OpenSSL: a obter o certificado público do servidor de SQL

quero usar o OpenSSL ou qualquer Comando Nativo do Linux para obter o certificado de um servidor de SQL. Tentei da mesma forma que com um Servidor HTTP, mas não funciona.

openssl s_client -showcerts -connect MY.MSSQL.SERVER:1433
CONNECTED(00000003)
write:errno=104
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no peer certificate available
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No client certificate CA names sent
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SSL handshake has read 0 bytes and written 249 bytes
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New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
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