X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/11f73ad248fa22461ca040baa8dc94b864509efa..06df4f81b66c76be479e2dd1e2d18a011410037b:/print-esp.c

diff --git a/print-esp.c b/print-esp.c
index 50cc2d1f..52081491 100644
--- a/print-esp.c
+++ b/print-esp.c
@@ -21,6 +21,8 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: IPSEC Encapsulating Security Payload (ESP) printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
@@ -42,15 +44,15 @@
 #endif
 #endif
 
-#include "ip.h"
-#include "ip6.h"
-
 #include "netdissect.h"
 #include "strtoaddr.h"
 #include "extract.h"
 
 #include "ascii_strcasecmp.h"
 
+#include "ip.h"
+#include "ip6.h"
+
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  * All rights reserved.
@@ -117,6 +119,32 @@ 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
+
 /*
  * this will adjust ndo_packetp and ndo_snapend to new buffer!
  */
@@ -128,8 +156,9 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
 {
 	struct sa_list *sa;
 	const u_char *iv;
-	int len;
-	EVP_CIPHER_CTX ctx;
+	u_char *buf_mut, *output_buffer;
+	int len, block_size, cipher_nid, output_buffer_size ;
+	EVP_CIPHER_CTX *ctx;
 
 	/* initiator arg is any non-zero value */
 	if(initiator) initiator=1;
@@ -157,18 +186,35 @@ 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 (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);
+	EVP_CipherInit(ctx, NULL, NULL, iv, 0);
+
+	/* We need a block size */
+	block_size = EVP_CIPHER_CTX_block_size(ctx);
+	/* We need the buffer size to be multiple of a block size */
+	output_buffer_size = len + (block_size - len % block_size);
+	output_buffer = (u_char *)calloc(output_buffer_size, sizeof(u_char));
+	/* EVP_Cipher output buffer should be different from the input one.
+	 * Also it should be of size that is multiple of cipher block size. */
+	EVP_Cipher(ctx, output_buffer, buf, len);
+	EVP_CIPHER_CTX_free(ctx);
+
+	buf_mut = (u_char*) buf;
+	/* Of course this is wrong, because buf is a const buffer, but changing this
+	 * would require more complicated fix. */
+	memcpy(buf_mut, output_buffer, len);
+	free(output_buffer);
 
 	ndo->ndo_packetp = buf;
 	ndo->ndo_snapend = end;
 
 	return 1;
 
+
 }
 USES_APPLE_RST
 
@@ -435,8 +481,9 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *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));
+			return;
 		}
 
 		while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
@@ -501,8 +548,14 @@ 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
@@ -568,7 +621,9 @@ esp_print(netdissect_options *ndo,
 	int ivlen = 0;
 	const u_char *ivoff;
 	const u_char *p;
-	EVP_CIPHER_CTX ctx;
+	EVP_CIPHER_CTX *ctx;
+	u_char *buf_mut, *output_buffer;
+	int block_size, cipher_nid, output_buffer_size;
 #endif
 
 	esp = (const struct newesp *)bp;
@@ -672,15 +727,29 @@ esp_print(netdissect_options *ndo,
 	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 - (const u_char *)esp + ivlen;
+		ctx = EVP_CIPHER_CTX_new();
+		if (ctx != NULL) {
+			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);
+			len = ep - (p + ivlen);
+
+			/* We need a block size */
+			block_size = EVP_CIPHER_CTX_block_size(ctx);
+			/* We need the buffer size to be multiple of a block size */
+			output_buffer_size = len + (block_size - len % block_size);
+			output_buffer = (u_char *)calloc(output_buffer_size, sizeof(u_char));
+			/* EVP_Cipher output buffer should be different from the input one.
+			 * Also it should be of size that is multiple of cipher block size. */
+			EVP_Cipher(ctx, output_buffer, p + ivlen, len);
+			EVP_CIPHER_CTX_free(ctx);
+			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);