/*
 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
 * 2004.
 */
/* ====================================================================
 * Copyright (c) 2004 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com). */

#include <string.h>

#include <openssl/buf.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/stack.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>

#include "vpm_int.h"
#include "../internal.h"


/* X509_VERIFY_PARAM functions */

#define SET_HOST 0
#define ADD_HOST 1

static char *str_copy(char *s)
{
    return OPENSSL_strdup(s);
}

static void str_free(char *s)
{
    OPENSSL_free(s);
}

#define string_stack_free(sk) sk_OPENSSL_STRING_pop_free(sk, str_free)

static int int_x509_param_set_hosts(X509_VERIFY_PARAM_ID *id, int mode,
                                    const char *name, size_t namelen)
{
    char *copy;

    if (name == NULL || namelen == 0) {
        // Unlike OpenSSL, we reject trying to set or add an empty name.
        return 0;
    }

    /*
     * Refuse names with embedded NUL bytes.
     * XXX: Do we need to push an error onto the error stack?
     */
    if (name && OPENSSL_memchr(name, '\0', namelen))
        return 0;

    if (mode == SET_HOST && id->hosts) {
        string_stack_free(id->hosts);
        id->hosts = NULL;
    }

    copy = BUF_strndup(name, namelen);
    if (copy == NULL)
        return 0;

    if (id->hosts == NULL &&
        (id->hosts = sk_OPENSSL_STRING_new_null()) == NULL) {
        OPENSSL_free(copy);
        return 0;
    }

    if (!sk_OPENSSL_STRING_push(id->hosts, copy)) {
        OPENSSL_free(copy);
        if (sk_OPENSSL_STRING_num(id->hosts) == 0) {
            sk_OPENSSL_STRING_free(id->hosts);
            id->hosts = NULL;
        }
        return 0;
    }

    return 1;
}

static void x509_verify_param_zero(X509_VERIFY_PARAM *param)
{
    X509_VERIFY_PARAM_ID *paramid;
    if (!param)
        return;
    param->name = NULL;
    param->purpose = 0;
    param->trust = 0;
    /*
     * param->inh_flags = X509_VP_FLAG_DEFAULT;
     */
    param->inh_flags = 0;
    param->flags = 0;
    param->depth = -1;
    if (param->policies) {
        sk_ASN1_OBJECT_pop_free(param->policies, ASN1_OBJECT_free);
        param->policies = NULL;
    }
    paramid = param->id;
    if (paramid->hosts) {
        string_stack_free(paramid->hosts);
        paramid->hosts = NULL;
    }
    if (paramid->peername) {
        OPENSSL_free(paramid->peername);
        paramid->peername = NULL;
    }
    if (paramid->email) {
        OPENSSL_free(paramid->email);
        paramid->email = NULL;
        paramid->emaillen = 0;
    }
    if (paramid->ip) {
        OPENSSL_free(paramid->ip);
        paramid->ip = NULL;
        paramid->iplen = 0;
    }
    paramid->poison = 0;
}

X509_VERIFY_PARAM *X509_VERIFY_PARAM_new(void)
{
    X509_VERIFY_PARAM *param;
    X509_VERIFY_PARAM_ID *paramid;
    param = OPENSSL_malloc(sizeof(X509_VERIFY_PARAM));
    if (!param)
        return NULL;
    paramid = OPENSSL_malloc(sizeof(X509_VERIFY_PARAM_ID));
    if (!paramid) {
        OPENSSL_free(param);
        return NULL;
    }
    OPENSSL_memset(param, 0, sizeof(X509_VERIFY_PARAM));
    OPENSSL_memset(paramid, 0, sizeof(X509_VERIFY_PARAM_ID));
    param->id = paramid;
    x509_verify_param_zero(param);
    return param;
}

void X509_VERIFY_PARAM_free(X509_VERIFY_PARAM *param)
{
    if (param == NULL)
        return;
    x509_verify_param_zero(param);
    OPENSSL_free(param->id);
    OPENSSL_free(param);
}

/*-
 * This function determines how parameters are "inherited" from one structure
 * to another. There are several different ways this can happen.
 *
 * 1. If a child structure needs to have its values initialized from a parent
 *    they are simply copied across. For example SSL_CTX copied to SSL.
 * 2. If the structure should take on values only if they are currently unset.
 *    For example the values in an SSL structure will take appropriate value
 *    for SSL servers or clients but only if the application has not set new
 *    ones.
 *
 * The "inh_flags" field determines how this function behaves.
 *
 * Normally any values which are set in the default are not copied from the
 * destination and verify flags are ORed together.
 *
 * If X509_VP_FLAG_DEFAULT is set then anything set in the source is copied
 * to the destination. Effectively the values in "to" become default values
 * which will be used only if nothing new is set in "from".
 *
 * If X509_VP_FLAG_OVERWRITE is set then all value are copied across whether
 * they are set or not. Flags is still Ored though.
 *
 * If X509_VP_FLAG_RESET_FLAGS is set then the flags value is copied instead
 * of ORed.
 *
 * If X509_VP_FLAG_LOCKED is set then no values are copied.
 *
 * If X509_VP_FLAG_ONCE is set then the current inh_flags setting is zeroed
 * after the next call.
 */

