X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/91e08f888d86fc7bc83732ee216c4ea609691d1c..06df4f81b66c76be479e2dd1e2d18a011410037b:/print-esp.c

diff --git a/print-esp.c b/print-esp.c
index bdd591ef..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
@@ -154,7 +156,8 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
 {
 	struct sa_list *sa;
 	const u_char *iv;
-	int len;
+	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 */
@@ -189,14 +192,29 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
 	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);
+
+	/* 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
 
@@ -530,8 +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
@@ -598,6 +622,8 @@ esp_print(netdissect_options *ndo,
 	const u_char *ivoff;
 	const u_char *p;
 	EVP_CIPHER_CTX *ctx;
+	u_char *buf_mut, *output_buffer;
+	int block_size, cipher_nid, output_buffer_size;
 #endif
 
 	esp = (const struct newesp *)bp;
@@ -708,8 +734,19 @@ esp_print(netdissect_options *ndo,
 
 			p = ivoff;
 			EVP_CipherInit(ctx, NULL, NULL, p, 0);
-			EVP_Cipher(ctx, p + ivlen, p + ivlen, ep - (p + ivlen));
+			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);