/*

 * Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/*

 * Implementation of RFC 3779 section 3.2.

 */

#include <assert.h>

#include <stdio.h>

#include <string.h>

#include "internal/cryptlib.h"

#include <openssl/conf.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/x509v3.h>

#include <openssl/x509.h>

#include "crypto/x509.h"

#include <openssl/bn.h>

#include "ext_dat.h"

#ifndef OPENSSL_NO_RFC3779

/*

 * OpenSSL ASN.1 template translation of RFC 3779 3.2.3.

 */

ASN1_SEQUENCE(ASRange) = {

  ASN1_SIMPLE(ASRange, min, ASN1_INTEGER),

  ASN1_SIMPLE(ASRange, max, ASN1_INTEGER)

} ASN1_SEQUENCE_END(ASRange)

ASN1_CHOICE(ASIdOrRange) = {

  ASN1_SIMPLE(ASIdOrRange, u.id,    ASN1_INTEGER),

  ASN1_SIMPLE(ASIdOrRange, u.range, ASRange)

} ASN1_CHOICE_END(ASIdOrRange)

ASN1_CHOICE(ASIdentifierChoice) = {

  ASN1_SIMPLE(ASIdentifierChoice,      u.inherit,       ASN1_NULL),

  ASN1_SEQUENCE_OF(ASIdentifierChoice, u.asIdsOrRanges, ASIdOrRange)

} ASN1_CHOICE_END(ASIdentifierChoice)

ASN1_SEQUENCE(ASIdentifiers) = {

  ASN1_EXP_OPT(ASIdentifiers, asnum, ASIdentifierChoice, 0),

  ASN1_EXP_OPT(ASIdentifiers, rdi,   ASIdentifierChoice, 1)

} ASN1_SEQUENCE_END(ASIdentifiers)

IMPLEMENT_ASN1_FUNCTIONS(ASRange)

IMPLEMENT_ASN1_FUNCTIONS(ASIdOrRange)

IMPLEMENT_ASN1_FUNCTIONS(ASIdentifierChoice)

IMPLEMENT_ASN1_FUNCTIONS(ASIdentifiers)

/*

 * i2r method for an ASIdentifierChoice.

 */

static int i2r_ASIdentifierChoice(BIO *out,

                                  ASIdentifierChoice *choice,

                                  int indent, const char *msg)

{

    int i;

    char *s;

    if (choice == NULL)

        return 1;

    BIO_printf(out, "%*s%s:\n", indent, "", msg);

    switch (choice->type) {

    case ASIdentifierChoice_inherit:

        BIO_printf(out, "%*sinherit\n", indent + 2, "");

        break;

    case ASIdentifierChoice_asIdsOrRanges:

        for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges); i++) {

            ASIdOrRange *aor =

                sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);

            switch (aor->type) {

            case ASIdOrRange_id:

                if ((s = i2s_ASN1_INTEGER(NULL, aor->u.id)) == NULL)

                    return 0;

                BIO_printf(out, "%*s%s\n", indent + 2, "", s);

                OPENSSL_free(s);

                break;

            case ASIdOrRange_range:

                if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->min)) == NULL)

                    return 0;

                BIO_printf(out, "%*s%s-", indent + 2, "", s);

                OPENSSL_free(s);

                if ((s = i2s_ASN1_INTEGER(NULL, aor->u.range->max)) == NULL)

                    return 0;

                BIO_printf(out, "%s\n", s);

                OPENSSL_free(s);

                break;

            default:

                return 0;

            }

        }

        break;

    default:

        return 0;

    }

    return 1;

}

/*

 * i2r method for an ASIdentifier extension.

 */

static int i2r_ASIdentifiers(const X509V3_EXT_METHOD *method,

                             void *ext, BIO *out, int indent)

{

    ASIdentifiers *asid = ext;

    return (i2r_ASIdentifierChoice(out, asid->asnum, indent,

                                   "Autonomous System Numbers") &&

            i2r_ASIdentifierChoice(out, asid->rdi, indent,

                                   "Routing Domain Identifiers"));

}

/*

 * Sort comparison function for a sequence of ASIdOrRange elements.