/* Macro to test if a field should be copied from src to dest */

#define test_x509_verify_param_copy(field, def) \
  (to_overwrite ||                              \
   ((src->field != (def)) && (to_default || (dest->field == (def)))))

/* As above but for ID fields */

#define test_x509_verify_param_copy_id(idf, def) \
        test_x509_verify_param_copy(id->idf, def)

/* Macro to test and copy a field if necessary */

#define x509_verify_param_copy(field, def) \
        if (test_x509_verify_param_copy(field, def)) \
                dest->field = src->field

int X509_VERIFY_PARAM_inherit(X509_VERIFY_PARAM *dest,
                              const X509_VERIFY_PARAM *src)
{
    unsigned long inh_flags;
    int to_default, to_overwrite;
    X509_VERIFY_PARAM_ID *id;
    if (!src)
        return 1;
    id = src->id;
    inh_flags = dest->inh_flags | src->inh_flags;

    if (inh_flags & X509_VP_FLAG_ONCE)
        dest->inh_flags = 0;

    if (inh_flags & X509_VP_FLAG_LOCKED)
        return 1;

    if (inh_flags & X509_VP_FLAG_DEFAULT)
        to_default = 1;
    else
        to_default = 0;

    if (inh_flags & X509_VP_FLAG_OVERWRITE)
        to_overwrite = 1;
    else
        to_overwrite = 0;

    x509_verify_param_copy(purpose, 0);
    x509_verify_param_copy(trust, 0);
    x509_verify_param_copy(depth, -1);

    /* If overwrite or check time not set, copy across */

    if (to_overwrite || !(dest->flags & X509_V_FLAG_USE_CHECK_TIME)) {
        dest->check_time = src->check_time;
        dest->flags &= ~X509_V_FLAG_USE_CHECK_TIME;
        /* Don't need to copy flag: that is done below */
    }

    if (inh_flags & X509_VP_FLAG_RESET_FLAGS)
        dest->flags = 0;

    dest->flags |= src->flags;

    if (test_x509_verify_param_copy(policies, NULL)) {
        if (!X509_VERIFY_PARAM_set1_policies(dest, src->policies))
            return 0;
    }

    /* Copy the host flags if and only if we're copying the host list */
    if (test_x509_verify_param_copy_id(hosts, NULL)) {
        if (dest->id->hosts) {
            string_stack_free(dest->id->hosts);
            dest->id->hosts = NULL;
        }
        if (id->hosts) {
            dest->id->hosts =
                sk_OPENSSL_STRING_deep_copy(id->hosts, str_copy, str_free);
            if (dest->id->hosts == NULL)
                return 0;
            dest->id->hostflags = id->hostflags;
        }
    }

    if (test_x509_verify_param_copy_id(email, NULL)) {
        if (!X509_VERIFY_PARAM_set1_email(dest, id->email, id->emaillen))
            return 0;
    }

    if (test_x509_verify_param_copy_id(ip, NULL)) {
        if (!X509_VERIFY_PARAM_set1_ip(dest, id->ip, id->iplen))
            return 0;
    }

    dest->id->poison = src->id->poison;

    return 1;
}

int X509_VERIFY_PARAM_set1(X509_VERIFY_PARAM *to,
                           const X509_VERIFY_PARAM *from)
{
    unsigned long save_flags = to->inh_flags;
    int ret;
    to->inh_flags |= X509_VP_FLAG_DEFAULT;
    ret = X509_VERIFY_PARAM_inherit(to, from);
    to->inh_flags = save_flags;
    return ret;
}

static int int_x509_param_set1(char **pdest, size_t *pdestlen,
                               const char *src, size_t srclen)
{
    void *tmp;
    if (src == NULL || srclen == 0) {
        // Unlike OpenSSL, we do not allow an empty string to disable previously
        // configured checks.
        return 0;
    }

    tmp = BUF_memdup(src, srclen);
    if (!tmp) {
        return 0;
    }

    if (*pdest)
        OPENSSL_free(*pdest);
    *pdest = tmp;
    if (pdestlen)
        *pdestlen = srclen;
    return 1;
}

