[MSVC] libcurl.lib(rand.obj) : error LNK2001: unresolved external symbol BCryptGenRandom

[QuellaZhang]

Hi All,

openframeworks failed to build on MSVC due to libcurl.lib(rand.obj) : error LNK2001: unresolved external symbol BCryptGenRandom, this issue can be reproduced on bc87649, can someone help take a look? Thank you.

Repro steps:

1. git clone https://github.com/openframeworks/openFrameworks C:\gitP\openframeworks\openFrameworks
2. cd /d C:\gitP\openframeworks\openFrameworks
3. "C:\Program Files\Git\bin\sh.exe" ./scripts/ci/vs/install.sh
4. cd /d C:\gitP\openframeworks\openFrameworks
5. msbuild /m /p:Platform=x64 /p:Configuration=Release examples/templates/emptyExample/emptyExample.sln /t:Rebuild /p:PlatformToolset=v145

Build log: Build.log

Error info:

libcurl.lib(rand.obj) : error LNK2001: unresolved external symbol BCryptGenRandom
bin\emptyExample.exe : fatal error LNK1120: 1 unresolved externals

[danoli3]

Working on it should be fixed in an hour

[QuellaZhang]

@danoli3 I noticed that the fix has been merged, then I got the following error under arm64 testing after updating SHA. openframeworks passed on x64.

LINK : fatal error LNK1181: cannot open input file 'libcairo.lib'
C:\Program Files\Microsoft Visual Studio\18\Enterprise\MSBuild\Microsoft\VC\v180\Microsoft.CppCommon.targets(1196,5): error MSB6006: "link.exe" exited with code 1181.

[danoli3]

Hi @QuellaZhang ! Yes cURL and openSSL should be fixed. I found that 12.1.1's OpenSSL doesn't pass the randomness tests required for secure transport / https. Now randomness and https working. OpenSSL required BCryptGenRandom for Windows / macOS / ios required ASM or the fallback random code I added (30% slower than ASM). Had to patch OpenSSL cmake..

Hmmm libcairo, can you redownload libs via oF Menu, how did you download them: download_libs.sh?
Latest libs:

• arm64 passed for me
• arm64ec passed for me

./of
3 Update / 1 Libraries / 1 apothecary / 8 Visual studio / 1 latest
ok — apothecary@latest · 2026-08-14T05:03:50Z · SHA-256 secure (4 pkg)

Looking into it though still I suspect some issues with scripts