http://dcx.sap.com/index.html#sqla170/en/html/8158be656ce2101482a8c1dc33218eeb.html
http://dcx.sap.com/index.html#sqla170/en/html/80f119a56ce210149f9ac95c6af384ed.html
Server certificate not trusted error and changes in UltraLite17 are documented in the links above
About the certificate that you use client side and specified by trusted_certificates, have you verified it is the correct root CA using openssl s_client? This would diplay the certificate chain.