diff --git a/contrib/oid2name/oid2name.c b/contrib/oid2name/oid2name.c
index 91b7958c48e..5a884e29049 100644
--- a/contrib/oid2name/oid2name.c
+++ b/contrib/oid2name/oid2name.c
@@ -12,6 +12,7 @@
 #include "catalog/pg_class_d.h"
 #include "common/connect.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "getopt_long.h"
 #include "libpq-fe.h"
 #include "pg_getopt.h"
@@ -293,8 +294,7 @@ PGconn *
 sql_conn(struct options *my_opts)
 {
 	PGconn	   *conn;
-	bool		have_password = false;
-	char		password[100];
+	char	   *password = NULL;
 	bool		new_pass;
 	PGresult   *res;
 
@@ -316,7 +316,7 @@ sql_conn(struct options *my_opts)
 		keywords[2] = "user";
 		values[2] = my_opts->username;
 		keywords[3] = "password";
-		values[3] = have_password ? password : NULL;
+		values[3] = password;
 		keywords[4] = "dbname";
 		values[4] = my_opts->dbname;
 		keywords[5] = "fallback_application_name";
@@ -336,11 +336,10 @@ sql_conn(struct options *my_opts)
 
 		if (PQstatus(conn) == CONNECTION_BAD &&
 			PQconnectionNeedsPassword(conn) &&
-			!have_password)
+			!password)
 		{
 			PQfinish(conn);
-			simple_prompt("Password: ", password, sizeof(password), false);
-			have_password = true;
+			password = simple_prompt("Password: ", false);
 			new_pass = true;
 		}
 	} while (new_pass);
diff --git a/contrib/vacuumlo/vacuumlo.c b/contrib/vacuumlo/vacuumlo.c
index e4019fafaa9..532cc596c41 100644
--- a/contrib/vacuumlo/vacuumlo.c
+++ b/contrib/vacuumlo/vacuumlo.c
@@ -24,6 +24,7 @@
 #include "catalog/pg_class_d.h"
 #include "common/connect.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "getopt_long.h"
 #include "libpq-fe.h"
 #include "pg_getopt.h"
@@ -69,15 +70,11 @@ vacuumlo(const char *database, const struct _param *param)
 	int			i;
 	bool		new_pass;
 	bool		success = true;
-	static bool have_password = false;
-	static char password[100];
+	static char *password = NULL;
 
 	/* Note: password can be carried over from a previous call */
-	if (param->pg_prompt == TRI_YES && !have_password)
-	{
-		simple_prompt("Password: ", password, sizeof(password), false);
-		have_password = true;
-	}
+	if (param->pg_prompt == TRI_YES && !password)
+		password = simple_prompt("Password: ", false);
 
 	/*
 	 * Start the connection.  Loop until we have a password if requested by
@@ -97,7 +94,7 @@ vacuumlo(const char *database, const struct _param *param)
 		keywords[2] = "user";
 		values[2] = param->pg_user;
 		keywords[3] = "password";
-		values[3] = have_password ? password : NULL;
+		values[3] = password;
 		keywords[4] = "dbname";
 		values[4] = database;
 		keywords[5] = "fallback_application_name";
@@ -115,12 +112,11 @@ vacuumlo(const char *database, const struct _param *param)
 
 		if (PQstatus(conn) == CONNECTION_BAD &&
 			PQconnectionNeedsPassword(conn) &&
-			!have_password &&
+			!password &&
 			param->pg_prompt != TRI_NO)
 		{
 			PQfinish(conn);
-			simple_prompt("Password: ", password, sizeof(password), false);
-			have_password = true;
+			password = simple_prompt("Password: ", false);
 			new_pass = true;
 		}
 	} while (new_pass);
diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
index 02b6c3f127c..36565df4fc1 100644
--- a/src/backend/libpq/auth.c
+++ b/src/backend/libpq/auth.c
@@ -698,7 +698,7 @@ recv_password_packet(Port *port)
 	}
 
 	initStringInfo(&buf);
-	if (pq_getmessage(&buf, 1000))	/* receive password */
+	if (pq_getmessage(&buf, 0)) /* receive password */
 	{
 		/* EOF - pq_getmessage already logged a suitable message */
 		pfree(buf.data);
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 786672b1b65..73ddf408654 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -67,6 +67,7 @@
 #include "common/file_utils.h"
 #include "common/logging.h"
 #include "common/restricted_token.h"
+#include "common/string.h"
 #include "common/username.h"
 #include "fe_utils/string_utils.h"
 #include "getaddrinfo.h"
@@ -1481,23 +1482,25 @@ setup_auth(FILE *cmdfd)
 static void
 get_su_pwd(void)
 {
-	char		pwd1[100];
-	char		pwd2[100];
+	char	   *pwd1;
 
