]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-esp.c
More UNALIGNED_MEM{CPY,CMP} on IP addresses.
[tcpdump] / print-esp.c
index 4e1c67b0b936a22bcfd7e710b5695633cc69dfc8..7e6f9302c6d81639624195e09c57de01fbe850e7 100644 (file)
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-#ifndef lint
-static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.7 2000-09-23 08:03:34 guy Exp $ (LBL)";
-#endif
-
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #include <string.h>
-#include <sys/param.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-
-#include <net/route.h>
-#include <net/if.h>
-
-#include <netinet/in.h>
-#include <netinet/in_systm.h>
-#include <netinet/ip.h>
-#include <netinet/ip_icmp.h>
-#include <netinet/ip_var.h>
-#include <netinet/udp.h>
-#include <netinet/udp_var.h>
-#include <netinet/tcp.h>
 
+#include <tcpdump-stdinc.h>
+
+#include <stdlib.h>
+
+/* Any code in this file that depends on HAVE_LIBCRYPTO depends on
+ * HAVE_OPENSSL_EVP_H too. Undefining the former when the latter isn't defined
+ * is the simplest way of handling the dependency.
+ */
 #ifdef HAVE_LIBCRYPTO
-#include <des.h>
-#include <blowfish.h>
-#ifdef HAVE_RC5_H
-#include <rc5.h>
-#endif
-#ifdef HAVE_CAST_H
-#include <cast.h>
+#ifdef HAVE_OPENSSL_EVP_H
+#include <openssl/evp.h>
+#else
+#undef HAVE_LIBCRYPTO
 #endif
 #endif
 
 #include <stdio.h>
 
+#include "ip.h"
 #ifdef INET6
-#include <netinet/ip6.h>
+#include "ip6.h"
 #endif
 
-/* there's no standard definition so we are on our own */
-struct esp {
-       u_int32_t       esp_spi;        /* ESP */
-       /*variable size, 32bit bound*/  /* Initialization Vector */
-       /*variable size*/               /* Payload data */
-       /*variable size*/               /* padding */
-       /*8bit*/                        /* pad size */
-       /*8bit*/                        /* next header */
-       /*8bit*/                        /* next header */
-       /*variable size, 32bit bound*/  /* Authentication data (new IPsec) */
-};
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE 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. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS 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 PROJECT OR 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.
+ */
+
+/*
+ * RFC1827/2406 Encapsulated Security Payload.
+ */
 
 struct newesp {
        u_int32_t       esp_spi;        /* ESP */
@@ -88,248 +98,628 @@ struct newesp {
        /*variable size, 32bit bound*/  /* Authentication data */
 };
 
