security/json_token.c

+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/security/json_token.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/security/b64.h"
+#include "src/core/support/string.h"
+
+#include <openssl/bio.h>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+
+/* --- Constants. --- */
+
+/* 1 hour max. */
+gpr_timespec grpc_max_auth_token_lifetime() {
+  gpr_timespec out;
+  out.tv_sec = 3600;
+  out.tv_nsec = 0;
+  out.clock_type = GPR_TIMESPAN;
+  return out;
+}
+
+#define GRPC_JWT_RSA_SHA256_ALGORITHM "RS256"
+#define GRPC_JWT_TYPE "JWT"
+
+/* --- Override for testing. --- */
+
+static grpc_jwt_encode_and_sign_override g_jwt_encode_and_sign_override = NULL;
+
+/* --- grpc_auth_json_key. --- */
+
+static const char *json_get_string_property(const grpc_json *json,
+                                            const char *prop_name) {
+  grpc_json *child;
+  for (child = json->child; child != NULL; child = child->next) {
+    if (strcmp(child->key, prop_name) == 0) break;
+  }
+  if (child == NULL || child->type != GRPC_JSON_STRING) {
+    gpr_log(GPR_ERROR, "Invalid or missing %s property.", prop_name);
+    return NULL;
+  }
+  return child->value;
+}
+
+static int set_json_key_string_property(const grpc_json *json,
+                                        const char *prop_name,
+                                        char **json_key_field) {
+  const char *prop_value = json_get_string_property(json, prop_name);
+  if (prop_value == NULL) return 0;
+  *json_key_field = gpr_strdup(prop_value);
+  return 1;
+}
+
+int grpc_auth_json_key_is_valid(const grpc_auth_json_key *json_key) {
+  return (json_key != NULL) &&
+         strcmp(json_key->type, GRPC_AUTH_JSON_TYPE_INVALID);
+}
+
+grpc_auth_json_key grpc_auth_json_key_create_from_json(const grpc_json *json) {
+  grpc_auth_json_key result;
+  BIO *bio = NULL;
+  const char *prop_value;
+  int success = 0;
+
+  memset(&result, 0, sizeof(grpc_auth_json_key));
+  result.type = GRPC_AUTH_JSON_TYPE_INVALID;
+  if (json == NULL) {
+    gpr_log(GPR_ERROR, "Invalid json.");
+    goto end;
+  }
+
+  prop_value = json_get_string_property(json, "type");
+  if (prop_value == NULL ||
+      strcmp(prop_value, GRPC_AUTH_JSON_TYPE_SERVICE_ACCOUNT)) {
+    goto end;
+  }
+  result.type = GRPC_AUTH_JSON_TYPE_SERVICE_ACCOUNT;
+
+  if (!set_json_key_string_property(json, "private_key_id",
+                                    &result.private_key_id) ||
+      !set_json_key_string_property(json, "client_id", &result.client_id) ||
+      !set_json_key_string_property(json, "client_email",
+                                    &result.client_email)) {
+    goto end;
+  }
+
+  prop_value = json_get_string_property(json, "private_key");
+  if (prop_value == NULL) {
+    goto end;
+  }
+  bio = BIO_new(BIO_s_mem());
+  success = BIO_puts(bio, prop_value);
+  if ((success < 0) || ((size_t)success != strlen(prop_value))) {
+    gpr_log(GPR_ERROR, "Could not write into openssl BIO.");
+    goto end;
+  }
+  result.private_key = PEM_read_bio_RSAPrivateKey(bio, NULL, NULL, "");
+  if (result.private_key == NULL) {
+    gpr_log(GPR_ERROR, "Could not deserialize private key.");
+    goto end;
+  }
+  success = 1;
+
+end:
+  if (bio != NULL) BIO_free(bio);
+  if (!success) grpc_auth_json_key_destruct(&result);
+  return result;
+}
+
+grpc_auth_json_key grpc_auth_json_key_create_from_string(
+    const char *json_string) {
+  char *scratchpad = gpr_strdup(json_string);
+  grpc_json *json = grpc_json_parse_string(scratchpad);
+  grpc_auth_json_key result = grpc_auth_json_key_create_from_json(json);
+  if (json != NULL) grpc_json_destroy(json);
+  gpr_free(scratchpad);
+  return result;
+}
+
+void grpc_auth_json_key_destruct(grpc_auth_json_key *json_key) {
+  if (json_key == NULL) return;
+  json_key->type = GRPC_AUTH_JSON_TYPE_INVALID;
+  if (json_key->client_id != NULL) {
+    gpr_free(json_key->client_id);
+    json_key->client_id = NULL;
+  }
+  if (json_key->private_key_id != NULL) {
+    gpr_free(json_key->private_key_id);
+    json_key->private_key_id = NULL;
+  }
+  if (json_key->client_email != NULL) {
+    gpr_free(json_key->client_email);
+    json_key->client_email = NULL;