 	if (pwprompt)
 	{
 		/*
 		 * Read password from terminal
 		 */
+		char	   *pwd2;
+
 		printf("\n");
 		fflush(stdout);
-		simple_prompt("Enter new superuser password: ", pwd1, sizeof(pwd1), false);
-		simple_prompt("Enter it again: ", pwd2, sizeof(pwd2), false);
+		pwd1 = simple_prompt("Enter new superuser password: ", false);
+		pwd2 = simple_prompt("Enter it again: ", false);
 		if (strcmp(pwd1, pwd2) != 0)
 		{
 			fprintf(stderr, _("Passwords didn't match.\n"));
 			exit(1);
 		}
+		free(pwd2);
 	}
 	else
 	{
@@ -1510,7 +1513,6 @@ get_su_pwd(void)
 		 * for now.
 		 */
 		FILE	   *pwf = fopen(pwfilename, "r");
-		int			i;
 
 		if (!pwf)
 		{
@@ -1518,7 +1520,8 @@ get_su_pwd(void)
 						 pwfilename);
 			exit(1);
 		}
-		if (!fgets(pwd1, sizeof(pwd1), pwf))
+		pwd1 = pg_get_line(pwf);
+		if (!pwd1)
 		{
 			if (ferror(pwf))
 				pg_log_error("could not read password from file \"%s\": %m",
@@ -1530,12 +1533,10 @@ get_su_pwd(void)
 		}
 		fclose(pwf);
 
-		i = strlen(pwd1);
-		while (i > 0 && (pwd1[i - 1] == '\r' || pwd1[i - 1] == '\n'))
-			pwd1[--i] = '\0';
+		(void) pg_strip_crlf(pwd1);
 	}
 
-	superuser_password = pg_strdup(pwd1);
+	superuser_password = pwd1;
 }
 
 /*
diff --git a/src/bin/pg_basebackup/streamutil.c b/src/bin/pg_basebackup/streamutil.c
index c08003e7f2c..be653ebb2d9 100644
--- a/src/bin/pg_basebackup/streamutil.c
+++ b/src/bin/pg_basebackup/streamutil.c
@@ -22,6 +22,7 @@
 #include "common/fe_memutils.h"
 #include "common/file_perm.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "datatype/timestamp.h"
 #include "port/pg_bswap.h"
 #include "pqexpbuffer.h"
@@ -49,8 +50,7 @@ char	   *dbuser = NULL;
 char	   *dbport = NULL;
 char	   *dbname = NULL;
 int			dbgetpassword = 0;	/* 0=auto, -1=never, 1=always */
-static bool have_password = false;
-static char password[100];
+static char *password = NULL;
 PGconn	   *conn = NULL;
 
 /*
@@ -150,20 +150,21 @@ GetConnection(void)
 	}
 
 	/* If -W was given, force prompt for password, but only the first time */
-	need_password = (dbgetpassword == 1 && !have_password);
+	need_password = (dbgetpassword == 1 && !password);
 
 	do
 	{
 		/* Get a new password if appropriate */
 		if (need_password)
 		{
-			simple_prompt("Password: ", password, sizeof(password), false);
-			have_password = true;
+			if (password)
+				free(password);
+			password = simple_prompt("Password: ", false);
 			need_password = false;
 		}
 
 		/* Use (or reuse, on a subsequent connection) password if we have it */
-		if (have_password)
+		if (password)
 		{
 			keywords[i] = "password";
 			values[i] = password;
diff --git a/src/bin/pg_dump/pg_backup_db.c b/src/bin/pg_dump/pg_backup_db.c
index 94af11b80a3..12899e26e29 100644
--- a/src/bin/pg_dump/pg_backup_db.c
+++ b/src/bin/pg_dump/pg_backup_db.c
@@ -18,6 +18,7 @@
 #endif
 
