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+/* $NetBSD: print-ah.c,v 1.4 1996/05/20 00:41:16 fvdl Exp $ */
+
+/*
+ * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code distributions
+ * retain the above copyright notice and this paragraph in its entirety, (2)
+ * distributions including binary code include the above copyright notice and
+ * this paragraph in its entirety in the documentation or other materials
+ * provided with the distribution, and (3) all advertising materials mentioning
+ * features or use of this software display the following acknowledgement:
+ * ``This product includes software developed by the University of California,
+ * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
+ * the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/* \summary: IPSEC Encapsulating Security Payload (ESP) printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include <string.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
+#ifdef HAVE_OPENSSL_EVP_H
+#include <openssl/evp.h>
+#else
+#undef HAVE_LIBCRYPTO
+#endif
+#endif
+
+#include "netdissect.h"
+#include "extract.h"
+
+#include "diag-control.h"
+
+#ifdef HAVE_LIBCRYPTO
+#include "strtoaddr.h"
+#include "ascii_strcasecmp.h"
+#endif
+
+#include "ip.h"
+#include "ip6.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 {
+ nd_uint32_t esp_spi; /* ESP */
+ nd_uint32_t esp_seq; /* Sequence number */
+ /*variable size*/ /* (IV and) Payload data */
+ /*variable size*/ /* padding */
+ /*8bit*/ /* pad size */
+ /*8bit*/ /* next header */
+ /*8bit*/ /* next header */
+ /*variable size, 32bit bound*/ /* Authentication data */
+};
+
+#ifdef HAVE_LIBCRYPTO
+union inaddr_u {
+ nd_ipv4 in4;
+ nd_ipv6 in6;
+};
+struct sa_list {
+ struct sa_list *next;
+ u_int daddr_version;
+ union inaddr_u daddr;
+ uint32_t spi; /* if == 0, then IKEv2 */
+ int initiator;
+ u_char spii[8]; /* for IKEv2 */
+ u_char spir[8];
+ const EVP_CIPHER *evp;
+ u_int ivlen;
+ int authlen;
+ u_char authsecret[256];
+ int authsecret_len;
+ u_char secret[256]; /* is that big enough for all secrets? */
+ int secretlen;
+};
+
+#ifndef HAVE_EVP_CIPHER_CTX_NEW
+/*
+ * Allocate an EVP_CIPHER_CTX.
+ * Used if we have an older version of OpenSSL that doesn't provide
+ * routines to allocate and free them.
+ */
+static EVP_CIPHER_CTX *
+EVP_CIPHER_CTX_new(void)
+{
+ EVP_CIPHER_CTX *ctx;
+
+ ctx = malloc(sizeof(*ctx));
+ if (ctx == NULL)
+ return (NULL);
+ memset(ctx, 0, sizeof(*ctx));
+ return (ctx);
+}
+
+static void
+EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
+{
+ EVP_CIPHER_CTX_cleanup(ctx);
+ free(ctx);
+}
+#endif
+
+#ifdef HAVE_EVP_DECRYPTINIT_EX
+/*
+ * Initialize the cipher by calling EVP_DecryptInit_ex(), because
+ * calling EVP_DecryptInit() will reset the cipher context, clearing
+ * the cipher, so calling it twice, with the second call having a
+ * null cipher, will clear the already-set cipher. EVP_DecryptInit_ex(),
+ * however, won't reset the cipher context, so you can use it to specify
+ * the IV in a second call after a first call to EVP_DecryptInit_ex()
+ * to set the cipher and the key.
+ *
+ * XXX - is there some reason why we need to make two calls?
+ */
+static int
+set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
+ const unsigned char *key,
+ const unsigned char *iv)
+{
+ return EVP_DecryptInit_ex(ctx, cipher, NULL, key, iv);
+}
+#else
+/*
+ * Initialize the cipher by calling EVP_DecryptInit(), because we don't
+ * have EVP_DecryptInit_ex(); we rely on it not trashing the context.
+ */
+static int
+set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
+ const unsigned char *key,
+ const unsigned char *iv)
+{
+ return EVP_DecryptInit(ctx, cipher, key, iv);
+}
+#endif
+
+static u_char *
+do_decrypt(netdissect_options *ndo, const char *caller, struct sa_list *sa,
+ const u_char *iv, const u_char *ct, unsigned int ctlen)
+{
+ EVP_CIPHER_CTX *ctx;
+ unsigned int block_size;
+ unsigned int ptlen;
+ u_char *pt;
+ int len;
+
+ ctx = EVP_CIPHER_CTX_new();
+ if (ctx == NULL) {
+ /*
+ * Failed to initialize the cipher context.