 */

static int ASIdOrRange_cmp(const ASIdOrRange *const *a_,

                           const ASIdOrRange *const *b_)

{

    const ASIdOrRange *a = *a_, *b = *b_;

    assert((a->type == ASIdOrRange_id && a->u.id != NULL) ||

           (a->type == ASIdOrRange_range && a->u.range != NULL &&

            a->u.range->min != NULL && a->u.range->max != NULL));

    assert((b->type == ASIdOrRange_id && b->u.id != NULL) ||

           (b->type == ASIdOrRange_range && b->u.range != NULL &&

            b->u.range->min != NULL && b->u.range->max != NULL));

    if (a->type == ASIdOrRange_id && b->type == ASIdOrRange_id)

        return ASN1_INTEGER_cmp(a->u.id, b->u.id);

    if (a->type == ASIdOrRange_range && b->type == ASIdOrRange_range) {

        int r = ASN1_INTEGER_cmp(a->u.range->min, b->u.range->min);

        return r != 0 ? r : ASN1_INTEGER_cmp(a->u.range->max,

                                             b->u.range->max);

    }

    if (a->type == ASIdOrRange_id)

        return ASN1_INTEGER_cmp(a->u.id, b->u.range->min);

    else

        return ASN1_INTEGER_cmp(a->u.range->min, b->u.id);

}

/*

 * Add an inherit element.

 */

int X509v3_asid_add_inherit(ASIdentifiers *asid, int which)

{

    ASIdentifierChoice **choice;

    if (asid == NULL)

        return 0;

    switch (which) {

    case V3_ASID_ASNUM:

        choice = &asid->asnum;

        break;

    case V3_ASID_RDI:

        choice = &asid->rdi;

        break;

    default:

        return 0;

    }

    if (*choice == NULL) {

        if ((*choice = ASIdentifierChoice_new()) == NULL)

            return 0;

        if (((*choice)->u.inherit = ASN1_NULL_new()) == NULL)

            return 0;

        (*choice)->type = ASIdentifierChoice_inherit;

    }

    return (*choice)->type == ASIdentifierChoice_inherit;

}

/*

 * Add an ID or range to an ASIdentifierChoice.

 */

int X509v3_asid_add_id_or_range(ASIdentifiers *asid,

                                int which, ASN1_INTEGER *min, ASN1_INTEGER *max)

{

    ASIdentifierChoice **choice;

    ASIdOrRange *aor;

    if (asid == NULL)

        return 0;

    switch (which) {

    case V3_ASID_ASNUM:

        choice = &asid->asnum;

        break;

    case V3_ASID_RDI:

        choice = &asid->rdi;

        break;

    default:

        return 0;

    }

    if (*choice != NULL && (*choice)->type == ASIdentifierChoice_inherit)

        return 0;

    if (*choice == NULL) {

        if ((*choice = ASIdentifierChoice_new()) == NULL)

            return 0;

        (*choice)->u.asIdsOrRanges = sk_ASIdOrRange_new(ASIdOrRange_cmp);

        if ((*choice)->u.asIdsOrRanges == NULL)

            return 0;

        (*choice)->type = ASIdentifierChoice_asIdsOrRanges;

    }

    if ((aor = ASIdOrRange_new()) == NULL)

        return 0;

    if (max == NULL) {

        aor->type = ASIdOrRange_id;

        aor->u.id = min;

    } else {

        aor->type = ASIdOrRange_range;

        if ((aor->u.range = ASRange_new()) == NULL)

            goto err;

        ASN1_INTEGER_free(aor->u.range->min);

        aor->u.range->min = min;

        ASN1_INTEGER_free(aor->u.range->max);

        aor->u.range->max = max;

    }

    if (!(sk_ASIdOrRange_push((*choice)->u.asIdsOrRanges, aor)))

        goto err;

    return 1;

 err:

    ASIdOrRange_free(aor);

    return 0;

}

/*

 * Extract min and max values from an ASIdOrRange.

