tests.c

/* PostSRSd - Sender Rewriting Scheme daemon for Postfix
 * Copyright (c) 2012-2020 Timo Röhling <timo@gaussglocke.de>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/* This program uses the libsrs2 library. The relevant source
 * files have been added to this distribution. */
#include "srs2.h"

#include <string.h>

static int run_srs(srs_t *srs, const char *address, const char *domain)
{
    int result, i;
    char buf1[1024];
    char buf2[1024];

    result = srs_forward(srs, buf1, sizeof(buf1), address, domain);
    if (result != SRS_SUCCESS)
    {
        printf("srs_forward(\"%s\", \"%s\") = %d (EXPECTED: 0)\n", address,
               domain, result);
        return 0;
    }
    result = srs_reverse(srs, buf2, sizeof(buf2), buf1);
    if (result != SRS_SUCCESS)
    {
        printf("srs_reverse(\"%s\") = %d\n (EXPECTED: 0)", buf1, result);
        return 0;
    }
    if (strcasecmp(address, buf2))
    {
        printf("SRS not idempotent: \"%s\" != \"%s\"\n", address, buf2);
        return 0;
    }

    i = strchr(buf1, '@') - buf1;
    while (i > 0)
    {
        --i;
        buf1[i]++;
        result = srs_reverse(srs, buf2, sizeof(buf2), buf1);
        if (result == SRS_SUCCESS)
        {
            printf("srs_reverse(\"%s\") = %d\n (EXPECTED: != 0)", buf1, result);
            return 0;
        }
        buf1[i]--;
    }
    return 1;
}

static void generate_random_address(char *buf, size_t len1, size_t len2)
{
    static const char chars[] = "abcdefghijklmnopqrstuvwxyz0123456789-+=";
    size_t i = 0, l1 = len1, l2 = len2;
    while (l1 > 0)
    {
        buf[i++] = chars[random() % 39];
        if (l1 < len1 && l1 > 1 && buf[i - 1] != '.' && (random() % 16 == 0))
            buf[i - 1] = '.';
        --l1;
    }
    buf[i++] = '@';
    while (l2 > 0)
    {
        buf[i++] = 'a' + random() % 26;
        if (l2 < len2 && l2 > 1 && buf[i - 1] != '.' && (random() % 16 == 0))
            buf[i - 1] = '.';
        --l2;
    }
    buf[i++] = 0;
}

#define ASSERT_SRS_OK(...)          \
    if (!run_srs(srs, __VA_ARGS__)) \
        exit(EXIT_FAILURE);

static void run_tests_with_secret(const char *secret)
{
    srs_t *srs;
    size_t l1, l2;
    char addr[128];

    srs = srs_new();
    printf("Testing with secret '%s'\n", secret);
    srs_add_secret(srs, secret);
    srs_set_hashlength(srs, 16);

    for (l1 = 1; l1 <= 63; ++l1)
    {
        for (l2 = 1; l2 <= 63; ++l2)
        {
            generate_random_address(addr, l1, l2);
            ASSERT_SRS_OK(addr, "example.com");
        }
    }
    srs_free(srs);
}

int main(int argc, char **argv)
{
    run_tests_with_secret("tops3cr3t");
    run_tests_with_secret(
        "string that has 119 bytes, which is excessively long from an "
        "operational point of view but should still work regardless");
    return EXIT_SUCCESS;
}