Thread

[PATCH 2/2] pgcrypto: use explicit_bzero() instead of px_memset(..., 0, ...)

Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> — 2026-04-09T10:35:13Z

px_memset() is only ever called with zero for the value, so use
explicit_bzero() instead and remove the function.
---
 contrib/pgcrypto/crypt-blowfish.c |  4 ++--
 contrib/pgcrypto/crypt-md5.c      |  4 ++--
 contrib/pgcrypto/crypt-sha.c      |  4 ++--
 contrib/pgcrypto/mbuf.c           | 12 ++++++------
 contrib/pgcrypto/pgp-cfb.c        |  2 +-
 contrib/pgcrypto/pgp-compress.c   |  4 ++--
 contrib/pgcrypto/pgp-decrypt.c    | 20 ++++++++++----------
 contrib/pgcrypto/pgp-encrypt.c    | 10 +++++-----
 contrib/pgcrypto/pgp-mpi.c        |  2 +-
 contrib/pgcrypto/pgp-pgsql.c      |  2 +-
 contrib/pgcrypto/pgp-pubenc.c     |  6 +++---
 contrib/pgcrypto/pgp-pubkey.c     |  8 ++++----
 contrib/pgcrypto/pgp-s2k.c        |  6 +++---
 contrib/pgcrypto/pgp.c            |  2 +-
 contrib/pgcrypto/px-crypt.c       |  2 +-
 contrib/pgcrypto/px-hmac.c        |  8 ++++----
 contrib/pgcrypto/px.c             |  9 +--------
 contrib/pgcrypto/px.h             |  2 --
 18 files changed, 49 insertions(+), 58 deletions(-)

diff --git a/contrib/pgcrypto/crypt-blowfish.c b/contrib/pgcrypto/crypt-blowfish.c
index 4d870fd65d7..b688d320ad8 100644
--- a/contrib/pgcrypto/crypt-blowfish.c
+++ b/contrib/pgcrypto/crypt-blowfish.c
@@ -621,7 +621,7 @@ _crypt_blowfish_rn(const char *key, const char *setting,
 	count = (BF_word) 1 << ((setting[4] - '0') * 10 + (setting[5] - '0'));
 	if (count < 16 || BF_decode(data.binary.salt, &setting[7], 16))
 	{
-		px_memset(data.binary.salt, 0, sizeof(data.binary.salt));
+		explicit_bzero(data.binary.salt, sizeof(data.binary.salt));
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("invalid salt")));
@@ -738,7 +738,7 @@ _crypt_blowfish_rn(const char *key, const char *setting,
 /* Overwrite the most obvious sensitive data we have on the stack. Note
  * that this does not guarantee there's no sensitive data left on the
  * stack and/or in registers; I'm not aware of portable code that does. */
-	px_memset(&data, 0, sizeof(data));
+	explicit_bzero(&data, sizeof(data));
 
 	return output;
 }
diff --git a/contrib/pgcrypto/crypt-md5.c b/contrib/pgcrypto/crypt-md5.c
index 33f93847a42..4e667063aef 100644
--- a/contrib/pgcrypto/crypt-md5.c
+++ b/contrib/pgcrypto/crypt-md5.c
@@ -95,7 +95,7 @@ px_crypt_md5(const char *pw, const char *salt, char *passwd, unsigned dstlen)
 		px_md_update(ctx, final, pl > MD5_SIZE ? MD5_SIZE : pl);
 
 	/* Don't leave anything around in vm they could use. */
-	px_memset(final, 0, sizeof final);
+	explicit_bzero(final, sizeof final);
 
 	/* Then something really weird... */
 	for (i = strlen(pw); i; i >>= 1)
@@ -160,7 +160,7 @@ px_crypt_md5(const char *pw, const char *salt, char *passwd, unsigned dstlen)
 	*p = '\0';
 
