diff --git a/drivers/auth/mbedtls/mbedtls_crypto.c b/drivers/auth/mbedtls/mbedtls_crypto.c
index 1a96e8f8d0cb54f72ceb63bc311402867a5269d1..11d3ede45abe0211d7279c3079fe9335edb55a6f 100644
--- a/drivers/auth/mbedtls/mbedtls_crypto.c
+++ b/drivers/auth/mbedtls/mbedtls_crypto.c
@@ -217,7 +217,7 @@ static int verify_hash(void *data_ptr, unsigned int data_len,
 	}
 
 	/* Compare values */
-	rc = memcmp(data_hash, hash, mbedtls_md_get_size(md_info));
+	rc = timingsafe_bcmp(data_hash, hash, mbedtls_md_get_size(md_info));
 	if (rc != 0) {
 		return CRYPTO_ERR_HASH;
 	}
diff --git a/drivers/auth/mbedtls/mbedtls_x509_parser.c b/drivers/auth/mbedtls/mbedtls_x509_parser.c
index 73da9d1e7c4d8a264073a8305e12a37e97f410de..f9485de3d205d305a3bc01805ea4a672103c545b 100644
--- a/drivers/auth/mbedtls/mbedtls_x509_parser.c
+++ b/drivers/auth/mbedtls/mbedtls_x509_parser.c
@@ -392,7 +392,7 @@ static int cert_parse(void *img, unsigned int img_len)
 	if (sig_alg1.len != sig_alg2.len) {
 		return IMG_PARSER_ERR_FORMAT;
 	}
-	if (0 != memcmp(sig_alg1.p, sig_alg2.p, sig_alg1.len)) {
+	if (0 != timingsafe_bcmp(sig_alg1.p, sig_alg2.p, sig_alg1.len)) {
 		return IMG_PARSER_ERR_FORMAT;
 	}
 	memcpy(&sig_alg, &sig_alg1, sizeof(sig_alg));
diff --git a/include/lib/stdlib/string.h b/include/lib/stdlib/string.h
index 9beeb448a6b77adc99a89375875498640cf4b0e8..902d9c13039e54779eec6ea6b19cd8e2d10d1408 100644
--- a/include/lib/stdlib/string.h
+++ b/include/lib/stdlib/string.h
@@ -61,6 +61,7 @@ size_t	 strlen(const char *) __pure;
 int	 strncmp(const char *, const char *, size_t) __pure;
 size_t	 strnlen(const char *, size_t) __pure;
 int	 strcasecmp(const char *, const char *);
+int	 timingsafe_bcmp(const void *, const void *, size_t);
 
 __END_DECLS
 
diff --git a/lib/stdlib/stdlib.mk b/lib/stdlib/stdlib.mk
index 4ff405fb6b098682467b5a6e26843dcafd2d71c9..5332717446daed61142f0639cdfd35f0744bfa35 100644
--- a/lib/stdlib/stdlib.mk
+++ b/lib/stdlib/stdlib.mk
@@ -42,7 +42,8 @@ STDLIB_SRCS	:=	$(addprefix lib/stdlib/,	\
 			strlen.c			\
 			strncmp.c			\
 			strnlen.c			\
-			subr_prf.c)
+			subr_prf.c			\
+			timingsafe_bcmp.c)
 
 INCLUDES	+=	-Iinclude/lib/stdlib		\
 			-Iinclude/lib/stdlib/sys
diff --git a/lib/stdlib/timingsafe_bcmp.c b/lib/stdlib/timingsafe_bcmp.c
new file mode 100644
index 0000000000000000000000000000000000000000..d098158059f343930610b54cd014552fe7679fc6
--- /dev/null
+++ b/lib/stdlib/timingsafe_bcmp.c
@@ -0,0 +1,36 @@
+/*	$OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther Exp $	*/
+/*
+ * Copyright (c) 2010 Damien Miller.  All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <string.h>
+
+int __timingsafe_bcmp(const void *, const void *, size_t);
+
+int
+__timingsafe_bcmp(const void *b1, const void *b2, size_t n)
+{
+	const unsigned char *p1 = b1, *p2 = b2;
+	int ret = 0;
+
+	for (; n > 0; n--)
+		ret |= *p1++ ^ *p2++;
+	return (ret != 0);
+}
+
+__weak_reference(__timingsafe_bcmp, timingsafe_bcmp);