-#include "interface.h"
-#include "addrtoname.h"
+#ifdef HAVE_LIBCRYPTO
+union inaddr_u {
+       struct in_addr in4;
+#ifdef INET6
+       struct in6_addr in6;
+#endif
+};
+struct sa_list {
+       struct sa_list  *next;
+       u_int           daddr_version;
+       union inaddr_u  daddr;
+       u_int32_t       spi;          /* if == 0, then IKEv2 */
+       int             initiator;
+       u_char          spii[8];      /* for IKEv2 */
+       u_char          spir[8];
+       const EVP_CIPHER *evp;
+       int             ivlen;
+       int             authlen;
+       u_char          authsecret[256];
+       int             authsecret_len;
+       u_char          secret[256];  /* is that big enough for all secrets? */
+       int             secretlen;
+};
+
+/*
+ * this will adjust ndo_packetp and ndo_snapend to new buffer!
+ */
+USES_APPLE_DEPRECATED_API
+int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
+                                     int initiator,
+                                     u_char spii[8], u_char spir[8],
+                                     u_char *buf, u_char *end)
+{
+       struct sa_list *sa;
+       u_char *iv;
+       int len;
+       EVP_CIPHER_CTX ctx;
+
+       /* initiator arg is any non-zero value */
+       if(initiator) initiator=1;
+
+       /* see if we can find the SA, and if so, decode it */
+       for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
+               if (sa->spi == 0
+                   && initiator == sa->initiator
+                   && memcmp(spii, sa->spii, 8) == 0
+                   && memcmp(spir, sa->spir, 8) == 0)
+                       break;
+       }
+
+       if(sa == NULL) return 0;
+       if(sa->evp == NULL) return 0;
+
+       /*
+        * remove authenticator, and see if we still have something to
+        * work with
+        */
+       end = end - sa->authlen;
+       iv  = buf;
+       buf = buf + sa->ivlen;
+       len = end-buf;
+
+       if(end <= buf) return 0;
+
+       memset(&ctx, 0, sizeof(ctx));
+       if (EVP_CipherInit(&ctx, sa->evp, sa->secret, NULL, 0) < 0)
+               (*ndo->ndo_warning)(ndo, "espkey init failed");
+       EVP_CipherInit(&ctx, NULL, NULL, iv, 0);
+       EVP_Cipher(&ctx, buf, buf, len);
+       EVP_CIPHER_CTX_cleanup(&ctx);
+
+       ndo->ndo_packetp = buf;
+       ndo->ndo_snapend = end;
+
+       return 1;
+
+}
+USES_APPLE_RST
+
+static void esp_print_addsa(netdissect_options *ndo,
+                           struct sa_list *sa, int sa_def)
+{
+       /* copy the "sa" */
+
+       struct sa_list *nsa;
+
+       nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
+       if (nsa == NULL)
+               (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure");
+
+       *nsa = *sa;
+
+       if (sa_def)
+               ndo->ndo_sa_default = nsa;
+
+       nsa->next = ndo->ndo_sa_list_head;
+       ndo->ndo_sa_list_head = nsa;
+}
+
+
+static u_int hexdigit(netdissect_options *ndo, char hex)
+{
+       if (hex >= '0' && hex <= '9')
+               return (hex - '0');
+       else if (hex >= 'A' && hex <= 'F')
+               return (hex - 'A' + 10);
+       else if (hex >= 'a' && hex <= 'f')
+               return (hex - 'a' + 10);
+       else {
+               (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex);
+               return 0;
+       }
+}
 
