--- /dev/null
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/tsi/grpc_shadow_boringssl.h"
+
+#include "src/core/lib/security/credentials/jwt/jwt_verifier.h"
+
+#include <limits.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/sync.h>
+
+extern "C" {
+#include <openssl/bn.h>
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+}
+
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/http/httpcli.h"
+#include "src/core/lib/iomgr/polling_entity.h"
+#include "src/core/lib/slice/b64.h"
+#include "src/core/lib/slice/slice_internal.h"
+#include "src/core/tsi/ssl_types.h"
+
+/* --- Utils. --- */
+
+const char* grpc_jwt_verifier_status_to_string(
+ grpc_jwt_verifier_status status) {
+ switch (status) {
+ case GRPC_JWT_VERIFIER_OK:
+ return "OK";
+ case GRPC_JWT_VERIFIER_BAD_SIGNATURE:
+ return "BAD_SIGNATURE";
+ case GRPC_JWT_VERIFIER_BAD_FORMAT:
+ return "BAD_FORMAT";
+ case GRPC_JWT_VERIFIER_BAD_AUDIENCE:
+ return "BAD_AUDIENCE";
+ case GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR:
+ return "KEY_RETRIEVAL_ERROR";
+ case GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE:
+ return "TIME_CONSTRAINT_FAILURE";
+ case GRPC_JWT_VERIFIER_GENERIC_ERROR:
+ return "GENERIC_ERROR";
+ default:
+ return "UNKNOWN";
+ }
+}
+
+static const EVP_MD* evp_md_from_alg(const char* alg) {
+ if (strcmp(alg, "RS256") == 0) {
+ return EVP_sha256();
+ } else if (strcmp(alg, "RS384") == 0) {
+ return EVP_sha384();
+ } else if (strcmp(alg, "RS512") == 0) {
+ return EVP_sha512();
+ } else {
+ return nullptr;
+ }
+}
+
+static grpc_json* parse_json_part_from_jwt(const char* str, size_t len,
+ grpc_slice* buffer) {
+ grpc_json* json;
+
+ *buffer = grpc_base64_decode_with_len(str, len, 1);
+ if (GRPC_SLICE_IS_EMPTY(*buffer)) {
+ gpr_log(GPR_ERROR, "Invalid base64.");
+ return nullptr;
+ }
+ json = grpc_json_parse_string_with_len(
+ reinterpret_cast<char*> GRPC_SLICE_START_PTR(*buffer),
+ GRPC_SLICE_LENGTH(*buffer));
+ if (json == nullptr) {
+ grpc_slice_unref_internal(*buffer);
+ gpr_log(GPR_ERROR, "JSON parsing error.");
+ }
+ return json;
+}
+
+static const char* validate_string_field(const grpc_json* json,
+ const char* key) {
+ if (json->type != GRPC_JSON_STRING) {
+ gpr_log(GPR_ERROR, "Invalid %s field [%s]", key, json->value);
+ return nullptr;
+ }
+ return json->value;
+}
+
+static gpr_timespec validate_time_field(const grpc_json* json,
+ const char* key) {
+ gpr_timespec result = gpr_time_0(GPR_CLOCK_REALTIME);
+ if (json->type != GRPC_JSON_NUMBER) {
+ gpr_log(GPR_ERROR, "Invalid %s field [%s]", key, json->value);
+ return result;
+ }
+ result.tv_sec = strtol(json->value, nullptr, 10);
+ return result;
+}
+
+/* --- JOSE header. see http://tools.ietf.org/html/rfc7515#section-4 --- */
+
+typedef struct {
+ const char* alg;
+ const char* kid;
+ const char* typ;
+ /* TODO(jboeuf): Add others as needed (jku, jwk, x5u, x5c and so on...). */
+ grpc_slice buffer;
+} jose_header;
+
+static void jose_header_destroy(jose_header* h) {
+ grpc_slice_unref_internal(h->buffer);
+ gpr_free(h);
+}
+
+/* Takes ownership of json and buffer. */
+static jose_header* jose_header_from_json(grpc_json* json,
+ const grpc_slice& buffer) {
+ grpc_json* cur;
+ jose_header* h = static_cast<jose_header*>(gpr_zalloc(sizeof(jose_header)));
+ h->buffer = buffer;
+ for (cur = json->child; cur != nullptr; cur = cur->next) {
+ if (strcmp(cur->key, "alg") == 0) {
+ /* We only support RSA-1.5 signatures for now.