+  }
+  if (json_key->private_key != NULL) {
+    RSA_free(json_key->private_key);
+    json_key->private_key = NULL;
+  }
+}
+
+/* --- jwt encoding and signature. --- */
+
+static grpc_json *create_child(grpc_json *brother, grpc_json *parent,
+                               const char *key, const char *value,
+                               grpc_json_type type) {
+  grpc_json *child = grpc_json_create(type);
+  if (brother) brother->next = child;
+  if (!parent->child) parent->child = child;
+  child->parent = parent;
+  child->value = value;
+  child->key = key;
+  return child;
+}
+
+static char *encoded_jwt_header(const char *key_id, const char *algorithm) {
+  grpc_json *json = grpc_json_create(GRPC_JSON_OBJECT);
+  grpc_json *child = NULL;
+  char *json_str = NULL;
+  char *result = NULL;
+
+  child = create_child(NULL, json, "alg", algorithm, GRPC_JSON_STRING);
+  child = create_child(child, json, "typ", GRPC_JWT_TYPE, GRPC_JSON_STRING);
+  create_child(child, json, "kid", key_id, GRPC_JSON_STRING);
+
+  json_str = grpc_json_dump_to_string(json, 0);
+  result = grpc_base64_encode(json_str, strlen(json_str), 1, 0);
+  gpr_free(json_str);
+  grpc_json_destroy(json);
+  return result;
+}
+
+static char *encoded_jwt_claim(const grpc_auth_json_key *json_key,
+                               const char *audience,
+                               gpr_timespec token_lifetime, const char *scope) {
+  grpc_json *json = grpc_json_create(GRPC_JSON_OBJECT);
+  grpc_json *child = NULL;
+  char *json_str = NULL;
+  char *result = NULL;
+  gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
+  gpr_timespec expiration = gpr_time_add(now, token_lifetime);
+  char now_str[GPR_LTOA_MIN_BUFSIZE];
+  char expiration_str[GPR_LTOA_MIN_BUFSIZE];
+  if (gpr_time_cmp(token_lifetime, grpc_max_auth_token_lifetime()) > 0) {
+    gpr_log(GPR_INFO, "Cropping token lifetime to maximum allowed value.");
+    expiration = gpr_time_add(now, grpc_max_auth_token_lifetime());
+  }
+  int64_ttoa(now.tv_sec, now_str);
+  int64_ttoa(expiration.tv_sec, expiration_str);
+
+  child =
+      create_child(NULL, json, "iss", json_key->client_email, GRPC_JSON_STRING);
+  if (scope != NULL) {
+    child = create_child(child, json, "scope", scope, GRPC_JSON_STRING);
+  } else {
+    /* Unscoped JWTs need a sub field. */
+    child = create_child(child, json, "sub", json_key->client_email,
+                         GRPC_JSON_STRING);
+  }
+
+  child = create_child(child, json, "aud", audience, GRPC_JSON_STRING);
+  child = create_child(child, json, "iat", now_str, GRPC_JSON_NUMBER);
+  create_child(child, json, "exp", expiration_str, GRPC_JSON_NUMBER);
+
+  json_str = grpc_json_dump_to_string(json, 0);
+  result = grpc_base64_encode(json_str, strlen(json_str), 1, 0);
+  gpr_free(json_str);
+  grpc_json_destroy(json);
+  return result;
+}
+
+static char *dot_concat_and_free_strings(char *str1, char *str2) {
+  size_t str1_len = strlen(str1);
+  size_t str2_len = strlen(str2);
+  size_t result_len = str1_len + 1 /* dot */ + str2_len;
+  char *result = gpr_malloc(result_len + 1 /* NULL terminated */);
+  char *current = result;
+  memcpy(current, str1, str1_len);
+  current += str1_len;
+  *(current++) = '.';
+  memcpy(current, str2, str2_len);
+  current += str2_len;
+  GPR_ASSERT(current >= result);
+  GPR_ASSERT((uintptr_t)(current - result) == result_len);
+  *current = '\0';
+  gpr_free(str1);
+  gpr_free(str2);
+  return result;
+}
+
+const EVP_MD *openssl_digest_from_algorithm(const char *algorithm) {
+  if (strcmp(algorithm, GRPC_JWT_RSA_SHA256_ALGORITHM) == 0) {
+    return EVP_sha256();
+  } else {
+    gpr_log(GPR_ERROR, "Unknown algorithm %s.", algorithm);
+    return NULL;
+  }
+}
+
+char *compute_and_encode_signature(const grpc_auth_json_key *json_key,
+                                   const char *signature_algorithm,
+                                   const char *to_sign) {
+  const EVP_MD *md = openssl_digest_from_algorithm(signature_algorithm);
+  EVP_MD_CTX *md_ctx = NULL;
+  EVP_PKEY *key = EVP_PKEY_new();
+  size_t sig_len = 0;
+  unsigned char *sig = NULL;
+  char *result = NULL;
+  if (md == NULL) return NULL;
+  md_ctx = EVP_MD_CTX_create();