+static u_int hex2byte(netdissect_options *ndo, char *hexstring)
+{
+       u_int byte;
+
+       byte = (hexdigit(ndo, hexstring[0]) << 4) + hexdigit(ndo, hexstring[1]);
+       return byte;
+}
+
+/*
+ * returns size of binary, 0 on failure.
+ */
+static
+int espprint_decode_hex(netdissect_options *ndo,
+                       u_char *binbuf, unsigned int binbuf_len,
+                       char *hex)
+{
+       unsigned int len;
+       int i;
+
+       len = strlen(hex) / 2;
+
+       if (len > binbuf_len) {
+               (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len);
+               return 0;
+       }
+
+       i = 0;
+       while (hex[0] != '\0' && hex[1]!='\0') {
+               binbuf[i] = hex2byte(ndo, hex);
+               hex += 2;
+               i++;
+       }
+
+       return i;
+}
+
+/*
+ * decode the form:    SPINUM@IP <tab> ALGONAME:0xsecret
+ */
+
+USES_APPLE_DEPRECATED_API
+static int
+espprint_decode_encalgo(netdissect_options *ndo,
+                       char *decode, struct sa_list *sa)
+{
+       size_t i;
+       const EVP_CIPHER *evp;
+       int authlen = 0;
+       char *colon, *p;
+
+       colon = strchr(decode, ':');
+       if (colon == NULL) {
+               (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
+               return 0;
+       }
+       *colon = '\0';
+
+       if (strlen(decode) > strlen("-hmac96") &&
+           !strcmp(decode + strlen(decode) - strlen("-hmac96"),
+                   "-hmac96")) {
+               p = strstr(decode, "-hmac96");
+               *p = '\0';
+               authlen = 12;
+       }
+       if (strlen(decode) > strlen("-cbc") &&
+           !strcmp(decode + strlen(decode) - strlen("-cbc"), "-cbc")) {
+               p = strstr(decode, "-cbc");
+               *p = '\0';
+       }
+       evp = EVP_get_cipherbyname(decode);
+
+       if (!evp) {
+               (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s\n", decode);
+               sa->evp = NULL;
+               sa->authlen = 0;
+               sa->ivlen = 0;
+               return 0;
+       }
+
+       sa->evp = evp;
+       sa->authlen = authlen;
+       sa->ivlen = EVP_CIPHER_iv_length(evp);
+
+       colon++;
+       if (colon[0] == '0' && colon[1] == 'x') {
+               /* decode some hex! */
+
+               colon += 2;
+               sa->secretlen = espprint_decode_hex(ndo, sa->secret, sizeof(sa->secret), colon);
+               if(sa->secretlen == 0) return 0;
+       } else {
+               i = strlen(colon);
+
+               if (i < sizeof(sa->secret)) {
+                       memcpy(sa->secret, colon, i);
+                       sa->secretlen = i;
+               } else {
+                       memcpy(sa->secret, colon, sizeof(sa->secret));
+                       sa->secretlen = sizeof(sa->secret);
+               }
+       }
+
+       return 1;
+}
+USES_APPLE_RST
+
+/*
+ * for the moment, ignore the auth algorith, just hard code the authenticator
+ * length. Need to research how openssl looks up HMAC stuff.
+ */
+static int
+espprint_decode_authalgo(netdissect_options *ndo,
+                        char *decode, struct sa_list *sa)
+{
+       char *colon;
+
+       colon = strchr(decode, ':');
+       if (colon == NULL) {
+               (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
+               return 0;
+       }
+       *colon = '\0';
+
+       if(strcasecmp(colon,"sha1") == 0 ||
+          strcasecmp(colon,"md5") == 0) {
+               sa->authlen = 12;
+       }
+       return 1;
+}
+
+static void esp_print_decode_ikeline(netdissect_options *ndo, char *line,
+                                    const char *file, int lineno)
+{
+       /* it's an IKEv2 secret, store it instead */
+       struct sa_list sa1;
+
+       char *init;
+       char *icookie, *rcookie;
+       int   ilen, rlen;
+       char *authkey;
+       char *enckey;
+
+       init = strsep(&line, " \t");
+       icookie = strsep(&line, " \t");
+       rcookie = strsep(&line, " \t");
+       authkey = strsep(&line, " \t");
+       enckey  = strsep(&line, " \t");
+
+       /* if any fields are missing */
+       if(!init || !icookie || !rcookie || !authkey || !enckey) {
+               (*ndo->ndo_warning)(ndo, "print_esp: failed to find all fields for ikev2 at %s:%u",
+                                   file, lineno);
+
+               return;
+       }
+
+       ilen = strlen(icookie);
+       rlen = strlen(rcookie);
+
+       if((init[0]!='I' && init[0]!='R')
+          || icookie[0]!='0' || icookie[1]!='x'
+          || rcookie[0]!='0' || rcookie[1]!='x'
+          || ilen!=18
+          || rlen!=18) {
+               (*ndo->ndo_warning)(ndo, "print_esp: line %s:%u improperly formatted.",
+                                   file, lineno);
+
+               (*ndo->ndo_warning)(ndo, "init=%s icookie=%s(%u) rcookie=%s(%u)",
+                                   init, icookie, ilen, rcookie, rlen);
+
+               return;
+       }
+
+       sa1.spi = 0;
+       sa1.initiator = (init[0] == 'I');
+       if(espprint_decode_hex(ndo, sa1.spii, sizeof(sa1.spii), icookie+2)!=8)
+               return;
+
+       if(espprint_decode_hex(ndo, sa1.spir, sizeof(sa1.spir), rcookie+2)!=8)
+               return;
+
+       if(!espprint_decode_encalgo(ndo, enckey, &sa1)) return;
+