 */

static int extract_min_max(ASIdOrRange *aor,

                           ASN1_INTEGER **min, ASN1_INTEGER **max)

{

    if (!ossl_assert(aor != NULL))

        return 0;

    switch (aor->type) {

    case ASIdOrRange_id:

        *min = aor->u.id;

        *max = aor->u.id;

        return 1;

    case ASIdOrRange_range:

        *min = aor->u.range->min;

        *max = aor->u.range->max;

        return 1;

    }

    return 0;

}

/*

 * Check whether an ASIdentifierChoice is in canonical form.

 */

static int ASIdentifierChoice_is_canonical(ASIdentifierChoice *choice)

{

    ASN1_INTEGER *a_max_plus_one = NULL;

    ASN1_INTEGER *orig;

    BIGNUM *bn = NULL;

    int i, ret = 0;

    /*

     * Empty element or inheritance is canonical.

     */

    if (choice == NULL || choice->type == ASIdentifierChoice_inherit)

        return 1;

    /*

     * If not a list, or if empty list, it's broken.

     */

    if (choice->type != ASIdentifierChoice_asIdsOrRanges ||

        sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0)

        return 0;

    /*

     * It's a list, check it.

     */

    for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {

        ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);

        ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);

        ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =

            NULL;

        if (!extract_min_max(a, &a_min, &a_max)

                || !extract_min_max(b, &b_min, &b_max))

            goto done;

        /*

         * Punt misordered list, overlapping start, or inverted range.

         */

        if (ASN1_INTEGER_cmp(a_min, b_min) >= 0 ||

            ASN1_INTEGER_cmp(a_min, a_max) > 0 ||

            ASN1_INTEGER_cmp(b_min, b_max) > 0)

            goto done;

        /*

         * Calculate a_max + 1 to check for adjacency.

         */

        if ((bn == NULL && (bn = BN_new()) == NULL) ||

            ASN1_INTEGER_to_BN(a_max, bn) == NULL ||

            !BN_add_word(bn, 1)) {

            X509V3err(X509V3_F_ASIDENTIFIERCHOICE_IS_CANONICAL,

                      ERR_R_MALLOC_FAILURE);

            goto done;

        }

        if ((a_max_plus_one =

                BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {

            a_max_plus_one = orig;

            X509V3err(X509V3_F_ASIDENTIFIERCHOICE_IS_CANONICAL,

                      ERR_R_MALLOC_FAILURE);

            goto done;

        }

        /*

         * Punt if adjacent or overlapping.

         */

        if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) >= 0)

            goto done;

    }

    /*

     * Check for inverted range.

     */

    i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;

    {

        ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);

        ASN1_INTEGER *a_min, *a_max;

        if (a != NULL && a->type == ASIdOrRange_range) {

            if (!extract_min_max(a, &a_min, &a_max)

                    || ASN1_INTEGER_cmp(a_min, a_max) > 0)

                goto done;

        }

    }

    ret = 1;

 done:

    ASN1_INTEGER_free(a_max_plus_one);

    BN_free(bn);

    return ret;

}

/*

 * Check whether an ASIdentifier extension is in canonical form.

 */

int X509v3_asid_is_canonical(ASIdentifiers *asid)

{

    return (asid == NULL ||

            (ASIdentifierChoice_is_canonical(asid->asnum) &&

             ASIdentifierChoice_is_canonical(asid->rdi)));

}

/*

 * Whack an ASIdentifierChoice into canonical form.

 */

static int ASIdentifierChoice_canonize(ASIdentifierChoice *choice)

{

    ASN1_INTEGER *a_max_plus_one = NULL;

    ASN1_INTEGER *orig;

    BIGNUM *bn = NULL;

    int i, ret = 0;

    /*

     * Nothing to do for empty element or inheritance.

     */

    if (choice == NULL || choice->type == ASIdentifierChoice_inherit)

        return 1;

    /*

     * If not a list, or if empty list, it's broken.

     */

    if (choice->type != ASIdentifierChoice_asIdsOrRanges ||

        sk_ASIdOrRange_num(choice->u.asIdsOrRanges) == 0) {

        X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,

                  X509V3_R_EXTENSION_VALUE_ERROR);

        return 0;

    }

    /*

     * We have a non-empty list.  Sort it.