+ Beware of this if we add HMAC support:
+ https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/
+ */
+ if (cur->type != GRPC_JSON_STRING || strncmp(cur->value, "RS", 2) ||
+ evp_md_from_alg(cur->value) == nullptr) {
+ gpr_log(GPR_ERROR, "Invalid alg field [%s]", cur->value);
+ goto error;
+ }
+ h->alg = cur->value;
+ } else if (strcmp(cur->key, "typ") == 0) {
+ h->typ = validate_string_field(cur, "typ");
+ if (h->typ == nullptr) goto error;
+ } else if (strcmp(cur->key, "kid") == 0) {
+ h->kid = validate_string_field(cur, "kid");
+ if (h->kid == nullptr) goto error;
+ }
+ }
+ if (h->alg == nullptr) {
+ gpr_log(GPR_ERROR, "Missing alg field.");
+ goto error;
+ }
+ grpc_json_destroy(json);
+ h->buffer = buffer;
+ return h;
+
+error:
+ grpc_json_destroy(json);
+ jose_header_destroy(h);
+ return nullptr;
+}
+
+/* --- JWT claims. see http://tools.ietf.org/html/rfc7519#section-4.1 */
+
+struct grpc_jwt_claims {
+ /* Well known properties already parsed. */
+ const char* sub;
+ const char* iss;
+ const char* aud;
+ const char* jti;
+ gpr_timespec iat;
+ gpr_timespec exp;
+ gpr_timespec nbf;
+
+ grpc_json* json;
+ grpc_slice buffer;
+};
+
+void grpc_jwt_claims_destroy(grpc_jwt_claims* claims) {
+ grpc_json_destroy(claims->json);
+ grpc_slice_unref_internal(claims->buffer);
+ gpr_free(claims);
+}
+
+const grpc_json* grpc_jwt_claims_json(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return nullptr;
+ return claims->json;
+}
+
+const char* grpc_jwt_claims_subject(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return nullptr;
+ return claims->sub;
+}
+
+const char* grpc_jwt_claims_issuer(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return nullptr;
+ return claims->iss;
+}
+
+const char* grpc_jwt_claims_id(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return nullptr;
+ return claims->jti;
+}
+
+const char* grpc_jwt_claims_audience(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return nullptr;
+ return claims->aud;
+}
+
+gpr_timespec grpc_jwt_claims_issued_at(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return gpr_inf_past(GPR_CLOCK_REALTIME);
+ return claims->iat;
+}
+
+gpr_timespec grpc_jwt_claims_expires_at(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return gpr_inf_future(GPR_CLOCK_REALTIME);
+ return claims->exp;
+}
+
+gpr_timespec grpc_jwt_claims_not_before(const grpc_jwt_claims* claims) {
+ if (claims == nullptr) return gpr_inf_past(GPR_CLOCK_REALTIME);
+ return claims->nbf;
+}
+
+/* Takes ownership of json and buffer even in case of failure. */
+grpc_jwt_claims* grpc_jwt_claims_from_json(grpc_json* json,
+ const grpc_slice& buffer) {
+ grpc_json* cur;
+ grpc_jwt_claims* claims =
+ static_cast<grpc_jwt_claims*>(gpr_malloc(sizeof(grpc_jwt_claims)));
+ memset(claims, 0, sizeof(grpc_jwt_claims));
+ claims->json = json;
+ claims->buffer = buffer;
+ claims->iat = gpr_inf_past(GPR_CLOCK_REALTIME);
+ claims->nbf = gpr_inf_past(GPR_CLOCK_REALTIME);
+ claims->exp = gpr_inf_future(GPR_CLOCK_REALTIME);
+
+ /* Per the spec, all fields are optional. */
+ for (cur = json->child; cur != nullptr; cur = cur->next) {
+ if (strcmp(cur->key, "sub") == 0) {
+ claims->sub = validate_string_field(cur, "sub");
+ if (claims->sub == nullptr) goto error;
+ } else if (strcmp(cur->key, "iss") == 0) {
+ claims->iss = validate_string_field(cur, "iss");
+ if (claims->iss == nullptr) goto error;
+ } else if (strcmp(cur->key, "aud") == 0) {
+ claims->aud = validate_string_field(cur, "aud");
+ if (claims->aud == nullptr) goto error;
