ssl/libcrypto/src/crypto/x509v3/v3_addr.c
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ssl/libcrypto/src/crypto/x509v3/v3_addr.c	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,1280 @@
+/*
+ * Contributed to the OpenSSL Project by the American Registry for
+ * Internet Numbers ("ARIN").
+ */
+/* ====================================================================
+ * Copyright (c) 2006 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).
+ */
+
+/*
+ * Implementation of RFC 3779 section 2.2.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "cryptlib.h"
+#include <openssl/conf.h>
+#include <openssl/asn1.h>
+#include <openssl/asn1t.h>
+#include <openssl/buffer.h>
+#include <openssl/x509v3.h>
+
+#ifndef OPENSSL_NO_RFC3779
+
+/*
+ * OpenSSL ASN.1 template translation of RFC 3779 2.2.3.
+ */
+
+ASN1_SEQUENCE(IPAddressRange) = {
+  ASN1_SIMPLE(IPAddressRange, min, ASN1_BIT_STRING),
+  ASN1_SIMPLE(IPAddressRange, max, ASN1_BIT_STRING)
+} ASN1_SEQUENCE_END(IPAddressRange)
+
+ASN1_CHOICE(IPAddressOrRange) = {
+  ASN1_SIMPLE(IPAddressOrRange, u.addressPrefix, ASN1_BIT_STRING),
+  ASN1_SIMPLE(IPAddressOrRange, u.addressRange,  IPAddressRange)
+} ASN1_CHOICE_END(IPAddressOrRange)
+
+ASN1_CHOICE(IPAddressChoice) = {
+  ASN1_SIMPLE(IPAddressChoice,      u.inherit,           ASN1_NULL),
+  ASN1_SEQUENCE_OF(IPAddressChoice, u.addressesOrRanges, IPAddressOrRange)
+} ASN1_CHOICE_END(IPAddressChoice)
+
+ASN1_SEQUENCE(IPAddressFamily) = {
+  ASN1_SIMPLE(IPAddressFamily, addressFamily,   ASN1_OCTET_STRING),
+  ASN1_SIMPLE(IPAddressFamily, ipAddressChoice, IPAddressChoice)
+} ASN1_SEQUENCE_END(IPAddressFamily)
+
+ASN1_ITEM_TEMPLATE(IPAddrBlocks) = 
+  ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SEQUENCE_OF, 0,
+			IPAddrBlocks, IPAddressFamily)
+ASN1_ITEM_TEMPLATE_END(IPAddrBlocks)
+
+IMPLEMENT_ASN1_FUNCTIONS(IPAddressRange)
+IMPLEMENT_ASN1_FUNCTIONS(IPAddressOrRange)
+IMPLEMENT_ASN1_FUNCTIONS(IPAddressChoice)
+IMPLEMENT_ASN1_FUNCTIONS(IPAddressFamily)
+
+/*
+ * How much buffer space do we need for a raw address?
+ */
+#define ADDR_RAW_BUF_LEN	16
+
+/*
+ * What's the address length associated with this AFI?
+ */
+static int length_from_afi(const unsigned afi)
+{
+  switch (afi) {
+  case IANA_AFI_IPV4:
+    return 4;
+  case IANA_AFI_IPV6:
+    return 16;
+  default:
+    return 0;
+  }
+}
+
+/*
+ * Extract the AFI from an IPAddressFamily.
+ */
+unsigned v3_addr_get_afi(const IPAddressFamily *f)
+{
+  return ((f != NULL &&
+	   f->addressFamily != NULL &&
+	   f->addressFamily->data != NULL)
+	  ? ((f->addressFamily->data[0] << 8) |
+	     (f->addressFamily->data[1]))
+	  : 0);
+}
+
+/*
+ * Expand the bitstring form of an address into a raw byte array.
+ * At the moment this is coded for simplicity, not speed.
+ */
+static void addr_expand(unsigned char *addr,
+			const ASN1_BIT_STRING *bs,
+			const int length,
+			const unsigned char fill)
+{
+  assert(bs->length >= 0 && bs->length <= length);
+  if (bs->length > 0) {
+    memcpy(addr, bs->data, bs->length);
+    if ((bs->flags & 7) != 0) {
+      unsigned char mask = 0xFF >> (8 - (bs->flags & 7));
+      if (fill == 0)
+	addr[bs->length - 1] &= ~mask;
+      else
+	addr[bs->length - 1] |= mask;
+    }
+  }
+  memset(addr + bs->length, fill, length - bs->length);
+}
+
+/*
+ * Extract the prefix length from a bitstring.
+ */
+#define addr_prefixlen(bs) ((int) ((bs)->length * 8 - ((bs)->flags & 7)))
+
+/*
+ * i2r handler for one address bitstring.
+ */
+static int i2r_address(BIO *out,
+		       const unsigned afi,
+		       const unsigned char fill,
+		       const ASN1_BIT_STRING *bs)
+{
+  unsigned char addr[ADDR_RAW_BUF_LEN];
+  int i, n;
+
+  switch (afi) {
+  case IANA_AFI_IPV4:
+    addr_expand(addr, bs, 4, fill);
+    BIO_printf(out, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
+    break;
+  case IANA_AFI_IPV6:
+    addr_expand(addr, bs, 16, fill);
+    for (n = 16; n > 1 && addr[n-1] == 0x00 && addr[n-2] == 0x00; n -= 2)
+      ;
+    for (i = 0; i < n; i += 2)
+      BIO_printf(out, "%x%s", (addr[i] << 8) | addr[i+1], (i < 14 ? ":" : ""));
+    if (i < 16)
+      BIO_puts(out, ":");
+    break;
+  default:
+    for (i = 0; i < bs->length; i++)
+      BIO_printf(out, "%s%02x", (i > 0 ? ":" : ""), bs->data[i]);
+    BIO_printf(out, "[%d]", (int) (bs->flags & 7));
+    break;
+  }
+  return 1;
+}
+
+/*
+ * i2r handler for a sequence of addresses and ranges.
