X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/57a643a0b59e9941cf23c33d40c5d4e4b547b7ba..refs/heads/tcpdump-4.9:/print-esp.c

diff --git a/print-esp.c b/print-esp.c
index 8b90641a..6fabff1e 100644
--- a/print-esp.c
+++ b/print-esp.c
@@ -21,14 +21,15 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: IPSEC Encapsulating Security Payload (ESP) printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <string.h>
-
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
+#include <string.h>
 #include <stdlib.h>
 
 /* Any code in this file that depends on HAVE_LIBCRYPTO depends on
@@ -43,29 +44,14 @@
 #endif
 #endif
 
-#include <stdio.h>
-
-#include "ip.h"
-#ifdef INET6
-#include "ip6.h"
-#endif
-
 #include "netdissect.h"
-#include "addrtoname.h"
+#include "strtoaddr.h"
 #include "extract.h"
 
-#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 */
+#include "ascii_strcasecmp.h"
+
+#include "ip.h"
+#include "ip6.h"
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -101,8 +87,8 @@ struct sockaddr_storage {
  */
 
 struct newesp {
-	u_int32_t	esp_spi;	/* ESP */
-	u_int32_t	esp_seq;	/* Sequence number */
+	uint32_t	esp_spi;	/* ESP */
+	uint32_t	esp_seq;	/* Sequence number */
 	/*variable size*/		/* (IV and) Payload data */
 	/*variable size*/		/* padding */
 	/*8bit*/			/* pad size */
@@ -112,10 +98,15 @@ struct newesp {
 };
 
 #ifdef HAVE_LIBCRYPTO
+union inaddr_u {
+	struct in_addr in4;
+	struct in6_addr in6;
+};
 struct sa_list {
 	struct sa_list	*next;
-	struct sockaddr_storage daddr;
-	u_int32_t	spi;          /* if == 0, then IKEv2 */
+	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];
@@ -128,6 +119,65 @@ struct sa_list {
 	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_CIPHERINIT_EX
+/*
+ * Initialize the cipher by calling EVP_CipherInit_ex(), because
+ * calling EVP_CipherInit() 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_CipherInit_ex(),
+ * however, won't reset the cipher context, so you can use it to specify
+ * the IV oin a second call after a first call to EVP_CipherInit_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, int enc)
+{
+	return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
+}
+#else
+/*
+ * Initialize the cipher by calling EVP_CipherInit(), because we don't
+ * have EVP_CipherInit_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, int enc)
+{
+	return EVP_CipherInit(ctx, cipher, key, iv, enc);
+}
+#endif
+
 /*
  * this will adjust ndo_packetp and ndo_snapend to new buffer!
  */
@@ -135,12 +185,14 @@ 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)
+				      const u_char *buf, const u_char *end)
 {
 	struct sa_list *sa;
-	u_char *iv;
-	int len;
-	EVP_CIPHER_CTX ctx;
+	const u_char *iv;
+	unsigned int len;
+	EVP_CIPHER_CTX *ctx;
+	unsigned int block_size, buffer_size;
+	u_char *input_buffer, *output_buffer;
 
 	/* initiator arg is any non-zero value */
 	if(initiator) initiator=1;
@@ -168,18 +220,60 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
 
 	if(end <= buf) return 0;
 
-	memset(&ctx, 0, sizeof(ctx));
-	if (EVP_CipherInit(&ctx, sa->evp, sa->secret, NULL, 0) < 0)
+	ctx = EVP_CIPHER_CTX_new();
+	if (ctx == NULL)
+		return 0;
+	if (set_cipher_parameters(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);
+	set_cipher_parameters(ctx, NULL, NULL, iv, 0);
+	/*
+	 * Allocate buffers for the encrypted and decrypted data.
+	 * Both buffers' sizes must be a multiple of the cipher block
+	 * size, and the output buffer must be separate from the input
+	 * buffer.
+	 */
+	block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
+	buffer_size = len + (block_size - len % block_size);
+
+	/*
+	 * Attempt to allocate the input buffer.
+	 */
+	input_buffer = (u_char *)malloc(buffer_size);
+	if (input_buffer == NULL) {
+		EVP_CIPHER_CTX_free(ctx);
+		(*ndo->ndo_error)(ndo, "can't allocate memory for encrypted data buffer");
+	}
+	/*
+	 * Copy the input data to the encrypted data buffer, and pad it
+	 * with zeroes.
+	 */
+	memcpy(input_buffer, buf, len);
+	memset(input_buffer + len, 0, buffer_size - len);
+
+	/*
+	 * Attempt to allocate the output buffer.
+	 */
+	output_buffer = (u_char *)malloc(buffer_size);
+	if (output_buffer == NULL) {
+		free(input_buffer);
+		EVP_CIPHER_CTX_free(ctx);
+		(*ndo->ndo_error)(ndo, "can't allocate memory for decryption buffer");
+	}
+	EVP_Cipher(ctx, output_buffer, input_buffer, len);
+	EVP_CIPHER_CTX_free(ctx);
+
+	/*
+	 * XXX - of course this is wrong, because buf is a const buffer,
+	 * but changing this would require a more complicated fix.
+	 */
+	memcpy(buf, output_buffer, len);
+	free(input_buffer);
+	free(output_buffer);
 