 	/* Don't leave anything around in vm they could use. */
-	px_memset(final, 0, sizeof final);
+	explicit_bzero(final, sizeof final);
 
 	px_md_free(ctx1);
 	px_md_free(ctx);
diff --git a/contrib/pgcrypto/crypt-sha.c b/contrib/pgcrypto/crypt-sha.c
index e8f32bc3896..91e31835f69 100644
--- a/contrib/pgcrypto/crypt-sha.c
+++ b/contrib/pgcrypto/crypt-sha.c
@@ -477,7 +477,7 @@ px_crypt_shacrypt(const char *pw, const char *salt, char *passwd, unsigned dstle
 	memcpy(cp, sha_buf_tmp, block);
 
 	/* Make sure we don't leave something important behind */
-	px_memset(&sha_buf_tmp, 0, sizeof sha_buf);
+	explicit_bzero(&sha_buf_tmp, sizeof sha_buf);
 
 	/*-
 	 * 21. Repeat a loop according to the number specified in the rounds=<N>
@@ -618,7 +618,7 @@ px_crypt_shacrypt(const char *pw, const char *salt, char *passwd, unsigned dstle
 	memcpy(passwd, out_buf->data, out_buf->len);
 
 	/* make sure nothing important is left behind */
-	px_memset(&sha_buf, 0, sizeof sha_buf);
+	explicit_bzero(&sha_buf, sizeof sha_buf);
 	destroyStringInfo(out_buf);
 	destroyStringInfo(decoded_salt);
 
diff --git a/contrib/pgcrypto/mbuf.c b/contrib/pgcrypto/mbuf.c
index 6a23ad99706..9f5824da557 100644
--- a/contrib/pgcrypto/mbuf.c
+++ b/contrib/pgcrypto/mbuf.c
@@ -63,7 +63,7 @@ mbuf_free(MBuf *mbuf)
 {
 	if (mbuf->own_data)
 	{
-		px_memset(mbuf->data, 0, mbuf->buf_end - mbuf->data);
+		explicit_bzero(mbuf->data, mbuf->buf_end - mbuf->data);
 		pfree(mbuf->data);
 	}
 	pfree(mbuf);
@@ -233,11 +233,11 @@ pullf_free(PullFilter *pf)
 
 	if (pf->buf)
 	{
-		px_memset(pf->buf, 0, pf->buflen);
+		explicit_bzero(pf->buf, pf->buflen);
 		pfree(pf->buf);
 	}
 
-	px_memset(pf, 0, sizeof(*pf));
+	explicit_bzero(pf, sizeof(*pf));
 	pfree(pf);
 }
 
@@ -282,7 +282,7 @@ pullf_read_max(PullFilter *pf, int len, uint8 **data_p, uint8 *tmpbuf)
 		if (res < 0)
 		{
 			/* so the caller must clear only on success */
-			px_memset(tmpbuf, 0, total);
+			explicit_bzero(tmpbuf, total);
 			return res;
 		}
 		if (res == 0)
@@ -399,11 +399,11 @@ pushf_free(PushFilter *mp)
 
 	if (mp->buf)
 	{
-		px_memset(mp->buf, 0, mp->block_size);
+		explicit_bzero(mp->buf, mp->block_size);
 		pfree(mp->buf);
 	}
 
-	px_memset(mp, 0, sizeof(*mp));
+	explicit_bzero(mp, sizeof(*mp));
 	pfree(mp);
 }
 
diff --git a/contrib/pgcrypto/pgp-cfb.c b/contrib/pgcrypto/pgp-cfb.c
index d8f1afc3aba..4cd5660cbcd 100644
--- a/contrib/pgcrypto/pgp-cfb.c
+++ b/contrib/pgcrypto/pgp-cfb.c
@@ -83,7 +83,7 @@ void
 pgp_cfb_free(PGP_CFB *ctx)
 {
 	px_cipher_free(ctx->ciph);
-	px_memset(ctx, 0, sizeof(*ctx));
+	explicit_bzero(ctx, sizeof(*ctx));
 	pfree(ctx);
 }
 
diff --git a/contrib/pgcrypto/pgp-compress.c b/contrib/pgcrypto/pgp-compress.c
index caa80ecdb45..5b827c96f2b 100644
--- a/contrib/pgcrypto/pgp-compress.c
+++ b/contrib/pgcrypto/pgp-compress.c
@@ -172,7 +172,7 @@ compress_free(void *priv)
 	struct ZipStat *st = priv;
 
 	deflateEnd(&st->stream);
-	px_memset(st, 0, sizeof(*st));
+	explicit_bzero(st, sizeof(*st));
 	pfree(st);
 }
 