+ */
+static int i2r_IPAddressOrRanges(BIO *out,
+				 const int indent,
+				 const IPAddressOrRanges *aors,
+				 const unsigned afi)
+{
+  int i;
+  for (i = 0; i < sk_IPAddressOrRange_num(aors); i++) {
+    const IPAddressOrRange *aor = sk_IPAddressOrRange_value(aors, i);
+    BIO_printf(out, "%*s", indent, "");
+    switch (aor->type) {
+    case IPAddressOrRange_addressPrefix:
+      if (!i2r_address(out, afi, 0x00, aor->u.addressPrefix))
+	return 0;
+      BIO_printf(out, "/%d\n", addr_prefixlen(aor->u.addressPrefix));
+      continue;
+    case IPAddressOrRange_addressRange:
+      if (!i2r_address(out, afi, 0x00, aor->u.addressRange->min))
+	return 0;
+      BIO_puts(out, "-");
+      if (!i2r_address(out, afi, 0xFF, aor->u.addressRange->max))
+	return 0;
+      BIO_puts(out, "\n");
+      continue;
+    }
+  }
+  return 1;
+}
+
+/*
+ * i2r handler for an IPAddrBlocks extension.
+ */
+static int i2r_IPAddrBlocks(X509V3_EXT_METHOD *method,
+			    void *ext,
+			    BIO *out,
+			    int indent)
+{
+  const IPAddrBlocks *addr = ext;
+  int i;
+  for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
+    IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
+    const unsigned afi = v3_addr_get_afi(f);
+    switch (afi) {
+    case IANA_AFI_IPV4:
+      BIO_printf(out, "%*sIPv4", indent, "");
+      break;
+    case IANA_AFI_IPV6:
+      BIO_printf(out, "%*sIPv6", indent, "");
+      break;
+    default:
+      BIO_printf(out, "%*sUnknown AFI %u", indent, "", afi);
+      break;
+    }
+    if (f->addressFamily->length > 2) {
+      switch (f->addressFamily->data[2]) {
+      case   1:
+	BIO_puts(out, " (Unicast)");
+	break;
+      case   2:
+	BIO_puts(out, " (Multicast)");
+	break;
+      case   3:
+	BIO_puts(out, " (Unicast/Multicast)");
+	break;
+      case   4:
+	BIO_puts(out, " (MPLS)");
+	break;
+      case  64:
+	BIO_puts(out, " (Tunnel)");
+	break;
+      case  65:
+	BIO_puts(out, " (VPLS)");
+	break;
+      case  66:
+	BIO_puts(out, " (BGP MDT)");
+	break;
+      case 128:
+	BIO_puts(out, " (MPLS-labeled VPN)");
+	break;
+      default:  
+	BIO_printf(out, " (Unknown SAFI %u)",
+		   (unsigned) f->addressFamily->data[2]);
+	break;
+      }
+    }
+    switch (f->ipAddressChoice->type) {
+    case IPAddressChoice_inherit:
+      BIO_puts(out, ": inherit\n");
+      break;
+    case IPAddressChoice_addressesOrRanges:
+      BIO_puts(out, ":\n");
+      if (!i2r_IPAddressOrRanges(out,
+				 indent + 2,
+				 f->ipAddressChoice->u.addressesOrRanges,
+				 afi))
+	return 0;
+      break;
+    }
+  }
+  return 1;
+}
+
+/*
+ * Sort comparison function for a sequence of IPAddressOrRange
+ * elements.
+ */
+static int IPAddressOrRange_cmp(const IPAddressOrRange *a,
+				const IPAddressOrRange *b,
+				const int length)
+{
+  unsigned char addr_a[ADDR_RAW_BUF_LEN], addr_b[ADDR_RAW_BUF_LEN];
+  int prefixlen_a = 0;
+  int prefixlen_b = 0;
+  int r;
+
+  switch (a->type) {
+  case IPAddressOrRange_addressPrefix:
+    addr_expand(addr_a, a->u.addressPrefix, length, 0x00);
+    prefixlen_a = addr_prefixlen(a->u.addressPrefix);
+    break;
+  case IPAddressOrRange_addressRange:
+    addr_expand(addr_a, a->u.addressRange->min, length, 0x00);
+    prefixlen_a = length * 8;
+    break;
+  }
+
+  switch (b->type) {
+  case IPAddressOrRange_addressPrefix:
+    addr_expand(addr_b, b->u.addressPrefix, length, 0x00);
+    prefixlen_b = addr_prefixlen(b->u.addressPrefix);
+    break;
+  case IPAddressOrRange_addressRange:
+    addr_expand(addr_b, b->u.addressRange->min, length, 0x00);
+    prefixlen_b = length * 8;
+    break;
+  }
+
+  if ((r = memcmp(addr_a, addr_b, length)) != 0)
+    return r;
+  else
+    return prefixlen_a - prefixlen_b;
+}
+
+/*
+ * IPv4-specific closure over IPAddressOrRange_cmp, since sk_sort()
+ * comparision routines are only allowed two arguments.