+       if(!espprint_decode_authalgo(ndo, authkey, &sa1)) return;
+
+       esp_print_addsa(ndo, &sa1, FALSE);
+}
+
+/*
+ *
+ * special form: file /name
+ * causes us to go read from this file instead.
+ *
+ */
+static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
+                                      const char *file, int lineno)
+{
+       struct sa_list sa1;
+       int sa_def;
+
+       char *spikey;
+       char *decode;
+
+       spikey = strsep(&line, " \t");
+       sa_def = 0;
+       memset(&sa1, 0, sizeof(struct sa_list));
+
+       /* if there is only one token, then it is an algo:key token */
+       if (line == NULL) {
+               decode = spikey;
+               spikey = NULL;
+               /* sa1.daddr.version = 0; */
+               /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */
+               /* sa1.spi = 0; */
+               sa_def    = 1;
+       } else
+               decode = line;
+
+       if (spikey && strcasecmp(spikey, "file") == 0) {
+               /* open file and read it */
+               FILE *secretfile;
+               char  fileline[1024];
+               int   lineno=0;
+               char  *nl;
+               char *filename = line;
+
+               secretfile = fopen(filename, FOPEN_READ_TXT);
+               if (secretfile == NULL) {
+                       perror(filename);
+                       exit(3);
+               }
+
+               while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
+                       lineno++;
+                       /* remove newline from the line */
+                       nl = strchr(fileline, '\n');
+                       if (nl)
+                               *nl = '\0';
+                       if (fileline[0] == '#') continue;
+                       if (fileline[0] == '\0') continue;
+
+                       esp_print_decode_onesecret(ndo, fileline, filename, lineno);
+               }
+               fclose(secretfile);
+
+               return;
+       }
+
+       if (spikey && strcasecmp(spikey, "ikev2") == 0) {
+               esp_print_decode_ikeline(ndo, line, file, lineno);
+               return;
+       }
+
+       if (spikey) {
+
+               char *spistr, *foo;
+               u_int32_t spino;
+
+               spistr = strsep(&spikey, "@");
+
+               spino = strtoul(spistr, &foo, 0);
+               if (spistr == foo || !spikey) {
+                       (*ndo->ndo_warning)(ndo, "print_esp: failed to decode spi# %s\n", foo);
+                       return;
+               }
+
+               sa1.spi = spino;
+
+#ifdef INET6
+               if (inet_pton(AF_INET6, spikey, &sa1.daddr.in6) == 1) {
+                       sa1.daddr_version = 6;
+               } else
+#endif
+                       if (inet_pton(AF_INET, spikey, &sa1.daddr.in4) == 1) {
+                               sa1.daddr_version = 4;
+                       } else {
+                               (*ndo->ndo_warning)(ndo, "print_esp: can not decode IP# %s\n", spikey);
+                               return;
+                       }
+       }
+
+       if (decode) {
+               /* skip any blank spaces */
+               while (isspace((unsigned char)*decode))
+                       decode++;
+
+               if(!espprint_decode_encalgo(ndo, decode, &sa1)) {
+                       return;
+               }
+       }
+
+       esp_print_addsa(ndo, &sa1, sa_def);
+}
+
+USES_APPLE_DEPRECATED_API
+static void esp_init(netdissect_options *ndo _U_)
+{
+
+       OpenSSL_add_all_algorithms();
+       EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
+}
+USES_APPLE_RST
+
+void esp_print_decodesecret(netdissect_options *ndo)
+{
+       char *line;
+       char *p;
+       static int initialized = 0;
+
+       if (!initialized) {
+               esp_init(ndo);
+               initialized = 1;
+       }
+
+       p = ndo->ndo_espsecret;
+
+       while (p && p[0] != '\0') {
+               /* pick out the first line or first thing until a comma */
+               if ((line = strsep(&p, "\n,")) == NULL) {
+                       line = p;
+                       p = NULL;
+               }
+
+               esp_print_decode_onesecret(ndo, line, "cmdline", 0);
+       }
+
+       ndo->ndo_espsecret = NULL;
+}
+
+#endif
+
+#ifdef HAVE_LIBCRYPTO
+USES_APPLE_DEPRECATED_API
+#endif
 int
-esp_print(register const u_char *bp, register const u_char *bp2, int *nhdr)
+esp_print(netdissect_options *ndo,
+         const u_char *bp, const int length, const u_char *bp2
+#ifndef HAVE_LIBCRYPTO
+       _U_
+#endif
+       ,
+       int *nhdr
+#ifndef HAVE_LIBCRYPTO
+       _U_
+#endif
+       ,
+       int *padlen
+#ifndef HAVE_LIBCRYPTO
+       _U_
+#endif
+       )
 {
-       register const struct esp *esp;
+       register const struct newesp *esp;
        register const u_char *ep;
-       u_int32_t spi;
-       enum { NONE, DESCBC, BLOWFISH, RC5, CAST128, DES3CBC } algo = NONE;
-       struct ip *ip = NULL;
+#ifdef HAVE_LIBCRYPTO
+       struct ip *ip;
+       struct sa_list *sa = NULL;
 #ifdef INET6
        struct ip6_hdr *ip6 = NULL;
 #endif
        int advance;
        int len;
-       char *secret = NULL;
+       u_char *secret;
        int ivlen = 0;
        u_char *ivoff;
+       u_char *p;
+       EVP_CIPHER_CTX ctx;
+#endif
 