+ } else if (strcmp(cur->key, "jti") == 0) {
+ claims->jti = validate_string_field(cur, "jti");
+ if (claims->jti == nullptr) goto error;
+ } else if (strcmp(cur->key, "iat") == 0) {
+ claims->iat = validate_time_field(cur, "iat");
+ if (gpr_time_cmp(claims->iat, gpr_time_0(GPR_CLOCK_REALTIME)) == 0)
+ goto error;
+ } else if (strcmp(cur->key, "exp") == 0) {
+ claims->exp = validate_time_field(cur, "exp");
+ if (gpr_time_cmp(claims->exp, gpr_time_0(GPR_CLOCK_REALTIME)) == 0)
+ goto error;
+ } else if (strcmp(cur->key, "nbf") == 0) {
+ claims->nbf = validate_time_field(cur, "nbf");
+ if (gpr_time_cmp(claims->nbf, gpr_time_0(GPR_CLOCK_REALTIME)) == 0)
+ goto error;
+ }
+ }
+ return claims;
+
+error:
+ grpc_jwt_claims_destroy(claims);
+ return nullptr;
+}
+
+grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims* claims,
+ const char* audience) {
+ gpr_timespec skewed_now;
+ int audience_ok;
+
+ GPR_ASSERT(claims != nullptr);
+
+ skewed_now =
+ gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_clock_skew);
+ if (gpr_time_cmp(skewed_now, claims->nbf) < 0) {
+ gpr_log(GPR_ERROR, "JWT is not valid yet.");
+ return GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE;
+ }
+ skewed_now =
+ gpr_time_sub(gpr_now(GPR_CLOCK_REALTIME), grpc_jwt_verifier_clock_skew);
+ if (gpr_time_cmp(skewed_now, claims->exp) > 0) {
+ gpr_log(GPR_ERROR, "JWT is expired.");
+ return GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE;
+ }
+
+ /* This should be probably up to the upper layer to decide but let's harcode
+ the 99% use case here for email issuers, where the JWT must be self
+ issued. */
+ if (grpc_jwt_issuer_email_domain(claims->iss) != nullptr &&
+ claims->sub != nullptr && strcmp(claims->iss, claims->sub) != 0) {
+ gpr_log(GPR_ERROR,
+ "Email issuer (%s) cannot assert another subject (%s) than itself.",
+ claims->iss, claims->sub);
+ return GRPC_JWT_VERIFIER_BAD_SUBJECT;
+ }
+
+ if (audience == nullptr) {
+ audience_ok = claims->aud == nullptr;
+ } else {
+ audience_ok = claims->aud != nullptr && strcmp(audience, claims->aud) == 0;
+ }
+ if (!audience_ok) {
+ gpr_log(GPR_ERROR, "Audience mismatch: expected %s and found %s.",
+ audience == nullptr ? "NULL" : audience,
+ claims->aud == nullptr ? "NULL" : claims->aud);
+ return GRPC_JWT_VERIFIER_BAD_AUDIENCE;
+ }
+ return GRPC_JWT_VERIFIER_OK;
+}
+
+/* --- verifier_cb_ctx object. --- */
+
+typedef enum {
+ HTTP_RESPONSE_OPENID = 0,
+ HTTP_RESPONSE_KEYS,
+ HTTP_RESPONSE_COUNT /* must be last */
+} http_response_index;
+
+typedef struct {
+ grpc_jwt_verifier* verifier;
+ grpc_polling_entity pollent;
+ jose_header* header;
+ grpc_jwt_claims* claims;
+ char* audience;
+ grpc_slice signature;
+ grpc_slice signed_data;
+ void* user_data;
+ grpc_jwt_verification_done_cb user_cb;
+ grpc_http_response responses[HTTP_RESPONSE_COUNT];
+} verifier_cb_ctx;
+
+/* Takes ownership of the header, claims and signature. */
+static verifier_cb_ctx* verifier_cb_ctx_create(
+ grpc_jwt_verifier* verifier, grpc_pollset* pollset, jose_header* header,
+ grpc_jwt_claims* claims, const char* audience, const grpc_slice& signature,
+ const char* signed_jwt, size_t signed_jwt_len, void* user_data,
+ grpc_jwt_verification_done_cb cb) {
+ grpc_core::ApplicationCallbackExecCtx callback_exec_ctx;
+ grpc_core::ExecCtx exec_ctx;
+ verifier_cb_ctx* ctx =
+ static_cast<verifier_cb_ctx*>(gpr_zalloc(sizeof(verifier_cb_ctx)));
+ ctx->verifier = verifier;
+ ctx->pollent = grpc_polling_entity_create_from_pollset(pollset);
