Index: head/lib/libmd/md4c.c
===================================================================
--- head/lib/libmd/md4c.c
+++ head/lib/libmd/md4c.c
@@ -183,7 +183,7 @@
 
   /* Zeroize sensitive information.
    */
-  memset ((POINTER)context, 0, sizeof (*context));
+  explicit_bzero(context, sizeof(*context));
 }
 
 /* MD4 basic transformation. Transforms state based on block.
Index: head/lib/libmd/md5c.c
===================================================================
--- head/lib/libmd/md5c.c
+++ head/lib/libmd/md5c.c
@@ -220,7 +220,7 @@
 	Encode (digest, context->state, 16);
 
 	/* Zeroize sensitive information. */
-	memset ((void *)context, 0, sizeof (*context));
+	explicit_bzero(context, sizeof(*context));
 }
 
 /* MD5 basic transformation. Transforms state based on block. */
Index: head/lib/libmd/mdX.3
===================================================================
--- head/lib/libmd/mdX.3
+++ head/lib/libmd/mdX.3
@@ -8,7 +8,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 26, 2016
+.Dd July 20, 2018
 .Dt MDX 3
 .Os
 .Sh NAME
@@ -78,7 +78,9 @@
 run over the data with
 .Fn MDXUpdate ,
 and finally extract the result using
-.Fn MDXFinal .
+.Fn MDXFinal ,
+which will also erase the
+.Vt MDX_CTX .
 .Pp
 The
 .Fn MDXPad
Index: head/lib/libmd/ripemd.3
===================================================================
--- head/lib/libmd/ripemd.3
+++ head/lib/libmd/ripemd.3
@@ -9,7 +9,7 @@
 .\" 	From: Id: mdX.3,v 1.14 1999/02/11 20:31:49 wollman Exp
 .\" $FreeBSD$
 .\"
-.Dd April 26, 2016
+.Dd July 20, 2018
 .Dt RIPEMD 3
 .Os
 .Sh NAME
@@ -65,7 +65,9 @@
 run over the data with
 .Fn RIPEMD160_Update ,
 and finally extract the result using
-.Fn RIPEMD160_Final .
+.Fn RIPEMD160_Final ,
+which will also erase the
+.Vt RIPEMD160_CTX .
 .Pp
 The
 .Fn RIPEMD160_End
Index: head/lib/libmd/rmd160c.c
===================================================================
--- head/lib/libmd/rmd160c.c
+++ head/lib/libmd/rmd160c.c
@@ -523,10 +523,8 @@
 	l=c->D; l2c(l,cp);
 	l=c->E; l2c(l,cp);
 
-	/* clear stuff, ripemd160_block may be leaving some stuff on the stack
-	 * but I'm not worried :-) */
-	c->num=0;
-/*	memset((char *)&c,0,sizeof(c));*/
+	/* Clear the context state */
+	explicit_bzero(&c, sizeof(c));
 	}
 
 #ifdef undef
Index: head/lib/libmd/sha.3
===================================================================
--- head/lib/libmd/sha.3
+++ head/lib/libmd/sha.3
@@ -9,7 +9,7 @@
 .\" 	From: Id: mdX.3,v 1.14 1999/02/11 20:31:49 wollman Exp
 .\" $FreeBSD$
 .\"
-.Dd April 26, 2016
+.Dd July 20, 2018
 .Dt SHA 3
 .Os
 .Sh NAME
@@ -100,7 +100,9 @@
 run over the data with
 .Fn SHA1_Update ,
 and finally extract the result using
-.Fn SHA1_Final .
+.Fn SHA1_Final ,
+which will also erase the
+.Vt SHA_CTX .
 .Pp
 .Fn SHA1_End
 is a wrapper for
Index: head/lib/libmd/sha0c.c
===================================================================
--- head/lib/libmd/sha0c.c
+++ head/lib/libmd/sha0c.c
@@ -446,9 +446,7 @@
 	l=c->h3; nl2c(l,cp);
 	l=c->h4; nl2c(l,cp);
 
-	/* clear stuff, sha_block may be leaving some stuff on the stack
-	 * but I'm not worried :-) */
-	c->num=0;
-/*	memset((char *)&c,0,sizeof(c));*/
+	/* Clear the context state */
+	explicit_bzero(&c, sizeof(c));
 	}
 
Index: head/lib/libmd/sha1c.c
===================================================================
--- head/lib/libmd/sha1c.c
+++ head/lib/libmd/sha1c.c
@@ -482,10 +482,8 @@
 	l=c->h3; nl2c(l,cp);
 	l=c->h4; nl2c(l,cp);
 
