When checking for pcap_if_t, add $V_INCLS to CFLAGS, so we look at the

[tcpdump] / print-esp.c

diff --git a/print-esp.c b/print-esp.c
index 07d192cb980967091bd9569b8a44c4b32958125e..25303e30d4457aa71fd851f821e0238da0859a8b 100644 (file)
--- a/print-esp.c
+++ b/print-esp.c
@@ -22,66 +22,493 @@
  */
 
 #ifndef lint
  */
 
 #ifndef lint

-static char rcsid[] =
-    "@(#) Header: print-ah.c,v 1.37 94/06/10 17:01:42 mccanne Exp (LBL)";
+static const char rcsid[] _U_ =
+    "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.51 2004-04-10 08:41:22 guy Exp $ (LBL)";

 #endif
 
 #endif
 

-#include <sys/param.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <sys/socket.h>
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>

 
 

-#include <netinet/in.h>
-#include <netinet/in_systm.h>
-#include <netinet/ip.h>
-#include <netinet/ip_var.h>
-#include <netinet/udp.h>
-#include <netinet/udp_var.h>
+#include <tcpdump-stdinc.h>

 
 

-#undef NOERROR                                 /* Solaris sucks */
-#include <arpa/nameser.h>
-#include <arpa/tftp.h>
+#include <stdlib.h>

 
 

-#ifdef SOLARIS
-#include <tiuser.h>
+#ifdef HAVE_LIBCRYPTO
+#ifdef HAVE_OPENSSL_EVP_H
+#include <openssl/evp.h>
+#endif

 #endif
 #endif

-#include <rpc/rpc.h>

 
 

-#include <errno.h>

 #include <stdio.h>
 
 #include <stdio.h>
 

-#include "interface.h"
+#include "ip.h"
+#include "esp.h"
+#ifdef INET6
+#include "ip6.h"
+#endif
+
+#if defined(__MINGW32__) || defined(__WATCOMC__)
+extern char *strsep(char **stringp, const char *delim); /* Missing/strsep.c */
+#endif
+
+#include "netdissect.h"

 #include "addrtoname.h"
 #include "addrtoname.h"

+#include "extract.h"

 
 

-extern int packettype;
+#ifndef HAVE_SOCKADDR_STORAGE
+#ifdef INET6
+struct sockaddr_storage {
+       union {
+               struct sockaddr_in sin;
+               struct sockaddr_in6 sin6;
+       } un;
+};
+#else
+#define sockaddr_storage sockaddr
+#endif
+#endif /* HAVE_SOCKADDR_STORAGE */

 
 

+#ifdef HAVE_LIBCRYPTO
+struct sa_list {
+       struct sa_list  *next;
+       struct sockaddr_storage daddr;
+       u_int32_t       spi;
+       const EVP_CIPHER *evp;
+       int             ivlen;
+       int             authlen;
+       char            secret[256];  /* is that big enough for all secrets? */
+       int             secretlen;
+};

 
 

-void
-esp_print(register const u_char *bp, int length, register const u_char *bp2)
+static void esp_print_addsa(netdissect_options *ndo,
+                           struct sa_list *sa, int sa_def)