+ ctx->header = header;
+ ctx->audience = gpr_strdup(audience);
+ ctx->claims = claims;
+ ctx->signature = signature;
+ ctx->signed_data = grpc_slice_from_copied_buffer(signed_jwt, signed_jwt_len);
+ ctx->user_data = user_data;
+ ctx->user_cb = cb;
+
+ return ctx;
+}
+
+void verifier_cb_ctx_destroy(verifier_cb_ctx* ctx) {
+ if (ctx->audience != nullptr) gpr_free(ctx->audience);
+ if (ctx->claims != nullptr) grpc_jwt_claims_destroy(ctx->claims);
+ grpc_slice_unref_internal(ctx->signature);
+ grpc_slice_unref_internal(ctx->signed_data);
+ jose_header_destroy(ctx->header);
+ for (size_t i = 0; i < HTTP_RESPONSE_COUNT; i++) {
+ grpc_http_response_destroy(&ctx->responses[i]);
+ }
+ /* TODO: see what to do with claims... */
+ gpr_free(ctx);
+}
+
+/* --- grpc_jwt_verifier object. --- */
+
+/* Clock skew defaults to one minute. */
+gpr_timespec grpc_jwt_verifier_clock_skew = {60, 0, GPR_TIMESPAN};
+
+/* Max delay defaults to one minute. */
+grpc_millis grpc_jwt_verifier_max_delay = 60 * GPR_MS_PER_SEC;
+
+typedef struct {
+ char* email_domain;
+ char* key_url_prefix;
+} email_key_mapping;
+
+struct grpc_jwt_verifier {
+ email_key_mapping* mappings;
+ size_t num_mappings; /* Should be very few, linear search ok. */
+ size_t allocated_mappings;
+ grpc_httpcli_context http_ctx;
+};
+
+static grpc_json* json_from_http(const grpc_httpcli_response* response) {
+ grpc_json* json = nullptr;
+
+ if (response == nullptr) {
+ gpr_log(GPR_ERROR, "HTTP response is NULL.");
+ return nullptr;
+ }
+ if (response->status != 200) {
+ gpr_log(GPR_ERROR, "Call to http server failed with error %d.",
+ response->status);
+ return nullptr;
+ }
+
+ json = grpc_json_parse_string_with_len(response->body, response->body_length);
+ if (json == nullptr) {
+ gpr_log(GPR_ERROR, "Invalid JSON found in response.");
+ }
+ return json;
+}
+
+static const grpc_json* find_property_by_name(const grpc_json* json,
+ const char* name) {
+ const grpc_json* cur;
+ for (cur = json->child; cur != nullptr; cur = cur->next) {
+ if (strcmp(cur->key, name) == 0) return cur;
+ }
+ return nullptr;
+}
+
+static EVP_PKEY* extract_pkey_from_x509(const char* x509_str) {
+ X509* x509 = nullptr;
+ EVP_PKEY* result = nullptr;
+ BIO* bio = BIO_new(BIO_s_mem());
+ size_t len = strlen(x509_str);
+ GPR_ASSERT(len < INT_MAX);
+ BIO_write(bio, x509_str, static_cast<int>(len));
+ x509 = PEM_read_bio_X509(bio, nullptr, nullptr, nullptr);
+ if (x509 == nullptr) {
+ gpr_log(GPR_ERROR, "Unable to parse x509 cert.");
+ goto end;
+ }
+ result = X509_get_pubkey(x509);
+ if (result == nullptr) {
+ gpr_log(GPR_ERROR, "Cannot find public key in X509 cert.");
+ }
+
+end:
+ BIO_free(bio);
+ X509_free(x509);
+ return result;
+}
+
+static BIGNUM* bignum_from_base64(const char* b64) {
+ BIGNUM* result = nullptr;
+ grpc_slice bin;
+
+ if (b64 == nullptr) return nullptr;
+ bin = grpc_base64_decode(b64, 1);
+ if (GRPC_SLICE_IS_EMPTY(bin)) {
+ gpr_log(GPR_ERROR, "Invalid base64 for big num.");
+ return nullptr;
+ }
+ result = BN_bin2bn(GRPC_SLICE_START_PTR(bin),
+ TSI_SIZE_AS_SIZE(GRPC_SLICE_LENGTH(bin)), nullptr);
+ grpc_slice_unref_internal(bin);
+ return result;
+}
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+
+// Provide compatibility across OpenSSL 1.02 and 1.1.
+static int RSA_set0_key(RSA* r, BIGNUM* n, BIGNUM* e, BIGNUM* d) {
+ /* If the fields n and e in r are NULL, the corresponding input
+ * parameters MUST be non-NULL for n and e. d may be
+ * left NULL (in case only the public key is used).
