Merge branch 'bugfix/backport_certificate_bundle_fixes_v4.3' into 'release/v4.3'

Certificate bundle fixes (v4.3)

See merge request espressif/esp-idf!18353
This commit is contained in:
Jiang Jiang Jian
2022-06-09 11:13:41 +08:00
8 changed files with 1019 additions and 931 deletions

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@ -15,9 +15,9 @@ if(CONFIG_MBEDTLS_CERTIFICATE_BUNDLE)
set(GENERATE_CERT_BUNDLEPY ${python} ${COMPONENT_DIR}/esp_crt_bundle/gen_crt_bundle.py)
if(CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_DEFAULT_FULL)
list(APPEND crt_paths ${DEFAULT_CRT_DIR}/cacrt_all.pem)
list(APPEND crt_paths ${DEFAULT_CRT_DIR}/cacrt_all.pem ${DEFAULT_CRT_DIR}/cacrt_local.pem)
elseif(CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_DEFAULT_CMN)
list(APPEND crt_paths ${DEFAULT_CRT_DIR}/cacrt_all.pem)
list(APPEND crt_paths ${DEFAULT_CRT_DIR}/cacrt_all.pem ${DEFAULT_CRT_DIR}/cacrt_local.pem)
list(APPEND args --filter ${DEFAULT_CRT_DIR}/cmn_crt_authorities.csv)
endif()

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@ -323,6 +323,12 @@ menu "mbedTLS"
help
Name of the custom certificate directory or file. This path is evaluated
relative to the project root directory.
config MBEDTLS_CERTIFICATE_BUNDLE_MAX_CERTS
int "Maximum no of certificates allowed in certificate bundle"
default 200
depends on MBEDTLS_CERTIFICATE_BUNDLE
endmenu
config MBEDTLS_ECP_RESTARTABLE

File diff suppressed because it is too large Load Diff

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@ -0,0 +1,33 @@
##
## Local CA Root Certificates
##
## Local CA Root Certificates that gets appended to "cacrt_all.pem"
## letsencrypt has generated a cross signed certificate with DST ROOT CA X3
## for compatibility after the expiry of the certificate.
## The new certificate has the ISSUER name as DST Root CA X3.
## Thus, the handshake fails if esp_crt_bundle does not find the
## respective name in the crt_bundle.
## Keeping this certificate for compatibility reasons.
## This will be removed once the cross-signed certificate expires in Sep 2024.
DST Root CA X3
==============
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

