ct_test.c

/*
 * Tests the Certificate Transparency public API.
 *
 * Author:      Rob Percival (robpercival@google.com)
 *
 * ====================================================================
 * Copyright (c) 2016 The OpenSSL Project.    All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *        notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. All advertising materials mentioning features or use of this
 *        software must display the following acknowledgment:
 *        "This product includes software developed by the OpenSSL Project
 *        for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *        endorse or promote products derived from this software without
 *        prior written permission. For written permission, please contact
 *        licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *        nor may "OpenSSL" appear in their names without prior written
 *        permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *        acknowledgment:
 *        "This product includes software developed by the OpenSSL Project
 *        for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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 <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/ct.h>
#include <openssl/err.h>
#include <openssl/pem.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include "testutil.h"

#ifndef OPENSSL_NO_CT

/* Used when declaring buffers to read text files into */
#define CT_TEST_MAX_FILE_SIZE 8096

static char *certs_dir = NULL;
static char *ct_dir = NULL;

typedef struct ct_test_fixture {
    const char *test_case_name;
    /* The CT log store to use during tests */
    CTLOG_STORE* ctlog_store;
    /* Set the following to test handling of SCTs in X509 certificates */
    const char *certs_dir;
    char *certificate_file;
    char *issuer_file;
    int expected_sct_count;
    /* Set the following to test handling of SCTs in TLS format */
    const unsigned char *tls_sct;
    size_t tls_sct_len;
    SCT *sct;
    /*
     * A file to load the expected SCT text from.
     * This text will be compared to the actual text output during the test.
     * A maximum of |CT_TEST_MAX_FILE_SIZE| bytes will be read of this file.
     */
    const char *sct_dir;
    const char *sct_text_file;
    /* Whether to test the validity of the SCT(s) */
    int test_validity;

} CT_TEST_FIXTURE;

static CT_TEST_FIXTURE set_up(const char *const test_case_name)
{
    CT_TEST_FIXTURE fixture;
    int setup_ok = 1;
    CTLOG_STORE *ctlog_store = CTLOG_STORE_new();

    if (ctlog_store == NULL) {
        setup_ok = 0;
        fprintf(stderr, "Failed to create a new CT log store\n");
        goto end;
    }

    if (CTLOG_STORE_load_default_file(ctlog_store) != 1) {
        setup_ok = 0;
        fprintf(stderr, "Failed to load CT log list\n");
        goto end;
    }

    memset(&fixture, 0, sizeof(fixture));
    fixture.test_case_name = test_case_name;
    fixture.ctlog_store = ctlog_store;

end:
    if (!setup_ok) {
        exit(EXIT_FAILURE);
    }
    return fixture;
}

static void tear_down(CT_TEST_FIXTURE fixture)
{
    CTLOG_STORE_free(fixture.ctlog_store);
    SCT_free(fixture.sct);
    ERR_print_errors_fp(stderr);
}

static char *mk_file_path(const char *dir, const char *file)
{
    char *full_file = NULL;
    size_t full_file_l = 0;
    const char *sep = "";
#ifndef OPENSSL_SYS_VMS
    sep = "/";
#endif

    full_file_l = strlen(dir) + strlen(sep) + strlen(file) + 1;
    full_file = OPENSSL_zalloc(full_file_l);
    if (full_file != NULL) {
        OPENSSL_strlcpy(full_file, dir, full_file_l);
        OPENSSL_strlcat(full_file, sep, full_file_l);
        OPENSSL_strlcat(full_file, file, full_file_l);
    }

    return full_file;
}

static X509 *load_pem_cert(const char *dir, const char *file)
{
    X509 *cert = NULL;
    char *file_path = mk_file_path(dir, file);

    if (file_path != NULL) {
        BIO *cert_io = BIO_new_file(file_path, "r");
        OPENSSL_free(file_path);

        if (cert_io != NULL)
            cert = PEM_read_bio_X509(cert_io, NULL, NULL, NULL);

