pgcrypto: fix memset() calls that might be optimized away

Specifically, on-stack memset() might be removed, so:

	* Replace memset() with px_memset()
	* Add px_memset to copy_crlf()
	* Add px_memset to pgp-s2k.c

Patch by Marko Kreen

Report by PVS-Studio

Backpatch through 8.4.

1 files changed, 3 insertions, 0 deletions

diff --git a/contrib/pgcrypto/pgp-s2k.c b/contrib/pgcrypto/pgp-s2k.c
index 349234e243c..40c05a1a96e 100644
--- a/contrib/pgcrypto/pgp-s2k.c
+++ b/contrib/pgcrypto/pgp-s2k.c
@@ -75,6 +75,7 @@ calc_s2k_simple(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
 			remain = 0;
 		}
 	}
+	px_memset(buf, 0, sizeof(buf));
 	return 0;
 }
 
@@ -118,6 +119,7 @@ calc_s2k_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key, unsigned key_len)
 			remain = 0;
 		}
 	}
+	px_memset(buf, 0, sizeof(buf));
 	return 0;
 }
 
@@ -189,6 +191,7 @@ calc_s2k_iter_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
 			remain = 0;
 		}
 	}
+	px_memset(buf, 0, sizeof(buf));
 	return 0;
 }