diff --git a/ChangeLog b/ChangeLog
index 2fe65e2..b991ae9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -26,6 +26,12 @@
    * Fix returning the value 1 when mbedtls_ecdsa_genkey failed.
    * Fix false failure in all.sh when backup files exist in include/mbedtls
      (e.g. config.h.bak). Fixed by Peter Kolbus (Garmin) #2407.
+   * Ensure that unused bits are zero when writing ASN.1 bitstrings when using
+     mbedtls_asn1_write_bitstring().
+   * Fix issue when writing the named bitstrings in KeyUsage and NsCertType
+     extensions in CSRs and CRTs that caused these bitstrings to not be encoded
+     correctly as trailing zeroes were not accounted for as unused bits in the
+     leading content octet. Fixes #1610.
 
 Changes
    * Include configuration file in all header files that use configuration,
diff --git a/include/mbedtls/x509_csr.h b/include/mbedtls/x509_csr.h
index 0c6ccad..a3c2804 100644
--- a/include/mbedtls/x509_csr.h
+++ b/include/mbedtls/x509_csr.h
@@ -205,6 +205,14 @@
  * \param key_usage key usage flags to set
  *
  * \return          0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ *
+ * \note            The <code>decipherOnly</code> flag from the Key Usage
+ *                  extension is represented by bit 8 (i.e.
+ *                  <code>0x8000</code>), which cannot typically be represented
+ *                  in an unsigned char. Therefore, the flag
+ *                  <code>decipherOnly</code> (i.e.
+ *                  #MBEDTLS_X509_KU_DECIPHER_ONLY) cannot be set using this
+ *                  function.
  */
 int mbedtls_x509write_csr_set_key_usage( mbedtls_x509write_csr *ctx, unsigned char key_usage );
 
diff --git a/library/asn1write.c b/library/asn1write.c
index a4d23f6..c0b4622 100644
--- a/library/asn1write.c
+++ b/library/asn1write.c
@@ -294,22 +294,28 @@
                           const unsigned char *buf, size_t bits )
 {
     int ret;
-    size_t len = 0, size;
+    size_t len = 0;
+    size_t unused_bits, byte_len;
 
-    size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 );
+    byte_len = ( bits + 7 ) / 8;
+    unused_bits = ( byte_len * 8 ) - bits;
 
-    // Calculate byte length
-    //
-    if( *p < start || (size_t)( *p - start ) < size + 1 )
+    if( *p < start || (size_t)( *p - start ) < byte_len + 1 )
         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
-    len = size + 1;
-    (*p) -= size;
-    memcpy( *p, buf, size );
+    len = byte_len + 1;
 
-    // Write unused bits
-    //
-    *--(*p) = (unsigned char) (size * 8 - bits);
+    /* Write the bitstring. Ensure the unused bits are zeroed */
+    if( byte_len > 0 )
+    {
+        byte_len--;
+        *--( *p ) = buf[byte_len] & ~( ( 0x1 << unused_bits ) - 1 );
+        ( *p ) -= byte_len;
+        memcpy( *p, buf, byte_len );
+    }
+
+    /* Write unused bits */
+    *--( *p ) = (unsigned char)unused_bits;
 
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
     MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_BIT_STRING ) );
diff --git a/library/x509write_crt.c b/library/x509write_crt.c
index b1ef216..10497e7 100644
--- a/library/x509write_crt.c
+++ b/library/x509write_crt.c
@@ -218,26 +218,51 @@
 }
 #endif /* MBEDTLS_SHA1_C */
 
