MINOR: checks: Add support of server side ssl sample fetches

SSL sample fetches acting on the server connection can now be called from any
sample expression or log-format string in a tcp-check based ruleset. ssl_bc and
ssl_bc_* sample fetches are concerned.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 86f3f1a..4a1c150 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -16281,11 +16281,13 @@
 ssl_bc : boolean
   Returns true when the back connection was made via an SSL/TLS transport
   layer and is locally deciphered. This means the outgoing connection was made
-  other a server with the "ssl" option.
+  other a server with the "ssl" option. It can be used in a tcp-check or an
+  http-check ruleset.
 
 ssl_bc_alg_keysize : integer
   Returns the symmetric cipher key size supported in bits when the outgoing
-  connection was made over an SSL/TLS transport layer.
+  connection was made over an SSL/TLS transport layer. It can be used in a
+  tcp-check or an http-check ruleset.
 
 ssl_bc_alpn : string
   This extracts the Application Layer Protocol Negotiation field from an
@@ -16296,21 +16298,25 @@
   not advertised unless the "alpn" keyword on the "server" line specifies a
   protocol list. Also, nothing forces the server to pick a protocol from this
   list, any other one may be requested. The TLS ALPN extension is meant to
-  replace the TLS NPN extension. See also "ssl_bc_npn".
+  replace the TLS NPN extension. See also "ssl_bc_npn". It can be used in a
+  tcp-check or an http-check ruleset.
 
 ssl_bc_cipher : string
   Returns the name of the used cipher when the outgoing connection was made
-  over an SSL/TLS transport layer.
+  over an SSL/TLS transport layer. It can be used in a tcp-check or an
+  http-check ruleset.
 
 ssl_bc_client_random : binary
   Returns the client random of the back connection when the incoming connection
   was made over an SSL/TLS transport layer. It is useful to to decrypt traffic
   sent using ephemeral ciphers. This requires OpenSSL >= 1.1.0, or BoringSSL.
+  It can be used in a tcp-check or an http-check ruleset.
 
 ssl_bc_is_resumed : boolean
   Returns true when the back connection was made over an SSL/TLS transport
   layer and the newly created SSL session was resumed using a cached
-  session or a TLS ticket.
+  session or a TLS ticket. It can be used in a tcp-check or an http-check
+  ruleset.
 
 ssl_bc_npn : string
   This extracts the Next Protocol Negotiation field from an outgoing connection
@@ -16320,36 +16326,42 @@
   the TLS NPN extension is not advertised unless the "npn" keyword on the
   "server" line specifies a protocol list. Also, nothing forces the server to
   pick a protocol from this list, any other one may be used. Please note that
-  the TLS NPN extension was replaced with ALPN.
+  the TLS NPN extension was replaced with ALPN. It can be used in a tcp-check
+  or an http-check ruleset.
 
 ssl_bc_protocol : string
   Returns the name of the used protocol when the outgoing connection was made
-  over an SSL/TLS transport layer.
+  over an SSL/TLS transport layer. It can be used in a tcp-check or an
+  http-check ruleset.
 
 ssl_bc_unique_id : binary
   When the outgoing connection was made over an SSL/TLS transport layer,
   returns the TLS unique ID as defined in RFC5929 section 3. The unique id
-  can be encoded to base64 using the converter: "ssl_bc_unique_id,base64".
+  can be encoded to base64 using the converter: "ssl_bc_unique_id,base64". It
+  can be used in a tcp-check or an http-check ruleset.
 
 ssl_bc_server_random : binary
   Returns the server random of the back connection when the incoming connection
   was made over an SSL/TLS transport layer. It is useful to to decrypt traffic
   sent using ephemeral ciphers. This requires OpenSSL >= 1.1.0, or BoringSSL.
+  It can be used in a tcp-check or an http-check ruleset.
 
 ssl_bc_session_id : binary
   Returns the SSL ID of the back connection when the outgoing connection was
   made over an SSL/TLS transport layer. It is useful to log if we want to know
-  if session was reused or not.
+  if session was reused or not. It can be used in a tcp-check or an http-check
+  ruleset.
 
 ssl_bc_session_key : binary
   Returns the SSL session master key of the back connection when the outgoing
   connection was made over an SSL/TLS transport layer. It is useful to decrypt
   traffic sent using ephemeral ciphers. This requires OpenSSL >= 1.1.0, or
-  BoringSSL.
+  BoringSSL. It can be used in a tcp-check or an http-check ruleset.
 