        BIO_free(cert_io);
    }
    return cert;
}

static int read_text_file(const char *dir, const char *file,
                          char *buffer, int buffer_length)
{
    int result = -1;
    char *file_path = mk_file_path(dir, file);

    if (file_path != NULL) {
        BIO *file_io = BIO_new_file(file_path, "r");
        OPENSSL_free(file_path);

        if (file_io != NULL) {
            result = BIO_read(file_io, buffer, buffer_length);
            BIO_free(file_io);
        }
    }

    return result;
}

static int compare_sct_printout(SCT *sct,
    const char *expected_output)
{
    BIO *text_buffer = NULL;
    char *actual_output = NULL;
    int result = 1;

    text_buffer = BIO_new(BIO_s_mem());
    if (text_buffer == NULL) {
        fprintf(stderr, "Unable to allocate buffer\n");
        goto end;
    }

    SCT_print(sct, text_buffer, 0);

    /* Append null terminator because we're about to use the buffer contents
    * as a string. */
    if (BIO_write(text_buffer, "\0", 1) != 1) {
        fprintf(stderr, "Failed to append null terminator to SCT text\n");
        goto end;
    }

    BIO_get_mem_data(text_buffer, &actual_output);
    result = strcmp(actual_output, expected_output);

    if (result != 0) {
        fprintf(stderr,
            "Expected SCT printout:\n%s\nActual SCT printout:\n%s\n",
            expected_output, actual_output);
    }

end:
    BIO_free(text_buffer);
    return result;
}

static int compare_extension_printout(X509_EXTENSION *extension,
                                      const char *expected_output)
{
    BIO *text_buffer = NULL;
    char *actual_output = NULL;
    int result = 1;

    text_buffer = BIO_new(BIO_s_mem());
    if (text_buffer == NULL) {
        fprintf(stderr, "Unable to allocate buffer\n");
        goto end;
    }

    if (!X509V3_EXT_print(text_buffer, extension, X509V3_EXT_DEFAULT, 0)) {
        fprintf(stderr, "Failed to print extension\n");
        goto end;
    }

    /* Append null terminator because we're about to use the buffer contents
     * as a string. */
    if (BIO_write(text_buffer, "\0", 1) != 1) {
        fprintf(stderr, "Failed to append null terminator to extension text\n");
        goto end;
    }

    BIO_get_mem_data(text_buffer, &actual_output);
    result = strcmp(actual_output, expected_output);

    if (result != 0) {
        fprintf(stderr,
                "Expected SCT printout:\n%s\nActual SCT printout:\n%s\n",
                expected_output, actual_output);
    }

end:
    BIO_free(text_buffer);
    return result;
}

static int execute_cert_test(CT_TEST_FIXTURE fixture)
{
    int test_failed = 0;
    X509 *cert = NULL, *issuer = NULL;
    STACK_OF(SCT) *scts = NULL;
    SCT *sct = NULL;
    char expected_sct_text[CT_TEST_MAX_FILE_SIZE];
    int sct_text_len = 0;
    unsigned char *tls_sct = NULL;
    size_t tls_sct_len = 0;
    CT_POLICY_EVAL_CTX *ct_policy_ctx = CT_POLICY_EVAL_CTX_new();

    if (fixture.sct_text_file != NULL) {
        sct_text_len = read_text_file(fixture.sct_dir, fixture.sct_text_file,
                                      expected_sct_text,
                                      CT_TEST_MAX_FILE_SIZE - 1);

        if (sct_text_len < 0) {
            test_failed = 1;
            fprintf(stderr, "Test data file not found: %s\n",
                fixture.sct_text_file);
            goto end;
        }

        expected_sct_text[sct_text_len] = '\0';
    }

    CT_POLICY_EVAL_CTX_set0_log_store(ct_policy_ctx, fixture.ctlog_store);

    if (fixture.certificate_file != NULL) {
        int sct_extension_index;
        X509_EXTENSION *sct_extension = NULL;
        cert = load_pem_cert(fixture.certs_dir, fixture.certificate_file);

        if (cert == NULL) {
            test_failed = 1;
            fprintf(stderr, "Unable to load certificate: %s\n",
                fixture.certificate_file);
            goto end;
        }

