Unresolved external symbol when using Crypto++ 8.6 as dll

[Benjamin Mahr]

I have to add crypto++ as dll into our project. The project is using several functions of crypto++ but a few used give an "unresolved extern symbol" linking error:

CryptoPP::DSAConvertSignatureFormat

CryptoPP::Base64Encoder::IsolatedInitialize

CryptoPP::Base64Decoder::GetDecodingLookupArray

Clearly, this can't work because non of those functions have CRYPTOPP_DLL set. Is this by intention? Which functions should we call instead?

Best regards,

Ben

[Jeffrey Walton]

On Wed, Jun 8, 2022 at 3:12 AM Benjamin Mahr <ben....@gmail.com> wrote:
>
> I have to add crypto++ as dll into our project. The project is using several functions of crypto++ but a few used give an "unresolved extern symbol" linking error:
> CryptoPP::DSAConvertSignatureFormat
> CryptoPP::Base64Encoder::IsolatedInitialize
> CryptoPP::Base64Decoder::GetDecodingLookupArray
>

> Clearly, this can't work because none of those functions have CRYPTOPP_DLL set. Is this by intention?

Yes, this is by design. Also see https://cryptopp.com/wiki/FIPS_DLL

> Which functions should we call instead?

You still have to link to cryptlib.lib for the missing functions.

If you want to continue with the FIPS DLL, then see the preprocessor
defines that are set in cryptdll and dlltest projects.

Jeff