 #include "common/connect.h"
+#include "common/string.h"
 #include "dumputils.h"
 #include "fe_utils/string_utils.h"
 #include "parallel.h"
@@ -122,7 +123,6 @@ _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 	const char *newdb;
 	const char *newuser;
 	char	   *password;
-	char		passbuf[100];
 	bool		new_pass;
 
 	if (!reqdb)
@@ -141,10 +141,7 @@ _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 	password = AH->savedPassword;
 
 	if (AH->promptPassword == TRI_YES && password == NULL)
-	{
-		simple_prompt("Password: ", passbuf, sizeof(passbuf), false);
-		password = passbuf;
-	}
+		password = simple_prompt("Password: ", false);
 
 	initPQExpBuffer(&connstr);
 	appendPQExpBufferStr(&connstr, "dbname=");
@@ -191,8 +188,9 @@ _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 
 			if (AH->promptPassword != TRI_NO)
 			{
-				simple_prompt("Password: ", passbuf, sizeof(passbuf), false);
-				password = passbuf;
+				if (password && password != AH->savedPassword)
+					free(password);
+				password = simple_prompt("Password: ", false);
 			}
 			else
 				fatal("connection needs password");
@@ -201,6 +199,9 @@ _connectDB(ArchiveHandle *AH, const char *reqdb, const char *requser)
 		}
 	} while (new_pass);
 
+	if (password && password != AH->savedPassword)
+		free(password);
+
 	/*
 	 * We want to remember connection's actual password, whether or not we got
 	 * it by prompting.  So we don't just store the password variable.
@@ -242,7 +243,6 @@ ConnectDatabase(Archive *AHX,
 {
 	ArchiveHandle *AH = (ArchiveHandle *) AHX;
 	char	   *password;
-	char		passbuf[100];
 	bool		new_pass;
 
 	if (AH->connection)
@@ -251,10 +251,8 @@ ConnectDatabase(Archive *AHX,
 	password = AH->savedPassword;
 
 	if (prompt_password == TRI_YES && password == NULL)
-	{
-		simple_prompt("Password: ", passbuf, sizeof(passbuf), false);
-		password = passbuf;
-	}
+		password = simple_prompt("Password: ", false);
+
 	AH->promptPassword = prompt_password;
 
 	/*
@@ -293,8 +291,7 @@ ConnectDatabase(Archive *AHX,
 			prompt_password != TRI_NO)
 		{
 			PQfinish(AH->connection);
-			simple_prompt("Password: ", passbuf, sizeof(passbuf), false);
-			password = passbuf;
+			password = simple_prompt("Password: ", false);
 			new_pass = true;
 		}
 	} while (new_pass);
@@ -309,6 +306,9 @@ ConnectDatabase(Archive *AHX,
 	PQclear(ExecuteSqlQueryForSingleRow((Archive *) AH,
 										ALWAYS_SECURE_SEARCH_PATH_SQL));
 
+	if (password && password != AH->savedPassword)
+		free(password);
+
 	/*
 	 * We want to remember connection's actual password, whether or not we got
 	 * it by prompting.  So we don't just store the password variable.
diff --git a/src/bin/pg_dump/pg_dumpall.c b/src/bin/pg_dump/pg_dumpall.c
index 2c82b39af0d..97d2b8dac1c 100644
--- a/src/bin/pg_dump/pg_dumpall.c
+++ b/src/bin/pg_dump/pg_dumpall.c
@@ -21,6 +21,7 @@
 #include "common/connect.h"
 #include "common/file_utils.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "dumputils.h"
 #include "fe_utils/string_utils.h"
 #include "getopt_long.h"
@@ -1643,14 +1644,10 @@ connectDatabase(const char *dbname, const char *connection_string,
 	const char **keywords = NULL;
 	const char **values = NULL;
 	PQconninfoOption *conn_opts = NULL;
-	static bool have_password = false;
-	static char password[100];
+	static char *password = NULL;
 
-	if (prompt_password == TRI_YES && !have_password)
-	{
-		simple_prompt("Password: ", password, sizeof(password), false);
-		have_password = true;
-	}
+	if (prompt_password == TRI_YES && !password)
+		password = simple_prompt("Password: ", false);
 
 	/*
 	 * Start the connection.  Loop until we have a password if requested by
@@ -1730,7 +1727,7 @@ connectDatabase(const char *dbname, const char *connection_string,
 			values[i] = pguser;
 			i++;
 		}
-		if (have_password)
+		if (password)
 		{
 			keywords[i] = "password";
 			values[i] = password;
@@ -1757,12 +1754,11 @@ connectDatabase(const char *dbname, const char *connection_string,
 
 		if (PQstatus(conn) == CONNECTION_BAD &&
 			PQconnectionNeedsPassword(conn) &&
-			!have_password &&
+			!password &&
 			prompt_password != TRI_NO)
 		{
 			PQfinish(conn);
-			simple_prompt("Password: ", password, sizeof(password), false);
-			have_password = true;
+			password = simple_prompt("Password: ", false);
 			new_pass = true;
 		}
 	} while (new_pass);
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 08a5947a9e6..332eabf6379 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -59,6 +59,7 @@
 