@@ -315,7 +315,7 @@ decompress_free(void *priv)
 	struct DecomprData *dec = priv;
 
 	inflateEnd(&dec->stream);
-	px_memset(dec, 0, sizeof(*dec));
+	explicit_bzero(dec, sizeof(*dec));
 	pfree(dec);
 }
 
diff --git a/contrib/pgcrypto/pgp-decrypt.c b/contrib/pgcrypto/pgp-decrypt.c
index 52ca7840c6d..9696d609d03 100644
--- a/contrib/pgcrypto/pgp-decrypt.c
+++ b/contrib/pgcrypto/pgp-decrypt.c
@@ -210,7 +210,7 @@ pktreader_free(void *priv)
 {
 	struct PktData *pkt = priv;
 
-	px_memset(pkt, 0, sizeof(*pkt));
+	explicit_bzero(pkt, sizeof(*pkt));
 	pfree(pkt);
 }
 
@@ -260,7 +260,7 @@ prefix_init(void **priv_p, void *arg, PullFilter *src)
 	if (res != len + 2)
 	{
 		px_debug("prefix_init: short read");
-		px_memset(tmpbuf, 0, sizeof(tmpbuf));
+		explicit_bzero(tmpbuf, sizeof(tmpbuf));
 		return PXE_PGP_CORRUPT_DATA;
 	}
 
@@ -270,7 +270,7 @@ prefix_init(void **priv_p, void *arg, PullFilter *src)
 		/* report error in pgp_decrypt() */
 		ctx->corrupt_prefix = 1;
 	}
-	px_memset(tmpbuf, 0, sizeof(tmpbuf));
+	explicit_bzero(tmpbuf, sizeof(tmpbuf));
 	return 0;
 }
 
@@ -381,8 +381,8 @@ mdc_finish(PGP_Context *ctx, PullFilter *src, int len)
 	 */
 	px_md_finish(ctx->mdc_ctx, hash);
 	res = memcmp(hash, data, 20);
-	px_memset(hash, 0, 20);
-	px_memset(tmpbuf, 0, sizeof(tmpbuf));
+	explicit_bzero(hash, 20);
+	explicit_bzero(tmpbuf, sizeof(tmpbuf));
 	if (res != 0)
 	{
 		px_debug("mdc_finish: mdc failed");
@@ -475,7 +475,7 @@ mdcbuf_finish(struct MDCBufData *st)
 	px_md_update(st->ctx->mdc_ctx, st->mdc_buf, 2);
 	px_md_finish(st->ctx->mdc_ctx, hash);
 	res = memcmp(hash, st->mdc_buf + 2, 20);
-	px_memset(hash, 0, 20);
+	explicit_bzero(hash, 20);
 	if (res)
 	{
 		px_debug("mdcbuf_finish: MDC does not match");
@@ -575,7 +575,7 @@ mdcbuf_free(void *priv)
 
 	px_md_free(st->ctx->mdc_ctx);
 	st->ctx->mdc_ctx = NULL;
-	px_memset(st, 0, sizeof(*st));
+	explicit_bzero(st, sizeof(*st));
 	pfree(st);
 }
 
@@ -686,7 +686,7 @@ parse_symenc_sesskey(PGP_Context *ctx, PullFilter *src)
 		res = decrypt_key(ctx, p, res);
 	}
 
-	px_memset(tmpbuf, 0, sizeof(tmpbuf));
+	explicit_bzero(tmpbuf, sizeof(tmpbuf));
 	return res;
 }
 