-       esp = (struct esp *)bp;
-       spi = (u_int32_t)ntohl(esp->esp_spi);
+       esp = (struct newesp *)bp;
 
-       /* 'ep' points to the end of avaible data. */
-       ep = snapend;
+#ifdef HAVE_LIBCRYPTO
+       secret = NULL;
+       advance = 0;
+#endif
+
+#if 0
+       /* keep secret out of a register */
+       p = (u_char *)&secret;
+#endif
 
-       if ((u_char *)(esp + 1) >= ep - sizeof(struct esp)) {
+       /* 'ep' points to the end of available data. */
+       ep = ndo->ndo_snapend;
+
+       if ((u_char *)(esp + 1) >= ep) {
                fputs("[|ESP]", stdout);
                goto fail;
        }
-       printf("ESP(spi=%u", spi);
-       printf(",seq=0x%x", (u_int32_t)ntohl(*(u_int32_t *)(esp + 1)));
-       printf(")");
+       (*ndo->ndo_printf)(ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi));
+       (*ndo->ndo_printf)(ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq));
+        (*ndo->ndo_printf)(ndo, ", length %u", length);
 
-       /* if we don't have decryption key, we can't decrypt this packet. */
-       if (!espsecret)
-               goto fail;
+#ifndef HAVE_LIBCRYPTO
+       goto fail;
+#else
+       /* initiailize SAs */
+       if (ndo->ndo_sa_list_head == NULL) {
+               if (!ndo->ndo_espsecret)
+                       goto fail;
 
-       if (strncmp(espsecret, "des-cbc:", 8) == 0
-        && strlen(espsecret + 8) == 8) {
-               algo = DESCBC;
-               ivlen = 8;
-               secret = espsecret + 8;
-       } else if (strncmp(espsecret, "blowfish-cbc:", 13) == 0) {
-               algo = BLOWFISH;
-               ivlen = 8;
-               secret = espsecret + 13;
-       } else if (strncmp(espsecret, "rc5-cbc:", 8) == 0) {
-               algo = RC5;
-               ivlen = 8;
-               secret = espsecret + 8;
-       } else if (strncmp(espsecret, "cast128-cbc:", 12) == 0) {
-               algo = CAST128;
-               ivlen = 8;
-               secret = espsecret + 12;
-       } else if (strncmp(espsecret, "3des-cbc:", 9) == 0
-               && strlen(espsecret + 9) == 24) {
-               algo = DES3CBC;
-               ivlen = 8;
-               secret = espsecret + 9;
-       } else if (strncmp(espsecret, "none:", 5) == 0) {
-               algo = NONE;
-               ivlen = 0;
-               secret = espsecret + 5;
-       } else if (strlen(espsecret) == 8) {
-               algo = DESCBC;
-               ivlen = 8;
-               secret = espsecret;
-       } else {
-               algo = NONE;
-               ivlen = 0;
-               secret = espsecret;
+               esp_print_decodesecret(ndo);
        }
 