     */

    sk_ASIdOrRange_sort(choice->u.asIdsOrRanges);

    /*

     * Now check for errors and suboptimal encoding, rejecting the

     * former and fixing the latter.

     */

    for (i = 0; i < sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1; i++) {

        ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);

        ASIdOrRange *b = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i + 1);

        ASN1_INTEGER *a_min = NULL, *a_max = NULL, *b_min = NULL, *b_max =

            NULL;

        if (!extract_min_max(a, &a_min, &a_max)

                || !extract_min_max(b, &b_min, &b_max))

            goto done;

        /*

         * Make sure we're properly sorted (paranoia).

         */

        if (!ossl_assert(ASN1_INTEGER_cmp(a_min, b_min) <= 0))

            goto done;

        /*

         * Punt inverted ranges.

         */

        if (ASN1_INTEGER_cmp(a_min, a_max) > 0 ||

            ASN1_INTEGER_cmp(b_min, b_max) > 0)

            goto done;

        /*

         * Check for overlaps.

         */

        if (ASN1_INTEGER_cmp(a_max, b_min) >= 0) {

            X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,

                      X509V3_R_EXTENSION_VALUE_ERROR);

            goto done;

        }

        /*

         * Calculate a_max + 1 to check for adjacency.

         */

        if ((bn == NULL && (bn = BN_new()) == NULL) ||

            ASN1_INTEGER_to_BN(a_max, bn) == NULL ||

            !BN_add_word(bn, 1)) {

            X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,

                      ERR_R_MALLOC_FAILURE);

            goto done;

        }

        if ((a_max_plus_one =

                 BN_to_ASN1_INTEGER(bn, orig = a_max_plus_one)) == NULL) {

            a_max_plus_one = orig;

            X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,

                      ERR_R_MALLOC_FAILURE);

            goto done;

        }

        /*

         * If a and b are adjacent, merge them.

         */

        if (ASN1_INTEGER_cmp(a_max_plus_one, b_min) == 0) {

            ASRange *r;

            switch (a->type) {

            case ASIdOrRange_id:

                if ((r = OPENSSL_malloc(sizeof(*r))) == NULL) {

                    X509V3err(X509V3_F_ASIDENTIFIERCHOICE_CANONIZE,

                              ERR_R_MALLOC_FAILURE);

                    goto done;

                }

                r->min = a_min;

                r->max = b_max;

                a->type = ASIdOrRange_range;

                a->u.range = r;

                break;

            case ASIdOrRange_range:

                ASN1_INTEGER_free(a->u.range->max);

                a->u.range->max = b_max;

                break;

            }

            switch (b->type) {

            case ASIdOrRange_id:

                b->u.id = NULL;

                break;

            case ASIdOrRange_range:

                b->u.range->max = NULL;

                break;

            }

            ASIdOrRange_free(b);

            (void)sk_ASIdOrRange_delete(choice->u.asIdsOrRanges, i + 1);

            i--;

            continue;

        }

    }

    /*

     * Check for final inverted range.

     */

    i = sk_ASIdOrRange_num(choice->u.asIdsOrRanges) - 1;

    {

        ASIdOrRange *a = sk_ASIdOrRange_value(choice->u.asIdsOrRanges, i);

        ASN1_INTEGER *a_min, *a_max;

        if (a != NULL && a->type == ASIdOrRange_range) {

            if (!extract_min_max(a, &a_min, &a_max)

                    || ASN1_INTEGER_cmp(a_min, a_max) > 0)

                goto done;

        }

    }

    /* Paranoia */

    if (!ossl_assert(ASIdentifierChoice_is_canonical(choice)))

        goto done;

    ret = 1;

 done:

    ASN1_INTEGER_free(a_max_plus_one);

    BN_free(bn);

    return ret;

}

/*

 * Whack an ASIdentifier extension into canonical form.

 */

int X509v3_asid_canonize(ASIdentifiers *asid)

{

    return (asid == NULL ||

            (ASIdentifierChoice_canonize(asid->asnum) &&

             ASIdentifierChoice_canonize(asid->rdi)));

}

/*

 * v2i method for an ASIdentifier extension.