 {
 {

-  register const struct ip *ip;
-  register const u_char *cp, *nh;
-  u_short ahlen, authlen;
-  u_long  spi, seqno;
+       /* 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 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 int hex2byte(netdissect_options *ndo, char *hexstring)
+{
+       int byte;
+
+       byte = (hexdigit(ndo, hexstring[0]) << 4) + hexdigit(ndo, hexstring[1]);
+       return byte;
+}
+
+/*
+ * decode the form:    SPINUM@IP <tab> ALGONAME:0xsecret
+ *
+ * special form: file /name
+ * causes us to go read from this file instead.
+ *
+ */
+static void esp_print_decode_onesecret(netdissect_options *ndo, char *line)
+{
+       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;
+               /* 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];
+               char  *nl;
+
+               secretfile = fopen(line, FOPEN_READ_TXT);
+               if (secretfile == NULL) {
+                       perror(line);
+                       exit(3);
+               }
+
+               while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
+                       /* 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);
+               }
+               fclose(secretfile);
+
+               return;
+       }
+
+       if (spikey) {
+               char *spistr, *foo;
+               u_int32_t spino;
+               struct sockaddr_in *sin;
+#ifdef INET6
+               struct sockaddr_in6 *sin6;
+#endif
+
+               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;
+
+               sin = (struct sockaddr_in *)&sa1.daddr;
+#ifdef INET6
+               sin6 = (struct sockaddr_in6 *)&sa1.daddr;
+               if (inet_pton(AF_INET6, spikey, &sin6->sin6_addr) == 1) {
+#ifdef HAVE_SOCKADDR_SA_LEN
+                       sin6->sin6_len = sizeof(struct sockaddr_in6);
+#endif
+                       sin6->sin6_family = AF_INET6;
+               } else
+#endif
+               if (inet_pton(AF_INET, spikey, &sin->sin_addr) == 1) {
+#ifdef HAVE_SOCKADDR_SA_LEN
+                       sin->sin_len = sizeof(struct sockaddr_in);
+#endif
+                       sin->sin_family = AF_INET;
+               } else {
+                       (*ndo->ndo_warning)(ndo, "print_esp: can not decode IP# %s\n", spikey);
+                       return;
+               }
+       }
+
+       if (decode) {
+               char *colon, *p;
+               char  espsecret_key[256];
+               int len;
+               size_t i;
+               const EVP_CIPHER *evp;
+               int authlen = 0;
+
+               /* skip any blank spaces */
+               while (isspace((unsigned char)*decode))
+                       decode++;
+
+               colon = strchr(decode, ':');
+               if (colon == NULL) {
+                       (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
+                       return;
+               }
+               *colon = '\0';
+
+               len = colon - decode;
+               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);
+                       sa1.evp = NULL;
+                       sa1.authlen = 0;
+                       sa1.ivlen = 0;
+                       return;
+               }

 
 

-  ip = (struct ip *)bp2;
+               sa1.evp = evp;
+               sa1.authlen = authlen;
+               sa1.ivlen = EVP_CIPHER_iv_length(evp);

 
 

-  (void)printf("ESP %s > %s\n\t\t",
-              ipaddr_string(&ip->ip_src), 
-              ipaddr_string(&ip->ip_dst));
+               colon++;
+               if (colon[0] == '0' && colon[1] == 'x') {
+                       /* decode some hex! */
+                       colon += 2;
+                       len = strlen(colon) / 2;

 
 

-  if (length < 8) {
-    (void)printf(" [|esp] truncated-esp %d", length);
-    return;
-  }
+                       if (len > 256) {
+                               (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len);
+                               return;
+                       }

 
 

-  spi        = ntohl(*((u_long *)(bp)));
-  seqno      = ntohl(*((u_long *)(bp+4)));
+                       i = 0;
+                       while (colon[0] != '\0' && colon[1]!='\0') {
+                               espsecret_key[i] = hex2byte(ndo, colon);
+                               colon += 2;
+                               i++;
+                       }

 
 

-  nh         = bp+ahlen;
+                       memcpy(sa1.secret, espsecret_key, i);
+                       sa1.secretlen = i;
+               } else {
+                       i = strlen(colon);

 
 

-  (void)printf("spi:%08x seqno:%d ciphertext: ", spi, seqno);
-  (void)default_print_unaligned(bp+8, length-8);
+                       if (i < sizeof(sa1.secret)) {
+                               memcpy(sa1.secret, colon, i);
+                               sa1.secretlen = i;
+                       } else {
+                               memcpy(sa1.secret, colon, sizeof(sa1.secret));
+                               sa1.secretlen = sizeof(sa1.secret);
+                       }
+               }
+       }

 
 

-  /* XXX it would be nice to decrypt! */
+       esp_print_addsa(ndo, &sa1, sa_def);

