Lay groundwork to support X.509 v3 extensions for IP Addresses and AS Identifiers

These extensions are defined in RFC 3779 and used in the RPKI (RFC 6482, RFC 8360).
Imported from OpenSSL 1.1.1j (aaf2fcb575cdf6491b98ab4829abf78a3dec8402b8b81efc8f23c00d443981bf)
This changeset is a no-op, as there are 10+ issues and at least 2 security issues.
Work will continue in-tree.

OK tb@, discussed with beck@

1 files changed, 894 insertions, 0 deletions

diff --git a/src/lib/libcrypto/x509/x509_asid.c b/src/lib/libcrypto/x509/x509_asid.c
new file mode 100644
index 0000000000..ac68572672
--- /dev/null
+++ b/src/lib/libcrypto/x509/x509_asid.c
@@ -0,0 +1,894 @@
+/*
+ * 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.
+ */
+int X509v3_asid_validate_resource_set(STACK_OF(X509) *chain,
+                                      ASIdentifiers *ext, int allow_inheritance)
+{
+    if (ext == NULL)
+        return 1;
+    if (chain == NULL || sk_X509_num(chain) == 0)
+        return 0;
+    if (!allow_inheritance && X509v3_asid_inherits(ext))
+        return 0;
+    return asid_validate_path_internal(NULL, chain, ext);
+}
+
+#endif                          /* OPENSSL_NO_RFC3779 */