+       if (ndo->ndo_sa_list_head == NULL)
+               goto fail;
+
        ip = (struct ip *)bp2;
-       switch (ip->ip_v) {
+       switch (IP_V(ip)) {
 #ifdef INET6
        case 6:
                ip6 = (struct ip6_hdr *)bp2;
-               ip = NULL;
                /* we do not attempt to decrypt jumbograms */
-               if (!ntohs(ip6->ip6_plen))
+               if (!EXTRACT_16BITS(&ip6->ip6_plen))
                        goto fail;
                /* if we can't get nexthdr, we do not need to decrypt it */
-               len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
+               len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen);
+
+               /* see if we can find the SA, and if so, decode it */
+               for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
+                       if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
+                           sa->daddr_version == 6 &&
+                           UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst,
+                                  sizeof(struct in6_addr)) == 0) {
+                               break;
+                       }
+               }
                break;
 #endif /*INET6*/
        case 4:
-#ifdef INET6
-               ip6 = NULL;
-#endif
-               len = ntohs(ip->ip_len);
-               break;
-       default:
-               goto fail;
-       }
-
-       /* if we can't get nexthdr, we do not need to decrypt it */
-       if (ep - bp2 < len)
-               goto fail;
-
-       if (Rflag)
-               ivoff = (u_char *)(esp + 1) + sizeof(u_int32_t);
-       else
-               ivoff = (u_char *)(esp + 1);
-
-       switch (algo) {
-       case DESCBC:
-#ifdef HAVE_LIBCRYPTO
-           {
-               u_char iv[8];
-               des_key_schedule schedule;
-               u_char *p;
-
-               switch (ivlen) {
-               case 4:
-                       memcpy(iv, ivoff, 4);
-                       memcpy(&iv[4], ivoff, 4);
-                       p = &iv[4];
-                       *p++ ^= 0xff;
-                       *p++ ^= 0xff;
-                       *p++ ^= 0xff;
-                       *p++ ^= 0xff;
-                       break;
-               case 8:
-                       memcpy(iv, ivoff, 8);
-                       break;
-               default:
+               /* nexthdr & padding are in the last fragment */
+               if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
                        goto fail;
+               len = EXTRACT_16BITS(&ip->ip_len);
+
+               /* see if we can find the SA, and if so, decode it */
+               for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
+                       if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
+                           sa->daddr_version == 4 &&
+                           UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst,
+                                  sizeof(struct in_addr)) == 0) {
+                               break;
+                       }
                }
-
-               des_check_key = 0;
-               des_set_key((void *)secret, schedule);
-
-               p = ivoff + ivlen;
-               des_cbc_encrypt((void *)p, (void *)p,
-                       (long)(ep - p), schedule, (void *)iv,
-                       DES_DECRYPT);
-               advance = ivoff - (u_char *)esp + ivlen;
                break;
-           }
-#else
+       default:
                goto fail;
-#endif /*HAVE_LIBCRYPTO*/
-
-       case BLOWFISH:
-#ifdef HAVE_LIBCRYPTO
-           {
-               BF_KEY schedule;
-               u_char *p;
+       }
 
-               BF_set_key(&schedule, strlen(secret), secret);
+       /* if we didn't find the specific one, then look for
+        * an unspecified one.
+        */
+       if (sa == NULL)
+               sa = ndo->ndo_sa_default;
 
