Current FreeBSD kernels require SA records for both directions. Thanks to Joseph Mulloy and Andrey V. Elsukov for reporting and solving the issue.
Add code for manipulation with TCP-MD5 keys in the IPsec SA/SP database at FreeBSD systems. Now, BGP MD5 authentication (RFC 2385) keys are handled automatically on both Linux and FreeBSD. Based on patches from Pavel Tvrdik.