+ */
+ if ((r->n == nullptr && n == nullptr) || (r->e == nullptr && e == nullptr)) {
+ return 0;
+ }
+
+ if (n != nullptr) {
+ BN_free(r->n);
+ r->n = n;
+ }
+ if (e != nullptr) {
+ BN_free(r->e);
+ r->e = e;
+ }
+ if (d != nullptr) {
+ BN_free(r->d);
+ r->d = d;
+ }
+
+ return 1;
+}
+#endif // OPENSSL_VERSION_NUMBER < 0x10100000L
+
+static EVP_PKEY* pkey_from_jwk(const grpc_json* json, const char* kty) {
+ const grpc_json* key_prop;
+ RSA* rsa = nullptr;
+ EVP_PKEY* result = nullptr;
+ BIGNUM* tmp_n = nullptr;
+ BIGNUM* tmp_e = nullptr;
+
+ GPR_ASSERT(kty != nullptr && json != nullptr);
+ if (strcmp(kty, "RSA") != 0) {
+ gpr_log(GPR_ERROR, "Unsupported key type %s.", kty);
+ goto end;
+ }
+ rsa = RSA_new();
+ if (rsa == nullptr) {
+ gpr_log(GPR_ERROR, "Could not create rsa key.");
+ goto end;
+ }
+ for (key_prop = json->child; key_prop != nullptr; key_prop = key_prop->next) {
+ if (strcmp(key_prop->key, "n") == 0) {
+ tmp_n = bignum_from_base64(validate_string_field(key_prop, "n"));
+ if (tmp_n == nullptr) goto end;
+ } else if (strcmp(key_prop->key, "e") == 0) {
+ tmp_e = bignum_from_base64(validate_string_field(key_prop, "e"));
+ if (tmp_e == nullptr) goto end;
+ }
+ }
+ if (tmp_e == nullptr || tmp_n == nullptr) {
+ gpr_log(GPR_ERROR, "Missing RSA public key field.");
+ goto end;
+ }
+ if (!RSA_set0_key(rsa, tmp_n, tmp_e, nullptr)) {
+ gpr_log(GPR_ERROR, "Cannot set RSA key from inputs.");
+ goto end;
+ }
+ /* RSA_set0_key takes ownership on success. */
+ tmp_n = nullptr;
+ tmp_e = nullptr;
+ result = EVP_PKEY_new();
+ EVP_PKEY_set1_RSA(result, rsa); /* uprefs rsa. */
+
+end:
+ RSA_free(rsa);
+ BN_free(tmp_n);
+ BN_free(tmp_e);
+ return result;
+}
+
+static EVP_PKEY* find_verification_key(const grpc_json* json,
+ const char* header_alg,
+ const char* header_kid) {
+ const grpc_json* jkey;
+ const grpc_json* jwk_keys;
+ /* Try to parse the json as a JWK set:
+ https://tools.ietf.org/html/rfc7517#section-5. */
+ jwk_keys = find_property_by_name(json, "keys");
+ if (jwk_keys == nullptr) {
+ /* Use the google proprietary format which is:
+ { <kid1>: <x5091>, <kid2>: <x5092>, ... } */
+ const grpc_json* cur = find_property_by_name(json, header_kid);
+ if (cur == nullptr) return nullptr;
+ return extract_pkey_from_x509(cur->value);
+ }
+
+ if (jwk_keys->type != GRPC_JSON_ARRAY) {
+ gpr_log(GPR_ERROR,
+ "Unexpected value type of keys property in jwks key set.");
+ return nullptr;
+ }
+ /* Key format is specified in:
+ https://tools.ietf.org/html/rfc7518#section-6. */
+ for (jkey = jwk_keys->child; jkey != nullptr; jkey = jkey->next) {
+ grpc_json* key_prop;
+ const char* alg = nullptr;
+ const char* kid = nullptr;
+ const char* kty = nullptr;
+
+ if (jkey->type != GRPC_JSON_OBJECT) continue;
+ for (key_prop = jkey->child; key_prop != nullptr;
+ key_prop = key_prop->next) {
+ if (strcmp(key_prop->key, "alg") == 0 &&
+ key_prop->type == GRPC_JSON_STRING) {
+ alg = key_prop->value;
+ } else if (strcmp(key_prop->key, "kid") == 0 &&
+ key_prop->type == GRPC_JSON_STRING) {
+ kid = key_prop->value;
+ } else if (strcmp(key_prop->key, "kty") == 0 &&
+ key_prop->type == GRPC_JSON_STRING) {
+ kty = key_prop->value;
+ }
+ }
+ if (alg != nullptr && kid != nullptr && kty != nullptr &&
+ strcmp(kid, header_kid) == 0 && strcmp(alg, header_alg) == 0) {
+ return pkey_from_jwk(jkey, kty);
+ }
+ }
+ gpr_log(GPR_ERROR,
+ "Could not find matching key in key set for kid=%s and alg=%s",
+ header_kid, header_alg);
+ return nullptr;
+}
+
+static int verify_jwt_signature(EVP_PKEY* key, const char* alg,
+ const grpc_slice& signature,
+ const grpc_slice& signed_data) {
+ EVP_MD_CTX* md_ctx = EVP_MD_CTX_create();
+ const EVP_MD* md = evp_md_from_alg(alg);
+ int result = 0;
+
+ GPR_ASSERT(md != nullptr); /* Checked before. */
