From 0ad0732b8fbacd3519b4e3ecf8c394681b314672 Mon Sep 17 00:00:00 2001
From: "Alexander V. Lukyanov" <lavv17f@gmail.com>
Date: Thu, 5 Dec 2019 21:34:11 +0300
Subject: [PATCH] SSH_Access: fixed yes/no/[fingerprint] recognition (fix #547,
 fix #525)

---
 src/SSH_Access.cc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/SSH_Access.cc b/src/SSH_Access.cc
index 97683a3f..adf0c196 100644
--- a/src/SSH_Access.cc
+++ b/src/SSH_Access.cc
@@ -20,6 +20,8 @@
 #include <config.h>
 #include "SSH_Access.h"
 #include "misc.h"
+#include <algorithm>
+#include "ascii_ctype.h"
 
 void SSH_Access::MakePtyBuffers()
 {
@@ -70,6 +70,26 @@ static bool IsPasswordPrompt(const char *b,const char *e)
    return (e-b>=len && !strncasecmp(b,suffix,len));
 }
 
+struct nocase_eq
+{
+   inline bool operator() (char lhs, char rhs) const
+   {
+      return c_tolower(lhs) == c_tolower(rhs);
+   };
+};
+
+static bool contains(char const *begin, char const *end, char const *needle)
+{
+   return std::search(begin, end, needle, needle+strlen(needle), nocase_eq()) != end;
+}
+
+static bool IsConfirmPrompt(const char *b,const char *e)
+{
+   if(b==e)
+      return false;
+   return e[-1]=='?' && contains(b,e,"yes/no");
+}
+
 int SSH_Access::HandleSSHMessage()
 {
    int m=STALL;
@@ -99,7 +106,7 @@ int SSH_Access::HandleSSHMessage()
 	 password_sent++;
 	 return m;
       }
-      if(ends_with(b,b+s,"(yes/no)?"))
+      if(IsConfirmPrompt(b,b+s))
       {
 	 const char *answer=QueryBool("auto-confirm",hostname)?"yes\n":"no\n";
 	 pty_recv_buf->Put(answer);