+ */
+static int v4IPAddressOrRange_cmp(const IPAddressOrRange * const *a,
+				  const IPAddressOrRange * const *b)
+{
+  return IPAddressOrRange_cmp(*a, *b, 4);
+}
+
+/*
+ * IPv6-specific closure over IPAddressOrRange_cmp, since sk_sort()
+ * comparision routines are only allowed two arguments.
+ */
+static int v6IPAddressOrRange_cmp(const IPAddressOrRange * const *a,
+				  const IPAddressOrRange * const *b)
+{
+  return IPAddressOrRange_cmp(*a, *b, 16);
+}
+
+/*
+ * Calculate whether a range collapses to a prefix.
+ * See last paragraph of RFC 3779 2.2.3.7.
+ */
+static int range_should_be_prefix(const unsigned char *min,
+				  const unsigned char *max,
+				  const int length)
+{
+  unsigned char mask;
+  int i, j;
+
+  for (i = 0; i < length && min[i] == max[i]; i++)
+    ;
+  for (j = length - 1; j >= 0 && min[j] == 0x00 && max[j] == 0xFF; j--)
+    ;
+  if (i < j)
+    return -1;
+  if (i > j)
+    return i * 8;
+  mask = min[i] ^ max[i];
+  switch (mask) {
+  case 0x01: j = 7; break;
+  case 0x03: j = 6; break;
+  case 0x07: j = 5; break;
+  case 0x0F: j = 4; break;
+  case 0x1F: j = 3; break;
+  case 0x3F: j = 2; break;
+  case 0x7F: j = 1; break;
+  default:   return -1;
+  }
+  if ((min[i] & mask) != 0 || (max[i] & mask) != mask)
+    return -1;
+  else
+    return i * 8 + j;
+}
+
+/*
+ * Construct a prefix.
+ */
+static int make_addressPrefix(IPAddressOrRange **result,
+			      unsigned char *addr,
+			      const int prefixlen)
+{
+  int bytelen = (prefixlen + 7) / 8, bitlen = prefixlen % 8;
+  IPAddressOrRange *aor = IPAddressOrRange_new();
+
+  if (aor == NULL)
+    return 0;
+  aor->type = IPAddressOrRange_addressPrefix;
+  if (aor->u.addressPrefix == NULL &&
+      (aor->u.addressPrefix = ASN1_BIT_STRING_new()) == NULL)
+    goto err;
+  if (!ASN1_BIT_STRING_set(aor->u.addressPrefix, addr, bytelen))
+    goto err;
+  aor->u.addressPrefix->flags &= ~7;
+  aor->u.addressPrefix->flags |= ASN1_STRING_FLAG_BITS_LEFT;
+  if (bitlen > 0) {
+    aor->u.addressPrefix->data[bytelen - 1] &= ~(0xFF >> bitlen);
+    aor->u.addressPrefix->flags |= 8 - bitlen;
+  }
+  
+  *result = aor;
+  return 1;
+
+ err:
+  IPAddressOrRange_free(aor);
+  return 0;
+}
+
+/*
+ * Construct a range.  If it can be expressed as a prefix,
+ * return a prefix instead.  Doing this here simplifies
+ * the rest of the code considerably.
+ */
+static int make_addressRange(IPAddressOrRange **result,
+			     unsigned char *min,
+			     unsigned char *max,
+			     const int length)
+{
+  IPAddressOrRange *aor;
+  int i, prefixlen;
+
+  if ((prefixlen = range_should_be_prefix(min, max, length)) >= 0)
+    return make_addressPrefix(result, min, prefixlen);
+
+  if ((aor = IPAddressOrRange_new()) == NULL)
+    return 0;
+  aor->type = IPAddressOrRange_addressRange;
+  assert(aor->u.addressRange == NULL);
+  if ((aor->u.addressRange = IPAddressRange_new()) == NULL)
+    goto err;
+  if (aor->u.addressRange->min == NULL &&
+      (aor->u.addressRange->min = ASN1_BIT_STRING_new()) == NULL)
+    goto err;
+  if (aor->u.addressRange->max == NULL &&
+      (aor->u.addressRange->max = ASN1_BIT_STRING_new()) == NULL)
+    goto err;
+
+  for (i = length; i > 0 && min[i - 1] == 0x00; --i)
+    ;
+  if (!ASN1_BIT_STRING_set(aor->u.addressRange->min, min, i))
+    goto err;
+  aor->u.addressRange->min->flags &= ~7;
+  aor->u.addressRange->min->flags |= ASN1_STRING_FLAG_BITS_LEFT;
+  if (i > 0) {
+    unsigned char b = min[i - 1];
+    int j = 1;
+    while ((b & (0xFFU >> j)) != 0) 
+      ++j;
+    aor->u.addressRange->min->flags |= 8 - j;
+  }
+
+  for (i = length; i > 0 && max[i - 1] == 0xFF; --i)
+    ;
+  if (!ASN1_BIT_STRING_set(aor->u.addressRange->max, max, i))
+    goto err;
+  aor->u.addressRange->max->flags &= ~7;
+  aor->u.addressRange->max->flags |= ASN1_STRING_FLAG_BITS_LEFT;
+  if (i > 0) {
+    unsigned char b = max[i - 1];
+    int j = 1;
+    while ((b & (0xFFU >> j)) != (0xFFU >> j))
+      ++j;
+    aor->u.addressRange->max->flags |= 8 - j;
+  }
+
+  *result = aor;
+  return 1;
+
+ err:
+  IPAddressOrRange_free(aor);
+  return 0;
+}
+
+/*
+ * Construct a new address family or find an existing one.