+ if (md_ctx == nullptr) {
+ gpr_log(GPR_ERROR, "Could not create EVP_MD_CTX.");
+ goto end;
+ }
+ if (EVP_DigestVerifyInit(md_ctx, nullptr, md, nullptr, key) != 1) {
+ gpr_log(GPR_ERROR, "EVP_DigestVerifyInit failed.");
+ goto end;
+ }
+ if (EVP_DigestVerifyUpdate(md_ctx, GRPC_SLICE_START_PTR(signed_data),
+ GRPC_SLICE_LENGTH(signed_data)) != 1) {
+ gpr_log(GPR_ERROR, "EVP_DigestVerifyUpdate failed.");
+ goto end;
+ }
+ if (EVP_DigestVerifyFinal(md_ctx, GRPC_SLICE_START_PTR(signature),
+ GRPC_SLICE_LENGTH(signature)) != 1) {
+ gpr_log(GPR_ERROR, "JWT signature verification failed.");
+ goto end;
+ }
+ result = 1;
+
+end:
+ EVP_MD_CTX_destroy(md_ctx);
+ return result;
+}
+
+static void on_keys_retrieved(void* user_data, grpc_error* error) {
+ verifier_cb_ctx* ctx = static_cast<verifier_cb_ctx*>(user_data);
+ grpc_json* json = json_from_http(&ctx->responses[HTTP_RESPONSE_KEYS]);
+ EVP_PKEY* verification_key = nullptr;
+ grpc_jwt_verifier_status status = GRPC_JWT_VERIFIER_GENERIC_ERROR;
+ grpc_jwt_claims* claims = nullptr;
+
+ if (json == nullptr) {
+ status = GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR;
+ goto end;
+ }
+ verification_key =
+ find_verification_key(json, ctx->header->alg, ctx->header->kid);
+ if (verification_key == nullptr) {
+ gpr_log(GPR_ERROR, "Could not find verification key with kid %s.",
+ ctx->header->kid);
+ status = GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR;
+ goto end;
+ }
+
+ if (!verify_jwt_signature(verification_key, ctx->header->alg, ctx->signature,
+ ctx->signed_data)) {
+ status = GRPC_JWT_VERIFIER_BAD_SIGNATURE;
+ goto end;
+ }
+
+ status = grpc_jwt_claims_check(ctx->claims, ctx->audience);
+ if (status == GRPC_JWT_VERIFIER_OK) {
+ /* Pass ownership. */
+ claims = ctx->claims;
+ ctx->claims = nullptr;
+ }
+
+end:
+ grpc_json_destroy(json);
+ EVP_PKEY_free(verification_key);
+ ctx->user_cb(ctx->user_data, status, claims);
+ verifier_cb_ctx_destroy(ctx);
+}
+
+static void on_openid_config_retrieved(void* user_data, grpc_error* error) {
+ const grpc_json* cur;
+ verifier_cb_ctx* ctx = static_cast<verifier_cb_ctx*>(user_data);
+ const grpc_http_response* response = &ctx->responses[HTTP_RESPONSE_OPENID];
+ grpc_json* json = json_from_http(response);
+ grpc_httpcli_request req;
+ const char* jwks_uri;
+ grpc_resource_quota* resource_quota = nullptr;
+
+ /* TODO(jboeuf): Cache the jwks_uri in order to avoid this hop next time. */
+ if (json == nullptr) goto error;
+ cur = find_property_by_name(json, "jwks_uri");
+ if (cur == nullptr) {
+ gpr_log(GPR_ERROR, "Could not find jwks_uri in openid config.");
+ goto error;
+ }
+ jwks_uri = validate_string_field(cur, "jwks_uri");
+ if (jwks_uri == nullptr) goto error;
+ if (strstr(jwks_uri, "https://") != jwks_uri) {
+ gpr_log(GPR_ERROR, "Invalid non https jwks_uri: %s.", jwks_uri);
+ goto error;
+ }
+ jwks_uri += 8;
+ req.handshaker = &grpc_httpcli_ssl;
+ req.host = gpr_strdup(jwks_uri);
+ req.http.path = const_cast<char*>(strchr(jwks_uri, '/'));
+ if (req.http.path == nullptr) {
+ req.http.path = (char*)"";
+ } else {
+ *(req.host + (req.http.path - jwks_uri)) = '\0';
+ }
+
+ /* TODO(ctiller): Carry the resource_quota in ctx and share it with the host
+ channel. This would allow us to cancel an authentication query when under
+ extreme memory pressure. */
+ resource_quota = grpc_resource_quota_create("jwt_verifier");
+ grpc_httpcli_get(
+ &ctx->verifier->http_ctx, &ctx->pollent, resource_quota, &req,
+ grpc_core::ExecCtx::Get()->Now() + grpc_jwt_verifier_max_delay,
+ GRPC_CLOSURE_CREATE(on_keys_retrieved, ctx, grpc_schedule_on_exec_ctx),
+ &ctx->responses[HTTP_RESPONSE_KEYS]);
+ grpc_resource_quota_unref_internal(resource_quota);
+ grpc_json_destroy(json);
+ gpr_free(req.host);
+ return;
+
+error:
+ grpc_json_destroy(json);
+ ctx->user_cb(ctx->user_data, GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR, nullptr);
+ verifier_cb_ctx_destroy(ctx);
+}
+
+static email_key_mapping* verifier_get_mapping(grpc_jwt_verifier* v,
+ const char* email_domain) {
+ size_t i;
+ if (v->mappings == nullptr) return nullptr;
+ for (i = 0; i < v->num_mappings; i++) {
+ if (strcmp(email_domain, v->mappings[i].email_domain) == 0) {
+ return &v->mappings[i];
+ }
+ }
+ return nullptr;
+}
+
+static void verifier_put_mapping(grpc_jwt_verifier* v, const char* email_domain,
+ const char* key_url_prefix) {
+ email_key_mapping* mapping = verifier_get_mapping(v, email_domain);
+ GPR_ASSERT(v->num_mappings < v->allocated_mappings);
+ if (mapping != nullptr) {
+ gpr_free(mapping->key_url_prefix);
+ mapping->key_url_prefix = gpr_strdup(key_url_prefix);
+ return;
+ }
+ v->mappings[v->num_mappings].email_domain = gpr_strdup(email_domain);
+ v->mappings[v->num_mappings].key_url_prefix = gpr_strdup(key_url_prefix);
+ v->num_mappings++;
+ GPR_ASSERT(v->num_mappings <= v->allocated_mappings);
+}
+
+/* Very non-sophisticated way to detect an email address. Should be good
+ enough for now... */
+const char* grpc_jwt_issuer_email_domain(const char* issuer) {
+ const char* at_sign = strchr(issuer, '@');
+ if (at_sign == nullptr) return nullptr;
+ const char* email_domain = at_sign + 1;
+ if (*email_domain == '\0') return nullptr;
+ const char* dot = strrchr(email_domain, '.');
+ if (dot == nullptr || dot == email_domain) return email_domain;
+ GPR_ASSERT(dot > email_domain);
+ /* There may be a subdomain, we just want the domain. */
+ dot = static_cast<const char*>(gpr_memrchr(
+ (void*)email_domain, '.', static_cast<size_t>(dot - email_domain)));
+ if (dot == nullptr) return email_domain;
+ return dot + 1;
+}
+
+/* Takes ownership of ctx. */
+static void retrieve_key_and_verify(verifier_cb_ctx* ctx) {
+ const char* email_domain;
+ grpc_closure* http_cb;
+ char* path_prefix = nullptr;
+ const char* iss;
+ grpc_httpcli_request req;
+ grpc_resource_quota* resource_quota = nullptr;
+ memset(&req, 0, sizeof(grpc_httpcli_request));
+ req.handshaker = &grpc_httpcli_ssl;
+ http_response_index rsp_idx;
+
+ GPR_ASSERT(ctx != nullptr && ctx->header != nullptr &&
+ ctx->claims != nullptr);
+ iss = ctx->claims->iss;
+ if (ctx->header->kid == nullptr) {
+ gpr_log(GPR_ERROR, "Missing kid in jose header.");
+ goto error;
+ }
+ if (iss == nullptr) {
+ gpr_log(GPR_ERROR, "Missing iss in claims.");
+ goto error;
+ }
+
+ /* This code relies on:
+ https://openid.net/specs/openid-connect-discovery-1_0.html
+ Nobody seems to implement the account/email/webfinger part 2. of the spec
+ so we will rely instead on email/url mappings if we detect such an issuer.
+ Part 4, on the other hand is implemented by both google and salesforce. */
+ email_domain = grpc_jwt_issuer_email_domain(iss);
+ if (email_domain != nullptr) {
+ email_key_mapping* mapping;
+ GPR_ASSERT(ctx->verifier != nullptr);
+ mapping = verifier_get_mapping(ctx->verifier, email_domain);
+ if (mapping == nullptr) {
+ gpr_log(GPR_ERROR, "Missing mapping for issuer email.");
+ goto error;
+ }
+ req.host = gpr_strdup(mapping->key_url_prefix);
+ path_prefix = strchr(req.host, '/');
+ if (path_prefix == nullptr) {
+ gpr_asprintf(&req.http.path, "/%s", iss);
+ } else {
+ *(path_prefix++) = '\0';
+ gpr_asprintf(&req.http.path, "/%s/%s", path_prefix, iss);
+ }
+ http_cb =
+ GRPC_CLOSURE_CREATE(on_keys_retrieved, ctx, grpc_schedule_on_exec_ctx);
+ rsp_idx = HTTP_RESPONSE_KEYS;
+ } else {
+ req.host = gpr_strdup(strstr(iss, "https://") == iss ? iss + 8 : iss);
+ path_prefix = strchr(req.host, '/');
+ if (path_prefix == nullptr) {
+ req.http.path = gpr_strdup(GRPC_OPENID_CONFIG_URL_SUFFIX);
+ } else {
