diff --git a/Changes.rst b/Changes.rst
index db9b18b9..a6090cf5 100644
--- a/Changes.rst
+++ b/Changes.rst
@@ -321,6 +321,18 @@ Maintainer-visible changes
   i386/i686 builds on RHEL5.
 
 
+Version 2.4.5
+=============
+
+New features
+------------
+- The new option ``--tls-cert-profile`` can be used to restrict the set of
+  allowed crypto algorithms in TLS certificates in mbed TLS builds.  The
+  default profile is 'legacy' for now, which allows SHA1+, RSA-1024+ and any
+  elliptic curve certificates.  The default will be changed to the 'preferred'
+  profile in the future, which requires SHA2+, RSA-2048+ and any curve.
+
+
 Version 2.4.3
 =============
 
diff --git a/doc/openvpn.8 b/doc/openvpn.8
index a4189ac2..549d96cb 100644
--- a/doc/openvpn.8
+++ b/doc/openvpn.8
@@ -4917,6 +4917,37 @@ when using mbed TLS or
 OpenSSL.
 .\"*********************************************************
 .TP
+.B \-\-tls\-cert\-profile profile
+Set the allowed cryptographic algorithms for certificates according to
+.B profile\fN.
+
+The following profiles are supported:
+
+.B legacy
+(default): SHA1 and newer, RSA 2048-bit+, any elliptic curve.
+
+.B preferred
+: SHA2 and newer, RSA 2048-bit+, any elliptic curve.
+
+.B suiteb
+: SHA256/SHA384, ECDSA with P-256 or P-384.
+
+This option is only fully supported for mbed TLS builds.  OpenSSL builds use
+the following approximation:
+
+.B legacy
+(default): sets "security level 1"
+
+.B preferred
+: sets "security level 2"
+
+.B suiteb
+: sets "security level 3" and \-\-tls\-cipher "SUITEB128".
+
+OpenVPN will migrate to 'preferred' as default in the future.  Please ensure
+that your keys already comply.
+.\"*********************************************************
+.TP
 .B \-\-tls\-timeout n
 Packet retransmit timeout on TLS control channel
 if no acknowledgment from remote within
diff --git a/src/openvpn/init.c b/src/openvpn/init.c
index 1ed2c55e..cccc63b2 100644
--- a/src/openvpn/init.c
+++ b/src/openvpn/init.c
@@ -1016,7 +1016,8 @@ print_openssl_info(const struct options *options)
         }
         if (options->show_tls_ciphers)
         {
-            show_available_tls_ciphers(options->cipher_list);
+            show_available_tls_ciphers(options->cipher_list,
+                                       options->tls_cert_profile);
         }
         if (options->show_curves)
         {
diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 49ed004b..e91ab742 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -599,6 +599,8 @@ static const char usage_message[] =
 #endif
     "--tls-cipher l  : A list l of allowable TLS ciphers separated by : (optional).\n"
     "                : Use --show-tls to see a list of supported TLS ciphers.\n"
+    "--tls-cert-profile p : Set the allowed certificate crypto algorithm profile\n"
+    "                  (default=%s).\n"
     "--tls-timeout n : Packet retransmit timeout on TLS control channel\n"
     "                  if no ACK from remote within n seconds (default=%d).\n"
     "--reneg-bytes n : Renegotiate data chan. key after n bytes sent and recvd.\n"
@@ -872,6 +874,7 @@ init_options(struct options *o, const bool init_gc)
     o->renegotiate_seconds = 3600;
     o->handshake_window = 60;
     o->transition_window = 3600;
+    o->tls_cert_profile = "legacy";
     o->ecdh_curve = NULL;
 #ifdef ENABLE_X509ALTUSERNAME
     o->x509_username_field = X509_USERNAME_FIELD_DEFAULT;
@@ -1750,6 +1753,7 @@ show_settings(const struct options *o)
     SHOW_STR(cryptoapi_cert);
 #endif
     SHOW_STR(cipher_list);
+    SHOW_STR(tls_cert_profile);
     SHOW_STR(tls_verify);
     SHOW_STR(tls_export_cert);
     SHOW_INT(verify_x509_type);
@@ -2729,6 +2733,7 @@ options_postprocess_verify_ce(const struct options *options, const struct connec
         MUST_BE_UNDEF(pkcs12_file);
 #endif
         MUST_BE_UNDEF(cipher_list);
+        MUST_BE_UNDEF(tls_cert_profile);
         MUST_BE_UNDEF(tls_verify);
         MUST_BE_UNDEF(tls_export_cert);
         MUST_BE_UNDEF(verify_x509_name);
@@ -4086,7 +4091,7 @@ usage(void)
             o.verbosity,
             o.authname, o.ciphername,
             o.replay_window, o.replay_time,
-            o.tls_timeout, o.renegotiate_seconds,
+            o.tls_cert_profile, o.tls_timeout, o.renegotiate_seconds,
             o.handshake_window, o.transition_window);
 #else  /* ifdef ENABLE_CRYPTO */
     fprintf(fp, usage_message,
@@ -7831,6 +7836,11 @@ add_option(struct options *options,
         VERIFY_PERMISSION(OPT_P_GENERAL);
         options->cipher_list = p[1];
     }
+    else if (streq(p[0], "tls-cert-profile") && p[1] && !p[2])
+    {
+        VERIFY_PERMISSION(OPT_P_GENERAL);
+        options->tls_cert_profile = p[1];
+    }
     else if (streq(p[0], "crl-verify") && p[1] && ((p[2] && streq(p[2], "dir"))
                                                    || (p[2] && streq(p[1], INLINE_FILE_TAG) ) || !p[2]) && !p[3])
     {
diff --git a/src/openvpn/options.h b/src/openvpn/options.h
index 496c1143..85ff200b 100644
--- a/src/openvpn/options.h
+++ b/src/openvpn/options.h
@@ -502,6 +502,7 @@ struct options
     const char *priv_key_file;
     const char *pkcs12_file;
     const char *cipher_list;
+    const char *tls_cert_profile;
     const char *ecdh_curve;
     const char *tls_verify;
     int verify_x509_type;
diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
index cb94229a..359ef635 100644
--- a/src/openvpn/ssl.c
+++ b/src/openvpn/ssl.c
@@ -616,6 +616,9 @@ init_ssl(const struct options *options, struct tls_root_ctx *new_ctx)
         tls_ctx_client_new(new_ctx);
     }
 