+ */
+static IPAddressFamily *make_IPAddressFamily(IPAddrBlocks *addr,
+					     const unsigned afi,
+					     const unsigned *safi)
+{
+  IPAddressFamily *f;
+  unsigned char key[3];
+  unsigned keylen;
+  int i;
+
+  key[0] = (afi >> 8) & 0xFF;
+  key[1] = afi & 0xFF;
+  if (safi != NULL) {
+    key[2] = *safi & 0xFF;
+    keylen = 3;
+  } else {
+    keylen = 2;
+  }
+
+  for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
+    f = sk_IPAddressFamily_value(addr, i);
+    assert(f->addressFamily->data != NULL);
+    if (f->addressFamily->length == keylen &&
+	!memcmp(f->addressFamily->data, key, keylen))
+      return f;
+  }
+
+  if ((f = IPAddressFamily_new()) == NULL)
+    goto err;
+  if (f->ipAddressChoice == NULL &&
+      (f->ipAddressChoice = IPAddressChoice_new()) == NULL)
+    goto err;
+  if (f->addressFamily == NULL && 
+      (f->addressFamily = ASN1_OCTET_STRING_new()) == NULL)
+    goto err;
+  if (!ASN1_OCTET_STRING_set(f->addressFamily, key, keylen))
+    goto err;
+  if (!sk_IPAddressFamily_push(addr, f))
+    goto err;
+
+  return f;
+
+ err:
+  IPAddressFamily_free(f);
+  return NULL;
+}
+
+/*
+ * Add an inheritance element.
+ */
+int v3_addr_add_inherit(IPAddrBlocks *addr,
+			const unsigned afi,
+			const unsigned *safi)
+{
+  IPAddressFamily *f = make_IPAddressFamily(addr, afi, safi);
+  if (f == NULL ||
+      f->ipAddressChoice == NULL ||
+      (f->ipAddressChoice->type == IPAddressChoice_addressesOrRanges &&
+       f->ipAddressChoice->u.addressesOrRanges != NULL))
+    return 0;
+  if (f->ipAddressChoice->type == IPAddressChoice_inherit &&
+      f->ipAddressChoice->u.inherit != NULL)
+    return 1;
+  if (f->ipAddressChoice->u.inherit == NULL &&
+      (f->ipAddressChoice->u.inherit = ASN1_NULL_new()) == NULL)
+    return 0;
+  f->ipAddressChoice->type = IPAddressChoice_inherit;
+  return 1;
+}
+
+/*
+ * Construct an IPAddressOrRange sequence, or return an existing one.
+ */
+static IPAddressOrRanges *make_prefix_or_range(IPAddrBlocks *addr,
+					       const unsigned afi,
+					       const unsigned *safi)
+{
+  IPAddressFamily *f = make_IPAddressFamily(addr, afi, safi);
+  IPAddressOrRanges *aors = NULL;
+
+  if (f == NULL ||
+      f->ipAddressChoice == NULL ||
+      (f->ipAddressChoice->type == IPAddressChoice_inherit &&
+       f->ipAddressChoice->u.inherit != NULL))
+    return NULL;
+  if (f->ipAddressChoice->type == IPAddressChoice_addressesOrRanges)
+    aors = f->ipAddressChoice->u.addressesOrRanges;
+  if (aors != NULL)
+    return aors;
+  if ((aors = sk_IPAddressOrRange_new_null()) == NULL)
+    return NULL;
+  switch (afi) {
+  case IANA_AFI_IPV4:
+    sk_IPAddressOrRange_set_cmp_func(aors, v4IPAddressOrRange_cmp);
+    break;
+  case IANA_AFI_IPV6:
+    sk_IPAddressOrRange_set_cmp_func(aors, v6IPAddressOrRange_cmp);
+    break;
+  }
+  f->ipAddressChoice->type = IPAddressChoice_addressesOrRanges;
+  f->ipAddressChoice->u.addressesOrRanges = aors;
+  return aors;
+}
+
+/*
+ * Add a prefix.
+ */
+int v3_addr_add_prefix(IPAddrBlocks *addr,
+		       const unsigned afi,
+		       const unsigned *safi,
+		       unsigned char *a,
+		       const int prefixlen)
+{
+  IPAddressOrRanges *aors = make_prefix_or_range(addr, afi, safi);
+  IPAddressOrRange *aor;
+  if (aors == NULL || !make_addressPrefix(&aor, a, prefixlen))
+    return 0;
+  if (sk_IPAddressOrRange_push(aors, aor))
+    return 1;
+  IPAddressOrRange_free(aor);
+  return 0;
+}
+
+/*
+ * Add a range.
+ */
+int v3_addr_add_range(IPAddrBlocks *addr,
+		      const unsigned afi,
+		      const unsigned *safi,
+		      unsigned char *min,
+		      unsigned char *max)
+{
+  IPAddressOrRanges *aors = make_prefix_or_range(addr, afi, safi);
+  IPAddressOrRange *aor;
+  int length = length_from_afi(afi);
+  if (aors == NULL)
+    return 0;
+  if (!make_addressRange(&aor, min, max, length))
+    return 0;
+  if (sk_IPAddressOrRange_push(aors, aor))
+    return 1;
+  IPAddressOrRange_free(aor);
+  return 0;
+}
+
+/*
+ * Extract min and max values from an IPAddressOrRange.