int X509_VERIFY_PARAM_set1_name(X509_VERIFY_PARAM *param, const char *name)
{
    if (param->name)
        OPENSSL_free(param->name);
    param->name = BUF_strdup(name);
    if (param->name)
        return 1;
    return 0;
}

int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param, unsigned long flags)
{
    param->flags |= flags;
    if (flags & X509_V_FLAG_POLICY_MASK)
        param->flags |= X509_V_FLAG_POLICY_CHECK;
    return 1;
}

int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
                                  unsigned long flags)
{
    param->flags &= ~flags;
    return 1;
}

unsigned long X509_VERIFY_PARAM_get_flags(X509_VERIFY_PARAM *param)
{
    return param->flags;
}

int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param, int purpose)
{
    return X509_PURPOSE_set(&param->purpose, purpose);
}

int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param, int trust)
{
    return X509_TRUST_set(&param->trust, trust);
}

void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param, int depth)
{
    param->depth = depth;
}

void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param, time_t t)
{
    param->check_time = t;
    param->flags |= X509_V_FLAG_USE_CHECK_TIME;
}

int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
                                  ASN1_OBJECT *policy)
{
    if (!param->policies) {
        param->policies = sk_ASN1_OBJECT_new_null();
        if (!param->policies)
            return 0;
    }
    if (!sk_ASN1_OBJECT_push(param->policies, policy))
        return 0;
    return 1;
}

int X509_VERIFY_PARAM_set1_policies(X509_VERIFY_PARAM *param,
                                    STACK_OF(ASN1_OBJECT) *policies)
{
    size_t i;
    ASN1_OBJECT *oid, *doid;
    if (!param)
        return 0;
    if (param->policies)
        sk_ASN1_OBJECT_pop_free(param->policies, ASN1_OBJECT_free);

    if (!policies) {
        param->policies = NULL;
        return 1;
    }

    param->policies = sk_ASN1_OBJECT_new_null();
    if (!param->policies)
        return 0;

    for (i = 0; i < sk_ASN1_OBJECT_num(policies); i++) {
        oid = sk_ASN1_OBJECT_value(policies, i);
        doid = OBJ_dup(oid);
        if (!doid)
            return 0;
        if (!sk_ASN1_OBJECT_push(param->policies, doid)) {
            ASN1_OBJECT_free(doid);
            return 0;
        }
    }
    param->flags |= X509_V_FLAG_POLICY_CHECK;
    return 1;
}

int X509_VERIFY_PARAM_set1_host(X509_VERIFY_PARAM *param,
                                const char *name, size_t namelen)
{
    if (!int_x509_param_set_hosts(param->id, SET_HOST, name, namelen)) {
        param->id->poison = 1;
        return 0;
    }
    return 1;
}

int X509_VERIFY_PARAM_add1_host(X509_VERIFY_PARAM *param,
                                const char *name, size_t namelen)
{
    if (!int_x509_param_set_hosts(param->id, ADD_HOST, name, namelen)) {
        param->id->poison = 1;
        return 0;
    }
    return 1;
}

void X509_VERIFY_PARAM_set_hostflags(X509_VERIFY_PARAM *param,
                                     unsigned int flags)
{
    param->id->hostflags = flags;
}

char *X509_VERIFY_PARAM_get0_peername(X509_VERIFY_PARAM *param)
{
    return param->id->peername;
}

int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
                                 const char *email, size_t emaillen)
{
    if (OPENSSL_memchr(email, '\0', emaillen) != NULL ||
        !int_x509_param_set1(&param->id->email, &param->id->emaillen,
                               email, emaillen)) {
        param->id->poison = 1;
        return 0;
    }

    return 1;
}

int X509_VERIFY_PARAM_set1_ip(X509_VERIFY_PARAM *param,
                              const unsigned char *ip, size_t iplen)
{
    if ((iplen != 4 && iplen != 16) ||
        !int_x509_param_set1((char **)&param->id->ip, &param->id->iplen,
                             (char *)ip, iplen)) {
        param->id->poison = 1;
        return 0;
    }

    return 1;
}

int X509_VERIFY_PARAM_set1_ip_asc(X509_VERIFY_PARAM *param, const char *ipasc)
{
    unsigned char ipout[16];
    size_t iplen;

    iplen = (size_t)a2i_ipadd(ipout, ipasc);
    if (iplen == 0)
        return 0;
    return X509_VERIFY_PARAM_set1_ip(param, ipout, iplen);
}

int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param)
{
    return param->depth;
}

const char *X509_VERIFY_PARAM_get0_name(const X509_VERIFY_PARAM *param)
{
    return param->name;
}

static const X509_VERIFY_PARAM_ID _empty_id =
    { NULL, 0U, NULL, NULL, 0, NULL, 0, 0 };