+static size_t crt_get_unused_bits_for_named_bitstring( unsigned char bitstring,
+                                                       size_t bit_offset )
+{
+    size_t unused_bits;
+
+     /* Count the unused bits removing trailing 0s */
+    for( unused_bits = bit_offset; unused_bits < 8; unused_bits++ )
+        if( ( ( bitstring >> unused_bits ) & 0x1 ) != 0 )
+            break;
+
+     return( unused_bits );
+}
+
 int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
                                          unsigned int key_usage )
 {
     unsigned char buf[4], ku;
     unsigned char *c;
     int ret;
+    size_t unused_bits;
+    const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE |
+        MBEDTLS_X509_KU_NON_REPUDIATION   |
+        MBEDTLS_X509_KU_KEY_ENCIPHERMENT  |
+        MBEDTLS_X509_KU_DATA_ENCIPHERMENT |
+        MBEDTLS_X509_KU_KEY_AGREEMENT     |
+        MBEDTLS_X509_KU_KEY_CERT_SIGN     |
+        MBEDTLS_X509_KU_CRL_SIGN;
 
-    /* We currently only support 7 bits, from 0x80 to 0x02 */
-    if( ( key_usage & ~0xfe ) != 0 )
+    /* Check that nothing other than the allowed flags is set */
+    if( ( key_usage & ~allowed_bits ) != 0 )
         return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
 
     c = buf + 4;
-    ku = (unsigned char) key_usage;
+    ku = (unsigned char)key_usage;
+    unused_bits = crt_get_unused_bits_for_named_bitstring( ku, 1 );
+    ret = mbedtls_asn1_write_bitstring( &c, buf, &ku, 8 - unused_bits );
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ku, 7 ) ) != 4 )
+    if( ret < 0 )
         return( ret );
+    else if( ret < 3 || ret > 4 )
+        return( MBEDTLS_ERR_X509_INVALID_FORMAT );
 
     ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
-                                       1, buf, 4 );
+                                       1, c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
@@ -249,16 +274,22 @@
 {
     unsigned char buf[4];
     unsigned char *c;
+    size_t unused_bits;
     int ret;
 
     c = buf + 4;
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
+    unused_bits = crt_get_unused_bits_for_named_bitstring( ns_cert_type, 0 );
+    ret = mbedtls_asn1_write_bitstring( &c,
+                                        buf,
+                                        &ns_cert_type,
+                                        8 - unused_bits );
+    if( ret < 3 || ret > 4 )
         return( ret );
 
     ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
-                                       0, buf, 4 );
+                                       0, c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
diff --git a/library/x509write_csr.c b/library/x509write_csr.c
index 66cee56..d70ba0e 100644
--- a/library/x509write_csr.c
+++ b/library/x509write_csr.c
@@ -81,20 +81,39 @@
                                0, val, val_len );
 }
 
+static size_t csr_get_unused_bits_for_named_bitstring( unsigned char bitstring,
+                                                       size_t bit_offset )
+{
+    size_t unused_bits;
+
+     /* Count the unused bits removing trailing 0s */
+    for( unused_bits = bit_offset; unused_bits < 8; unused_bits++ )
+        if( ( ( bitstring >> unused_bits ) & 0x1 ) != 0 )
+            break;
+
+     return( unused_bits );
+}
+
 int mbedtls_x509write_csr_set_key_usage( mbedtls_x509write_csr *ctx, unsigned char key_usage )
 {
     unsigned char buf[4];
     unsigned char *c;
+    size_t unused_bits;
     int ret;
 
     c = buf + 4;
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
+    unused_bits = csr_get_unused_bits_for_named_bitstring( key_usage, 0 );
+    ret = mbedtls_asn1_write_bitstring( &c, buf, &key_usage, 8 - unused_bits );
+
+    if( ret < 0 )
         return( ret );
+    else if( ret < 3 || ret > 4 )
+        return( MBEDTLS_ERR_X509_INVALID_FORMAT );
 
     ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
-                                       buf, 4 );
+                                       c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
@@ -106,16 +125,25 @@
 {
     unsigned char buf[4];
     unsigned char *c;
+    size_t unused_bits;
     int ret;
 
     c = buf + 4;
 
