Question about s2n-tls vs OpenSSL usage on Android build

[huyemotiv]

Hello aws-sdk-cpp development team,

When building aws-sdk-cpp v1.11.682 for Android, does enabling USE_S2N=ON mean that s2n-tls is used to replace OpenSSL libssl as the TLS backend?
Additionally, if we want to use an externally prebuilt OpenSSL package (libssl/libcrypto) instead of the internally built one, what is the correct and supported way to configure the Android build to do so?

Thank you.

[sbaluja]

We don't directly expose the USE_S2N parameter, as that lives in the aws-c-io submodule, which is used by the aws-crt-cpp. However, the SDK uses s2n-tls by default on Android platforms (USE_S2N=ON) when using the CRT HTTP client (USE_CRT_HTTP_CLIENT=ON). But yes, when this flag is enabled, s2n-tls replaces OpenSSL's libssl.

Additionally, if we want to use an externally prebuilt OpenSSL package (libssl/libcrypto) instead of the internally built one, what is the correct and supported way to configure the Android build to do so?

Here is some documentation which has a step by step on how to use a custom libcrypto library in the SDK.