ALPN negotiation failure with BC provider during SSL Handshake

[Sujatha H]

Hi,

We have a requirement to connect to temporal server using java temporal sdk via SSLcontext which uses grpc internally. This needs to be run on FIPS mode which essentially is using BouncyCastleProvider.

While creating SSLContext on FIPS mode to temporal, handshake is failing with below error:

Failed ALPN negotiation: Unable to find compatible protocol

Checked with jdk 11 and 17, same issue is seen. Noticed grpc code netty/src/main/java/io/grpc/netty/GrpcSslContexts.java, there are some checks based for alpn protocol based on the provider used for SSL Context. Do we have support for alpn for BouncyCastle provider in grpc? In which version of grpc is this support available? If not, please suggest if there is a workaround to get resolve this issue