Move SSL API comments to header files

Move the documentation of the SSL API calls are supposed to do into the
headers files, instead of keeping them in the files for the OpenSSL
implementation.  That way, they don't have to be duplicated or be
inconsistent when other implementations are added.

src/interfaces/libpq/fe-secure-openssl.c

@@ -98,10 +98,6 @@ static long win32_ssl_create_mutex = 0;
 /*			 Procedures common to all secure sessions			*/
 /* ------------------------------------------------------------ */
 
-/*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL and/or libcrypto.
- */
 void
 pgtls_init_library(bool do_ssl, int do_crypto)
 {
@@ -119,9 +115,6 @@ pgtls_init_library(bool do_ssl, int do_crypto)
 	pq_init_crypto_lib = do_crypto;
 }
 
-/*
- *	Begin or continue negotiating a secure session.
- */
 PostgresPollingStatusType
 pgtls_open_client(PGconn *conn)
 {
@@ -144,22 +137,6 @@ pgtls_open_client(PGconn *conn)
 	return open_client_SSL(conn);
 }
 
-/*
- *	Is there unread data waiting in the SSL read buffer?
- */
-bool
-pgtls_read_pending(PGconn *conn)
-{
-	return SSL_pending(conn->ssl);
-}
-
-/*
- *	Read data from a secure connection.
- *
- * On failure, this function is responsible for putting a suitable message
- * into conn->errorMessage.  The caller must still inspect errno, but only
- * to determine whether to continue/retry after error.
- */
 ssize_t
 pgtls_read(PGconn *conn, void *ptr, size_t len)
 {
@@ -284,13 +261,12 @@ rloop:
 	return n;
 }
 
-/*
- *	Write data to a secure connection.
- *
- * On failure, this function is responsible for putting a suitable message
- * into conn->errorMessage.  The caller must still inspect errno, but only
- * to determine whether to continue/retry after error.
- */
+bool
+pgtls_read_pending(PGconn *conn)
+{
+	return SSL_pending(conn->ssl);
+}
+
 ssize_t
 pgtls_write(PGconn *conn, const void *ptr, size_t len)
 {
@@ -393,12 +369,6 @@ pgtls_write(PGconn *conn, const void *ptr, size_t len)
 	return n;
 }
 
-/*
- *	Get the TLS finish message sent during last handshake
- *
- * This information is useful for callers doing channel binding during
- * authentication.
- */
 char *
 pgtls_get_finished(PGconn *conn, size_t *len)
 {
@@ -419,13 +389,6 @@ pgtls_get_finished(PGconn *conn, size_t *len)
 	return result;
 }
 
-/*
- * Get the hash of the server certificate, for SCRAM channel binding type
- * tls-server-end-point.
- *
- * NULL is sent back to the caller in the event of an error, with an
- * error message for the caller to consume.
- */
 char *
 pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
 {
@@ -854,11 +817,6 @@ pq_lockingcallback(int mode, int n, const char *file, int line)
  * If the caller has told us (through PQinitOpenSSL) that he's taking care
  * of libcrypto, we expect that callbacks are already set, and won't try to
  * override it.
- *
- * The conn parameter is only used to be able to pass back an error
- * message - no connection-local setup is made here.
- *
- * Returns 0 if OK, -1 on failure (with a message in conn->errorMessage).
  */
 int
 pgtls_init(PGconn *conn)
@@ -1493,9 +1451,6 @@ open_client_SSL(PGconn *conn)
 	return PGRES_POLLING_OK;
 }
 
-/*
- *	Close SSL connection.
- */
 void
 pgtls_close(PGconn *conn)
 {

src/interfaces/libpq/libpq-int.h

@@ -661,19 +661,79 @@ extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
 				 bool got_epipe);
 #endif
 
+/* === SSL === */
+
 /*
- * The SSL implementation provides these functions (fe-secure-openssl.c)
+ * The SSL implementation provides these functions.
+ */
+
+/*
+ *	Implementation of PQinitSSL().
  */
 extern void pgtls_init_library(bool do_ssl, int do_crypto);
+
+/*
+ * Initialize SSL library.
+ *
+ * The conn parameter is only used to be able to pass back an error
+ * message - no connection-local setup is made here.
+ *
+ * Returns 0 if OK, -1 on failure (with a message in conn->errorMessage).
+ */
 extern int	pgtls_init(PGconn *conn);
+
+/*
+ *	Begin or continue negotiating a secure session.
+ */
 extern PostgresPollingStatusType pgtls_open_client(PGconn *conn);
+
+/*
+ *	Close SSL connection.
+ */
 extern void pgtls_close(PGconn *conn);
+
+/*
+ *	Read data from a secure connection.
+ *
+ * On failure, this function is responsible for putting a suitable message
+ * into conn->errorMessage.  The caller must still inspect errno, but only
+ * to determine whether to continue/retry after error.
+ */
 extern ssize_t pgtls_read(PGconn *conn, void *ptr, size_t len);
+
+/*
+ *	Is there unread data waiting in the SSL read buffer?
+ */
 extern bool pgtls_read_pending(PGconn *conn);
+
+/*
+ *	Write data to a secure connection.
+ *
+ * On failure, this function is responsible for putting a suitable message
+ * into conn->errorMessage.  The caller must still inspect errno, but only
+ * to determine whether to continue/retry after error.
+ */
 extern ssize_t pgtls_write(PGconn *conn, const void *ptr, size_t len);
+
+/*
+ * Get the TLS finish message sent during last handshake.
+ *
+ * This information is useful for callers doing channel binding during
+ * authentication.
+ */
 extern char *pgtls_get_finished(PGconn *conn, size_t *len);
+
+/*
+ * Get the hash of the server certificate, for SCRAM channel binding type
+ * tls-server-end-point.
+ *
+ * NULL is sent back to the caller in the event of an error, with an
+ * error message for the caller to consume.
+ */
 extern char *pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len);
 
+/* === miscellaneous macros === */
+
 /*
  * this is so that we can check if a connection is non-blocking internally
  * without the overhead of a function call