-    if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
+    unused_bits = csr_get_unused_bits_for_named_bitstring( ns_cert_type, 0 );
+    ret = mbedtls_asn1_write_bitstring( &c,
+                                        buf,
+                                        &ns_cert_type,
+                                        8 - unused_bits );
+
+    if( ret < 0 )
+        return( ret );
+    else if( ret < 3 || ret > 4 )
         return( ret );
 
     ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
                                        MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
-                                       buf, 4 );
+                                       c, (size_t)ret );
     if( ret != 0 )
         return( ret );
 
diff --git a/programs/x509/cert_req.c b/programs/x509/cert_req.c
index 027050c..d25ad4c 100644
--- a/programs/x509/cert_req.c
+++ b/programs/x509/cert_req.c
@@ -65,7 +65,9 @@
 #define DFL_OUTPUT_FILENAME     "cert.req"
 #define DFL_SUBJECT_NAME        "CN=Cert,O=mbed TLS,C=UK"
 #define DFL_KEY_USAGE           0
+#define DFL_FORCE_KEY_USAGE     0
 #define DFL_NS_CERT_TYPE        0
+#define DFL_FORCE_NS_CERT_TYPE  0
 #define DFL_MD_ALG              MBEDTLS_MD_SHA256
 
 #define USAGE \
@@ -85,6 +87,8 @@
     "                          key_agreement\n"         \
     "                          key_cert_sign\n"  \
     "                          crl_sign\n"              \
+    "    force_key_usage=0/1  default: off\n"           \
+    "                          Add KeyUsage even if it is empty\n"  \
     "    ns_cert_type=%%s     default: (empty)\n"       \
     "                        Comma-separated-list of values:\n"     \
     "                          ssl_client\n"            \
@@ -94,6 +98,8 @@
     "                          ssl_ca\n"                \
     "                          email_ca\n"              \
     "                          object_signing_ca\n"     \
+    "    force_ns_cert_type=0/1 default: off\n"         \
+    "                          Add NsCertType even if it is empty\n"    \
     "    md=%%s               default: SHA256\n"       \
     "                          possible values:\n"     \
     "                          MD4, MD5, SHA1\n"       \
@@ -123,7 +129,9 @@
     const char *output_file;    /* where to store the constructed key file  */
     const char *subject_name;   /* subject name for certificate request */
     unsigned char key_usage;    /* key usage flags                      */
+    int force_key_usage;        /* Force adding the KeyUsage extension  */
     unsigned char ns_cert_type; /* NS cert type                         */
+    int force_ns_cert_type;     /* Force adding NsCertType extension    */
     mbedtls_md_type_t md_alg;   /* Hash algorithm used for signature.   */
 } opt;
 
@@ -190,7 +198,9 @@
     opt.output_file         = DFL_OUTPUT_FILENAME;
     opt.subject_name        = DFL_SUBJECT_NAME;
     opt.key_usage           = DFL_KEY_USAGE;
+    opt.force_key_usage     = DFL_FORCE_KEY_USAGE;
     opt.ns_cert_type        = DFL_NS_CERT_TYPE;
+    opt.force_ns_cert_type  = DFL_FORCE_NS_CERT_TYPE;
     opt.md_alg              = DFL_MD_ALG;
 
     for( i = 1; i < argc; i++ )
@@ -292,6 +302,15 @@
                 q = r;
             }
         }
+        else if( strcmp( p, "force_key_usage" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0: opt.force_key_usage = 0; break;
+                case 1: opt.force_key_usage = 1; break;
+                default: goto usage;
+            }
+        }
         else if( strcmp( p, "ns_cert_type" ) == 0 )
         {
             while( q != NULL )
@@ -319,16 +338,25 @@
                 q = r;
             }
         }
+        else if( strcmp( p, "force_ns_cert_type" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0: opt.force_ns_cert_type = 0; break;
+                case 1: opt.force_ns_cert_type = 1; break;
+                default: goto usage;
+            }
+        }
         else
             goto usage;
     }
 
     mbedtls_x509write_csr_set_md_alg( &req, opt.md_alg );
 
