Add askpass.c source code

askpass.c

@@ -0,0 +1,24 @@
+/*
+    ssh-add on Windows (probably part of the source at https://github.com/PowerShell/openssh-portable)
+    does not/can not read the passphrase from stdin.
+    
+    However, when the DISPLAY env var is set and ssh-add is not run from a terminal (however it tests
+    that), it will run the executable pointed to by SSH_ASKPASS in a subprocess and read the passphrase
+    from that subprocess' stdout.
+    
+    This program can be used as the SSH_ASKPASS implementation. It will return the passphrase set
+    in the SSH_PASS env variable.
+    
+    To cross-compile from Ubuntu, I installed the `mingw-w64` package and ran
+    $ x86_64-w64-mingw32-gcc askpass.c -static -o askpass.exe
+*/    
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char** argv)
+{
+    printf("%s\n", getenv("SSH_PASS"));
+
+    return 0;
+}