-               p = ivoff + ivlen;
-               BF_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
-                       BF_DECRYPT);
-               advance = ivoff - (u_char *)esp + ivlen;
-               break;
-           }
-#else
+       /* if not found fail */
+       if (sa == NULL)
                goto fail;
-#endif /*HAVE_LIBCRYPTO*/
-
-       case RC5:
-#if defined(HAVE_LIBCRYPTO) && defined(HAVE_RC5_H)
-           {
-               RC5_32_KEY schedule;
-               u_char *p;
-
-               RC5_32_set_key(&schedule, strlen(secret), secret,
-                       RC5_16_ROUNDS);
 
-               p = ivoff + ivlen;
-               RC5_32_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
-                       RC5_DECRYPT);
-               advance = ivoff - (u_char *)esp + ivlen;
-               break;
-           }
-#else
+       /* if we can't get nexthdr, we do not need to decrypt it */
+       if (ep - bp2 < len)
                goto fail;
-#endif /*HAVE_LIBCRYPTO*/
+       if (ep - bp2 > len) {
+               /* FCS included at end of frame (NetBSD 1.6 or later) */
+               ep = bp2 + len;
+       }
 
-       case CAST128:
-#if defined(HAVE_LIBCRYPTO) && defined(HAVE_CAST_H) && !defined(HAVE_BUGGY_CAST128)
-           {
-               CAST_KEY schedule;
-               u_char *p;
+       ivoff = (u_char *)(esp + 1) + 0;
+       ivlen = sa->ivlen;
+       secret = sa->secret;
+       ep = ep - sa->authlen;
 
-               CAST_set_key(&schedule, strlen(secret), secret);
+       if (sa->evp) {
+               memset(&ctx, 0, sizeof(ctx));
+               if (EVP_CipherInit(&ctx, sa->evp, secret, NULL, 0) < 0)
+                       (*ndo->ndo_warning)(ndo, "espkey init failed");
 
-               p = ivoff + ivlen;
-               CAST_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff,
-                       CAST_DECRYPT);
+               p = ivoff;
+               EVP_CipherInit(&ctx, NULL, NULL, p, 0);
+               EVP_Cipher(&ctx, p + ivlen, p + ivlen, ep - (p + ivlen));
+               EVP_CIPHER_CTX_cleanup(&ctx);
                advance = ivoff - (u_char *)esp + ivlen;
-               break;
-           }
-#else
-               goto fail;
-#endif /*HAVE_LIBCRYPTO*/
-
-       case DES3CBC:
-#if defined(HAVE_LIBCRYPTO)
-           {
-               des_key_schedule s1, s2, s3;
-               u_char *p;
-
-               des_check_key = 0;
-               des_set_key((void *)secret, s1);
-               des_set_key((void *)(secret + 8), s2);
-               des_set_key((void *)(secret + 16), s3);
-
-               p = ivoff + ivlen;
-               des_ede3_cbc_encrypt((void *)p, (void *)p,
-                       (long)(ep - p), s1, s2, s3, (void *)ivoff, DES_DECRYPT);
-               advance = ivoff - (u_char *)esp + ivlen;
-               break;
-           }
-#else
-               goto fail;
-#endif /*HAVE_LIBCRYPTO*/
-
-       case NONE:
-       default:
-               if (Rflag)
-                       advance = sizeof(struct esp) + sizeof(u_int32_t);
-               else
-                       advance = sizeof(struct esp);
-               break;
-       }
+       } else
+               advance = sizeof(struct newesp);
 
        /* sanity check for pad length */
        if (ep - bp < *(ep - 2))
                goto fail;
 
+       if (padlen)
+               *padlen = *(ep - 2) + 2;
+
        if (nhdr)
                *nhdr = *(ep - 1);
 
-       printf(": ");
+       (ndo->ndo_printf)(ndo, ": ");
        return advance;
+#endif
 
 fail:
-       if (nhdr)
-               *nhdr = -1;
-       return 65536;
+       return -1;
 }
+#ifdef HAVE_LIBCRYPTO
+USES_APPLE_RST
+#endif
+
+/*
+ * Local Variables:
+ * c-style: whitesmith
+ * c-basic-offset: 8
+ * End:
+ */