+ */
+static void extract_min_max(IPAddressOrRange *aor,
+			    unsigned char *min,
+			    unsigned char *max,
+			    int length)
+{
+  assert(aor != NULL && min != NULL && max != NULL);
+  switch (aor->type) {
+  case IPAddressOrRange_addressPrefix:
+    addr_expand(min, aor->u.addressPrefix, length, 0x00);
+    addr_expand(max, aor->u.addressPrefix, length, 0xFF);
+    return;
+  case IPAddressOrRange_addressRange:
+    addr_expand(min, aor->u.addressRange->min, length, 0x00);
+    addr_expand(max, aor->u.addressRange->max, length, 0xFF);
+    return;
+  }
+}
+
+/*
+ * Public wrapper for extract_min_max().
+ */
+int v3_addr_get_range(IPAddressOrRange *aor,
+		      const unsigned afi,
+		      unsigned char *min,
+		      unsigned char *max,
+		      const int length)
+{
+  int afi_length = length_from_afi(afi);
+  if (aor == NULL || min == NULL || max == NULL ||
+      afi_length == 0 || length < afi_length ||
+      (aor->type != IPAddressOrRange_addressPrefix &&
+       aor->type != IPAddressOrRange_addressRange))
+    return 0;
+  extract_min_max(aor, min, max, afi_length);
+  return afi_length;
+}
+
+/*
+ * Sort comparision function for a sequence of IPAddressFamily.
+ *
+ * The last paragraph of RFC 3779 2.2.3.3 is slightly ambiguous about
+ * the ordering: I can read it as meaning that IPv6 without a SAFI
+ * comes before IPv4 with a SAFI, which seems pretty weird.  The
+ * examples in appendix B suggest that the author intended the
+ * null-SAFI rule to apply only within a single AFI, which is what I
+ * would have expected and is what the following code implements.
+ */
+static int IPAddressFamily_cmp(const IPAddressFamily * const *a_,
+			       const IPAddressFamily * const *b_)
+{
+  const ASN1_OCTET_STRING *a = (*a_)->addressFamily;
+  const ASN1_OCTET_STRING *b = (*b_)->addressFamily;
+  int len = ((a->length <= b->length) ? a->length : b->length);
+  int cmp = memcmp(a->data, b->data, len);
+  return cmp ? cmp : a->length - b->length;
+}
+
+/*
+ * Check whether an IPAddrBLocks is in canonical form.
+ */
+int v3_addr_is_canonical(IPAddrBlocks *addr)
+{
+  unsigned char a_min[ADDR_RAW_BUF_LEN], a_max[ADDR_RAW_BUF_LEN];
+  unsigned char b_min[ADDR_RAW_BUF_LEN], b_max[ADDR_RAW_BUF_LEN];
+  IPAddressOrRanges *aors;
+  int i, j, k;
+
+  /*
+   * Empty extension is cannonical.
+   */
+  if (addr == NULL)
+    return 1;
+
+  /*
+   * Check whether the top-level list is in order.
+   */
+  for (i = 0; i < sk_IPAddressFamily_num(addr) - 1; i++) {
+    const IPAddressFamily *a = sk_IPAddressFamily_value(addr, i);
+    const IPAddressFamily *b = sk_IPAddressFamily_value(addr, i + 1);
+    if (IPAddressFamily_cmp(&a, &b) >= 0)
+      return 0;
+  }
+
+  /*
+   * Top level's ok, now check each address family.
+   */
+  for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
+    IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
+    int length = length_from_afi(v3_addr_get_afi(f));
+
+    /*
+     * Inheritance is canonical.  Anything other than inheritance or
+     * a SEQUENCE OF IPAddressOrRange is an ASN.1 error or something.
+     */
+    if (f == NULL || f->ipAddressChoice == NULL)
+      return 0;
+    switch (f->ipAddressChoice->type) {
+    case IPAddressChoice_inherit:
+      continue;
+    case IPAddressChoice_addressesOrRanges:
+      break;
+    default:
+      return 0;
+    }
+
+    /*
+     * It's an IPAddressOrRanges sequence, check it.
+     */
+    aors = f->ipAddressChoice->u.addressesOrRanges;
+    if (sk_IPAddressOrRange_num(aors) == 0)
+      return 0;
+    for (j = 0; j < sk_IPAddressOrRange_num(aors) - 1; j++) {
+      IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, j);
+      IPAddressOrRange *b = sk_IPAddressOrRange_value(aors, j + 1);
+
+      extract_min_max(a, a_min, a_max, length);
+      extract_min_max(b, b_min, b_max, length);
+
+      /*
+       * Punt misordered list, overlapping start, or inverted range.
+       */
+      if (memcmp(a_min, b_min, length) >= 0 ||
+	  memcmp(a_min, a_max, length) > 0 ||
+	  memcmp(b_min, b_max, length) > 0)
+	return 0;
+
+      /*
+       * Punt if adjacent or overlapping.  Check for adjacency by
+       * subtracting one from b_min first.
+       */
+      for (k = length - 1; k >= 0 && b_min[k]-- == 0x00; k--)
+	;
+      if (memcmp(a_max, b_min, length) >= 0)
+	return 0;
+
+      /*
+       * Check for range that should be expressed as a prefix.
+       */
+      if (a->type == IPAddressOrRange_addressRange &&
+	  range_should_be_prefix(a_min, a_max, length) >= 0)
+	return 0;
+    }
+
+    /*
+     * Check final range to see if it should be a prefix.