 */

static void *v2i_ASIdentifiers(const struct v3_ext_method *method,

                               struct v3_ext_ctx *ctx,

                               STACK_OF(CONF_VALUE) *values)

{

    ASN1_INTEGER *min = NULL, *max = NULL;

    ASIdentifiers *asid = NULL;

    int i;

    if ((asid = ASIdentifiers_new()) == NULL) {

        X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    for (i = 0; i < sk_CONF_VALUE_num(values); i++) {

        CONF_VALUE *val = sk_CONF_VALUE_value(values, i);

        int i1 = 0, i2 = 0, i3 = 0, is_range = 0, which = 0;

        /*

         * Figure out whether this is an AS or an RDI.

         */

        if (!name_cmp(val->name, "AS")) {

            which = V3_ASID_ASNUM;

        } else if (!name_cmp(val->name, "RDI")) {

            which = V3_ASID_RDI;

        } else {

            X509V3err(X509V3_F_V2I_ASIDENTIFIERS,

                      X509V3_R_EXTENSION_NAME_ERROR);

            X509V3_conf_err(val);

            goto err;

        }

        /*

         * Handle inheritance.

         */

        if (strcmp(val->value, "inherit") == 0) {

            if (X509v3_asid_add_inherit(asid, which))

                continue;

            X509V3err(X509V3_F_V2I_ASIDENTIFIERS,

                      X509V3_R_INVALID_INHERITANCE);

            X509V3_conf_err(val);

            goto err;

        }

        /*

         * Number, range, or mistake, pick it apart and figure out which.

         */

        i1 = strspn(val->value, "0123456789");

        if (val->value[i1] == '\0') {

            is_range = 0;

        } else {

            is_range = 1;

            i2 = i1 + strspn(val->value + i1, " \t");

            if (val->value[i2] != '-') {

                X509V3err(X509V3_F_V2I_ASIDENTIFIERS,

                          X509V3_R_INVALID_ASNUMBER);

                X509V3_conf_err(val);

                goto err;

            }

            i2++;

            i2 = i2 + strspn(val->value + i2, " \t");

            i3 = i2 + strspn(val->value + i2, "0123456789");

            if (val->value[i3] != '\0') {

                X509V3err(X509V3_F_V2I_ASIDENTIFIERS,

                          X509V3_R_INVALID_ASRANGE);

                X509V3_conf_err(val);

                goto err;

            }

        }

        /*

         * Syntax is ok, read and add it.

         */

        if (!is_range) {

            if (!X509V3_get_value_int(val, &min)) {

                X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);

                goto err;

            }

        } else {

            char *s = OPENSSL_strdup(val->value);

            if (s == NULL) {

                X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);

                goto err;

            }

            s[i1] = '\0';

            min = s2i_ASN1_INTEGER(NULL, s);

            max = s2i_ASN1_INTEGER(NULL, s + i2);

            OPENSSL_free(s);

            if (min == NULL || max == NULL) {

                X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);

                goto err;

            }

            if (ASN1_INTEGER_cmp(min, max) > 0) {

                X509V3err(X509V3_F_V2I_ASIDENTIFIERS,

                          X509V3_R_EXTENSION_VALUE_ERROR);

                goto err;

            }

        }

        if (!X509v3_asid_add_id_or_range(asid, which, min, max)) {

            X509V3err(X509V3_F_V2I_ASIDENTIFIERS, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        min = max = NULL;

    }

    /*

     * Canonize the result, then we're done.

     */

    if (!X509v3_asid_canonize(asid))

        goto err;

    return asid;

 err:

    ASIdentifiers_free(asid);

    ASN1_INTEGER_free(min);

    ASN1_INTEGER_free(max);

    return NULL;

}

/*

 * OpenSSL dispatch.

 */

const X509V3_EXT_METHOD v3_asid = {

    NID_sbgp_autonomousSysNum,  /* nid */

    0,                          /* flags */

    ASN1_ITEM_ref(ASIdentifiers), /* template */

    0, 0, 0, 0,                 /* old functions, ignored */

    0,                          /* i2s */

    0,                          /* s2i */

    0,                          /* i2v */

    v2i_ASIdentifiers,          /* v2i */

    i2r_ASIdentifiers,          /* i2r */

    0,                          /* r2i */

    NULL                        /* extension-specific data */

};

/*

 * Figure out whether extension uses inheritance.