 #include "common/int.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "fe_utils/cancel.h"
 #include "fe_utils/conditional.h"
 #include "getopt_long.h"
@@ -1174,8 +1175,7 @@ doConnect(void)
 {
 	PGconn	   *conn;
 	bool		new_pass;
-	static bool have_password = false;
-	static char password[100];
+	static char *password = NULL;
 
 	/*
 	 * Start the connection.  Loop until we have a password if requested by
@@ -1195,7 +1195,7 @@ doConnect(void)
 		keywords[2] = "user";
 		values[2] = login;
 		keywords[3] = "password";
-		values[3] = have_password ? password : NULL;
+		values[3] = password;
 		keywords[4] = "dbname";
 		values[4] = dbName;
 		keywords[5] = "fallback_application_name";
@@ -1215,11 +1215,10 @@ doConnect(void)
 
 		if (PQstatus(conn) == CONNECTION_BAD &&
 			PQconnectionNeedsPassword(conn) &&
-			!have_password)
+			!password)
 		{
 			PQfinish(conn);
-			simple_prompt("Password: ", password, sizeof(password), false);
-			have_password = true;
+			password = simple_prompt("Password: ", false);
 			new_pass = true;
 		}
 	} while (new_pass);
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 9902a4a2ba8..d4aa0976b5b 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -26,6 +26,7 @@
 #include "command.h"
 #include "common.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "copy.h"
 #include "crosstabview.h"
 #include "describe.h"
@@ -1964,11 +1965,11 @@ exec_command_password(PsqlScanState scan_state, bool active_branch)
 	{
 		char	   *opt0 = psql_scan_slash_option(scan_state,
 												  OT_SQLID, NULL, true);
-		char		pw1[100];
-		char		pw2[100];
+		char	   *pw1;
+		char	   *pw2;
 
-		simple_prompt("Enter new password: ", pw1, sizeof(pw1), false);
-		simple_prompt("Enter it again: ", pw2, sizeof(pw2), false);
+		pw1 = simple_prompt("Enter new password: ", false);
+		pw2 = simple_prompt("Enter it again: ", false);
 
 		if (strcmp(pw1, pw2) != 0)
 		{
@@ -2013,6 +2014,8 @@ exec_command_password(PsqlScanState scan_state, bool active_branch)
 
 		if (opt0)
 			free(opt0);
+		free(pw1);
+		free(pw2);
 	}
 	else
 		ignore_slash_options(scan_state);
@@ -2058,8 +2061,7 @@ exec_command_prompt(PsqlScanState scan_state, bool active_branch,
 
 			if (!pset.inputfile)
 			{
-				result = (char *) pg_malloc(4096);
-				simple_prompt(prompt_text, result, 4096, true);
+				result = simple_prompt(prompt_text, true);
 			}
 			else
 			{
@@ -2982,19 +2984,19 @@ copy_previous_query(PQExpBuffer query_buf, PQExpBuffer previous_buf)
 static char *
 prompt_for_password(const char *username)
 {
-	char		buf[100];
+	char	   *result;
 
 	if (username == NULL || username[0] == '\0')
-		simple_prompt("Password: ", buf, sizeof(buf), false);
+		result = simple_prompt("Password: ", false);
 	else
 	{
 		char	   *prompt_text;
 
 		prompt_text = psprintf(_("Password for user %s: "), username);
-		simple_prompt(prompt_text, buf, sizeof(buf), false);
+		result = simple_prompt(prompt_text, false);
 		free(prompt_text);
 	}
-	return pg_strdup(buf);
+	return result;
 }
 
 static bool
diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 3302bd4dd32..8232a0143bc 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -17,6 +17,7 @@
 #include "command.h"
 #include "common.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "describe.h"
 #include "fe_utils/print.h"
 #include "getopt_long.h"
@@ -119,8 +120,7 @@ main(int argc, char *argv[])
 {
 	struct adhoc_opts options;
 	int			successResult;
-	bool		have_password = false;
-	char		password[100];
+	char	   *password = NULL;
 	bool		new_pass;
 
 	pg_logging_init(argv[0]);
@@ -233,8 +233,7 @@ main(int argc, char *argv[])
 		 * offer a potentially wrong one.  Typical uses of this option are
 		 * noninteractive anyway.
 		 */
-		simple_prompt("Password: ", password, sizeof(password), false);
-		have_password = true;
+		password = simple_prompt("Password: ", false);
 	}
 