+     */
+    j = sk_IPAddressOrRange_num(aors) - 1;
+    {
+      IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, j);
+      if (a->type == IPAddressOrRange_addressRange) {
+	extract_min_max(a, a_min, a_max, length);
+	if (range_should_be_prefix(a_min, a_max, length) >= 0)
+	  return 0;
+      }
+    }
+  }
+
+  /*
+   * If we made it through all that, we're happy.
+   */
+  return 1;
+}
+
+/*
+ * Whack an IPAddressOrRanges into canonical form.
+ */
+static int IPAddressOrRanges_canonize(IPAddressOrRanges *aors,
+				      const unsigned afi)
+{
+  int i, j, length = length_from_afi(afi);
+
+  /*
+   * Sort the IPAddressOrRanges sequence.
+   */
+  sk_IPAddressOrRange_sort(aors);
+
+  /*
+   * Clean up representation issues, punt on duplicates or overlaps.
+   */
+  for (i = 0; i < sk_IPAddressOrRange_num(aors) - 1; i++) {
+    IPAddressOrRange *a = sk_IPAddressOrRange_value(aors, i);
+    IPAddressOrRange *b = sk_IPAddressOrRange_value(aors, i + 1);
+    unsigned char a_min[ADDR_RAW_BUF_LEN], a_max[ADDR_RAW_BUF_LEN];
+    unsigned char b_min[ADDR_RAW_BUF_LEN], b_max[ADDR_RAW_BUF_LEN];
+
+    extract_min_max(a, a_min, a_max, length);
+    extract_min_max(b, b_min, b_max, length);
+
+    /*
+     * Punt overlaps.
+     */
+    if (memcmp(a_max, b_min, length) >= 0)
+      return 0;
+
+    /*
+     * Merge if a and b are adjacent.  We check for
+     * adjacency by subtracting one from b_min first.
+     */
+    for (j = length - 1; j >= 0 && b_min[j]-- == 0x00; j--)
+      ;
+    if (memcmp(a_max, b_min, length) == 0) {
+      IPAddressOrRange *merged;
+      if (!make_addressRange(&merged, a_min, b_max, length))
+	return 0;
+      sk_IPAddressOrRange_set(aors, i, merged);
+      sk_IPAddressOrRange_delete(aors, i + 1);
+      IPAddressOrRange_free(a);
+      IPAddressOrRange_free(b);
+      --i;
+      continue;
+    }
+  }
+
+  return 1;
+}
+
+/*
+ * Whack an IPAddrBlocks extension into canonical form.
+ */
+int v3_addr_canonize(IPAddrBlocks *addr)
+{
+  int i;
+  for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
+    IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
+    if (f->ipAddressChoice->type == IPAddressChoice_addressesOrRanges &&
+	!IPAddressOrRanges_canonize(f->ipAddressChoice->u.addressesOrRanges,
+				    v3_addr_get_afi(f)))
+      return 0;
+  }
+  sk_IPAddressFamily_sort(addr);
+  assert(v3_addr_is_canonical(addr));
+  return 1;
+}
+
+/*
+ * v2i handler for the IPAddrBlocks extension.
+ */
+static void *v2i_IPAddrBlocks(struct v3_ext_method *method,
+			      struct v3_ext_ctx *ctx,
+			      STACK_OF(CONF_VALUE) *values)
+{
+  static const char v4addr_chars[] = "0123456789.";
+  static const char v6addr_chars[] = "0123456789.:abcdefABCDEF";
+  IPAddrBlocks *addr = NULL;
+  char *s = NULL, *t;
+  int i;
+  
+  if ((addr = sk_IPAddressFamily_new(IPAddressFamily_cmp)) == NULL) {
+    X509V3err(X509V3_F_V2I_IPADDRBLOCKS, 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);
+    unsigned char min[ADDR_RAW_BUF_LEN], max[ADDR_RAW_BUF_LEN];
+    unsigned afi, *safi = NULL, safi_;
+    const char *addr_chars;
+    int prefixlen, i1, i2, delim, length;
+
+    if (       !name_cmp(val->name, "IPv4")) {
+      afi = IANA_AFI_IPV4;
+    } else if (!name_cmp(val->name, "IPv6")) {
+      afi = IANA_AFI_IPV6;
+    } else if (!name_cmp(val->name, "IPv4-SAFI")) {
+      afi = IANA_AFI_IPV4;
+      safi = &safi_;
+    } else if (!name_cmp(val->name, "IPv6-SAFI")) {
+      afi = IANA_AFI_IPV6;
+      safi = &safi_;
+    } else {
+      X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_NAME_ERROR);
+      X509V3_conf_err(val);
+      goto err;
+    }
+
+    switch (afi) {
+    case IANA_AFI_IPV4:
+      addr_chars = v4addr_chars;
+      break;
+    case IANA_AFI_IPV6:
+      addr_chars = v6addr_chars;
+      break;
+    }
+
+    length = length_from_afi(afi);
+
+    /*
+     * Handle SAFI, if any, and BUF_strdup() so we can null-terminate
+     * the other input values.
+     */
+    if (safi != NULL) {
+      *safi = strtoul(val->value, &t, 0);
+      t += strspn(t, " \t");
+      if (*safi > 0xFF || *t++ != ':') {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_SAFI);
+	X509V3_conf_err(val);
+	goto err;
+      }
+      t += strspn(t, " \t");
+      s = BUF_strdup(t);
+    } else {
+      s = BUF_strdup(val->value);
+    }
+    if (s == NULL) {
+      X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
+      goto err;
+    }
+
+    /*
+     * Check for inheritance.  Not worth additional complexity to
+     * optimize this (seldom-used) case.