#define vpm_empty_id ((X509_VERIFY_PARAM_ID *)&_empty_id)

/*
 * Default verify parameters: these are used for various applications and can
 * be overridden by the user specified table. NB: the 'name' field *must* be
 * in alphabetical order because it will be searched using OBJ_search.
 */

static const X509_VERIFY_PARAM default_table[] = {
    {
     (char *)"default",         /* X509 default parameters */
     0,                         /* Check time */
     0,                         /* internal flags */
     0,                         /* flags */
     0,                         /* purpose */
     0,                         /* trust */
     100,                       /* depth */
     NULL,                      /* policies */
     vpm_empty_id},
    {
     (char *)"pkcs7",           /* S/MIME sign parameters */
     0,                         /* Check time */
     0,                         /* internal flags */
     0,                         /* flags */
     X509_PURPOSE_SMIME_SIGN,   /* purpose */
     X509_TRUST_EMAIL,          /* trust */
     -1,                        /* depth */
     NULL,                      /* policies */
     vpm_empty_id},
    {
     (char *)"smime_sign",      /* S/MIME sign parameters */
     0,                         /* Check time */
     0,                         /* internal flags */
     0,                         /* flags */
     X509_PURPOSE_SMIME_SIGN,   /* purpose */
     X509_TRUST_EMAIL,          /* trust */
     -1,                        /* depth */
     NULL,                      /* policies */
     vpm_empty_id},
    {
     (char *)"ssl_client",      /* SSL/TLS client parameters */
     0,                         /* Check time */
     0,                         /* internal flags */
     0,                         /* flags */
     X509_PURPOSE_SSL_CLIENT,   /* purpose */
     X509_TRUST_SSL_CLIENT,     /* trust */
     -1,                        /* depth */
     NULL,                      /* policies */
     vpm_empty_id},
    {
     (char *)"ssl_server",      /* SSL/TLS server parameters */
     0,                         /* Check time */
     0,                         /* internal flags */
     0,                         /* flags */
     X509_PURPOSE_SSL_SERVER,   /* purpose */
     X509_TRUST_SSL_SERVER,     /* trust */
     -1,                        /* depth */
     NULL,                      /* policies */
     vpm_empty_id}
};

static STACK_OF(X509_VERIFY_PARAM) *param_table = NULL;

static int param_cmp(const X509_VERIFY_PARAM **a, const X509_VERIFY_PARAM **b)
{
    return strcmp((*a)->name, (*b)->name);
}

int X509_VERIFY_PARAM_add0_table(X509_VERIFY_PARAM *param)
{
    X509_VERIFY_PARAM *ptmp;
    if (!param_table) {
        param_table = sk_X509_VERIFY_PARAM_new(param_cmp);
        if (!param_table)
            return 0;
    } else {
        size_t idx;

        if (sk_X509_VERIFY_PARAM_find(param_table, &idx, param)) {
            ptmp = sk_X509_VERIFY_PARAM_value(param_table, idx);
            X509_VERIFY_PARAM_free(ptmp);
            (void)sk_X509_VERIFY_PARAM_delete(param_table, idx);
        }
    }
    if (!sk_X509_VERIFY_PARAM_push(param_table, param))
        return 0;
    return 1;
}

int X509_VERIFY_PARAM_get_count(void)
{
    int num = sizeof(default_table) / sizeof(X509_VERIFY_PARAM);
    if (param_table)
        num += sk_X509_VERIFY_PARAM_num(param_table);
    return num;
}

const X509_VERIFY_PARAM *X509_VERIFY_PARAM_get0(int id)
{
    int num = sizeof(default_table) / sizeof(X509_VERIFY_PARAM);
    if (id < num)
        return default_table + id;
    return sk_X509_VERIFY_PARAM_value(param_table, id - num);
}

const X509_VERIFY_PARAM *X509_VERIFY_PARAM_lookup(const char *name)
{
    X509_VERIFY_PARAM pm;
    unsigned i, limit;

    pm.name = (char *)name;
    if (param_table) {
        size_t idx;
        if (sk_X509_VERIFY_PARAM_find(param_table, &idx, &pm))
            return sk_X509_VERIFY_PARAM_value(param_table, idx);
    }

    limit = sizeof(default_table) / sizeof(X509_VERIFY_PARAM);
    for (i = 0; i < limit; i++) {
        if (strcmp(default_table[i].name, name) == 0) {
            return &default_table[i];
        }
    }
    return NULL;
}

void X509_VERIFY_PARAM_table_cleanup(void)
{
    if (param_table)
        sk_X509_VERIFY_PARAM_pop_free(param_table, X509_VERIFY_PARAM_free);
    param_table = NULL;
}