 	/* loop until we have a password if requested by backend */
@@ -251,7 +250,7 @@ main(int argc, char *argv[])
 		keywords[2] = "user";
 		values[2] = options.username;
 		keywords[3] = "password";
-		values[3] = have_password ? password : NULL;
+		values[3] = password;
 		keywords[4] = "dbname"; /* see do_connect() */
 		values[4] = (options.list_dbs && options.dbname == NULL) ?
 			"postgres" : options.dbname;
@@ -269,7 +268,7 @@ main(int argc, char *argv[])
 
 		if (PQstatus(pset.db) == CONNECTION_BAD &&
 			PQconnectionNeedsPassword(pset.db) &&
-			!have_password &&
+			!password &&
 			pset.getPassword != TRI_NO)
 		{
 			/*
@@ -287,9 +286,8 @@ main(int argc, char *argv[])
 				password_prompt = pg_strdup(_("Password: "));
 			PQfinish(pset.db);
 
-			simple_prompt(password_prompt, password, sizeof(password), false);
+			password = simple_prompt(password_prompt, false);
 			free(password_prompt);
-			have_password = true;
 			new_pass = true;
 		}
 	} while (new_pass);
diff --git a/src/bin/scripts/common.c b/src/bin/scripts/common.c
index 420d0d11a5a..e987eef2343 100644
--- a/src/bin/scripts/common.c
+++ b/src/bin/scripts/common.c
@@ -20,6 +20,7 @@
 #include "common.h"
 #include "common/connect.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "fe_utils/cancel.h"
 #include "fe_utils/string_utils.h"
 
@@ -68,18 +69,17 @@ connectDatabase(const char *dbname, const char *pghost,
 {
 	PGconn	   *conn;
 	bool		new_pass;
-	static bool have_password = false;
-	static char password[100];
+	static char *password = NULL;
 
-	if (!allow_password_reuse)
-		have_password = false;
-
-	if (!have_password && prompt_password == TRI_YES)
+	if (!allow_password_reuse && password)
 	{
-		simple_prompt("Password: ", password, sizeof(password), false);
-		have_password = true;
+		free(password);
+		password = NULL;
 	}
 
+	if (!password && prompt_password == TRI_YES)
+		password = simple_prompt("Password: ", false);
+
 	/*
 	 * Start the connection.  Loop until we have a password if requested by
 	 * backend.
@@ -96,7 +96,7 @@ connectDatabase(const char *dbname, const char *pghost,
 		keywords[2] = "user";
 		values[2] = pguser;
 		keywords[3] = "password";
-		values[3] = have_password ? password : NULL;
+		values[3] = password;
 		keywords[4] = "dbname";
 		values[4] = dbname;
 		keywords[5] = "fallback_application_name";
@@ -122,8 +122,9 @@ connectDatabase(const char *dbname, const char *pghost,
 			prompt_password != TRI_NO)
 		{
 			PQfinish(conn);
-			simple_prompt("Password: ", password, sizeof(password), false);
-			have_password = true;
+			if (password)
+				free(password);
+			password = simple_prompt("Password: ", false);
 			new_pass = true;
 		}
 	} while (new_pass);
@@ -444,14 +445,21 @@ yesno_prompt(const char *question)
 
 	for (;;)
 	{
-		char		resp[10];
+		char	   *resp;
 
-		simple_prompt(prompt, resp, sizeof(resp), true);
+		resp = simple_prompt(prompt, true);
 
 		if (strcmp(resp, _(PG_YESLETTER)) == 0)
+		{
+			free(resp);
 			return true;
+		}
 		if (strcmp(resp, _(PG_NOLETTER)) == 0)
+		{
+			free(resp);
 			return false;
+		}
+		free(resp);
 
 		printf(_("Please answer \"%s\" or \"%s\".\n"),
 			   _(PG_YESLETTER), _(PG_NOLETTER));
diff --git a/src/bin/scripts/createuser.c b/src/bin/scripts/createuser.c
index 9ced079ac75..6179199563c 100644
--- a/src/bin/scripts/createuser.c
+++ b/src/bin/scripts/createuser.c
@@ -13,6 +13,7 @@
 #include "postgres_fe.h"
 #include "common.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "fe_utils/simple_list.h"
 #include "fe_utils/string_utils.h"
 
@@ -63,8 +64,6 @@ main(int argc, char *argv[])
 	int			conn_limit = -2;	/* less than minimum valid value */
 	bool		pwprompt = false;
 	char	   *newpassword = NULL;
-	char		newuser_buf[128];
-	char		newpassword_buf[100];
 