+    /* Restrict allowed certificate crypto algorithms */
+    tls_ctx_set_cert_profile(new_ctx, options->tls_cert_profile);
+
     /* Allowable ciphers */
     /* Since @SECLEVEL also influces loading of certificates, set the
      * cipher restrictions before loading certificates */
diff --git a/src/openvpn/ssl_backend.h b/src/openvpn/ssl_backend.h
index aba5a4de..f588110c 100644
--- a/src/openvpn/ssl_backend.h
+++ b/src/openvpn/ssl_backend.h
@@ -176,6 +176,16 @@ void tls_ctx_set_options(struct tls_root_ctx *ctx, unsigned int ssl_flags);
  */
 void tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers);
 
+/**
+ * Set the TLS certificate profile.  The profile defines which crypto
+ * algorithms may be used in the supplied certificate.
+ *
+ * @param ctx           TLS context to restrict, must be valid.
+ * @param profile       The profile name ('preferred', 'legacy' or 'suiteb').
+ *                      Defaults to 'preferred' if NULL.
+ */
+void tls_ctx_set_cert_profile(struct tls_root_ctx *ctx, const char *profile);
+
 /**
  * Check our certificate notBefore and notAfter fields, and warn if the cert is
  * either not yet valid or has expired.  Note that this is a non-fatal error,
@@ -505,9 +515,12 @@ void print_details(struct key_state_ssl *ks_ssl, const char *prefix);
  * Show the TLS ciphers that are available for us to use in the OpenSSL
  * library.
  *
- * @param               - list of allowed TLS cipher, or NULL.
+ * @param cipher_list       list of allowed TLS cipher, or NULL.
+ * @param tls_cert_profile  TLS certificate crypto profile name.
  */
-void show_available_tls_ciphers(const char *tls_ciphers);
+void
+show_available_tls_ciphers(const char *cipher_list,
+                           const char *tls_cert_profile);
 
 /*
  * Show the available elliptic curves in the crypto library
diff --git a/src/openvpn/ssl_mbedtls.c b/src/openvpn/ssl_mbedtls.c
index 861d936d..858bdd13 100644
--- a/src/openvpn/ssl_mbedtls.c
+++ b/src/openvpn/ssl_mbedtls.c
@@ -62,6 +62,34 @@
 #include <mbedtls/pem.h>
 #include <mbedtls/sha256.h>
 
+static const mbedtls_x509_crt_profile openvpn_x509_crt_profile_legacy =
+{
+    /* Hashes from SHA-1 and above */
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_RIPEMD160 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
+    0xFFFFFFF, /* Any PK alg    */
+    0xFFFFFFF, /* Any curve     */
+    1024,      /* RSA-1024 and larger */
+};
+
+static const mbedtls_x509_crt_profile openvpn_x509_crt_profile_preferred =
+{
+    /* SHA-2 and above */
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA384 ) |
+    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA512 ),
+    0xFFFFFFF, /* Any PK alg    */
+    0xFFFFFFF, /* Any curve     */
+    2048,      /* RSA-2048 and larger */
+};
+
+#define openvpn_x509_crt_profile_suiteb mbedtls_x509_crt_profile_suiteb;
+
 void
 tls_init_lib(void)
 {
@@ -250,6 +278,27 @@ tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
     free(tmp_ciphers_orig);
 }
 