+  if (md_ctx == NULL) {
+    gpr_log(GPR_ERROR, "Could not create MD_CTX");
+    goto end;
+  }
+  EVP_PKEY_set1_RSA(key, json_key->private_key);
+  if (EVP_DigestSignInit(md_ctx, NULL, md, NULL, key) != 1) {
+    gpr_log(GPR_ERROR, "DigestInit failed.");
+    goto end;
+  }
+  if (EVP_DigestSignUpdate(md_ctx, to_sign, strlen(to_sign)) != 1) {
+    gpr_log(GPR_ERROR, "DigestUpdate failed.");
+    goto end;
+  }
+  if (EVP_DigestSignFinal(md_ctx, NULL, &sig_len) != 1) {
+    gpr_log(GPR_ERROR, "DigestFinal (get signature length) failed.");
+    goto end;
+  }
+  sig = gpr_malloc(sig_len);
+  if (EVP_DigestSignFinal(md_ctx, sig, &sig_len) != 1) {
+    gpr_log(GPR_ERROR, "DigestFinal (signature compute) failed.");
+    goto end;
+  }
+  result = grpc_base64_encode(sig, sig_len, 1, 0);
+
+end:
+  if (key != NULL) EVP_PKEY_free(key);
+  if (md_ctx != NULL) EVP_MD_CTX_destroy(md_ctx);
+  if (sig != NULL) gpr_free(sig);
+  return result;
+}
+
+char *grpc_jwt_encode_and_sign(const grpc_auth_json_key *json_key,
+                               const char *audience,
+                               gpr_timespec token_lifetime, const char *scope) {
+  if (g_jwt_encode_and_sign_override != NULL) {
+    return g_jwt_encode_and_sign_override(json_key, audience, token_lifetime,
+                                          scope);
+  } else {
+    const char *sig_algo = GRPC_JWT_RSA_SHA256_ALGORITHM;
+    char *to_sign = dot_concat_and_free_strings(
+        encoded_jwt_header(json_key->private_key_id, sig_algo),
+        encoded_jwt_claim(json_key, audience, token_lifetime, scope));
+    char *sig = compute_and_encode_signature(json_key, sig_algo, to_sign);
+    if (sig == NULL) {
+      gpr_free(to_sign);
+      return NULL;
+    }
+    return dot_concat_and_free_strings(to_sign, sig);
+  }
+}
+
+void grpc_jwt_encode_and_sign_set_override(
+    grpc_jwt_encode_and_sign_override func) {
+  g_jwt_encode_and_sign_override = func;
+}
+
+/* --- grpc_auth_refresh_token --- */
+
+int grpc_auth_refresh_token_is_valid(
+    const grpc_auth_refresh_token *refresh_token) {
+  return (refresh_token != NULL) &&
+         strcmp(refresh_token->type, GRPC_AUTH_JSON_TYPE_INVALID);
+}
+
+grpc_auth_refresh_token grpc_auth_refresh_token_create_from_json(
+    const grpc_json *json) {
+  grpc_auth_refresh_token result;
+  const char *prop_value;
+  int success = 0;
+
+  memset(&result, 0, sizeof(grpc_auth_refresh_token));
+  result.type = GRPC_AUTH_JSON_TYPE_INVALID;
+  if (json == NULL) {
+    gpr_log(GPR_ERROR, "Invalid json.");
+    goto end;
+  }
+
+  prop_value = json_get_string_property(json, "type");
+  if (prop_value == NULL ||
+      strcmp(prop_value, GRPC_AUTH_JSON_TYPE_AUTHORIZED_USER)) {
+    goto end;
+  }
+  result.type = GRPC_AUTH_JSON_TYPE_AUTHORIZED_USER;
+
+  if (!set_json_key_string_property(json, "client_secret",
+                                    &result.client_secret) ||
+      !set_json_key_string_property(json, "client_id", &result.client_id) ||
+      !set_json_key_string_property(json, "refresh_token",
+                                    &result.refresh_token)) {
+    goto end;
+  }
+  success = 1;
+
+end:
+  if (!success) grpc_auth_refresh_token_destruct(&result);
+  return result;
+}
+
+grpc_auth_refresh_token grpc_auth_refresh_token_create_from_string(
+    const char *json_string) {
+  char *scratchpad = gpr_strdup(json_string);
+  grpc_json *json = grpc_json_parse_string(scratchpad);
+  grpc_auth_refresh_token result =
+      grpc_auth_refresh_token_create_from_json(json);
+  if (json != NULL) grpc_json_destroy(json);
+  gpr_free(scratchpad);
+  return result;
+}
+
+void grpc_auth_refresh_token_destruct(grpc_auth_refresh_token *refresh_token) {
+  if (refresh_token == NULL) return;
+  refresh_token->type = GRPC_AUTH_JSON_TYPE_INVALID;
+  if (refresh_token->client_id != NULL) {
+    gpr_free(refresh_token->client_id);
+    refresh_token->client_id = NULL;
+  }
+  if (refresh_token->client_secret != NULL) {
+    gpr_free(refresh_token->client_secret);
+    refresh_token->client_secret = NULL;
+  }
+  if (refresh_token->refresh_token != NULL) {
+    gpr_free(refresh_token->refresh_token);
+    refresh_token->refresh_token = NULL;
+  }
+}