 	/* Tri-valued variables.  */
 	enum trivalue createdb = TRI_DEFAULT,
@@ -191,9 +190,7 @@ main(int argc, char *argv[])
 	{
 		if (interactive)
 		{
-			simple_prompt("Enter name of role to add: ",
-						  newuser_buf, sizeof(newuser_buf), true);
-			newuser = newuser_buf;
+			newuser = simple_prompt("Enter name of role to add: ", true);
 		}
 		else
 		{
@@ -206,17 +203,16 @@ main(int argc, char *argv[])
 
 	if (pwprompt)
 	{
-		char		pw2[100];
+		char	   *pw2;
 
-		simple_prompt("Enter password for new role: ",
-					  newpassword_buf, sizeof(newpassword_buf), false);
-		simple_prompt("Enter it again: ", pw2, sizeof(pw2), false);
-		if (strcmp(newpassword_buf, pw2) != 0)
+		newpassword = simple_prompt("Enter password for new role: ", false);
+		pw2 = simple_prompt("Enter it again: ", false);
+		if (strcmp(newpassword, pw2) != 0)
 		{
 			fprintf(stderr, _("Passwords didn't match.\n"));
 			exit(1);
 		}
-		newpassword = newpassword_buf;
+		free(pw2);
 	}
 
 	if (superuser == 0)
diff --git a/src/bin/scripts/dropuser.c b/src/bin/scripts/dropuser.c
index fee270d4f6d..f7ddd1402db 100644
--- a/src/bin/scripts/dropuser.c
+++ b/src/bin/scripts/dropuser.c
@@ -13,6 +13,7 @@
 #include "postgres_fe.h"
 #include "common.h"
 #include "common/logging.h"
+#include "common/string.h"
 #include "fe_utils/string_utils.h"
 
 
@@ -47,7 +48,6 @@ main(int argc, char *argv[])
 	enum trivalue prompt_password = TRI_DEFAULT;
 	bool		echo = false;
 	bool		interactive = false;
-	char		dropuser_buf[128];
 
 	PQExpBufferData sql;
 
@@ -112,9 +112,7 @@ main(int argc, char *argv[])
 	{
 		if (interactive)
 		{
-			simple_prompt("Enter name of role to drop: ",
-						  dropuser_buf, sizeof(dropuser_buf), true);
-			dropuser = dropuser_buf;
+			dropuser = simple_prompt("Enter name of role to drop: ", true);
 		}
 		else
 		{
diff --git a/src/common/Makefile b/src/common/Makefile
index 16619e4ba88..ad8fd9e41c4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -63,6 +63,7 @@ OBJS_COMMON = \
 	kwlookup.o \
 	link-canary.o \
 	md5.o \
+	pg_get_line.o \
 	pg_lzcompress.o \
 	pgfnames.o \
 	psprintf.o \
@@ -92,7 +93,8 @@ OBJS_FRONTEND = \
 	fe_memutils.o \
 	file_utils.o \
 	logging.o \
-	restricted_token.o
+	restricted_token.o \
+	sprompt.o
 