-    if( opt.key_usage )
+    if( opt.key_usage || opt.force_key_usage == 1 )
         mbedtls_x509write_csr_set_key_usage( &req, opt.key_usage );
 
-    if( opt.ns_cert_type )
+    if( opt.ns_cert_type || opt.force_ns_cert_type == 1 )
         mbedtls_x509write_csr_set_ns_cert_type( &req, opt.ns_cert_type );
 
     /*
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 2ed32e6..43fbe16 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -16,7 +16,6 @@
 MBEDTLS_CERT_WRITE ?= $(PWD)/../../programs/x509/cert_write
 MBEDTLS_CERT_REQ ?= $(PWD)/../../programs/x509/cert_req
 
-
 ## Build the generated test data. Note that since the final outputs
 ## are committed to the repository, this target should do nothing on a
 ## fresh checkout. Furthermore, since the generation is randomized,
@@ -739,6 +738,37 @@
 	$(OPENSSL) pkey -in $< -inform DER -out $@
 all_final += ec_prv.pk8param.pem
 
+# server5*
+
+# The use of 'Server 1' in the DN is intentional here, as the DN is hardcoded in the x509_write test suite.'
+server5.req.ku.sha1: server5.key
+	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< key_usage=digital_signature,non_repudiation subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1
+all_final += server5.req.ku.sha1
+
+################################################################
+### Generate CSRs for X.509 write test suite
+################################################################
+
+server1.req.cert_type: server1.key
+	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< ns_cert_type=ssl_server subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1
+all_final += server1.req.cert_type
+
+server1.req.key_usage: server1.key
+	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< key_usage=digital_signature,non_repudiation,key_encipherment subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1
+all_final += server1.req.key_usage
+
+server1.req.ku-ct: server1.key
+	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< key_usage=digital_signature,non_repudiation,key_encipherment ns_cert_type=ssl_server subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1
+all_final += server1.req.ku-ct
+
+server1.req.key_usage_empty: server1.key
+	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1 force_key_usage=1
+all_final += server1.req.key_usage_empty
+
+server1.req.cert_type_empty: server1.key