@@ -736,7 +736,7 @@ copy_crlf(MBuf *dst, uint8 *data, int len, int *got_cr)
 		if (res < 0)
 			return res;
 	}
-	px_memset(tmpbuf, 0, sizeof(tmpbuf));
+	explicit_bzero(tmpbuf, sizeof(tmpbuf));
 	return 0;
 }
 
@@ -776,7 +776,7 @@ parse_literal_data(PGP_Context *ctx, MBuf *dst, PullFilter *pkt)
 		px_debug("parse_literal_data: unexpected eof");
 		return PXE_PGP_CORRUPT_DATA;
 	}
-	px_memset(tmpbuf, 0, 4);
+	explicit_bzero(tmpbuf, 4);
 
 	/*
 	 * If called from an SQL function that returns text, pgp_decrypt() rejects
diff --git a/contrib/pgcrypto/pgp-encrypt.c b/contrib/pgcrypto/pgp-encrypt.c
index 2c059804706..0a23fe59a5f 100644
--- a/contrib/pgcrypto/pgp-encrypt.c
+++ b/contrib/pgcrypto/pgp-encrypt.c
@@ -127,7 +127,7 @@ mdc_flush(PushFilter *dst, void *priv)
 	px_md_finish(md, pkt + 2);
 
 	res = pushf_write(dst, pkt, 2 + MDC_DIGEST_LEN);
-	px_memset(pkt, 0, 2 + MDC_DIGEST_LEN);
+	explicit_bzero(pkt, 2 + MDC_DIGEST_LEN);
 	return res;
 }
 
@@ -217,7 +217,7 @@ encrypt_free(void *priv)
 
 	if (st->ciph)
 		pgp_cfb_free(st->ciph);
-	px_memset(st, 0, sizeof(*st));
+	explicit_bzero(st, sizeof(*st));
 	pfree(st);
 }
 
@@ -299,7 +299,7 @@ pkt_stream_free(void *priv)
 {
 	struct PktStreamStat *st = priv;
 
-	px_memset(st, 0, sizeof(*st));
+	explicit_bzero(st, sizeof(*st));
 	pfree(st);
 }
 
@@ -489,7 +489,7 @@ write_prefix(PGP_Context *ctx, PushFilter *dst)
 	prefix[bs + 1] = prefix[bs - 1];
 
 	res = pushf_write(dst, prefix, bs + 2);
-	px_memset(prefix, 0, bs + 2);
+	explicit_bzero(prefix, bs + 2);
 	return res < 0 ? res : 0;
 }
 
@@ -551,7 +551,7 @@ write_symenc_sesskey(PGP_Context *ctx, PushFilter *dst)
 	if (res >= 0)
 		res = pushf_write(dst, pkt, pktlen);
 
-	px_memset(pkt, 0, pktlen);
+	explicit_bzero(pkt, pktlen);
 	return res;
 }
 
diff --git a/contrib/pgcrypto/pgp-mpi.c b/contrib/pgcrypto/pgp-mpi.c
index 03be27973be..95e4e9ba138 100644
--- a/contrib/pgcrypto/pgp-mpi.c
+++ b/contrib/pgcrypto/pgp-mpi.c
@@ -71,7 +71,7 @@ pgp_mpi_free(PGP_MPI *mpi)
 {
 	if (mpi == NULL)
 		return 0;
-	px_memset(mpi, 0, sizeof(*mpi) + mpi->bytes);
+	explicit_bzero(mpi, sizeof(*mpi) + mpi->bytes);
 	pfree(mpi);
 	return 0;
 }
diff --git a/contrib/pgcrypto/pgp-pgsql.c b/contrib/pgcrypto/pgp-pgsql.c
index d3e7895b0d9..c9d9e230a2e 100644
--- a/contrib/pgcrypto/pgp-pgsql.c
+++ b/contrib/pgcrypto/pgp-pgsql.c
@@ -96,7 +96,7 @@ convert_to_utf8(text *src)
 static void
 clear_and_pfree(text *p)
 {
-	px_memset(p, 0, VARSIZE_ANY(p));
+	explicit_bzero(p, VARSIZE_ANY(p));
 	pfree(p);
 }
 