 # foo.o, foo_shlib.o, and foo_srv.o are all built from foo.c
 OBJS_SHLIB = $(OBJS_FRONTEND:%.o=%_shlib.o)
diff --git a/src/common/pg_get_line.c b/src/common/pg_get_line.c
new file mode 100644
index 00000000000..38433675d43
--- /dev/null
+++ b/src/common/pg_get_line.c
@@ -0,0 +1,85 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_get_line.c
+ *	  fgets() with an expansible result buffer
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/pg_get_line.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/string.h"
+#include "lib/stringinfo.h"
+
+
+/*
+ * pg_get_line()
+ *
+ * This is meant to be equivalent to fgets(), except that instead of
+ * reading into a caller-supplied, fixed-size buffer, it reads into
+ * a palloc'd (in frontend, really malloc'd) string, which is resized
+ * as needed to handle indefinitely long input lines.  The caller is
+ * responsible for pfree'ing the result string when appropriate.
+ *
+ * As with fgets(), returns NULL if there is a read error or if no
+ * characters are available before EOF.  The caller can distinguish
+ * these cases by checking ferror(stream).
+ *
+ * Since this is meant to be equivalent to fgets(), the trailing newline
+ * (if any) is not stripped.  Callers may wish to apply pg_strip_crlf().
+ *
+ * Note that while I/O errors are reflected back to the caller to be
+ * dealt with, an OOM condition for the palloc'd buffer will not be;
+ * there'll be an ereport(ERROR) or exit(1) inside stringinfo.c.
+ */
+char *
+pg_get_line(FILE *stream)
+{
+	StringInfoData buf;
+
+	initStringInfo(&buf);
+
+	/* Read some data, appending it to whatever we already have */
+	while (fgets(buf.data + buf.len, buf.maxlen - buf.len, stream) != NULL)
+	{
+		buf.len += strlen(buf.data + buf.len);
+
+		/* Done if we have collected a newline */
+		if (buf.len > 0 && buf.data[buf.len - 1] == '\n')
+			return buf.data;
+
+		/* Make some more room in the buffer, and loop to read more data */
+		enlargeStringInfo(&buf, 128);
+	}
+
+	/* Did fgets() fail because of an I/O error? */
+	if (ferror(stream))
+	{
+		/* ensure that free() doesn't mess up errno */
+		int			save_errno = errno;
+
+		pfree(buf.data);
+		errno = save_errno;
+		return NULL;
+	}
+
+	/* If we read no data before reaching EOF, we should return NULL */
+	if (buf.len == 0)
+	{
+		pfree(buf.data);
+		return NULL;
+	}
+
+	/* No newline at EOF ... so return what we have */
+	return buf.data;
+}
diff --git a/src/common/saslprep.c b/src/common/saslprep.c
index 2dedf6b0fb6..d60452f75f2 100644
--- a/src/common/saslprep.c
+++ b/src/common/saslprep.c
@@ -29,12 +29,6 @@
 #include "common/unicode_norm.h"
 #include "mb/pg_wchar.h"
 
-/*
- * Limit on how large password's we will try to process.  A password
- * larger than this will be treated the same as out-of-memory.
- */
-#define MAX_PASSWORD_LENGTH		1024
-
 /*
  * In backend, we will use palloc/pfree.  In frontend, use malloc, and
  * return SASLPREP_OOM on out-of-memory.
@@ -1078,18 +1072,6 @@ pg_saslprep(const char *input, char **output)
 	/* Ensure we return *output as NULL on failure */
 	*output = NULL;
 
-	/* Check that the password isn't stupendously long */
-	if (strlen(input) > MAX_PASSWORD_LENGTH)
-	{
-#ifndef FRONTEND
-		ereport(ERROR,
-				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
-				 errmsg("password too long")));
-#else
-		return SASLPREP_OOM;
-#endif
-	}
-
 	/*
 	 * Quick check if the input is pure ASCII.  An ASCII string requires no
 	 * further processing.
diff --git a/src/port/sprompt.c b/src/common/sprompt.c
similarity index 81%
rename from src/port/sprompt.c
rename to src/common/sprompt.c
index 6d8a8b2609f..0ec75da5bfe 100644
--- a/src/port/sprompt.c
+++ b/src/common/sprompt.c
@@ -8,12 +8,15 @@
  *
  *
  * IDENTIFICATION
- *	  src/port/sprompt.c
+ *	  src/common/sprompt.c
  *
  *-------------------------------------------------------------------------
  */
 #include "c.h"
 
+#include "common/fe_memutils.h"
+#include "common/string.h"
+
 #ifdef HAVE_TERMIOS_H
 #include <termios.h>
 #endif
@@ -26,20 +29,17 @@
  * passwords interactively.  Reads from /dev/tty or stdin/stderr.
  *
  * prompt:		The prompt to print, or NULL if none (automatically localized)
- * destination: buffer in which to store result
- * destlen:		allocated length of destination
  * echo:		Set to false if you want to hide what is entered (for passwords)
  *
- * The input (without trailing newline) is returned in the destination buffer,
- * with a '\0' appended.
+ * The input (without trailing newline) is returned as a malloc'd string.
+ * Caller is responsible for freeing it when done.
  */
-void
-simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)
+char *
+simple_prompt(const char *prompt, bool echo)
 {
-	int			length;
+	char	   *result;
 	FILE	   *termin,
 			   *termout;
-
 #if defined(HAVE_TERMIOS_H)
 	struct termios t_orig,
 				t;
@@ -126,29 +126,14 @@ simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)
 		fflush(termout);
 	}
 
-	if (fgets(destination, destlen, termin) == NULL)
-		destination[0] = '\0';
+	result = pg_get_line(termin);
 