        CT_POLICY_EVAL_CTX_set0_cert(ct_policy_ctx, cert);

        if (fixture.issuer_file != NULL) {
            issuer = load_pem_cert(fixture.certs_dir, fixture.issuer_file);

            if (issuer == NULL) {
                test_failed = 1;
                fprintf(stderr, "Unable to load issuer certificate: %s\n",
                        fixture.issuer_file);
                goto end;
            }

            CT_POLICY_EVAL_CTX_set0_issuer(ct_policy_ctx, issuer);
        }

        sct_extension_index =
                X509_get_ext_by_NID(cert, NID_ct_precert_scts, -1);
        sct_extension = X509_get_ext(cert, sct_extension_index);
        if (fixture.expected_sct_count > 0) {
            if (sct_extension == NULL) {
                test_failed = 1;
                fprintf(stderr, "SCT extension not found in: %s\n",
                    fixture.certificate_file);
                goto end;
            }

            if (fixture.sct_text_file) {
                test_failed = compare_extension_printout(sct_extension,
                                                    expected_sct_text);
                if (test_failed != 0)
                    goto end;
            }

            if (fixture.test_validity) {
                int are_scts_validated = 0;
                int i;

                scts = X509V3_EXT_d2i(sct_extension);
                for (i = 0; i < sk_SCT_num(scts); ++i) {
                    SCT *sct_i = sk_SCT_value(scts, i);

                    if (!SCT_set_source(sct_i, SCT_SOURCE_X509V3_EXTENSION)) {
                        fprintf(stderr,
                                "Error setting SCT source to X509v3 extension\n");
                        test_failed = 1;
                        goto end;
                    }
                }

                are_scts_validated = SCT_LIST_validate(scts, ct_policy_ctx);
                if (are_scts_validated < 0) {
                    fprintf(stderr, "Error verifying SCTs\n");
                    test_failed = 1;
                } else if (!are_scts_validated) {
                    int invalid_sct_count = 0;
                    int valid_sct_count = 0;

                    for (i = 0; i < sk_SCT_num(scts); ++i) {
                        SCT *sct_i = sk_SCT_value(scts, i);
                        switch (SCT_get_validation_status(sct_i)) {
                        case SCT_VALIDATION_STATUS_VALID:
                            ++valid_sct_count;
                            break;
                        case SCT_VALIDATION_STATUS_INVALID:
                            ++invalid_sct_count;
                            break;
                        default:
                            /* Ignore other validation statuses. */
                            break;
                        }
                    }

                    if (valid_sct_count != fixture.expected_sct_count) {
                        int unverified_sct_count = sk_SCT_num(scts) -
                                invalid_sct_count - valid_sct_count;

                        fprintf(stderr,
                                "%d SCTs failed verification\n"
                                "%d SCTs passed verification (%d expected)\n"
                                "%d SCTs were unverified\n",
                                invalid_sct_count,
                                valid_sct_count,
                                fixture.expected_sct_count,
                                unverified_sct_count);
                    }
                    test_failed = 1;
                }

                if (test_failed != 0)
                    goto end;
            }
        } else if (sct_extension != NULL) {
            test_failed = 1;
            fprintf(stderr,
                    "Expected no SCTs, but found SCT extension in: %s\n",
                    fixture.certificate_file);
            goto end;
        }
    }

    if (fixture.tls_sct != NULL) {
        const unsigned char *p = fixture.tls_sct;
        if (o2i_SCT(&sct, &p, fixture.tls_sct_len) == NULL) {
            test_failed = 1;
            fprintf(stderr, "Failed to decode SCT from TLS format\n");
            goto end;
        }

        if (fixture.sct_text_file) {
            test_failed = compare_sct_printout(sct, expected_sct_text);
            if (test_failed != 0)
                goto end;
        }

        tls_sct_len = i2o_SCT(sct, &tls_sct);
        if (tls_sct_len != fixture.tls_sct_len ||
            memcmp(fixture.tls_sct, tls_sct, tls_sct_len) != 0) {
            test_failed = 1;
            fprintf(stderr, "Failed to encode SCT into TLS format correctly\n");
            goto end;
        }