diff --git a/contrib/pgcrypto/pgp-pubenc.c b/contrib/pgcrypto/pgp-pubenc.c
index c254a372750..aaae01da810 100644
--- a/contrib/pgcrypto/pgp-pubenc.c
+++ b/contrib/pgcrypto/pgp-pubenc.c
@@ -63,7 +63,7 @@ pad_eme_pkcs1_v15(uint8 *data, int data_len, int res_len, uint8 **res_p)
 		{
 			if (!pg_strong_random(p, 1))
 			{
-				px_memset(buf, 0, res_len);
+				explicit_bzero(buf, res_len);
 				pfree(buf);
 				return PXE_NO_RANDOM;
 			}
@@ -117,10 +117,10 @@ create_secmsg(PGP_Context *ctx, PGP_MPI **msg_p, int full_bytes)
 
 	if (padded)
 	{
-		px_memset(padded, 0, full_bytes);
+		explicit_bzero(padded, full_bytes);
 		pfree(padded);
 	}
-	px_memset(secmsg, 0, klen + 3);
+	explicit_bzero(secmsg, klen + 3);
 	pfree(secmsg);
 
 	if (res >= 0)
diff --git a/contrib/pgcrypto/pgp-pubkey.c b/contrib/pgcrypto/pgp-pubkey.c
index 6f118865917..f866eb19eeb 100644
--- a/contrib/pgcrypto/pgp-pubkey.c
+++ b/contrib/pgcrypto/pgp-pubkey.c
@@ -76,7 +76,7 @@ pgp_key_free(PGP_PubKey *pk)
 			pgp_mpi_free(pk->sec.dsa.x);
 			break;
 	}
-	px_memset(pk, 0, sizeof(*pk));
+	explicit_bzero(pk, sizeof(*pk));
 	pfree(pk);
 }
 
@@ -149,7 +149,7 @@ calc_key_id(PGP_PubKey *pk)
 	px_md_free(md);
 
 	memcpy(pk->key_id, hash + 12, 8);
-	px_memset(hash, 0, 20);
+	explicit_bzero(hash, 20);
 
 	return 0;
 }
@@ -290,8 +290,8 @@ check_key_sha1(PullFilter *src, PGP_PubKey *pk)
 		res = PXE_PGP_KEYPKT_CORRUPT;
 	}
 err:
-	px_memset(got_sha1, 0, 20);
-	px_memset(my_sha1, 0, 20);
+	explicit_bzero(got_sha1, 20);
+	explicit_bzero(my_sha1, 20);
 	return res;
 }
 
diff --git a/contrib/pgcrypto/pgp-s2k.c b/contrib/pgcrypto/pgp-s2k.c
index 81ca1f094a1..ea7a99d1eec 100644
--- a/contrib/pgcrypto/pgp-s2k.c
+++ b/contrib/pgcrypto/pgp-s2k.c
@@ -74,7 +74,7 @@ calc_s2k_simple(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
 			remain = 0;
 		}
 	}
-	px_memset(buf, 0, sizeof(buf));
+	explicit_bzero(buf, sizeof(buf));
 	return 0;
 }
 
@@ -118,7 +118,7 @@ calc_s2k_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key, unsigned key_len)
 			remain = 0;
 		}
 	}
-	px_memset(buf, 0, sizeof(buf));
+	explicit_bzero(buf, sizeof(buf));
 	return 0;
 }
 
@@ -188,7 +188,7 @@ calc_s2k_iter_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
 			remain = 0;
 		}
 	}
-	px_memset(buf, 0, sizeof(buf));
+	explicit_bzero(buf, sizeof(buf));
 	return 0;
 }
 