 */

int X509v3_asid_inherits(ASIdentifiers *asid)

{

    return (asid != NULL &&

            ((asid->asnum != NULL &&

              asid->asnum->type == ASIdentifierChoice_inherit) ||

             (asid->rdi != NULL &&

              asid->rdi->type == ASIdentifierChoice_inherit)));

}

/*

 * Figure out whether parent contains child.

 */

static int asid_contains(ASIdOrRanges *parent, ASIdOrRanges *child)

{

    ASN1_INTEGER *p_min = NULL, *p_max = NULL, *c_min = NULL, *c_max = NULL;

    int p, c;

    if (child == NULL || parent == child)

        return 1;

    if (parent == NULL)

        return 0;

    p = 0;

    for (c = 0; c < sk_ASIdOrRange_num(child); c++) {

        if (!extract_min_max(sk_ASIdOrRange_value(child, c), &c_min, &c_max))

            return 0;

        for (;; p++) {

            if (p >= sk_ASIdOrRange_num(parent))

                return 0;

            if (!extract_min_max(sk_ASIdOrRange_value(parent, p), &p_min,

                                 &p_max))

                return 0;

            if (ASN1_INTEGER_cmp(p_max, c_max) < 0)

                continue;

            if (ASN1_INTEGER_cmp(p_min, c_min) > 0)

                return 0;

            break;

        }

    }

    return 1;

}

/*

 * Test whether a is a subset of b.

 */

int X509v3_asid_subset(ASIdentifiers *a, ASIdentifiers *b)

{

    return (a == NULL ||

            a == b ||

            (b != NULL &&

             !X509v3_asid_inherits(a) &&

             !X509v3_asid_inherits(b) &&

             asid_contains(b->asnum->u.asIdsOrRanges,

                           a->asnum->u.asIdsOrRanges) &&

             asid_contains(b->rdi->u.asIdsOrRanges,

                           a->rdi->u.asIdsOrRanges)));

}

/*

 * Validation error handling via callback.

 */

#define validation_err(_err_)           \

  do {                                  \

    if (ctx != NULL) {                  \

      ctx->error = _err_;               \

      ctx->error_depth = i;             \

      ctx->current_cert = x;            \

      ret = ctx->verify_cb(0, ctx);     \

    } else {                            \

      ret = 0;                          \

    }                                   \

    if (!ret)                           \

      goto done;                        \

  } while (0)

/*

 * Core code for RFC 3779 3.3 path validation.

 */

static int asid_validate_path_internal(X509_STORE_CTX *ctx,

                                       STACK_OF(X509) *chain,

                                       ASIdentifiers *ext)

{

    ASIdOrRanges *child_as = NULL, *child_rdi = NULL;

    int i, ret = 1, inherit_as = 0, inherit_rdi = 0;

    X509 *x;

    if (!ossl_assert(chain != NULL && sk_X509_num(chain) > 0)

            || !ossl_assert(ctx != NULL || ext != NULL)

            || !ossl_assert(ctx == NULL || ctx->verify_cb != NULL)) {

        if (ctx != NULL)

            ctx->error = X509_V_ERR_UNSPECIFIED;

        return 0;

    }

    /*

     * Figure out where to start.  If we don't have an extension to

     * check, we're done.  Otherwise, check canonical form and

     * set up for walking up the chain.

