Handle OpenSSL 1.1.x.

In 1.1.x, EVP_CIPHER_CTX is an opaque structure, so we can't declare it
on the stack.

Instead, if we don't have EVP_CIPHER_CTX_new() and EVP_CIPHER_CTX_free()
in libcrypto, define our own versions, with the same signatures as the
ones in OpenSSL 1.1.x's libcrypto, and have the code use
EVP_CIPHER_CTX_new() to allocate the structure and EVP_CIPHER_CTX_free()
to free it.

4 files changed, 80 insertions, 18 deletions

diff --git a/config.h.in b/config.h.in
index 6f6bb11a..27ba4b10 100644
--- a/config.h.in
+++ b/config.h.in
@@ -34,6 +34,9 @@
 /* Define to 1 if you have the `ether_ntohost' function. */
 #undef HAVE_ETHER_NTOHOST
 
+/* Define to 1 if you have the `EVP_CIPHER_CTX_new' function. */
+#undef HAVE_EVP_CIPHER_CTX_NEW
+
 /* Define to 1 if you have the <fcntl.h> header file. */
 #undef HAVE_FCNTL_H
 
diff --git a/configure b/configure
index a3a3e01e..aab7239a 100755
--- a/configure
+++ b/configure
@@ -8041,7 +8041,8 @@ _ACEOF
 
 fi
 
-		for ac_header in openssl/evp.h
+		if test "$ac_cv_lib_crypto_DES_cbc_encrypt" = "yes"; then
+			for ac_header in openssl/evp.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "openssl/evp.h" "ac_cv_header_openssl_evp_h" "$ac_includes_default"
 if test "x$ac_cv_header_openssl_evp_h" = xyes; then :
@@ -8053,6 +8054,24 @@ fi
 
 done
 
+			#
+			# OK, do we have EVP_CIPHER_CTX_new?
+			# If so, we use it to allocate an
+			# EVP_CIPHER_CTX, as EVP_CIPHER_CTX may be
+			# opaque; otherwise, we allocate it ourselves.
+			#
+			for ac_func in EVP_CIPHER_CTX_new
+do :
+  ac_fn_c_check_func "$LINENO" "EVP_CIPHER_CTX_new" "ac_cv_func_EVP_CIPHER_CTX_new"
+if test "x$ac_cv_func_EVP_CIPHER_CTX_new" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_EVP_CIPHER_CTX_NEW 1
+_ACEOF
+
+fi
+done
+
+		fi
 
 fi
 
diff --git a/configure.in b/configure.in
index 8ceb46bb..22ecee6f 100644
--- a/configure.in
+++ b/configure.in
@@ -918,7 +918,16 @@ if test "$want_libcrypto" != "no"; then
 	AC_CHECK_HEADER(openssl/crypto.h,
 	[
 		AC_CHECK_LIB(crypto, DES_cbc_encrypt)
-		AC_CHECK_HEADERS(openssl/evp.h)
+		if test "$ac_cv_lib_crypto_DES_cbc_encrypt" = "yes"; then
+			AC_CHECK_HEADERS(openssl/evp.h)
+			#
+			# OK, do we have EVP_CIPHER_CTX_new?
+			# If so, we use it to allocate an
+			# EVP_CIPHER_CTX, as EVP_CIPHER_CTX may be
+			# opaque; otherwise, we allocate it ourselves.
+			#
+			AC_CHECK_FUNCS(EVP_CIPHER_CTX_new)
+		fi
 	])
 fi
 
diff --git a/print-esp.c b/print-esp.c
index 247796da..8339a567 100644
--- a/print-esp.c
+++ b/print-esp.c
@@ -117,6 +117,32 @@ 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 (EVP_CIPHER_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!
  */
@@ -129,7 +155,7 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
 	struct sa_list *sa;
 	const u_char *iv;
 	int len;
-	EVP_CIPHER_CTX ctx;
+	EVP_CIPHER_CTX *ctx;
 
 	/* initiator arg is any non-zero value */
 	if(initiator) initiator=1;
@@ -157,12 +183,14 @@ 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);
+	EVP_Cipher(ctx, buf, buf, len);
+	EVP_CIPHER_CTX_free(ctx);
 
 	ndo->ndo_packetp = buf;
 	ndo->ndo_snapend = end;
@@ -568,7 +596,7 @@ esp_print(netdissect_options *ndo,
 	int ivlen = 0;
 	const u_char *ivoff;
 	const u_char *p;
-	EVP_CIPHER_CTX ctx;
+	EVP_CIPHER_CTX *ctx;
 #endif
 
 	esp = (const struct newesp *)bp;
@@ -672,15 +700,18 @@ 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);
+			EVP_Cipher(ctx, p + ivlen, p + ivlen, ep - (p + ivlen));
+			EVP_CIPHER_CTX_free(ctx);
+			advance = ivoff - (const u_char *)esp + ivlen;
+		} else
+			advance = sizeof(struct newesp);
 	} else
 		advance = sizeof(struct newesp);