X11Forwarding yes ssh -X vs. ssh -Y

[Greg Veldman]

On Sat, May 02, 2020 at 03:42:24PM +0200, Christoph Kukulies wrote:
> OK, here is (doesn???t seem to have anything related to security extensions):

Indeed, it appears that way (see below).

> name of display:    /private/tmp/com.apple.launchd.NM3gWpA6AH/org.macports:0

This is an interesting line.  Are you by chance doing this on a
MacOS system?  If so I believe MacOS does not support the X11
SECURITY extension at all, so your only option is to use trusted
forwarding (the -Y flag).  At least it didn't as of the last
time I looked, which was around Sierra/High Sierra.  Not sure
what the current state is.

> number of extensions:    21
>     Apple-DRI  (opcode: 128, base event: 64, base error: 128)
>     Apple-WM  (opcode: 129, base event: 68, base error: 130)
>     BIG-REQUESTS  (opcode: 134)
>     DAMAGE  (opcode: 142, base event: 97, base error: 154)
>     DOUBLE-BUFFER  (opcode: 144, base error: 155)
>     GLX  (opcode: 148, base event: 101, base error: 159)
>     Generic Event Extension  (opcode: 130)
>     MIT-SCREEN-SAVER  (opcode: 143, base event: 98)
>     MIT-SHM  (opcode: 132, base event: 72, base error: 132)
>     Present  (opcode: 145)
>     RANDR  (opcode: 141, base event: 95, base error: 149)
>     RENDER  (opcode: 140, base error: 144)
>     SHAPE  (opcode: 131, base event: 71)
>     SYNC  (opcode: 135, base event: 90, base error: 138)
>     X-Resource  (opcode: 146)
>     XC-MISC  (opcode: 137)
>     XFIXES  (opcode: 139, base event: 93, base error: 142)
>     XINERAMA  (opcode: 138)
>     XInputExtension  (opcode: 133, base event: 73, base error: 133)
>     XKEYBOARD  (opcode: 136, base event: 92, base error: 141)
>     XVideo  (opcode: 147, base event: 99, base error: 156)

This is where it would be.  You'd be looking for a line similar
to the following (from my FreeBSD 11.3 desktop):

    SECURITY  (opcode: 137, base event: 86, base error: 138)

-- 
Greg Veldman
freebsd at gregv.net