-	length = strlen(destination);
-	if (length > 0 && destination[length - 1] != '\n')
-	{
-		/* eat rest of the line */
-		char		buf[128];
-		int			buflen;
-
-		do
-		{
-			if (fgets(buf, sizeof(buf), termin) == NULL)
-				break;
-			buflen = strlen(buf);
-		} while (buflen > 0 && buf[buflen - 1] != '\n');
-	}
+	/* If we failed to read anything, just return an empty string */
+	if (result == NULL)
+		result = pg_strdup("");
 
 	/* strip trailing newline, including \r in case we're on Windows */
-	while (length > 0 &&
-		   (destination[length - 1] == '\n' ||
-			destination[length - 1] == '\r'))
-		destination[--length] = '\0';
+	(void) pg_strip_crlf(result);
 
 	if (!echo)
 	{
@@ -169,4 +154,6 @@ simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)
 		fclose(termin);
 		fclose(termout);
 	}
+
+	return result;
 }
diff --git a/src/include/common/string.h b/src/include/common/string.h
index 5113c04434c..18aa1dc5aa5 100644
--- a/src/include/common/string.h
+++ b/src/include/common/string.h
@@ -10,10 +10,17 @@
 #ifndef COMMON_STRING_H
 #define COMMON_STRING_H
 
+/* functions in src/common/string.c */
 extern bool pg_str_endswith(const char *str, const char *end);
 extern int	strtoint(const char *pg_restrict str, char **pg_restrict endptr,
 					 int base);
 extern void pg_clean_ascii(char *str);
 extern int	pg_strip_crlf(char *str);
 
+/* functions in src/common/pg_get_line.c */
+extern char *pg_get_line(FILE *stream);
+
+/* functions in src/common/sprompt.c */
+extern char *simple_prompt(const char *prompt, bool echo);
+
 #endif							/* COMMON_STRING_H */
diff --git a/src/include/port.h b/src/include/port.h
index 271ff0d00bc..84bf2c363f5 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -213,10 +213,6 @@ extern char *pg_strerror_r(int errnum, char *buf, size_t buflen);
 /* Wrap strsignal(), or provide our own version if necessary */
 extern const char *pg_strsignal(int signum);
 
-/* Portable prompt handling */
-extern void simple_prompt(const char *prompt, char *destination, size_t destlen,
-						  bool echo);
-
 extern int	pclose_check(FILE *stream);
 
 /* Global variable holding time zone information. */
diff --git a/src/port/Makefile b/src/port/Makefile
index 8defa1257bb..e41b005c4f1 100644
--- a/src/port/Makefile
+++ b/src/port/Makefile
@@ -35,6 +35,8 @@ include $(top_builddir)/src/Makefile.global
 override CPPFLAGS := -I$(top_builddir)/src/port -DFRONTEND $(CPPFLAGS)
 LIBS += $(PTHREAD_LIBS)
 
+# If you add objects here, see also src/tools/msvc/Mkvcbuild.pm
+
 OBJS = \
 	$(LIBOBJS) \
 	$(PG_CRC32C_OBJS) \
@@ -55,7 +57,6 @@ OBJS = \
 	qsort_arg.o \
 	quotes.o \
 	snprintf.o \
-	sprompt.o \
 	strerror.o \
 	tar.o \
 	thread.o
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 20da7985c10..536df5a92e7 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -102,7 +102,7 @@ sub mkvcbuild
 	  pread.c pwrite.c pg_bitutils.c
 	  pg_strong_random.c pgcheckdir.c pgmkdirp.c pgsleep.c pgstrcasecmp.c
 	  pqsignal.c mkdtemp.c qsort.c qsort_arg.c quotes.c system.c
-	  sprompt.c strerror.c tar.c thread.c
+	  strerror.c tar.c thread.c
 	  win32env.c win32error.c win32security.c win32setlocale.c);
 
 	push(@pgportfiles, 'strtof.c') if ($vsVersion < '14.00');
@@ -123,7 +123,7 @@ sub mkvcbuild
 	  config_info.c controldata_utils.c d2s.c encnames.c exec.c
 	  f2s.c file_perm.c hashfn.c ip.c jsonapi.c
 	  keywords.c kwlookup.c link-canary.c md5.c
-	  pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
+	  pg_get_line.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
 	  saslprep.c scram-common.c string.c stringinfo.c unicode_norm.c username.c
 	  wait_error.c wchar.c);
 
@@ -139,7 +139,7 @@ sub mkvcbuild
 
 	our @pgcommonfrontendfiles = (
 		@pgcommonallfiles, qw(fe_memutils.c file_utils.c
-		  logging.c restricted_token.c));
+		  logging.c restricted_token.c sprompt.c));
 
 	our @pgcommonbkndfiles = @pgcommonallfiles;