diff --git a/crypto/asn1/a_verify.c b/crypto/asn1/a_verify.c

index 3ffd934..23271be 100644

--- a/crypto/asn1/a_verify.c

+++ b/crypto/asn1/a_verify.c

@@ -56,6 +56,9 @@

  * [including the GNU Public Licence.]

  */

+/* for secure_getenv */

+#define _GNU_SOURCE

+

 #include <stdio.h>

 #include <time.h>

@@ -133,6 +136,30 @@ int ASN1_verify(i2d_of_void *i2d, X509_ALGOR *a, ASN1_BIT_STRING *signature,

 #endif

+static int legacy_mds[] = { NID_md5, NID_sha, NID_md4, NID_md2, 0 };

+extern int private_ossl_allowed_legacy_mds[];

+

+static int is_md_legacy_disallowed(int mdnid)

+{

+    int i;

+

+    if (mdnid == NID_md5 && secure_getenv("OPENSSL_ENABLE_MD5_VERIFY") != NULL)

+        return 0;

+

+    for (i = 0; legacy_mds[i] != 0; ++i) {

+         if (mdnid == legacy_mds[i]) {

+            int j;

+

+            for (j = 0; private_ossl_allowed_legacy_mds[j] != 0; ++j) {

+                 if (mdnid == private_ossl_allowed_legacy_mds[j])

+                     return 0;

+            }

+            return 1;

+        }

+     }

+     return 0;

+}

+

 int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a,

                      ASN1_BIT_STRING *signature, void *asn, EVP_PKEY *pkey)

 {

@@ -174,6 +201,10 @@ int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a,

         if (ret != 2)

             goto err;

         ret = -1;

+    } else if (is_md_legacy_disallowed(mdnid)) {

+        ASN1err(ASN1_F_ASN1_ITEM_VERIFY,

+                ASN1_R_UNKNOWN_MESSAGE_DIGEST_ALGORITHM);

+        goto err;

     } else {

         const EVP_MD *type;

         type = EVP_get_digestbynid(mdnid);

diff --git a/crypto/o_init.c b/crypto/o_init.c

index 2f754ef..59439c2 100644

--- a/crypto/o_init.c

+++ b/crypto/o_init.c

@@ -55,6 +55,12 @@

 #include <e_os.h>

 #include <openssl/err.h>

+# include <stdio.h>

+# include <string.h>

+# include <strings.h>

+# include <ctype.h>

+# include <openssl/dh.h>

+# include <openssl/objects.h>

 #ifdef OPENSSL_FIPS

 # include <sys/types.h>

 # include <sys/stat.h>

@@ -89,6 +95,121 @@ static void init_fips_mode(void)

 }

 #endif

+# define LEGACY_SETTINGS_FILE "/etc/pki/tls/legacy-settings"

+

+# define NUM_MAX_LEGACY_MDS 8

+

+int private_ossl_allowed_legacy_mds[NUM_MAX_LEGACY_MDS + 1]; /* zero terminated */

+

+int private_ossl_minimum_dh_bits;

+

+#if !defined(_WIN32)

+static void parse_legacy_mds(char *p)

+{

+    int idx = 0;

+    char *e = p;

+

+    while (p[0] != '\0') {

+        while (e[0] != '\0' && !isspace(e[0]) && e[0] != ',') {

+            ++e;

+        }

+        if (e[0] != '\0') {

+            e[0] = '\0';

+            ++e;

+        }

+

+        if (strcasecmp(p, "md5") == 0) {

+            private_ossl_allowed_legacy_mds[idx++] = NID_md5;

+        } else if (strcasecmp(p, "md4") == 0) {

+            private_ossl_allowed_legacy_mds[idx++] = NID_md4;

+        } else if (strcasecmp(p, "sha") == 0) {

+            private_ossl_allowed_legacy_mds[idx++] = NID_sha;

+        } else if (strcasecmp(p, "md2") == 0) {

+            private_ossl_allowed_legacy_mds[idx++] = NID_md2;

+        }

+

+        if (idx >=

+            sizeof(private_ossl_allowed_legacy_mds) /

+            sizeof(private_ossl_allowed_legacy_mds[0])) {

+            break;

+        }

+

+        while (e[0] == ',' || isspace(e[0])) {

+            ++e;

+        }

+

+        p = e;

+    }

+}

+

+static void parse_minimum_dh_bits(char *p)

+{

+    private_ossl_minimum_dh_bits = strtol(p, NULL, 10);

+    if (private_ossl_minimum_dh_bits < 512

+        || private_ossl_minimum_dh_bits > OPENSSL_DH_MAX_MODULUS_BITS) {

+        /* use default */

+        private_ossl_minimum_dh_bits = 0;

+    }

+}

+

+static void load_legacy_settings(void)

+{

+    FILE *f;

+    char *line = NULL;

+    size_t len = 0;

+

+    if ((f = fopen(LEGACY_SETTINGS_FILE, "r")) == NULL) {

+        return;

+    }

+

+    while (getline(&line, &len, f) > 0) {

+        char *p = line, *e, *val;

+

+        /* skip initial whitespace */

+        while (isspace(p[0])) {

+            ++p;

+        }

+

+        e = p;

+

+        while (e[0] != '\0' && !isspace(e[0])) {

+            ++e;

+        }

+

+        /* terminate name, skip whitespace between name and value */

+        if (e[0] != '\0') {

+            e[0] = '\0';

+            ++e;

+            while (isspace(e[0])) {

+                ++e;

+            }

+        }

+

+        val = e;

+

+        e = e + strlen(val);

+

+        /* trim terminating whitespace */

+        while (e > val) {

+            --e;

+            if (isspace(e[0])) {

+                e[0] = '\0';

+            } else {

+                break;

+            }

+        }

+

+        if (strcasecmp(p, "LegacySigningMDs") == 0) {

+            parse_legacy_mds(val);

+        } else if (strcasecmp(line, "MinimumDHBits") == 0) {

+            parse_minimum_dh_bits(val);

+        }

+        /* simply skip other unrecognized lines */

+    }

+    (void)fclose(f);

+}

+#endif

+

 /*

  * Perform any essential OpenSSL initialization operations. Currently only

  * sets FIPS callbacks

@@ -100,6 +221,10 @@ void OPENSSL_init_library(void)

     if (done)

         return;

     done = 1;

+

+#if !defined(_WIN32)

+    load_legacy_settings();

+#endif

 #ifdef OPENSSL_FIPS

     RAND_init_fips();

     init_fips_mode();

diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c

index 32f2f1a..6734e8a 100644

--- a/ssl/s3_clnt.c

+++ b/ssl/s3_clnt.c

@@ -3500,6 +3500,8 @@ int ssl3_send_client_certificate(SSL *s)

 #define has_bits(i,m)   (((i)&(m)) == (m))

+extern int private_ossl_minimum_dh_bits;

+

 int ssl3_check_cert_and_algorithm(SSL *s)

 {

     int i, idx;

@@ -3630,8 +3632,7 @@ int ssl3_check_cert_and_algorithm(SSL *s)

             DH_free(dh_srvr);

         }

-        if ((!SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) && dh_size < 1024)

-            || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) && dh_size < 512)) {

+        if (dh_size < (private_ossl_minimum_dh_bits ? private_ossl_minimum_dh_bits : 1024)) {

             SSLerr(SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM, SSL_R_DH_KEY_TOO_SMALL);

             goto f_err;

         }