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@ -17,7 +17,6 @@
#include <esp_system.h>
#include "esp_crt_bundle.h"
#include "esp_log.h"
#include "esp_err.h"
#define BUNDLE_HEADER_OFFSET 2
#define CRT_HEADER_OFFSET 4
@ -157,27 +156,56 @@ int esp_crt_verify_callback(void *buf, mbedtls_x509_crt *crt, int depth, uint32_
/* Initialize the bundle into an array so we can do binary search for certs,
the bundle generated by the python utility is already presorted by subject name
*/
static esp_err_t esp_crt_bundle_init(const uint8_t *x509_bundle)
static esp_err_t esp_crt_bundle_init(const uint8_t *x509_bundle, size_t bundle_size)
{
s_crt_bundle.num_certs = (x509_bundle[0] << 8) | x509_bundle[1];
s_crt_bundle.crts = calloc(s_crt_bundle.num_certs, sizeof(x509_bundle));
if (bundle_size < BUNDLE_HEADER_OFFSET + CRT_HEADER_OFFSET) {
ESP_LOGE(TAG, "Invalid certificate bundle");
return ESP_ERR_INVALID_ARG;
}
if (s_crt_bundle.crts == NULL) {
uint16_t num_certs = (x509_bundle[0] << 8) | x509_bundle[1];
if (num_certs > CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_MAX_CERTS) {
ESP_LOGE(TAG, "No. of certs in the certificate bundle = %d exceeds\n"
"Max allowed certificates in the certificate bundle = %d\n"
"Please update the menuconfig option with appropriate value", num_certs, CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_MAX_CERTS);
return ESP_ERR_INVALID_ARG;
}
const uint8_t **crts = calloc(num_certs, sizeof(x509_bundle));
if (crts == NULL) {
ESP_LOGE(TAG, "Unable to allocate memory for bundle");
return ESP_ERR_NO_MEM;
}
const uint8_t *cur_crt;
/* This is the maximum region that is allowed to access */
const uint8_t *bundle_end = x509_bundle + bundle_size;
cur_crt = x509_bundle + BUNDLE_HEADER_OFFSET;
for (int i = 0; i < s_crt_bundle.num_certs; i++) {
s_crt_bundle.crts[i] = cur_crt;
for (int i = 0; i < num_certs; i++) {
crts[i] = cur_crt;
if (cur_crt + CRT_HEADER_OFFSET > bundle_end) {
ESP_LOGE(TAG, "Invalid certificate bundle");
free(crts);
return ESP_ERR_INVALID_ARG;
}
size_t name_len = cur_crt[0] << 8 | cur_crt[1];
size_t key_len = cur_crt[2] << 8 | cur_crt[3];
cur_crt = cur_crt + CRT_HEADER_OFFSET + name_len + key_len;
}
if (cur_crt > bundle_end) {
ESP_LOGE(TAG, "Invalid certificate bundle");
free(crts);
return ESP_ERR_INVALID_ARG;
}
/* The previous crt bundle is only updated when initialization of the
* current crt_bundle is successful */
/* Free previous crt_bundle */
free(s_crt_bundle.crts);
s_crt_bundle.num_certs = num_certs;
s_crt_bundle.crts = crts;
return ESP_OK;
}
@ -186,7 +214,7 @@ esp_err_t esp_crt_bundle_attach(void *conf)
esp_err_t ret = ESP_OK;
// If no bundle has been set by the user then use the bundle embedded in the binary
if (s_crt_bundle.crts == NULL) {
ret = esp_crt_bundle_init(x509_crt_imported_bundle_bin_start);
ret = esp_crt_bundle_init(x509_crt_imported_bundle_bin_start, x509_crt_imported_bundle_bin_end - x509_crt_imported_bundle_bin_start);
}
if (ret != ESP_OK) {
@ -217,9 +245,7 @@ void esp_crt_bundle_detach(mbedtls_ssl_config *conf)
}
}
void esp_crt_bundle_set(const uint8_t *x509_bundle)
esp_err_t esp_crt_bundle_set(const uint8_t *x509_bundle, size_t bundle_size)
{
// Free any previously used bundle
free(s_crt_bundle.crts);
esp_crt_bundle_init(x509_bundle);
return esp_crt_bundle_init(x509_bundle, bundle_size);
}

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@ -1,21 +1,14 @@
// Copyright 2017-2019 Espressif Systems (Shanghai) PTE LTD
//
// 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.
/*
* SPDX-FileCopyrightText: 2017-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef _ESP_CRT_BUNDLE_H_
#define _ESP_CRT_BUNDLE_H_
#include "esp_err.h"
#include "mbedtls/ssl.h"
#ifdef __cplusplus
@ -52,13 +45,19 @@ void esp_crt_bundle_detach(mbedtls_ssl_config *conf);
/**
* @brief Set the default certificate bundle used for verification
*
* Overrides the default certificate bundle. In most use cases the bundle should be
* Overrides the default certificate bundle only in case of successful initialization. In most use cases the bundle should be
* set through menuconfig. The bundle needs to be sorted by subject name since binary search is
* used to find certificates.
*
* @param[in] x509_bundle A pointer to the certificate bundle.
*
* @param[in] bundle_size Size of the certificate bundle in bytes.
*
* @return
* - ESP_OK if adding certificates was successful.
* - Other if an error occured or an action must be taken by the calling process.
*/
void esp_crt_bundle_set(const uint8_t *x509_bundle);
esp_err_t esp_crt_bundle_set(const uint8_t *x509_bundle, size_t bundle_size);
#ifdef __cplusplus