+     */
+    if (!strcmp(s, "inherit")) {
+      if (!v3_addr_add_inherit(addr, afi, safi)) {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_INHERITANCE);
+	X509V3_conf_err(val);
+	goto err;
+      }
+      OPENSSL_free(s);
+      s = NULL;
+      continue;
+    }
+
+    i1 = strspn(s, addr_chars);
+    i2 = i1 + strspn(s + i1, " \t");
+    delim = s[i2++];
+    s[i1] = '\0';
+
+    if (a2i_ipadd(min, s) != length) {
+      X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_IPADDRESS);
+      X509V3_conf_err(val);
+      goto err;
+    }
+
+    switch (delim) {
+    case '/':
+      prefixlen = (int) strtoul(s + i2, &t, 10);
+      if (t == s + i2 || *t != '\0') {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
+	X509V3_conf_err(val);
+	goto err;
+      }
+      if (!v3_addr_add_prefix(addr, afi, safi, min, prefixlen)) {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
+	goto err;
+      }
+      break;
+    case '-':
+      i1 = i2 + strspn(s + i2, " \t");
+      i2 = i1 + strspn(s + i1, addr_chars);
+      if (i1 == i2 || s[i2] != '\0') {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
+	X509V3_conf_err(val);
+	goto err;
+      }
+      if (a2i_ipadd(max, s + i1) != length) {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_INVALID_IPADDRESS);
+	X509V3_conf_err(val);
+	goto err;
+      }
+      if (!v3_addr_add_range(addr, afi, safi, min, max)) {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
+	goto err;
+      }
+      break;
+    case '\0':
+      if (!v3_addr_add_prefix(addr, afi, safi, min, length * 8)) {
+	X509V3err(X509V3_F_V2I_IPADDRBLOCKS, ERR_R_MALLOC_FAILURE);
+	goto err;
+      }
+      break;
+    default:
+      X509V3err(X509V3_F_V2I_IPADDRBLOCKS, X509V3_R_EXTENSION_VALUE_ERROR);
+      X509V3_conf_err(val);
+      goto err;
+    }
+
+    OPENSSL_free(s);
+    s = NULL;
+  }
+
+  /*
+   * Canonize the result, then we're done.
+   */
+  if (!v3_addr_canonize(addr))
+    goto err;    
+  return addr;
+
+ err:
+  OPENSSL_free(s);
+  sk_IPAddressFamily_pop_free(addr, IPAddressFamily_free);
+  return NULL;
+}
+
+/*
+ * OpenSSL dispatch
+ */
+const X509V3_EXT_METHOD v3_addr = {
+  NID_sbgp_ipAddrBlock,		/* nid */
+  0,				/* flags */
+  ASN1_ITEM_ref(IPAddrBlocks),	/* template */
+  0, 0, 0, 0,			/* old functions, ignored */
+  0,				/* i2s */
+  0,				/* s2i */
+  0,				/* i2v */
+  v2i_IPAddrBlocks,		/* v2i */
+  i2r_IPAddrBlocks,		/* i2r */
+  0,				/* r2i */
+  NULL				/* extension-specific data */
+};
+
+/*
+ * Figure out whether extension sues inheritance.
+ */
+int v3_addr_inherits(IPAddrBlocks *addr)
+{
+  int i;
+  if (addr == NULL)
+    return 0;
+  for (i = 0; i < sk_IPAddressFamily_num(addr); i++) {
+    IPAddressFamily *f = sk_IPAddressFamily_value(addr, i);
+    if (f->ipAddressChoice->type == IPAddressChoice_inherit)
+      return 1;
+  }
+  return 0;
+}
+
+/*
+ * Figure out whether parent contains child.
+ */
+static int addr_contains(IPAddressOrRanges *parent,
+			 IPAddressOrRanges *child,
+			 int length)
+{
+  unsigned char p_min[ADDR_RAW_BUF_LEN], p_max[ADDR_RAW_BUF_LEN];
+  unsigned char c_min[ADDR_RAW_BUF_LEN], c_max[ADDR_RAW_BUF_LEN];
+  int p, c;
+
+  if (child == NULL || parent == child)
+    return 1;
+  if (parent == NULL)
+    return 0;
+
+  p = 0;
+  for (c = 0; c < sk_IPAddressOrRange_num(child); c++) {
+    extract_min_max(sk_IPAddressOrRange_value(child, c),
+		    c_min, c_max, length);
+    for (;; p++) {
+      if (p >= sk_IPAddressOrRange_num(parent))
+	return 0;
+      extract_min_max(sk_IPAddressOrRange_value(parent, p),
+		      p_min, p_max, length);
+      if (memcmp(p_max, c_max, length) < 0)
+	continue;
+      if (memcmp(p_min, c_min, length) > 0)
+	return 0;
+      break;
+    }
+  }
+
+  return 1;
+}
+
+/*
+ * Test whether a is a subset of b.
