On 2019-06-23 21:55, Peter Eisentraut wrote:
> On 2019-06-21 15:25, Tom Lane wrote:
>> Peter Eisentraut <peter.eisentr...@2ndquadrant.com> writes:
>>> +#ifndef HAVE_EXPLICIT_BZERO
>>> +#define explicit_bzero(b, len) bzero(b, len)
>>> +#endif
>>
>> This presumes that every platform has bzero, which is unsafe (POSIX
>> doesn't specify it) and is an assumption we kicked to the curb a dozen
>> years ago (067a5cdb3). Please use memset() for the substitute instead.
>
> OK, done.
and with patch attached
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
From e193fbcf04833de829069b5e737a27b83c667703 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Sun, 23 Jun 2019 21:53:14 +0200
Subject: [PATCH v2] Use explicit_bzero
---
configure | 2 +-
configure.in | 1 +
src/backend/libpq/be-secure-common.c | 1 +
src/include/pg_config.h.in | 3 +++
src/include/port.h | 4 ++++
src/interfaces/libpq/fe-connect.c | 8 ++++++++
6 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/configure b/configure
index 8d47071e4a..c88153fff5 100755
--- a/configure
+++ b/configure
@@ -15176,7 +15176,7 @@ fi
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
-for ac_func in cbrt clock_gettime copyfile fdatasync getifaddrs getpeerucred
getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat
pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open
strchrnul strsignal symlink sync_file_range uselocale utime utimes wcstombs_l
+for ac_func in cbrt clock_gettime copyfile explicit_bzero fdatasync getifaddrs
getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate ppoll pstat
pthread_is_threaded_np readlink setproctitle setproctitle_fast setsid shm_open
strchrnul strsignal symlink sync_file_range uselocale utime utimes wcstombs_l
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index 74938d4190..7e96d1d419 100644
--- a/configure.in
+++ b/configure.in
@@ -1615,6 +1615,7 @@ AC_CHECK_FUNCS(m4_normalize([
cbrt
clock_gettime
copyfile
+ explicit_bzero
fdatasync
getifaddrs
getpeerucred
diff --git a/src/backend/libpq/be-secure-common.c
b/src/backend/libpq/be-secure-common.c
index 877226d377..4c1c6cb3c4 100644
--- a/src/backend/libpq/be-secure-common.c
+++ b/src/backend/libpq/be-secure-common.c
@@ -118,6 +118,7 @@ run_ssl_passphrase_command(const char *prompt, bool
is_server_start, char *buf,
buf[--len] = '\0';
error:
+ explicit_bzero(buf, size);
pfree(command.data);
return len;
}
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 6cd4cfed0a..0062a4a426 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -201,6 +201,9 @@
/* Define to 1 if you have the <editline/readline.h> header file. */
#undef HAVE_EDITLINE_READLINE_H
+/* Define to 1 if you have the `explicit_bzero' function. */
+#undef HAVE_EXPLICIT_BZERO
+
/* Define to 1 if you have the `fdatasync' function. */
#undef HAVE_FDATASYNC
diff --git a/src/include/port.h b/src/include/port.h
index b5c03d912b..7c8b5138ba 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -381,6 +381,10 @@ extern int isinf(double x);
#endif /* __clang__ &&
!__cplusplus */
#endif /* !HAVE_ISINF */
+#ifndef HAVE_EXPLICIT_BZERO
+#define explicit_bzero(b, len) memset(b, 0, len)
+#endif
+
#ifndef HAVE_STRTOF
extern float strtof(const char *nptr, char **endptr);
#endif
diff --git a/src/interfaces/libpq/fe-connect.c
b/src/interfaces/libpq/fe-connect.c
index c800d7921e..887b8f6775 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3884,7 +3884,10 @@ freePGconn(PGconn *conn)
if (conn->connhost[i].port != NULL)
free(conn->connhost[i].port);
if (conn->connhost[i].password != NULL)
+ {
+ explicit_bzero(conn->connhost[i].password,
strlen(conn->connhost[i].password));
free(conn->connhost[i].password);
+ }
}
free(conn->connhost);
}
@@ -3918,7 +3921,10 @@ freePGconn(PGconn *conn)
if (conn->pguser)
free(conn->pguser);
if (conn->pgpass)
+ {
+ explicit_bzero(conn->pgpass, strlen(conn->pgpass));
free(conn->pgpass);
+ }
if (conn->pgpassfile)
free(conn->pgpassfile);
if (conn->keepalives)
@@ -6935,6 +6941,7 @@ passwordFromFile(const char *hostname, const char *port,
const char *dbname,
if (!ret)
{
/* Out of memory. XXX: an error message would be nice.
*/
+ explicit_bzero(buf, sizeof(buf));
return NULL;
}
@@ -6951,6 +6958,7 @@ passwordFromFile(const char *hostname, const char *port,
const char *dbname,
}
fclose(fp);
+ explicit_bzero(buf, sizeof(buf));
return NULL;
#undef LINELEN
base-commit: 1323bfce55109dd54ee164828aab7983d3020a25
--
2.22.0