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@ -35,6 +35,7 @@
#include "mbedtls/debug.h"
#include "esp_crt_bundle.h"
// #include "esp_random.h"
#include "unity.h"
#include "test_utils.h"
@ -253,7 +254,7 @@ esp_err_t client_setup(mbedtls_endpoint_t *client)
return ESP_OK;
}
int client_task(const uint8_t *bundle, esp_crt_validate_res_t *res)
int client_task(const uint8_t *bundle, size_t bundle_size, esp_crt_validate_res_t *res)
{
int ret = ESP_FAIL;
@ -269,7 +270,7 @@ int client_task(const uint8_t *bundle, esp_crt_validate_res_t *res)
esp_crt_bundle_attach(&client.conf);
if (bundle) {
/* Set a bundle different from the menuconfig bundle */
esp_crt_bundle_set(bundle);
esp_crt_bundle_set(bundle, bundle_size);
}
ESP_LOGI(TAG, "Connecting to %s:%s...", SERVER_ADDRESS, SERVER_PORT);
@ -329,11 +330,11 @@ TEST_CASE("custom certificate bundle", "[mbedtls]")
}
/* Test with default crt bundle that doesnt contain the ca crt */
client_task(NULL, &validate_res);
client_task(NULL, 0, &validate_res);
TEST_ASSERT(validate_res == ESP_CRT_VALIDATE_FAIL);
/* Test with bundle that does contain the CA crt */
client_task(server_cert_bundle_start, &validate_res);
client_task(server_cert_bundle_start, server_cert_bundle_end - server_cert_bundle_start, &validate_res);
TEST_ASSERT(validate_res == ESP_CRT_VALIDATE_OK);
exit_flag = true;
@ -390,3 +391,50 @@ TEST_CASE("custom certificate bundle - wrong signature", "[mbedtls]")
esp_crt_bundle_detach(NULL);
}
TEST_CASE("custom certificate bundle init API - bound checking", "[mbedtls]")
{
uint8_t test_bundle[256] = {0};
esp_err_t esp_ret;
/* The API should fail with bundle size given as 1 */
esp_ret = esp_crt_bundle_set(test_bundle, 1);
TEST_ASSERT( esp_ret == ESP_ERR_INVALID_ARG);
/* Check that the esp_crt_bundle_set API will not accept a bundle
* which has more no. of certs than configured in
* CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_MAX_CERTS */
uint8_t rand;
esp_fill_random(&rand, 1);
test_bundle[0] = rand;
/* Make sure that the number of certs will always be greater than
* CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_MAX_CERTS */
test_bundle[1] = rand + CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_MAX_CERTS;
esp_ret = esp_crt_bundle_set(test_bundle, sizeof(test_bundle));
TEST_ASSERT( esp_ret == ESP_ERR_INVALID_ARG);
/* The API should fail with bundle_size < BUNDLE_HEADER_OFFSET (2) + CRT_HEADER_OFFSET (4) */
test_bundle[0] = 0;
test_bundle[1] = 1; /* set num_certs = 1 */
esp_ret = esp_crt_bundle_set(test_bundle, 5);
TEST_ASSERT(esp_ret == ESP_ERR_INVALID_ARG);
/* Cert number is greater than actual certs present, The API should fail */
/* Actual No. of certs present in bundle = 1, setting num_certs to 5 */
test_bundle[1] = 5; /* num_certs */
test_bundle[3] = 5; /* cert_1_name_len */
test_bundle[5] = 10; /* cert_1_pub_key_len */
/* Actual bundle size becomes BUNDLE_HEADER_OFFSET (2) + CRT_HEADER_OFFSET (4) + cert_1_name_len(5) + cert_1_pub_key_len(10)
* i.e. 21 bytes */
esp_ret = esp_crt_bundle_set(test_bundle, 21);
TEST_ASSERT(esp_ret == ESP_ERR_INVALID_ARG);
/* The API should fail if bundle_size < BUNDLE_HEADER_OFFSET (2) + CRT_HEADER_OFFSET (4) + cert_1_name_len(5) + cert_1_pub_key_len(10) */
esp_ret = esp_crt_bundle_set(test_bundle, 20);
TEST_ASSERT(esp_ret == ESP_ERR_INVALID_ARG);
esp_crt_bundle_detach(NULL);
}

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@ -12,7 +12,7 @@ The bundle comes with the complete list of root certificates from Mozillas NS
When generating the bundle you may choose between:
* The full root certificate bundle from Mozilla, containing more than 130 certificates. The current bundle was updated Wed Jan 23 04:12:09 2019 GMT.
* The full root certificate bundle from Mozilla, containing more than 130 certificates. The current bundle was updated Tue Apr 26 03:12:05 2022 GMT.
* A pre-selected filter list of the name of the most commonly used root certificates, reducing the amount of certificates to around 35 while still having around 90 % coverage according to market share statistics.
In addition it is possible to specify a path to a certificate file or a directory containing certificates which then will be added to the generated bundle.