Linking problems in MSVC++

Dr. Matthias St. Pierre Matthias.St.Pierre at
Fri Sep 8 16:45:23 UTC 2023


also in C, the MSVC compiler adds decorations to the function for the linker, depending on the calling convention:

`__cdecl` calling convention:
a leading underscore `_` is added

`__stdcall` calling convention:
a leading underscore `_` is added a trailing at sign `@` followed by the number of bytes in the parameter list in decimal


From: openssl-users <openssl-users-bounces at> On Behalf Of Don Payette
Sent: Wednesday, September 6, 2023 3:23 PM
To: openssl-users at
Subject: Re: Linking problems in MSVC++

Well, the linker is giving me this error, plus other similar errors:

    Error LNK2019 unresolved external symbol _SSL_CTX_new referenced in function ...

My code is calling SSL_CTX_new, so it appears something is adding an underscore on the front.
I looked in libssl.def and SSL_CTX_new is there, but not _SSL_CTX_new. Anybody know where
the underscore is coming from?

Don Payette
(cell) 479-216-6320<tel:(479)%20216-6320>

On Thu, Aug 31, 2023 at 11:53 AM Kenneth Porter <shiva at<mailto:shiva at>> wrote:
On 8/31/2023 8:24 AM, Don Payette wrote:
I'm using Microsoft Visual Studio, so no command line.
In the linker settings there is an External Dependencies. I added libcrypto.lib and<>.
We'll see what happens.

Open the project configuration, go to Configuration Properties | Linker | Command Line, and you can copy and paste the arguments that the IDE will pass to the linker. (There's a similar feature under C/C++ in that dialog for the command line compiler.) If it says "different options", you need to use the drop-down menus at the top of the dialog to select a specific configuration (like Debug and x64) to see the command line for that configuration.

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