 ssl_bc_use_keysize : integer
   Returns the symmetric cipher key size used in bits when the outgoing
-  connection was made over an SSL/TLS transport layer.
+  connection was made over an SSL/TLS transport layer. It can be used in a
+  tcp-check or an http-check ruleset.
 
 ssl_c_ca_err : integer
   When the incoming connection was made over an SSL/TLS transport layer,
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index c4f9a86..dfaea05 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -8468,8 +8468,13 @@
 static int
 smp_fetch_ssl_fc(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
+
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
 
 	smp->data.type = SMP_T_BOOL;
 	smp->data.u.sint = (conn && conn->xprt == &ssl_sock);
@@ -8501,10 +8506,16 @@
 static int
 smp_fetch_ssl_fc_is_resumed(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
-	struct ssl_sock_ctx *ctx = conn ? conn->xprt_ctx : NULL;
+	struct connection *conn;
+	struct ssl_sock_ctx *ctx;
+
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
 
+	ctx = conn ? conn->xprt_ctx : NULL;
 
 	smp->data.type = SMP_T_BOOL;
 	smp->data.u.sint = (conn && conn->xprt == &ssl_sock) &&
@@ -8520,10 +8531,15 @@
 static int
 smp_fetch_ssl_fc_cipher(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	struct ssl_sock_ctx *ctx;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	smp->flags = 0;
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
@@ -8548,11 +8564,16 @@
 static int
 smp_fetch_ssl_fc_alg_keysize(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	struct ssl_sock_ctx *ctx;
 	int sint;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	smp->flags = 0;
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
@@ -8574,10 +8595,15 @@
 static int
 smp_fetch_ssl_fc_use_keysize(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	struct ssl_sock_ctx *ctx;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	smp->flags = 0;
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
@@ -8603,8 +8629,12 @@
 	smp->flags = SMP_F_CONST;
 	smp->data.type = SMP_T_STR;
 
-	conn = (kw[4] != 'b' ) ? objt_conn(smp->sess->origin) :
-	    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
 	ctx = conn->xprt_ctx;
@@ -8633,8 +8663,11 @@
 	smp->flags = SMP_F_CONST;
 	smp->data.type = SMP_T_STR;
 
-	conn = (kw[4] != 'b' ) ? objt_conn(smp->sess->origin) :
-	    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
 
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
@@ -8660,10 +8693,15 @@
 static int
 smp_fetch_ssl_fc_protocol(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	struct ssl_sock_ctx *ctx;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	smp->flags = 0;
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
@@ -8688,8 +8726,7 @@
 static int
 smp_fetch_ssl_fc_session_id(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	SSL_SESSION *ssl_sess;
 	struct ssl_sock_ctx *ctx;
 	unsigned int len = 0;
@@ -8697,6 +8734,12 @@
 	smp->flags = SMP_F_CONST;
 	smp->data.type = SMP_T_BIN;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
 	ctx = conn->xprt_ctx;
@@ -8719,11 +8762,16 @@
 static int
 smp_fetch_ssl_fc_random(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                           smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	struct buffer *data;
 	struct ssl_sock_ctx *ctx;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
 	ctx = conn->xprt_ctx;
@@ -8750,12 +8798,17 @@
 static int
 smp_fetch_ssl_fc_session_key(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	SSL_SESSION *ssl_sess;
 	struct buffer *data;
 	struct ssl_sock_ctx *ctx;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;
 	ctx = conn->xprt_ctx;
@@ -8903,12 +8956,17 @@
 static int
 smp_fetch_ssl_fc_unique_id(const struct arg *args, struct sample *smp, const char *kw, void *private)
 {
-	struct connection *conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
-	                                    smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+	struct connection *conn;
 	int finished_len;
 	struct buffer *finished_trash;
 	struct ssl_sock_ctx *ctx;
 
+	if (smp->sess && obj_type(smp->sess->origin) == OBJ_TYPE_CHECK)
+		conn = (kw[4] != 'b') ? cs_conn(__objt_check(smp->sess->origin)->cs) : NULL;
+	else
+		conn = (kw[4] != 'b') ? objt_conn(smp->sess->origin) :
+			smp->strm ? cs_conn(objt_cs(smp->strm->si[1].end)) : NULL;
+
 	smp->flags = 0;
 	if (!conn || !conn->xprt_ctx || conn->xprt != &ssl_sock)
 		return 0;