        if (fixture.test_validity && cert != NULL) {
            int is_sct_validated = SCT_validate(sct, ct_policy_ctx);
            if (is_sct_validated < 0) {
                test_failed = 1;
                fprintf(stderr, "Error validating SCT\n");
                goto end;
            } else if (!is_sct_validated) {
                test_failed = 1;
                fprintf(stderr, "SCT failed verification\n");
                goto end;
            }
        }
    }

end:
    X509_free(cert);
    X509_free(issuer);
    SCT_LIST_free(scts);
    SCT_free(sct);
    CT_POLICY_EVAL_CTX_free(ct_policy_ctx);
    OPENSSL_free(tls_sct);
    return test_failed;
}

#define SETUP_CT_TEST_FIXTURE() SETUP_TEST_FIXTURE(CT_TEST_FIXTURE, set_up)
#define EXECUTE_CT_TEST() EXECUTE_TEST(execute_cert_test, tear_down)

static int test_no_scts_in_certificate()
{
    SETUP_CT_TEST_FIXTURE();
    fixture.certs_dir = certs_dir;
    fixture.certificate_file = "leaf.pem";
    fixture.issuer_file = "subinterCA.pem";
    fixture.expected_sct_count = 0;
    EXECUTE_CT_TEST();
}

static int test_one_sct_in_certificate()
{
    SETUP_CT_TEST_FIXTURE();
    fixture.certs_dir = certs_dir;
    fixture.certificate_file = "embeddedSCTs1.pem";
    fixture.issuer_file = "embeddedSCTs1_issuer.pem";
    fixture.expected_sct_count = 1;
    fixture.sct_dir = certs_dir;
    fixture.sct_text_file = "embeddedSCTs1.sct";
    EXECUTE_CT_TEST();
}

static int test_multiple_scts_in_certificate()
{
    SETUP_CT_TEST_FIXTURE();
    fixture.certs_dir = certs_dir;
    fixture.certificate_file = "embeddedSCTs3.pem";
    fixture.issuer_file = "embeddedSCTs3_issuer.pem";
    fixture.expected_sct_count = 3;
    fixture.sct_dir = certs_dir;
    fixture.sct_text_file = "embeddedSCTs3.sct";
    EXECUTE_CT_TEST();
}

static int test_verify_one_sct()
{
    SETUP_CT_TEST_FIXTURE();
    fixture.certs_dir = certs_dir;
    fixture.certificate_file = "embeddedSCTs1.pem";
    fixture.issuer_file = "embeddedSCTs1_issuer.pem";
    fixture.expected_sct_count = 1;
    fixture.test_validity = 1;
    EXECUTE_CT_TEST();
}

static int test_verify_multiple_scts()
{
    SETUP_CT_TEST_FIXTURE();
    fixture.certs_dir = certs_dir;
    fixture.certificate_file = "embeddedSCTs3.pem";
    fixture.issuer_file = "embeddedSCTs3_issuer.pem";
    fixture.expected_sct_count = 3;
    fixture.test_validity = 1;
    EXECUTE_CT_TEST();
}

static int test_decode_tls_sct()
{
    const unsigned char tls_sct[] = "\x00" /* version */
        /* log ID */
        "\xDF\x1C\x2E\xC1\x15\x00\x94\x52\x47\xA9\x61\x68\x32\x5D\xDC\x5C\x79"
        "\x59\xE8\xF7\xC6\xD3\x88\xFC\x00\x2E\x0B\xBD\x3F\x74\xD7\x64"
        "\x00\x00\x01\x3D\xDB\x27\xDF\x93" /* timestamp */
        "\x00\x00" /* extensions length */
        "" /* extensions */
        "\x04\x03" /* hash and signature algorithms */
        "\x00\x47" /* signature length */
        /* signature */
        "\x30\x45\x02\x20\x48\x2F\x67\x51\xAF\x35\xDB\xA6\x54\x36\xBE\x1F\xD6"
        "\x64\x0F\x3D\xBF\x9A\x41\x42\x94\x95\x92\x45\x30\x28\x8F\xA3\xE5\xE2"
        "\x3E\x06\x02\x21\x00\xE4\xED\xC0\xDB\x3A\xC5\x72\xB1\xE2\xF5\xE8\xAB"
        "\x6A\x68\x06\x53\x98\x7D\xCF\x41\x02\x7D\xFE\xFF\xA1\x05\x51\x9D\x89"
        "\xED\xBF\x08";