+void
+tls_ctx_set_cert_profile(struct tls_root_ctx *ctx, const char *profile)
+{
+    if (0 == strcmp(profile, "preferred"))
+    {
+        ctx->cert_profile = openvpn_x509_crt_profile_preferred;
+    }
+    else if (0 == strcmp(profile, "legacy"))
+    {
+        ctx->cert_profile = openvpn_x509_crt_profile_legacy;
+    }
+    else if (0 == strcmp(profile, "suiteb"))
+    {
+        ctx->cert_profile = openvpn_x509_crt_profile_suiteb;
+    }
+    else
+    {
+        msg (M_FATAL, "ERROR: Invalid cert profile: %s", profile);
+    }
+}
+
 void
 tls_ctx_check_cert_time(const struct tls_root_ctx *ctx)
 {
@@ -917,6 +966,8 @@ key_state_ssl_init(struct key_state_ssl *ks_ssl,
     mbedtls_ssl_conf_rng(&ks_ssl->ssl_config, mbedtls_ctr_drbg_random,
                          rand_ctx_get());
 
+    mbedtls_ssl_conf_cert_profile(&ks_ssl->ssl_config, &ssl_ctx->cert_profile);
+
     if (ssl_ctx->allowed_ciphers)
     {
         mbedtls_ssl_conf_ciphersuites(&ks_ssl->ssl_config, ssl_ctx->allowed_ciphers);
@@ -1271,12 +1322,14 @@ print_details(struct key_state_ssl *ks_ssl, const char *prefix)
 }
 
 void
-show_available_tls_ciphers(const char *cipher_list)
+show_available_tls_ciphers(const char *cipher_list,
+                           const char *tls_cert_profile)
 {
     struct tls_root_ctx tls_ctx;
     const int *ciphers = mbedtls_ssl_list_ciphersuites();
 
     tls_ctx_server_new(&tls_ctx);
+    tls_ctx_set_cert_profile(&tls_ctx, tls_cert_profile);
     tls_ctx_restrict_ciphers(&tls_ctx, cipher_list);
 
     if (tls_ctx.allowed_ciphers)
diff --git a/src/openvpn/ssl_mbedtls.h b/src/openvpn/ssl_mbedtls.h
index f69b6100..341da7d4 100644
--- a/src/openvpn/ssl_mbedtls.h
+++ b/src/openvpn/ssl_mbedtls.h
@@ -82,6 +82,7 @@ struct tls_root_ctx {
     struct external_context *external_key; /**< Management external key */
 #endif
     int *allowed_ciphers;       /**< List of allowed ciphers for this connection */
+    mbedtls_x509_crt_profile cert_profile; /**< Allowed certificate types */
 };
 
 struct key_state_ssl {
diff --git a/src/openvpn/ssl_openssl.c b/src/openvpn/ssl_openssl.c
index 0bfb6939..9b60cedd 100644
--- a/src/openvpn/ssl_openssl.c
+++ b/src/openvpn/ssl_openssl.c
@@ -383,6 +383,32 @@ tls_ctx_restrict_ciphers(struct tls_root_ctx *ctx, const char *ciphers)
     }
 }
 
+void
+tls_ctx_set_cert_profile(struct tls_root_ctx *ctx, const char *profile)
+{
+    /* OpenSSL does not have certificate profiles, but a complex set of
+     * callbacks that we could try to implement to achieve something similar.
+     * For now, use OpenSSL's security levels to achieve similar (but not equal)
+     * behaviour. */
+    if (0 == strcmp(profile, "preferred"))
+    {
+        SSL_CTX_set_security_level(ctx->ctx, 2);
+    }
+    else if (0 == strcmp(profile, "legacy"))
+    {
+        SSL_CTX_set_security_level(ctx->ctx, 1);
+    }
+    else if (0 == strcmp(profile, "suiteb"))
+    {
+        SSL_CTX_set_security_level(ctx->ctx, 3);
+        SSL_CTX_set_cipher_list(ctx->ctx, "SUITEB128");
+    }
+    else
+    {
+        msg (M_FATAL, "ERROR: Invalid cert profile: %s", profile);
+    }
+}
+
 void
 tls_ctx_check_cert_time(const struct tls_root_ctx *ctx)
 {
@@ -1722,7 +1748,8 @@ print_details(struct key_state_ssl *ks_ssl, const char *prefix)
 }
 
 void
-show_available_tls_ciphers(const char *cipher_list)
+show_available_tls_ciphers(const char *cipher_list,
+                           const char *tls_cert_profile)
 {
     struct tls_root_ctx tls_ctx;
     SSL *ssl;
@@ -1742,6 +1769,7 @@ show_available_tls_ciphers(const char *cipher_list)
         crypto_msg(M_FATAL, "Cannot create SSL object");
     }
 
+    tls_ctx_set_cert_profile(&tls_ctx, tls_cert_profile);
     tls_ctx_restrict_ciphers(&tls_ctx, cipher_list);
 
     printf("Available TLS Ciphers,\n");
