Merge pull request #1308 from drwetter/binchar_fix

Binary string washer (0x00 bytes) (probably) after completed ClientHello

testssl.sh

@@ -1262,7 +1262,14 @@ strip_trailing_space() {
 # retrieve cipher from ServerHello (via openssl)
 get_cipher() {
      local cipher=""
-     local server_hello="$(< "$1")"
+     local server_hello="$(cat -v "$1")"
+     # This and two other following instances are not best practice and normally a useless use of "cat", see
+     # https://web.archive.org/web/20160711205930/http://porkmail.org/era/unix/award.html#uucaletter
+     # However there seem to be cases where the preferred  $(< "$1")  logic has a problem.
+     # Esepcially with bash 3.2 (Mac OS X) and when on the server side binary chars
+     # are returned, see https://stackoverflow.com/questions/7427262/how-to-read-a-file-into-a-variable-in-shell#22607352
+     # and https://github.com/drwetter/testssl.sh/issues/1292
+     # Performance measurements showed no to barely measureable penalty (1s displayed in 9 tries).
 
      if [[ "$server_hello" =~ Cipher\ *:\ ([A-Z0-9]+-[A-Za-z0-9\-]+|TLS_[A-Za-z0-9_]+) ]]; then
           cipher="${BASH_REMATCH##* }"
@@ -1275,7 +1282,7 @@ get_cipher() {
 # retrieve protocol from ServerHello (via openssl)
 get_protocol() {
      local protocol=""
-     local server_hello="$(< "$1")"
+     local server_hello="$(cat -v "$1")"
 
      if [[ "$server_hello" =~ Protocol\ *:\ (SSLv[23]|TLSv1(\.[0-3])?) ]]; then
           protocol="${BASH_REMATCH##* }"
@@ -6938,7 +6945,7 @@ tls_time() {
 # returns 0 if connect was successful, 1 if not
 #
 sclient_connect_successful() {
-     local server_hello="$(<"$2")"
+     local server_hello="$(cat -v "$2")"
      local re='Master-Key: ([^\
 ]*)'