FIPs algorithm code vs default implementation

[Bala Duvvuri via openssl-users <openssl-users@xxxxxxxxxxx>]

Hi All,

This is a basic question regarding FIPs algorithm code in OpenSSL 3.0, can you kindly let me know:

1> Can you please help to understand the differences in the FIPs algorithm implementation code vs default? 

     Are there additional validations performed in FIPs code? 

     Can you point to any API (FIPs and non FIPs version) to make this clear?

2> In normal code, EVP_DigestFinal_ex->HASH_FINAL 

      Which API is equivalent to HASH_FINAL in FIPs code? How can we navigate to the FIPs code path?

3> When does "FIPS_MODULE" get defined?

Thanks
Bala