     */

    if (ext != NULL) {

        i = -1;

        x = NULL;

    } else {

        i = 0;

        x = sk_X509_value(chain, i);

        if ((ext = x->rfc3779_asid) == NULL)

            goto done;

    }

    if (!X509v3_asid_is_canonical(ext))

        validation_err(X509_V_ERR_INVALID_EXTENSION);

    if (ext->asnum != NULL) {

        switch (ext->asnum->type) {

        case ASIdentifierChoice_inherit:

            inherit_as = 1;

            break;

        case ASIdentifierChoice_asIdsOrRanges:

            child_as = ext->asnum->u.asIdsOrRanges;

            break;

        }

    }

    if (ext->rdi != NULL) {

        switch (ext->rdi->type) {

        case ASIdentifierChoice_inherit:

            inherit_rdi = 1;

            break;

        case ASIdentifierChoice_asIdsOrRanges:

            child_rdi = ext->rdi->u.asIdsOrRanges;

            break;

        }

    }

    /*

     * Now walk up the chain.  Extensions must be in canonical form, no

     * cert may list resources that its parent doesn't list.

     */

    for (i++; i < sk_X509_num(chain); i++) {

        x = sk_X509_value(chain, i);

        if (!ossl_assert(x != NULL)) {

            if (ctx != NULL)

                ctx->error = X509_V_ERR_UNSPECIFIED;

            return 0;

        }

        if (x->rfc3779_asid == NULL) {

            if (child_as != NULL || child_rdi != NULL)

                validation_err(X509_V_ERR_UNNESTED_RESOURCE);

            continue;

        }

        if (!X509v3_asid_is_canonical(x->rfc3779_asid))

            validation_err(X509_V_ERR_INVALID_EXTENSION);

        if (x->rfc3779_asid->asnum == NULL && child_as != NULL) {

            validation_err(X509_V_ERR_UNNESTED_RESOURCE);

            child_as = NULL;

            inherit_as = 0;

        }

        if (x->rfc3779_asid->asnum != NULL &&

            x->rfc3779_asid->asnum->type ==

            ASIdentifierChoice_asIdsOrRanges) {

            if (inherit_as

                || asid_contains(x->rfc3779_asid->asnum->u.asIdsOrRanges,

                                 child_as)) {

                child_as = x->rfc3779_asid->asnum->u.asIdsOrRanges;

                inherit_as = 0;

            } else {

                validation_err(X509_V_ERR_UNNESTED_RESOURCE);

            }

        }

        if (x->rfc3779_asid->rdi == NULL && child_rdi != NULL) {

            validation_err(X509_V_ERR_UNNESTED_RESOURCE);

            child_rdi = NULL;

            inherit_rdi = 0;

        }

        if (x->rfc3779_asid->rdi != NULL &&

            x->rfc3779_asid->rdi->type == ASIdentifierChoice_asIdsOrRanges) {

            if (inherit_rdi ||

                asid_contains(x->rfc3779_asid->rdi->u.asIdsOrRanges,

                              child_rdi)) {

                child_rdi = x->rfc3779_asid->rdi->u.asIdsOrRanges;

                inherit_rdi = 0;

            } else {

                validation_err(X509_V_ERR_UNNESTED_RESOURCE);

            }

        }

    }

    /*

     * Trust anchor can't inherit.

     */

    if (!ossl_assert(x != NULL)) {

        if (ctx != NULL)

            ctx->error = X509_V_ERR_UNSPECIFIED;

        return 0;

    }

    if (x->rfc3779_asid != NULL) {

        if (x->rfc3779_asid->asnum != NULL &&

            x->rfc3779_asid->asnum->type == ASIdentifierChoice_inherit)

            validation_err(X509_V_ERR_UNNESTED_RESOURCE);

        if (x->rfc3779_asid->rdi != NULL &&

            x->rfc3779_asid->rdi->type == ASIdentifierChoice_inherit)

            validation_err(X509_V_ERR_UNNESTED_RESOURCE);

    }

 done:

    return ret;

}

#undef validation_err

/*

 * RFC 3779 3.3 path validation -- called from X509_verify_cert().

 */

int X509v3_asid_validate_path(X509_STORE_CTX *ctx)

{

    if (ctx->chain == NULL

            || sk_X509_num(ctx->chain) == 0

            || ctx->verify_cb == NULL) {

        ctx->error = X509_V_ERR_UNSPECIFIED;

        return 0;

    }

    return asid_validate_path_internal(ctx, ctx->chain, NULL);

}

/*

 * RFC 3779 3.3 path validation of an extension.

 * Test whether chain covers extension.