From deb12f5613a1351eb78b09f61593eae64005b2d3 Mon Sep 17 00:00:00 2001
From: Peter Keresztes Schmidt <carbenium@outlook.com>
Date: Tue, 18 May 2021 00:18:26 +0200
Subject: [PATCH] Restore GnuTLS support after VLA removal

298415fff3ceac53d3d972700b584c08672f91eb made variables constexpr which led to build failures with GnuTLS.
---
 src/zm_rtsp_auth.cpp | 19 +++++++++++++------
 src/zm_user.cpp      |  7 +++++--
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/zm_rtsp_auth.cpp b/src/zm_rtsp_auth.cpp
index 1a7ea629b..ae05e1e7d 100644
--- a/src/zm_rtsp_auth.cpp
+++ b/src/zm_rtsp_auth.cpp
@@ -20,6 +20,7 @@
 
 #include "zm_logger.h"
 #include "zm_utils.h"
+#include <cassert>
 #include <cstring>
 
 namespace zm {
@@ -141,8 +142,10 @@ std::string Authenticator::computeDigestResponse(const std::string &method, cons
 #if HAVE_DECL_MD5
   MD5((unsigned char*)ha1Data.c_str(), ha1Data.length(), md5buf);
 #elif HAVE_DECL_GNUTLS_FINGERPRINT
-  gnutls_datum_t md5dataha1 = { (unsigned char*)ha1Data.c_str(), (unsigned int)ha1Data.length() };
-  gnutls_fingerprint( GNUTLS_DIG_MD5, &md5dataha1, md5buf, &md5len );
+  gnutls_datum_t md5dataha1 = {(unsigned char *) ha1Data.c_str(), (unsigned int) ha1Data.length()};
+  size_t md5_len_tmp = md5len;
+  gnutls_fingerprint(GNUTLS_DIG_MD5, &md5dataha1, md5buf, &md5_len_tmp);
+  assert(md5_len_tmp == md5len);
 #endif
   for ( unsigned int j = 0; j < md5len; j++ ) {
     sprintf(&md5HexBuf[2*j], "%02x", md5buf[j] );
@@ -156,8 +159,10 @@ std::string Authenticator::computeDigestResponse(const std::string &method, cons
 #if HAVE_DECL_MD5
   MD5((unsigned char*)ha2Data.c_str(), ha2Data.length(), md5buf );
 #elif HAVE_DECL_GNUTLS_FINGERPRINT
-  gnutls_datum_t md5dataha2 = { (unsigned char*)ha2Data.c_str(), (unsigned int)ha2Data.length() };
-  gnutls_fingerprint( GNUTLS_DIG_MD5, &md5dataha2, md5buf, &md5len );
+  gnutls_datum_t md5dataha2 = {(unsigned char *) ha2Data.c_str(), (unsigned int) ha2Data.length()};
+  md5_len_tmp = md5len;
+  gnutls_fingerprint(GNUTLS_DIG_MD5, &md5dataha2, md5buf, &md5_len_tmp);
+  assert(md5_len_tmp == md5len);
 #endif
   for ( unsigned int j = 0; j < md5len; j++ ) {
     sprintf( &md5HexBuf[2*j], "%02x", md5buf[j] );
@@ -177,8 +182,10 @@ std::string Authenticator::computeDigestResponse(const std::string &method, cons
 #if HAVE_DECL_MD5
   MD5((unsigned char*)digestData.c_str(), digestData.length(), md5buf);
 #elif HAVE_DECL_GNUTLS_FINGERPRINT
-  gnutls_datum_t md5datadigest = { (unsigned char*)digestData.c_str(), (unsigned int)digestData.length() };
-  gnutls_fingerprint( GNUTLS_DIG_MD5, &md5datadigest, md5buf, &md5len );
+  gnutls_datum_t md5datadigest = {(unsigned char *) digestData.c_str(), (unsigned int) digestData.length()};
+  md5_len_tmp = md5len;
+  gnutls_fingerprint(GNUTLS_DIG_MD5, &md5datadigest, md5buf, &md5_len_tmp);
+  assert(md5_len_tmp == md5len);
 #endif
   for ( unsigned int j = 0; j < md5len; j++ ) {
     sprintf( &md5HexBuf[2*j], "%02x", md5buf[j] );
diff --git a/src/zm_user.cpp b/src/zm_user.cpp
index 95f61da4e..a17db9e0f 100644
--- a/src/zm_user.cpp
+++ b/src/zm_user.cpp
@@ -22,6 +22,7 @@
 #include "zm_crypt.h"
 #include "zm_logger.h"
 #include "zm_utils.h"
+#include <cassert>
 #include <cstring>
 
 #if HAVE_GNUTLS_GNUTLS_H
@@ -262,8 +263,10 @@ User *zmLoadAuthUser(const char *auth, bool use_remote_addr) {
 #if HAVE_DECL_MD5
       MD5((unsigned char *)auth_key, strlen(auth_key), md5sum);
 #elif HAVE_DECL_GNUTLS_FINGERPRINT
-      gnutls_datum_t md5data = { (unsigned char *)auth_key, (unsigned int)strlen(auth_key) };
-      gnutls_fingerprint(GNUTLS_DIG_MD5, &md5data, md5sum, &md5len);
+      gnutls_datum_t md5data = {(unsigned char *) auth_key, (unsigned int) strlen(auth_key)};
+      size_t md5_len_tmp = md5len;
+      gnutls_fingerprint(GNUTLS_DIG_MD5, &md5data, md5sum, &md5_len_tmp);
+      assert(md5_len_tmp == md5len);
 #endif
       unsigned char *md5sum_ptr = md5sum;
       char *auth_md5_ptr = auth_md5;