+ * From a look at the OpenSSL code, this appears to
+ * mean "couldn't allocate memory for the cipher context";
+ * note that we're not passing any parameters, so there's
+ * not much else it can mean.
+ */
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't allocate memory for cipher context", caller);
+ return NULL;
+ }
+
+ if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL) < 0) {
+ EVP_CIPHER_CTX_free(ctx);
+ (*ndo->ndo_warning)(ndo, "%s: espkey init failed", caller);
+ return NULL;
+ }
+ if (set_cipher_parameters(ctx, NULL, NULL, iv) < 0) {
+ EVP_CIPHER_CTX_free(ctx);
+ (*ndo->ndo_warning)(ndo, "%s: IV init failed", caller);
+ return NULL;
+ }
+
+ /*
+ * At least as I read RFC 5996 section 3.14 and RFC 4303 section 2.4,
+ * if the cipher has a block size of which the ciphertext's size must
+ * be a multiple, the payload must be padded to make that happen, so
+ * the ciphertext length must be a multiple of the block size. Fail
+ * if that's not the case.
+ */
+ block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
+ if ((ctlen % block_size) != 0) {
+ EVP_CIPHER_CTX_free(ctx);
+ (*ndo->ndo_warning)(ndo,
+ "%s: ciphertext size %u is not a multiple of the cipher block size %u",
+ caller, ctlen, block_size);
+ return NULL;
+ }
+
+ /*
+ * Attempt to allocate a buffer for the decrypted data, because
+ * we can't decrypt on top of the input buffer.
+ */
+ ptlen = ctlen;
+ pt = (u_char *)calloc(1, ptlen);
+ if (pt == NULL) {
+ EVP_CIPHER_CTX_free(ctx);
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't allocate memory for decryption buffer", caller);
+ return NULL;
+ }
+
+ /*
+ * The size of the ciphertext handed to us is a multiple of the
+ * cipher block size, so we don't need to worry about padding.
+ */
+ if (!EVP_CIPHER_CTX_set_padding(ctx, 0)) {
+ free(pt);
+ EVP_CIPHER_CTX_free(ctx);
+ (*ndo->ndo_warning)(ndo,
+ "%s: EVP_CIPHER_CTX_set_padding failed", caller);
+ return NULL;
+ }
+ if (!EVP_DecryptUpdate(ctx, pt, &len, ct, ctlen)) {
+ free(pt);
+ EVP_CIPHER_CTX_free(ctx);
+ (*ndo->ndo_warning)(ndo, "%s: EVP_DecryptUpdate failed",
+ caller);
+ return NULL;
+ }
+ EVP_CIPHER_CTX_free(ctx);
+ return pt;
+}
+
+/*
+ * This will allocate a new buffer containing the decrypted data.
+ * It returns 1 on success and 0 on failure.
+ *
+ * It will push the new buffer and the values of ndo->ndo_packetp and
+ * ndo->ndo_snapend onto the buffer stack, and change ndo->ndo_packetp
+ * and ndo->ndo_snapend to refer to the new buffer.
+ *
+ * Our caller must pop the buffer off the stack when it's finished
+ * dissecting anything in it and before it does any dissection of
+ * anything in the old buffer. That will free the new buffer.
+ */
+DIAG_OFF_DEPRECATION
+int esp_decrypt_buffer_by_ikev2_print(netdissect_options *ndo,
+ int initiator,
+ const u_char spii[8],
+ const u_char spir[8],
+ const u_char *buf, const u_char *end)
+{
+ struct sa_list *sa;
+ const u_char *iv;
+ const u_char *ct;
+ unsigned int ctlen;
+ u_char *pt;
+
+ /* 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;
+ ct = iv + sa->ivlen;
+ ctlen = end-ct;
+
+ if(end <= ct) return 0;
+
+ pt = do_decrypt(ndo, __func__, sa, iv,
+ ct, ctlen);
+ if (pt == NULL)
+ return 0;
+
+ /*
+ * Switch to the output buffer for dissection, and save it
+ * on the buffer stack so it can be freed; our caller must
+ * pop it when done.