diff --git a/contrib/pgcrypto/pgp.c b/contrib/pgcrypto/pgp.c
index 8a6a6c2adf1..4c17282c573 100644
--- a/contrib/pgcrypto/pgp.c
+++ b/contrib/pgcrypto/pgp.c
@@ -214,7 +214,7 @@ pgp_free(PGP_Context *ctx)
 {
 	if (ctx->pub_key)
 		pgp_key_free(ctx->pub_key);
-	px_memset(ctx, 0, sizeof *ctx);
+	explicit_bzero(ctx, sizeof *ctx);
 	pfree(ctx);
 	return 0;
 }
diff --git a/contrib/pgcrypto/px-crypt.c b/contrib/pgcrypto/px-crypt.c
index d7729eec9bc..03eca3d6ae0 100644
--- a/contrib/pgcrypto/px-crypt.c
+++ b/contrib/pgcrypto/px-crypt.c
@@ -181,7 +181,7 @@ px_gen_salt(const char *salt_type, char *buf, int rounds)
 		return PXE_NO_RANDOM;
 
 	p = g->gen(rounds, rbuf, g->input_len, buf, PX_MAX_SALT_LEN);
-	px_memset(rbuf, 0, sizeof(rbuf));
+	explicit_bzero(rbuf, sizeof(rbuf));
 
 	if (p == NULL)
 		return PXE_BAD_SALT_ROUNDS;
diff --git a/contrib/pgcrypto/px-hmac.c b/contrib/pgcrypto/px-hmac.c
index 68e5cff6d6a..24511aa6ad6 100644
--- a/contrib/pgcrypto/px-hmac.c
+++ b/contrib/pgcrypto/px-hmac.c
@@ -74,7 +74,7 @@ hmac_init(PX_HMAC *h, const uint8 *key, unsigned klen)
 		h->p.opad[i] = keybuf[i] ^ HMAC_OPAD;
 	}
 
-	px_memset(keybuf, 0, bs);
+	explicit_bzero(keybuf, bs);
 	pfree(keybuf);
 
 	px_md_update(md, h->p.ipad, bs);
@@ -116,7 +116,7 @@ hmac_finish(PX_HMAC *h, uint8 *dst)
 	px_md_update(md, buf, hlen);
 	px_md_finish(md, dst);
 
-	px_memset(buf, 0, hlen);
+	explicit_bzero(buf, hlen);
 	pfree(buf);
 }
 
@@ -128,8 +128,8 @@ hmac_free(PX_HMAC *h)
 	bs = px_md_block_size(h->md);
 	px_md_free(h->md);
 
-	px_memset(h->p.ipad, 0, bs);
-	px_memset(h->p.opad, 0, bs);
+	explicit_bzero(h->p.ipad, bs);
+	explicit_bzero(h->p.opad, bs);
 	pfree(h->p.ipad);
 	pfree(h->p.opad);
 	pfree(h);
diff --git a/contrib/pgcrypto/px.c b/contrib/pgcrypto/px.c
index f08bc498ac8..e8f96232de8 100644
--- a/contrib/pgcrypto/px.c
+++ b/contrib/pgcrypto/px.c
@@ -119,13 +119,6 @@ px_strerror(int err)
 	return "Bad error code";
 }
 
-/* memset that must not be optimized away */
-void
-px_memset(void *ptr, int c, size_t len)
-{
-	memset(ptr, c, len);
-}
-
 const char *
 px_resolve_alias(const PX_Alias *list, const char *name)
 {
@@ -234,7 +227,7 @@ combo_free(PX_Combo *cx)
 {
 	if (cx->cipher)
 		px_cipher_free(cx->cipher);
-	px_memset(cx, 0, sizeof(*cx));
+	explicit_bzero(cx, sizeof(*cx));
 	pfree(cx);
 }
 
diff --git a/contrib/pgcrypto/px.h b/contrib/pgcrypto/px.h
index a09533a3582..bb5ee899d60 100644
--- a/contrib/pgcrypto/px.h
+++ b/contrib/pgcrypto/px.h
@@ -188,8 +188,6 @@ const char *px_resolve_alias(const PX_Alias *list, const char *name);
 
 void		px_set_debug_handler(void (*handler) (const char *));
 
-void		px_memset(void *ptr, int c, size_t len);
-
 bool		CheckFIPSMode(void);
 void		CheckBuiltinCryptoMode(void);
 
-- 
2.53.0


--=-=-=--