 }
 }

+
+static void esp_print_decodesecret(netdissect_options *ndo)
+{
+       char *line;
+       char *p;
+
+       p = ndo->ndo_espsecret;
+
+       while (ndo->ndo_espsecret && ndo->ndo_espsecret[0] != '\0') {
+               /* pick out the first line or first thing until a comma */
+               if ((line = strsep(&ndo->ndo_espsecret, "\n,")) == NULL) {
+                       line = ndo->ndo_espsecret;
+                       ndo->ndo_espsecret = NULL;
+               }
+
+               esp_print_decode_onesecret(ndo, line);
+       }
+}
+
+static void esp_init(netdissect_options *ndo _U_)
+{
+
+       OpenSSL_add_all_algorithms();
+       EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
+}
+#endif
+
+int
+esp_print(netdissect_options *ndo,
+         const u_char *bp, 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 newesp *esp;
+       register const u_char *ep;
+#ifdef HAVE_LIBCRYPTO
+       struct ip *ip;
+       struct sa_list *sa = NULL;
+       int espsecret_keylen;
+#ifdef INET6
+       struct ip6_hdr *ip6 = NULL;
+#endif
+       int advance;
+       int len;
+       char *secret;
+       int ivlen = 0;
+       u_char *ivoff;
+       u_char *p;
+       EVP_CIPHER_CTX ctx;
+       int blocksz;
+       static int initialized = 0;
+#endif
+
+       esp = (struct newesp *)bp;
+
+#ifdef HAVE_LIBCRYPTO
+       secret = NULL;
+       advance = 0;
+
+       if (!initialized) {
+               esp_init(ndo);
+               initialized = 1;
+       }
+#endif
+
+#if 0
+       /* keep secret out of a register */
+       p = (u_char *)&secret;
+#endif
+
+       /* 'ep' points to the end of available data. */
+       ep = ndo->ndo_snapend;
+
+       if ((u_char *)(esp + 1) >= ep) {
+               fputs("[|ESP]", stdout);
+               goto fail;
+       }
+       (*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));
+
+#ifndef HAVE_LIBCRYPTO
+       goto fail;
+#else
+       /* initiailize SAs */
+       if (ndo->ndo_sa_list_head == NULL) {
+               if (!ndo->ndo_espsecret)
+                       goto fail;
+
+               esp_print_decodesecret(ndo);
+       }
+
+       if (ndo->ndo_sa_list_head == NULL)
+               goto fail;
+
+       ip = (struct ip *)bp2;
+       switch (IP_V(ip)) {
+#ifdef INET6
+       case 6:
+               ip6 = (struct ip6_hdr *)bp2;
+               /* we do not attempt to decrypt jumbograms */
+               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) + 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) {
+                       struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa->daddr;
+                       if (sa->spi == ntohl(esp->esp_spi) &&
+                           sin6->sin6_family == AF_INET6 &&
+                           memcmp(&sin6->sin6_addr, &ip6->ip6_dst,
+                                  sizeof(struct in6_addr)) == 0) {
+                               break;
+                       }
+               }
+               break;
+#endif /*INET6*/
+       case 4:
+               /* 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) {
+                       struct sockaddr_in *sin = (struct sockaddr_in *)&sa->daddr;
+                       if (sa->spi == ntohl(esp->esp_spi) &&
+                           sin->sin_family == AF_INET &&
+                           sin->sin_addr.s_addr == ip->ip_dst.s_addr) {
+                               break;
+                       }
+               }
+               break;
+       default:
+               goto fail;
+       }
+
+       /* if we didn't find the specific one, then look for
+        * an unspecified one.
+        */
+       if (sa == NULL)
+               sa = ndo->ndo_sa_default;
+       
+       /* if not found fail */
+       if (sa == NULL)
+               goto fail;
+
+       /* if we can't get nexthdr, we do not need to decrypt it */
+       if (ep - bp2 < len)
+               goto fail;
+       if (ep - bp2 > len) {
+               /* FCS included at end of frame (NetBSD 1.6 or later) */
+               ep = bp2 + len;
+       }
+
+       ivoff = (u_char *)(esp + 1) + 0;
+       ivlen = sa->ivlen;
+       secret = sa->secret;
+       espsecret_keylen = sa->secretlen;
+       ep = ep - sa->authlen;
+
+       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");
+
+               blocksz = EVP_CIPHER_CTX_block_size(&ctx);
+
+               p = ivoff;
+               EVP_CipherInit(&ctx, NULL, NULL, p, 0);
+               EVP_Cipher(&ctx, p + ivlen, p + ivlen, ep - (p + ivlen));
+               advance = ivoff - (u_char *)esp + ivlen;
+       } 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);
+
+       (ndo->ndo_printf)(ndo, ": ");
+       return advance;
+#endif
+
+fail:
+       return -1;
+}
+
+/*
+ * Local Variables:
+ * c-style: whitesmith
+ * c-basic-offset: 8
+ * End:
+ */