-	/* clear stuff, sha1_block may be leaving some stuff on the stack
-	 * but I'm not worried :-) */
-	c->num=0;
-/*	memset((char *)&c,0,sizeof(c));*/
+	/* Clear the context state */
+	explicit_bzero(&c, sizeof(c));
 	}
 
 #ifdef WEAK_REFS
Index: head/lib/libmd/sha256.3
===================================================================
--- head/lib/libmd/sha256.3
+++ head/lib/libmd/sha256.3
@@ -9,7 +9,7 @@
 .\" 	From: Id: mdX.3,v 1.14 1999/02/11 20:31:49 wollman Exp
 .\" $FreeBSD$
 .\"
-.Dd July 9, 2018
+.Dd July 20, 2018
 .Dt SHA256 3
 .Os
 .Sh NAME
@@ -88,7 +88,9 @@
 run over the data with
 .Fn SHA256_Update ,
 and finally extract the result using
-.Fn SHA256_Final .
+.Fn SHA256_Final ,
+which will also erase the
+.Vt SHA256_CTX .
 .Pp
 .Fn SHA256_End
 is a wrapper for
Index: head/lib/libmd/sha512.3
===================================================================
--- head/lib/libmd/sha512.3
+++ head/lib/libmd/sha512.3
@@ -9,7 +9,7 @@
 .\" 	From: Id: mdX.3,v 1.14 1999/02/11 20:31:49 wollman Exp
 .\" $FreeBSD$
 .\"
-.Dd April 22, 2016
+.Dd July 20, 2018
 .Dt SHA512 3
 .Os
 .Sh NAME
@@ -110,7 +110,9 @@
 run over the data with
 .Fn SHA512_Update ,
 and finally extract the result using
-.Fn SHA512_Final .
+.Fn SHA512_Final ,
+which will also erase the
+.Vt SHA512_CTX .
 .Pp
 .Fn SHA512_End
 is a wrapper for
Index: head/lib/libmd/skein.3
===================================================================
--- head/lib/libmd/skein.3
+++ head/lib/libmd/skein.3
@@ -124,7 +124,9 @@
 run over the data with
 .Fn SKEIN256_Update ,
 and finally extract the result using
-.Fn SKEIN256_Final .
+.Fn SKEIN256_Final ,
+which will also erase the
+.Vt SKEIN256_CTX .
 .Pp
 .Fn SKEIN256_End
 is a wrapper for
Index: head/sys/crypto/sha2/sha256c.c
===================================================================
--- head/sys/crypto/sha2/sha256c.c
+++ head/sys/crypto/sha2/sha256c.c
@@ -298,7 +298,7 @@
 	be32enc_vect(digest, ctx->state, SHA256_DIGEST_LENGTH);
 
 	/* Clear the context state */
-	memset(ctx, 0, sizeof(*ctx));
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 /*** SHA-224: *********************************************************/
Index: head/sys/crypto/sha2/sha512c.c
===================================================================
--- head/sys/crypto/sha2/sha512c.c
+++ head/sys/crypto/sha2/sha512c.c
@@ -331,7 +331,7 @@
 	be64enc_vect(digest, ctx->state, SHA512_DIGEST_LENGTH);
 
 	/* Clear the context state */
-	memset(ctx, 0, sizeof(*ctx));
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 /*** SHA-512t: *********************************************************/
@@ -374,7 +374,7 @@
 	be64enc_vect(digest, ctx->state, SHA512_224_DIGEST_LENGTH);
 
 	/* Clear the context state */
-	memset(ctx, 0, sizeof(*ctx));
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 void
@@ -413,7 +413,7 @@
 	be64enc_vect(digest, ctx->state, SHA512_256_DIGEST_LENGTH);
 
 	/* Clear the context state */
-	memset(ctx, 0, sizeof(*ctx));
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 /*** SHA-384: *********************************************************/
@@ -463,7 +463,7 @@
 	be64enc_vect(digest, ctx->state, SHA384_DIGEST_LENGTH);
 
 	/* Clear the context state */
-	memset(ctx, 0, sizeof(*ctx));
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 #ifdef WEAK_REFS
Index: head/sys/crypto/skein/skein.c
===================================================================
--- head/sys/crypto/skein/skein.c
+++ head/sys/crypto/skein/skein.c
@@ -812,6 +812,7 @@
 {
 
 	Skein_256_Final(ctx, digest);
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 void
@@ -819,6 +820,7 @@
 {
 
 	Skein_512_Final(ctx, digest);
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 void
@@ -826,6 +828,7 @@
 {
 
 	Skein1024_Final(ctx, digest);
+	explicit_bzero(ctx, sizeof(*ctx));
 }
 
 #ifdef WEAK_REFS