+ */
+int v3_addr_subset(IPAddrBlocks *a, IPAddrBlocks *b)
+{
+  int i;
+  if (a == NULL || a == b)
+    return 1;
+  if (b == NULL || v3_addr_inherits(a) || v3_addr_inherits(b))
+    return 0;
+  sk_IPAddressFamily_set_cmp_func(b, IPAddressFamily_cmp);
+  for (i = 0; i < sk_IPAddressFamily_num(a); i++) {
+    IPAddressFamily *fa = sk_IPAddressFamily_value(a, i);
+    int j = sk_IPAddressFamily_find(b, fa);
+    IPAddressFamily *fb = sk_IPAddressFamily_value(b, j);
+    if (!addr_contains(fb->ipAddressChoice->u.addressesOrRanges, 
+		       fa->ipAddressChoice->u.addressesOrRanges,
+		       length_from_afi(v3_addr_get_afi(fb))))
+      return 0;
+  }
+  return 1;
+}
+
+/*
+ * 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 2.3 path validation.
+ */
+static int v3_addr_validate_path_internal(X509_STORE_CTX *ctx,
+					  STACK_OF(X509) *chain,
+					  IPAddrBlocks *ext)
+{
+  IPAddrBlocks *child = NULL;
+  int i, j, ret = 1;
+  X509 *x = NULL;
+
+  assert(chain != NULL && sk_X509_num(chain) > 0);
+  assert(ctx != NULL || ext != NULL);
+  assert(ctx == NULL || ctx->verify_cb != NULL);
+
+  /*
+   * 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;
+  } else {
+    i = 0;
+    x = sk_X509_value(chain, i);
+    assert(x != NULL);
+    if ((ext = x->rfc3779_addr) == NULL)
+      goto done;
+  }
+  if (!v3_addr_is_canonical(ext))
+    validation_err(X509_V_ERR_INVALID_EXTENSION);
+  sk_IPAddressFamily_set_cmp_func(ext, IPAddressFamily_cmp);
+  if ((child = sk_IPAddressFamily_dup(ext)) == NULL) {
+    X509V3err(X509V3_F_V3_ADDR_VALIDATE_PATH_INTERNAL, ERR_R_MALLOC_FAILURE);
+    ret = 0;
+    goto done;
+  }
+
+  /*
+   * Now walk up the chain.  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);
+    assert(x != NULL);
+    if (!v3_addr_is_canonical(x->rfc3779_addr))
+      validation_err(X509_V_ERR_INVALID_EXTENSION);
+    if (x->rfc3779_addr == NULL) {
+      for (j = 0; j < sk_IPAddressFamily_num(child); j++) {
+	IPAddressFamily *fc = sk_IPAddressFamily_value(child, j);
+	if (fc->ipAddressChoice->type != IPAddressChoice_inherit) {
+	  validation_err(X509_V_ERR_UNNESTED_RESOURCE);
+	  break;
+	}
+      }
+      continue;
+    }
+    sk_IPAddressFamily_set_cmp_func(x->rfc3779_addr, IPAddressFamily_cmp);
+    for (j = 0; j < sk_IPAddressFamily_num(child); j++) {
+      IPAddressFamily *fc = sk_IPAddressFamily_value(child, j);
+      int k = sk_IPAddressFamily_find(x->rfc3779_addr, fc);
+      IPAddressFamily *fp = sk_IPAddressFamily_value(x->rfc3779_addr, k);
+      if (fp == NULL) {
+	if (fc->ipAddressChoice->type == IPAddressChoice_addressesOrRanges) {
+	  validation_err(X509_V_ERR_UNNESTED_RESOURCE);
+	  break;
+	}
+	continue;
+      }
+      if (fp->ipAddressChoice->type == IPAddressChoice_addressesOrRanges) {
+	if (fc->ipAddressChoice->type == IPAddressChoice_inherit ||
+	    addr_contains(fp->ipAddressChoice->u.addressesOrRanges, 
+			  fc->ipAddressChoice->u.addressesOrRanges,
+			  length_from_afi(v3_addr_get_afi(fc))))
+	  sk_IPAddressFamily_set(child, j, fp);
+	else
+	  validation_err(X509_V_ERR_UNNESTED_RESOURCE);
+      }
+    }
+  }
+
+  /*
+   * Trust anchor can't inherit.
+   */
+  if (x->rfc3779_addr != NULL) {
+    for (j = 0; j < sk_IPAddressFamily_num(x->rfc3779_addr); j++) {
+      IPAddressFamily *fp = sk_IPAddressFamily_value(x->rfc3779_addr, j);
+      if (fp->ipAddressChoice->type == IPAddressChoice_inherit &&
+	  sk_IPAddressFamily_find(child, fp) >= 0)
+	validation_err(X509_V_ERR_UNNESTED_RESOURCE);
+    }
+  }
+
+ done:
+  sk_IPAddressFamily_free(child);
+  return ret;
+}
+
+#undef validation_err
+
+/*
+ * RFC 3779 2.3 path validation -- called from X509_verify_cert().
+ */
+int v3_addr_validate_path(X509_STORE_CTX *ctx)
+{
+  return v3_addr_validate_path_internal(ctx, ctx->chain, NULL);
+}
+
+/*
+ * RFC 3779 2.3 path validation of an extension.
+ * Test whether chain covers extension.
+ */
+int v3_addr_validate_resource_set(STACK_OF(X509) *chain,
+				  IPAddrBlocks *ext,
+				  int allow_inheritance)
+{
+  if (ext == NULL)
+    return 1;
+  if (chain == NULL || sk_X509_num(chain) == 0)
+    return 0;
+  if (!allow_inheritance && v3_addr_inherits(ext))
+    return 0;
+  return v3_addr_validate_path_internal(NULL, chain, ext);
+}
+
+#endif /* OPENSSL_NO_RFC3779 */