 	ndo->ndo_packetp = buf;
 	ndo->ndo_snapend = end;
 
 	return 1;
-
 }
 USES_APPLE_RST
 
@@ -214,7 +308,6 @@ static u_int hexdigit(netdissect_options *ndo, char hex)
 		return (hex - 'a' + 10);
 	else {
 		(*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex);
-		return 0;
 	}
 }
 
@@ -325,7 +418,7 @@ espprint_decode_encalgo(netdissect_options *ndo,
 USES_APPLE_RST
 
 /*
- * for the moment, ignore the auth algorith, just hard code the authenticator
+ * for the moment, ignore the auth algorithm, just hard code the authenticator
  * length. Need to research how openssl looks up HMAC stuff.
  */
 static int
@@ -341,8 +434,8 @@ espprint_decode_authalgo(netdissect_options *ndo,
 	}
 	*colon = '\0';
 
-	if(strcasecmp(colon,"sha1") == 0 ||
-	   strcasecmp(colon,"md5") == 0) {
+	if(ascii_strcasecmp(colon,"sha1") == 0 ||
+	   ascii_strcasecmp(colon,"md5") == 0) {
 		sa->authlen = 12;
 	}
 	return 1;
@@ -429,28 +522,29 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
 	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) {
+	if (spikey && ascii_strcasecmp(spikey, "file") == 0) {
 		/* open file and read it */
 		FILE *secretfile;
 		char  fileline[1024];
-		int   lineno=0;
+		int   subfile_lineno=0;
 		char  *nl;
 		char *filename = line;
 
 		secretfile = fopen(filename, FOPEN_READ_TXT);
 		if (secretfile == NULL) {
-			perror(filename);
-			exit(3);
+			(*ndo->ndo_error)(ndo, "print_esp: can't open %s: %s\n",
+			    filename, strerror(errno));
 		}
 
 		while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
-			lineno++;
+			subfile_lineno++;
 			/* remove newline from the line */
 			nl = strchr(fileline, '\n');
 			if (nl)
@@ -458,14 +552,14 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
 			if (fileline[0] == '#') continue;
 			if (fileline[0] == '\0') continue;
 
-			esp_print_decode_onesecret(ndo, fileline, filename, lineno);
+			esp_print_decode_onesecret(ndo, fileline, filename, subfile_lineno);
 		}
 		fclose(secretfile);
 
 		return;
 	}
 
-	if (spikey && strcasecmp(spikey, "ikev2") == 0) {
+	if (spikey && ascii_strcasecmp(spikey, "ikev2") == 0) {
 		esp_print_decode_ikeline(ndo, line, file, lineno);
 		return;
 	}
@@ -473,13 +567,13 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
 	if (spikey) {
 
 		char *spistr, *foo;
-		u_int32_t spino;
-		struct sockaddr_in *sin;
-#ifdef INET6
-		struct sockaddr_in6 *sin6;
-#endif
+		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) {
@@ -489,25 +583,14 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
 
 		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 (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) {
@@ -526,8 +609,14 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
 USES_APPLE_DEPRECATED_API
 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");
 }
 USES_APPLE_RST
@@ -584,21 +673,21 @@ esp_print(netdissect_options *ndo,
 	register const struct newesp *esp;
 	register const u_char *ep;
 #ifdef HAVE_LIBCRYPTO
-	struct ip *ip;
+	const struct ip *ip;
 	struct sa_list *sa = NULL;
-#ifdef INET6
-	struct ip6_hdr *ip6 = NULL;
-#endif
+	const struct ip6_hdr *ip6 = NULL;
 	int advance;
 	int len;
 	u_char *secret;
 	int ivlen = 0;
-	u_char *ivoff;
-	u_char *p;
-	EVP_CIPHER_CTX ctx;
+	const u_char *ivoff;
+	const u_char *p;
+	EVP_CIPHER_CTX *ctx;
+	unsigned int block_size, buffer_size;
+	u_char *input_buffer, *output_buffer;
 #endif
 
-	esp = (struct newesp *)bp;
+	esp = (const struct newesp *)bp;
 
 #ifdef HAVE_LIBCRYPTO
 	secret = NULL;
@@ -613,13 +702,13 @@ esp_print(netdissect_options *ndo,
 	/* 'ep' points to the end of available data. */
 	ep = ndo->ndo_snapend;
 