+ *(path_prefix++) = 0;
+ gpr_asprintf(&req.http.path, "/%s%s", path_prefix,
+ GRPC_OPENID_CONFIG_URL_SUFFIX);
+ }
+ http_cb = GRPC_CLOSURE_CREATE(on_openid_config_retrieved, ctx,
+ grpc_schedule_on_exec_ctx);
+ rsp_idx = HTTP_RESPONSE_OPENID;
+ }
+
+ /* TODO(ctiller): Carry the resource_quota in ctx and share it with the host
+ channel. This would allow us to cancel an authentication query when under
+ extreme memory pressure. */
+ resource_quota = grpc_resource_quota_create("jwt_verifier");
+ grpc_httpcli_get(
+ &ctx->verifier->http_ctx, &ctx->pollent, resource_quota, &req,
+ grpc_core::ExecCtx::Get()->Now() + grpc_jwt_verifier_max_delay, http_cb,
+ &ctx->responses[rsp_idx]);
+ grpc_resource_quota_unref_internal(resource_quota);
+ gpr_free(req.host);
+ gpr_free(req.http.path);
+ return;
+
+error:
+ ctx->user_cb(ctx->user_data, GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR, nullptr);
+ verifier_cb_ctx_destroy(ctx);
+}
+
+void grpc_jwt_verifier_verify(grpc_jwt_verifier* verifier,
+ grpc_pollset* pollset, const char* jwt,
+ const char* audience,
+ grpc_jwt_verification_done_cb cb,
+ void* user_data) {
+ const char* dot = nullptr;
+ grpc_json* json;
+ jose_header* header = nullptr;
+ grpc_jwt_claims* claims = nullptr;
+ grpc_slice header_buffer;
+ grpc_slice claims_buffer;
+ grpc_slice signature;
+ size_t signed_jwt_len;
+ const char* cur = jwt;
+
+ GPR_ASSERT(verifier != nullptr && jwt != nullptr && audience != nullptr &&
+ cb != nullptr);
+ dot = strchr(cur, '.');
+ if (dot == nullptr) goto error;
+ json = parse_json_part_from_jwt(cur, static_cast<size_t>(dot - cur),
+ &header_buffer);
+ if (json == nullptr) goto error;
+ header = jose_header_from_json(json, header_buffer);
+ if (header == nullptr) goto error;
+
+ cur = dot + 1;
+ dot = strchr(cur, '.');
+ if (dot == nullptr) goto error;
+ json = parse_json_part_from_jwt(cur, static_cast<size_t>(dot - cur),
+ &claims_buffer);
+ if (json == nullptr) goto error;
+ claims = grpc_jwt_claims_from_json(json, claims_buffer);
+ if (claims == nullptr) goto error;
+
+ signed_jwt_len = static_cast<size_t>(dot - jwt);
+ cur = dot + 1;
+ signature = grpc_base64_decode(cur, 1);
+ if (GRPC_SLICE_IS_EMPTY(signature)) goto error;
+ retrieve_key_and_verify(
+ verifier_cb_ctx_create(verifier, pollset, header, claims, audience,
+ signature, jwt, signed_jwt_len, user_data, cb));
+ return;
+
+error:
+ if (header != nullptr) jose_header_destroy(header);
+ if (claims != nullptr) grpc_jwt_claims_destroy(claims);
+ cb(user_data, GRPC_JWT_VERIFIER_BAD_FORMAT, nullptr);
+}
+
+grpc_jwt_verifier* grpc_jwt_verifier_create(
+ const grpc_jwt_verifier_email_domain_key_url_mapping* mappings,
+ size_t num_mappings) {
+ grpc_jwt_verifier* v =
+ static_cast<grpc_jwt_verifier*>(gpr_zalloc(sizeof(grpc_jwt_verifier)));
+ grpc_httpcli_context_init(&v->http_ctx);
+
+ /* We know at least of one mapping. */
+ v->allocated_mappings = 1 + num_mappings;
+ v->mappings = static_cast<email_key_mapping*>(
+ gpr_malloc(v->allocated_mappings * sizeof(email_key_mapping)));
+ verifier_put_mapping(v, GRPC_GOOGLE_SERVICE_ACCOUNTS_EMAIL_DOMAIN,
+ GRPC_GOOGLE_SERVICE_ACCOUNTS_KEY_URL_PREFIX);
+ /* User-Provided mappings. */
+ if (mappings != nullptr) {
+ size_t i;
+ for (i = 0; i < num_mappings; i++) {
+ verifier_put_mapping(v, mappings[i].email_domain,
+ mappings[i].key_url_prefix);
+ }
+ }
+ return v;
+}
+
+void grpc_jwt_verifier_destroy(grpc_jwt_verifier* v) {
+ size_t i;
+ if (v == nullptr) return;
+ grpc_httpcli_context_destroy(&v->http_ctx);
+ if (v->mappings != nullptr) {
+ for (i = 0; i < v->num_mappings; i++) {
+ gpr_free(v->mappings[i].email_domain);
+ gpr_free(v->mappings[i].key_url_prefix);
+ }
+ gpr_free(v->mappings);
+ }
+ gpr_free(v);
+}
git://repos.xcallymotion.com / motion2.git / blobdiff