+ */
+ if (!nd_push_buffer(ndo, pt, pt, ctlen)) {
+ free(pt);
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't push buffer on buffer stack", __func__);
+ }
+
+ return 1;
+}
+DIAG_ON_DEPRECATION
+
+static void esp_print_addsa(netdissect_options *ndo,
+ const struct sa_list *sa, int sa_def)
+{
+ /* copy the "sa" */
+
+ struct sa_list *nsa;
+
+ /* malloc() return used in a 'struct sa_list': do not free() */
+ nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
+ if (nsa == NULL)
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: malloc", __func__);
+
+ *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, S_ERR_ND_ESP_SECRET,
+ "invalid hex digit %c in espsecret\n", hex);
+ }
+}
+
+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: %u\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
+ */
+
+DIAG_OFF_DEPRECATION
+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;
+ /* This returns an int, but it should never be negative */
+ 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;
+}
+DIAG_ON_DEPRECATION
+
+/*
+ * for the moment, ignore the auth algorithm, 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(ascii_strcasecmp(decode,"sha1") == 0 ||
+ ascii_strcasecmp(decode,"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 && ascii_strcasecmp(spikey, "file") == 0) {
+ /* open file and read it */
+ FILE *secretfile;
+ char fileline[1024];
+ int subfile_lineno=0;
+ char *nl;
+ char *filename = line;
+
+ secretfile = fopen(filename, FOPEN_READ_TXT);
+ if (secretfile == NULL) {
+ (*ndo->ndo_error)(ndo, S_ERR_ND_OPEN_FILE,
+ "%s: can't open %s: %s\n",
+ __func__, filename, strerror(errno));
+ }
+
+ while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
+ subfile_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, subfile_lineno);
+ }
+ fclose(secretfile);
+
+ return;
+ }
+
+ if (spikey && ascii_strcasecmp(spikey, "ikev2") == 0) {
+ esp_print_decode_ikeline(ndo, line, file, lineno);
+ return;
+ }
+
+ if (spikey) {
+
+ char *spistr, *foo;
+ uint32_t spino;
+
+ spistr = strsep(&spikey, "@");
+ if (spistr == NULL) {
+ (*ndo->ndo_warning)(ndo, "print_esp: failed to find the @ token");
+ return;
+ }
+
+ 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;
+
+ if (strtoaddr6(spikey, &sa1.daddr.in6) == 1) {
+ sa1.daddr_version = 6;
+ } else if (strtoaddr(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 (*decode == ' ' || *decode == '\t' || *decode == '\r' || *decode == '\n')
+ decode++;
+
+ if(!espprint_decode_encalgo(ndo, decode, &sa1)) {
+ return;
+ }
+ }
+
+ esp_print_addsa(ndo, &sa1, sa_def);
+}
+
+DIAG_OFF_DEPRECATION
+static void esp_init(netdissect_options *ndo _U_)
+{
+ /*
+ * 0.9.6 doesn't appear to define OPENSSL_API_COMPAT, so
+ * we check whether it's undefined or it's less than the
+ * value for 1.1.0.
+ */
+#if !defined(OPENSSL_API_COMPAT) || OPENSSL_API_COMPAT < 0x10100000L
+ OpenSSL_add_all_algorithms();
+#endif
+ EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
+}
+DIAG_ON_DEPRECATION
+
+void esp_decodesecret_print(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
+#define USED_IF_LIBCRYPTO
+#else
+#define USED_IF_LIBCRYPTO _U_
+#endif
+
+#ifdef HAVE_LIBCRYPTO
+DIAG_OFF_DEPRECATION
+#endif
+void
+esp_print(netdissect_options *ndo,
+ const u_char *bp, u_int length,
+ const u_char *bp2 USED_IF_LIBCRYPTO,
+ u_int ver USED_IF_LIBCRYPTO,
+ int fragmented USED_IF_LIBCRYPTO,
+ u_int ttl_hl USED_IF_LIBCRYPTO)
+{
+ const struct newesp *esp;
+ const u_char *ep;
+#ifdef HAVE_LIBCRYPTO
+ const struct ip *ip;
+ struct sa_list *sa = NULL;
+ const struct ip6_hdr *ip6 = NULL;
+ const u_char *iv;
+ u_int ivlen;
+ u_int payloadlen;
+ const u_char *ct;
+ u_char *pt;
+ u_int padlen;
+ u_int nh;
+#endif
+
+ ndo->ndo_protocol = "esp";
+ esp = (const struct newesp *)bp;
+
+ /* 'ep' points to the end of available data. */
+ ep = ndo->ndo_snapend;
+
+ if ((const u_char *)(esp + 1) >= ep) {
+ nd_print_trunc(ndo);
+ return;
+ }
+ ND_PRINT("ESP(spi=0x%08x", GET_BE_U_4(esp->esp_spi));
+ ND_PRINT(",seq=0x%x)", GET_BE_U_4(esp->esp_seq));
+ ND_PRINT(", length %u", length);
+