-	if ((u_char *)(esp + 1) >= ep) {
-		fputs("[|ESP]", stdout);
+	if ((const u_char *)(esp + 1) >= ep) {
+		ND_PRINT((ndo, "[|ESP]"));
 		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));
-        (*ndo->ndo_printf)(ndo, ", length %u", length);
+	ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi)));
+	ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq)));
+	ND_PRINT((ndo, ", length %u", length));
 
 #ifndef HAVE_LIBCRYPTO
 	goto fail;
@@ -635,11 +724,10 @@ esp_print(netdissect_options *ndo,
 	if (ndo->ndo_sa_list_head == NULL)
 		goto fail;
 
-	ip = (struct ip *)bp2;
+	ip = (const struct ip *)bp2;
 	switch (IP_V(ip)) {
-#ifdef INET6
 	case 6:
-		ip6 = (struct ip6_hdr *)bp2;
+		ip6 = (const struct ip6_hdr *)bp2;
 		/* we do not attempt to decrypt jumbograms */
 		if (!EXTRACT_16BITS(&ip6->ip6_plen))
 			goto fail;
@@ -648,16 +736,14 @@ esp_print(netdissect_options *ndo,
 
 		/* 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 == EXTRACT_32BITS(&esp->esp_spi) &&
-			    sin6->sin6_family == AF_INET6 &&
-			    memcmp(&sin6->sin6_addr, &ip6->ip6_dst,
+			    sa->daddr_version == 6 &&
+			    UNALIGNED_MEMCMP(&sa->daddr.in6, &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)
@@ -666,10 +752,10 @@ esp_print(netdissect_options *ndo,
 
 		/* 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 == EXTRACT_32BITS(&esp->esp_spi) &&
-			    sin->sin_family == AF_INET &&
-			    sin->sin_addr.s_addr == ip->ip_dst.s_addr) {
+			    sa->daddr_version == 4 &&
+			    UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst,
+				   sizeof(struct in_addr)) == 0) {
 				break;
 			}
 		}
@@ -696,21 +782,70 @@ esp_print(netdissect_options *ndo,
 		ep = bp2 + len;
 	}
 
-	ivoff = (u_char *)(esp + 1) + 0;
+	/* pointer to the IV, if there is one */
+	ivoff = (const u_char *)(esp + 1) + 0;
+	/* length of the IV, if there is one; 0, if there isn't */
 	ivlen = sa->ivlen;
 	secret = sa->secret;
 	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");
-
-		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;
+		ctx = EVP_CIPHER_CTX_new();
+		if (ctx != NULL) {
+			if (set_cipher_parameters(ctx, sa->evp, secret, NULL, 0) < 0)
+				(*ndo->ndo_warning)(ndo, "espkey init failed");
+
+			p = ivoff;
+			set_cipher_parameters(ctx, NULL, NULL, p, 0);
+			len = ep - (p + ivlen);
+
+			/*
+			 * Allocate buffers for the encrypted and decrypted
+			 * data.  Both buffers' sizes must be a multiple of
+			 * the cipher block size, and the output buffer must
+			 * be separate from the input buffer.
+			 */
+			block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
+			buffer_size = len + (block_size - len % block_size);
+
+			/*
+			 * Attempt to allocate the input buffer.
+			 */
+			input_buffer = (u_char *)malloc(buffer_size);
+			if (input_buffer == NULL) {
+				EVP_CIPHER_CTX_free(ctx);
+				(*ndo->ndo_error)(ndo, "can't allocate memory for encrypted data buffer");
+			}
+			/*
+			 * Copy the input data to the encrypted data buffer,
+			 * and pad it with zeroes.
+			 */
+			memcpy(input_buffer, p + ivlen, len);
+			memset(input_buffer + len, 0, buffer_size - len);
+
+			/*
+			 * Attempt to allocate the output buffer.
+			 */
+			output_buffer = (u_char *)malloc(buffer_size);
+			if (output_buffer == NULL) {
+				free(input_buffer);
+				EVP_CIPHER_CTX_free(ctx);
+				(*ndo->ndo_error)(ndo, "can't allocate memory for decryption buffer");
+			}
+
+			EVP_Cipher(ctx, output_buffer, input_buffer, len);
+			free(input_buffer);
+			EVP_CIPHER_CTX_free(ctx);
+			/*
+			 * XXX - of course this is wrong, because buf is a
+			 * const buffer, but changing this would require a
+			 * more complicated fix.
+			 */
+			memcpy(p + ivlen, output_buffer, len);
+			free(output_buffer);
+			advance = ivoff - (const u_char *)esp + ivlen;
+		} else
+			advance = sizeof(struct newesp);
 	} else
 		advance = sizeof(struct newesp);
 
@@ -724,7 +859,7 @@ esp_print(netdissect_options *ndo,
 	if (nhdr)
 		*nhdr = *(ep - 1);
 
-	(ndo->ndo_printf)(ndo, ": ");
+	ND_PRINT((ndo, ": "));
 	return advance;
 #endif