    SETUP_CT_TEST_FIXTURE();
    fixture.tls_sct = tls_sct;
    fixture.tls_sct_len = 118;
    fixture.sct_dir = ct_dir;
    fixture.sct_text_file = "tls1.sct";
    EXECUTE_CT_TEST();
}

static int test_encode_tls_sct()
{
    const unsigned char log_id[] = "\xDF\x1C\x2E\xC1\x15\x00\x94\x52\x47\xA9"
            "\x61\x68\x32\x5D\xDC\x5C\x79\x59\xE8\xF7\xC6\xD3\x88\xFC\x00\x2E"
            "\x0B\xBD\x3F\x74\xD7\x64";

    const unsigned char signature[] = "\x45\x02\x20\x48\x2F\x67\x51\xAF\x35"
            "\xDB\xA6\x54\x36\xBE\x1F\xD6\x64\x0F\x3D\xBF\x9A\x41\x42\x94\x95"
            "\x92\x45\x30\x28\x8F\xA3\xE5\xE2\x3E\x06\x02\x21\x00\xE4\xED\xC0"
            "\xDB\x3A\xC5\x72\xB1\xE2\xF5\xE8\xAB\x6A\x68\x06\x53\x98\x7D\xCF"
            "\x41\x02\x7D\xFE\xFF\xA1\x05\x51\x9D\x89\xED\xBF\x08";

    SETUP_CT_TEST_FIXTURE();

    SCT *sct = SCT_new();
    if (!SCT_set_version(sct, SCT_VERSION_V1)) {
        fprintf(stderr, "Failed to set SCT version\n");
        return 1;
    }
    if (!SCT_set1_log_id(sct, log_id, 32)) {
        fprintf(stderr, "Failed to set SCT log ID\n");
        return 1;
    }
    SCT_set_timestamp(sct, 1);
    if (!SCT_set_signature_nid(sct, NID_ecdsa_with_SHA256)) {
        fprintf(stderr, "Failed to set SCT signature NID\n");
        return 1;
    }
    if (!SCT_set1_signature(sct, signature, 71)) {
        fprintf(stderr, "Failed to set SCT signature\n");
        return 1;
    }
    fixture.sct = sct;
    fixture.sct_dir = ct_dir;
    fixture.sct_text_file = "tls1.sct";
    EXECUTE_CT_TEST();
}

int main(int argc, char *argv[])
{
    int result = 0;
    char *tmp_env = NULL;

    tmp_env = getenv("CT_DIR");
    ct_dir = OPENSSL_strdup(tmp_env != NULL ? tmp_env : "ct");
    tmp_env = getenv("CERTS_DIR");
    certs_dir = OPENSSL_strdup(tmp_env != NULL ? tmp_env : "certs");

    ADD_TEST(test_no_scts_in_certificate);
    ADD_TEST(test_one_sct_in_certificate);
    ADD_TEST(test_multiple_scts_in_certificate);
    ADD_TEST(test_verify_one_sct);
    ADD_TEST(test_verify_multiple_scts);
    ADD_TEST(test_decode_tls_sct);
    ADD_TEST(test_encode_tls_sct);

    result = run_tests(argv[0]);
    ERR_print_errors_fp(stderr);

    OPENSSL_free(ct_dir);
    OPENSSL_free(certs_dir);

    return result;
}

#else /* OPENSSL_NO_CT */

int main(int argc, char* argv[])
{
    return EXIT_SUCCESS;
}

#endif /* OPENSSL_NO_CT */