+	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1 force_ns_cert_type=1
+all_final += server1.req.cert_type_empty
+
 ################################################################
 ### Generate CSRs for X.509 write test suite
 ################################################################
diff --git a/tests/data_files/server1.cert_type.crt b/tests/data_files/server1.cert_type.crt
index cf384cb..fb59ab8 100644
--- a/tests/data_files/server1.cert_type.crt
+++ b/tests/data_files/server1.cert_type.crt
@@ -11,10 +11,10 @@
 bp7OvViJ4lNZnm5akmXiiD8MlBmj3eXonZUT7Snbq3AS3FrKaxerUoJUsQIDAQAB
 o2AwXjAJBgNVHRMEAjAAMB0GA1UdDgQWBBQfdNY/KcF0dEU7BRIsPai9Q1kCpjAf
 BgNVHSMEGDAWgBS0WuSls97SUva51aaVD+s+vMf9/zARBglghkgBhvhCAQEEBAMC
-AEAwDQYJKoZIhvcNAQEFBQADggEBAEQOk5Ejgu/GsxvMo+RknXcta5Qr6MiNo1EM
-G5Xrf++aaf4Mi38p5ZxWDxQDyBmutSnuJgzO+Dxe5w/RNojFa4ri4g5Zk8zwfIcQ
-8jR6a9DJtxarxDj/UqEzaiBa5MpxsbQqbmou7X7YW9LHDzmCgzbaabyWCuGYxvmh
-lDbcISST73G+vJEeExcBHyom/GV9TNcFAGa66YV/FtABg2tiy9znmUeMnZeYkC9S
-05m6UstAU6pMdwiTpjZjovsTlAcmC76XmE/GpREhRvtGCKTb2pUi3agqsrapABmF
-EGZT9cpwkrl3cxh+jxAMEuhJLdEScDWHVsiNS5y9yxitWC4NqR4=
+BkAwDQYJKoZIhvcNAQEFBQADggEBAK1WXZYd6k7/zE2NcszT6rxNaSixPZrDYzRt
+Iz5rpH33IHkCdR956/ExCcDMqGNVtKtBdr8kw3+jzyPQhwyHVPNv4C/cgt0C89Pf
+qZLQGuEPVp1X4tzEY2Kno9c1tllLVzJdvz1mRhSb9z5CWQKNMT+8MMl3k+0NZ4LT
+NEx4gTZxYEsAGEuO/Yij9ctxp4RdSP585FXgiMC00ieMe/aJxlOIgpIhuWdu0KPP
+G5guYd4hQ9ZrGVOGdjv2cZbh4DuQOsCwU9in/e1RKFV6eMmyOdvLJ4jkTauwkGJG
+lCclZZQwzGawOiMl2OYPUia5bkaEsdE/0QW/lf36lco8CNjpUfY=
 -----END CERTIFICATE-----
diff --git a/tests/data_files/server1.cert_type_noauthid.crt b/tests/data_files/server1.cert_type_noauthid.crt
index 7545e0b..0082b14 100644
--- a/tests/data_files/server1.cert_type_noauthid.crt
+++ b/tests/data_files/server1.cert_type_noauthid.crt
@@ -10,11 +10,11 @@
 lZvc/kFeF6babFtpzAK6FCwWJJxK3M3Q91Jnc/EtoCP9fvQxyi1wyokLBNsupk9w
 bp7OvViJ4lNZnm5akmXiiD8MlBmj3eXonZUT7Snbq3AS3FrKaxerUoJUsQIDAQAB
 oz8wPTAJBgNVHRMEAjAAMB0GA1UdDgQWBBQfdNY/KcF0dEU7BRIsPai9Q1kCpjAR
-BglghkgBhvhCAQEEBAMCAEAwDQYJKoZIhvcNAQEFBQADggEBAJc3yZUS9X3/lb63
-Nlt8rtXC45wbWZUoOK8N55IzEJC7FrttAStq24kq9QV0qiox8m1WLA+6xVaeZaXu
-h2z3WlUlyCNaKqHEpuSYu/XQ0td6j3jCMj3VDSZGHnKgliQ9fkkt+waPVCAZldwj
-rHsZibl2Dqzb3KttKqD1VyEVOUJ+saXRDJLFdK1M9nwdWMfOg/XE0WbqfVzw9COs
-08dJ6KL7SOvXtiOVQLNv7XN/2j+wF6+IoLDdLCDByj5VtK2q2vyVk5tpDJI1S696