+#ifdef HAVE_LIBCRYPTO
+ /* initialize SAs */
+ if (ndo->ndo_sa_list_head == NULL) {
+ if (!ndo->ndo_espsecret)
+ return;
+
+ esp_decodesecret_print(ndo);
+ }
+
+ if (ndo->ndo_sa_list_head == NULL)
+ return;
+
+ ip = (const struct ip *)bp2;
+ switch (ver) {
+ case 6:
+ ip6 = (const struct ip6_hdr *)bp2;
+ /* we do not attempt to decrypt jumbograms */
+ if (!GET_BE_U_2(ip6->ip6_plen))
+ return;
+ /* XXX - check whether it's fragmented? */
+ /* if we can't get nexthdr, we do not need to decrypt it */
+
+ /* 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 == GET_BE_U_4(esp->esp_spi) &&
+ sa->daddr_version == 6 &&
+ UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst,
+ sizeof(nd_ipv6)) == 0) {
+ break;
+ }
+ }
+ break;
+ case 4:
+ /* nexthdr & padding are in the last fragment */
+ if (fragmented)
+ return;
+
+ /* 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 == GET_BE_U_4(esp->esp_spi) &&
+ sa->daddr_version == 4 &&
+ UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst,
+ sizeof(nd_ipv4)) == 0) {
+ break;
+ }
+ }
+ break;
+ default:
+ return;
+ }
+
+ /* 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)
+ return;
+
+ /* pointer to the IV, if there is one */
+ iv = (const u_char *)(esp + 1) + 0;
+ /* length of the IV, if there is one; 0, if there isn't */
+ ivlen = sa->ivlen;
+
+ /*
+ * Get a pointer to the ciphertext.
+ *
+ * p points to the beginning of the payload, i.e. to the
+ * initialization vector, so if we skip past the initialization
+ * vector, it points to the beginning of the ciphertext.
+ */
+ ct = iv + ivlen;
+
+ /*
+ * Make sure the authentication data/integrity check value length
+ * isn't bigger than the total amount of data available after
+ * the ESP header and initialization vector is removed and,
+ * if not, slice the authentication data/ICV off.
+ */
+ if (ep - ct < sa->authlen) {
+ nd_print_trunc(ndo);
+ return;
+ }
+ ep = ep - sa->authlen;
+
+ /*
+ * Calculate the length of the ciphertext. ep points to
+ * the beginning of the authentication data/integrity check
+ * value, i.e. right past the end of the ciphertext;
+ */
+ payloadlen = ep - ct;
+
+ if (sa->evp == NULL)
+ return;
+
+ /*
+ * If the next header value is past the end of the available
+ * data, we won't be able to fetch it once we've decrypted
+ * the ciphertext, so there's no point in decrypting the data.
+ *
+ * Report it as truncation.
+ */
+ if (!ND_TTEST_1(ep - 1)) {
+ nd_print_trunc(ndo);
+ return;
+ }
+
+ pt = do_decrypt(ndo, __func__, sa, iv, ct, payloadlen);
+ if (pt == NULL)
+ return;
+
+ /*
+ * Switch to the output buffer for dissection, and
+ * save it on the buffer stack so it can be freed.
+ */
+ if (!nd_push_buffer(ndo, pt, pt, payloadlen)) {
+ free(pt);
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't push buffer on buffer stack", __func__);
+ }
+
+ /*
+ * Sanity check for pad length; if it, plus 2 for the pad
+ * length and next header fields, is bigger than the ciphertext
+ * length (which is also the plaintext length), it's too big.
+ *
+ * XXX - the check can fail if the packet is corrupt *or* if
+ * it was not decrypted with the correct key, so that the
+ * "plaintext" is not what was being sent.
+ */
+ padlen = GET_U_1(pt + payloadlen - 2);
+ if (padlen + 2 > payloadlen) {
+ nd_print_trunc(ndo);
+ return;
+ }
+
+ /* Get the next header */
+ nh = GET_U_1(pt + payloadlen - 1);
+
+ ND_PRINT(": ");
+
+ /*
+ * Don't put padding + padding length(1 byte) + next header(1 byte)
+ * in the buffer because they are not part of the plaintext to decode.
+ */
+ if (!nd_push_snaplen(ndo, pt, payloadlen - (padlen + 2))) {
+ (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+ "%s: can't push snaplen on buffer stack", __func__);
+ }
+
+ /* Now dissect the plaintext. */
+ ip_demux_print(ndo, pt, payloadlen - (padlen + 2), ver, fragmented,
+ ttl_hl, nh, bp2);
+
+ /* Pop the buffer, freeing it. */
+ nd_pop_packet_info(ndo);
+ /* Pop the nd_push_snaplen */
+ nd_pop_packet_info(ndo);
+#endif
+}
+#ifdef HAVE_LIBCRYPTO
+DIAG_ON_DEPRECATION
+#endif
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