File download through ISAPI dll

Hello,

I have ISAPI dll, that submits specified file to the client (sample client
request: "dld.dll?download&id=123&bid=12345").

Generally, it works fine. However, when SSL is used, the client gets an
error:
"Internet Explorer cannot download ...dll?download&id=123&bid=12345 from ...

Internet Explorer was not able to open this Internet site. The requested
site is either unavailable or cannot be found. Please try again later."

IIS version: 5.0
Internet Explorer version: 6.0

Any advice would be great.
Thank you!

Hello,

I have ISAPI dll, that submits specified file to the client (sample client
request: "dld.dll?download&id=123&bid=12345").

Generally, it works fine. However, when SSL is used, the client gets an
error:
"Internet Explorer cannot download ...dll?download&id=123&bid=12345 from ...

Internet Explorer was not able to open this Internet site. The requested
site is either unavailable or cannot be found. Please try again later."

IIS version: 5.0
Internet Explorer version: 6.0

Any advice would be great.
Thank you!

IE is known to refuse to download files if it is over SSL and you have "Do
not cache encrypted pages to disk" option checked.

If so, there is nothing you can do on the server about it.

--
//David
IIS
This posting is provided "AS IS" with no warranties, and confers no rights.
//

Hello,

I have ISAPI dll, that submits specified file to the client (sample client
request: "dld.dll?download&id=123&bid=12345").

Generally, it works fine. However, when SSL is used, the client gets an
error:
"Internet Explorer cannot download ...dll?download&id=123&bid=12345 from ...

Internet Explorer was not able to open this Internet site. The requested
site is either unavailable or cannot be found. Please try again later."

IIS version: 5.0
Internet Explorer version: 6.0

Any advice would be great.
Thank you!

Thanks for the reply. However, even if the option you mentioned is enabled,
the result is the same.

There is one difference when SSL is enabled, that seems to be the cause of
the problem. Normally, when download is initiated (user clicks on the link),
I.E. shows a dialog, like:
------------------------------------------------------
[File Download]
....
File name: TestDoc.pdf
File type: Adobe Acrobat Do***ent
From: serverName

Would you like to open the file or save it to your computer?
[Open] [Save] [Cancel] [More Info]
------------------------------------------------------

When SSL is on (the same dll, the same file):
------------------------------------------------------
[File Download]
....
File name: ...dll?download&id=123&bid=1234
File type:
From: serverName

Would you like to open the file or save it to your computer?
[Open] [Save] [Cancel] [More Info]
------------------------------------------------------

It seems I.E. no longer recognizes the file name or the file type.

Myth

Does your ISAPI send the exact same bits, headers and all, regardless of
being requested over HTTPS or HTTP ?

I think you're looking at some client-side behavior.

--
//David
IIS
This posting is provided "AS IS" with no warranties, and confers no rights.
//

Thanks for the reply. However, even if the option you mentioned is enabled,
the result is the same.

There is one difference when SSL is enabled, that seems to be the cause of
the problem. Normally, when download is initiated (user clicks on the link),
I.E. shows a dialog, like:
------------------------------------------------------
[File Download]
....
File name: TestDoc.pdf
File type: Adobe Acrobat Do***ent
From: serverName

Would you like to open the file or save it to your computer?
[Open] [Save] [Cancel] [More Info]
------------------------------------------------------

When SSL is on (the same dll, the same file):
------------------------------------------------------
[File Download]
....
File name: ...dll?download&id=123&bid=1234
File type:
From: serverName

Would you like to open the file or save it to your computer?
[Open] [Save] [Cancel] [More Info]
------------------------------------------------------

It seems I.E. no longer recognizes the file name or the file type.
Myth
"David Wang [Msft]" <someone@online.microsoft.com> wrote in message news:OFpzlWXKEHA.2380@TK2MSFTNGP09.phx.gbl...

ISAPI code is the same. The question is if the client receives the same
data. Any suggestions, how I could see server response headers?

Debugging dll doesn't help, it only shows the headers that were set in the
code and not the actual IIS response.

Probably, but I still hope there is some workaround for this.

I'm not aware of any tools that allows you to peer into the encrypted server
response without the client (that would be a security violation, wouldn't
you say...)

Assuming that the ISAPI sends the exact same response headers and entity
body, I really have no more suggestions or work-arounds for client-behavior.
You probably need to query the IE newsgroups to see if they have any
recommendations on how to fool the browser.

My suspicion is that IE uses the URL extension, Content-Type, and sometimes
the content itself to determine how to open it -- and I suspect that IE has
some strange behavior when seeing the .DLL extension over SSL... so you may
have to scriptmap the .pdf extension to your ISAPI DLL to fool IE into
thinking it's a PDF (i.e. IE will see a request to
/foobar.pdf?download&id=123&bid=1234 where you scriptmap .pdf to your ISAPI
DLL with "Check if file exists" unchecked ).

--
//David
IIS
This posting is provided "AS IS" with no warranties, and confers no rights.
//

ISAPI code is the same. The question is if the client receives the same
data. Any suggestions, how I could see server response headers?

Debugging dll doesn't help, it only shows the headers that were set in the
code and not the actual IIS response.

Probably, but I still hope there is some workaround for this.
"David Wang [Msft]" <someone@online.microsoft.com> wrote in message news:u6CNgK6KEHA.556@TK2MSFTNGP10.phx.gbl...

Tried the mapping - didn't help. Tried another client (Opera 7.2) and it
worked. So it's really the client side issue.

Thanks for your input.

client-behavior.

sometimes

has

may

ISAPI

The problem was caused by SSL + "Cache-Control: no-cache" and "Pragma:
no-cache" headers. Removing those headers solved the problem.

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6 13th August 22:04 myth External User Posts: 1	File download through ISAPI dll ISAPI code is the same. The question is if the client receives the same data. Any suggestions, how I could see server response headers? Debugging dll doesn't help, it only shows the headers that were set in the code and not the actual IIS response. Probably, but I still hope there is some workaround for this.

8 13th August 22:04 myth External User Posts: 1	File download through ISAPI dll Tried the mapping - didn't help. Tried another client (Opera 7.2) and it worked. So it's really the client side issue. Thanks for your input. client-behavior. sometimes has may ISAPI

9 13th August 22:04 myth External User Posts: 1	File download through ISAPI dll The problem was caused by SSL + "Cache-Control: no-cache" and "Pragma: no-cache" headers. Removing those headers solved the problem.