Custom Provider - EVP_CIPHER_fetch fails

Hareesh Das Ulleri hareesh.ulleri at
Tue Dec 13 09:13:50 UTC 2022

Hello OpenSSL users,

  I am in preparation of a provider (for a custom crypto) by referring OpenSSL 3 design doc (I use Linux 5.10 + OpenSSL 3.0.7). I believe, the custom provider has all required call backs implemented for the cipher functionalities in its dispatch table.

  I have another test application (for encryption and decryption of a text message). At the starting of the app, it calls OSSL_PROVIDER_load and EVP_CIPHER_fetch functions to the custom provider. But unfortunately custom provider fetch function fails...

What could be the missing or how to make sure that the custom provider is loaded correctly before calling the fetch function?

cipher = EVP_CIPHER_fetch(NULL, "AES-256-CBC-CTS", NULL);  -> This will work, default provider
cipher = EVP_CIPHER_fetch(NULL, "CUSTOM_ALGO", NULL);  -> returns NULL, custom provider

Confg file:
openssl_conf = openssl_init

providers = provider_section

customProv = customProv_section
default = default_sect

provider_id = customProv
module_path = /userfs/lib/
algorithms = CUSTOM_ALGO
activate = 1

algorithms = AES-256-CBC-CTS
activate = 1

Thank you,

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