-dP8Zi7VbBTS9OlVC+Gw3CntDKZA8e215MNG6iBuEM2mgi4i0umo7mN8FoA1zusnE
-8mCO55Q=
+BglghkgBhvhCAQEEBAMCBkAwDQYJKoZIhvcNAQEFBQADggEBAGl6bYCGKvDCvfSU
+PTyaiFPNGXV98AnIG0Hu4EJjs1owBU/Yf8UdFbWJtOymR80SbzmeQ6rEIoY1oXDA
+o9Y8yRgW8t25Wmq/0DCu/5P0/L6asstLTxLG4qajClVwqDLEqZNixmq8QorAOtK1
+JngFA+A5jzc70Ikl9+Hbx/2SEMrCpo0QLSco7KDK7XpNOHbkRz2AqSm0se4jDMP1
+Cwd2UtcpctIZEbECZo6S9WrVMqIhRF1Y5FeauBA2ORvGIHohaYJ9VzYWYXIp7N8d
+QXGv+M7ffpZiERcRr8lxtboPnTXKlv1mLCEX7g+KuiJQUm4OGfTCd5VHzWM7O5Id
+b+IvZD0=
 -----END CERTIFICATE-----
diff --git a/tests/data_files/server1.key_usage.crt b/tests/data_files/server1.key_usage.crt
index 3a678ff..b5a2532 100644
--- a/tests/data_files/server1.key_usage.crt
+++ b/tests/data_files/server1.key_usage.crt
@@ -10,11 +10,11 @@
 lZvc/kFeF6babFtpzAK6FCwWJJxK3M3Q91Jnc/EtoCP9fvQxyi1wyokLBNsupk9w
 bp7OvViJ4lNZnm5akmXiiD8MlBmj3eXonZUT7Snbq3AS3FrKaxerUoJUsQIDAQAB
 o10wWzAJBgNVHRMEAjAAMB0GA1UdDgQWBBQfdNY/KcF0dEU7BRIsPai9Q1kCpjAf
-BgNVHSMEGDAWgBS0WuSls97SUva51aaVD+s+vMf9/zAOBgNVHQ8BAf8EBAMCAeAw
-DQYJKoZIhvcNAQEFBQADggEBAE4sz3ghfpolZ0rH6Q3CWIYQ1Q+aGBwQiCCBsApP
-8qZd880Kt+BiEdSsaU16S8CIMdOcHGQGB7dXK9wdTWkIqaW9I7fRPgDNDIhJoYDD
-67h1P+cEQeXT9900H173nYlM1vL9zLcnmmqEO7j8jXSpsR5mcCMPkR52RqxweLJw
-LGPeSlA+DF0WbezJc28FUgXAl8Kxm3Od40exMeicHtfgCnIykH1NEW3gXpc91nFT
-RoNRdEAIGHMX5Dd5QDlt2vlaKNXFtcx2xUXXIi71YNQybH3p6KXayPMFQzrBwoXJ
-YHevmjUaw7UH31fULa1dtd/dWmp8cCaKB4vBr0DBJPiMJMw=
+BgNVHSMEGDAWgBS0WuSls97SUva51aaVD+s+vMf9/zAOBgNVHQ8BAf8EBAMCBeAw
+DQYJKoZIhvcNAQEFBQADggEBAE6xegEHvwuQ8I4YCLX7oXmDJiDb7m2nMin+um0v
+TMqHAE3B9GvdWGUgMIEMf76ee7OMDzxfzM2vyNGemB0rn1djEv+knJBSdMQKD9X8
+tkT8cPqMHlRMYYbFFkkZEOeqeihZXQdUORao9ZSXrokYwv+Fr+PAmiUJEmkZHbA1
+Gqp6tPfGxJ2ah50Og9oAPwyND6kvE2o++Dth2evjljPCPM2Gw5kjQGw3V9CAUyUo
+KtLrtZdOeRHRCWCf3UQ/tYkG70tY/+grftrHqKB2E4qkmDiCPS9sEpa7jOGT6e4k
+jGVeZFNZZ10mD2Svr3xl/60++c7yLxrquujo8NOTCVcshfs=
 -----END CERTIFICATE-----
diff --git a/tests/data_files/server1.key_usage_noauthid.crt b/tests/data_files/server1.key_usage_noauthid.crt
index 4a72ac1..c82a979 100644
--- a/tests/data_files/server1.key_usage_noauthid.crt
+++ b/tests/data_files/server1.key_usage_noauthid.crt
@@ -10,11 +10,11 @@
 lZvc/kFeF6babFtpzAK6FCwWJJxK3M3Q91Jnc/EtoCP9fvQxyi1wyokLBNsupk9w
 bp7OvViJ4lNZnm5akmXiiD8MlBmj3eXonZUT7Snbq3AS3FrKaxerUoJUsQIDAQAB
 ozwwOjAJBgNVHRMEAjAAMB0GA1UdDgQWBBQfdNY/KcF0dEU7BRIsPai9Q1kCpjAO
-BgNVHQ8BAf8EBAMCAeAwDQYJKoZIhvcNAQEFBQADggEBALqfFzzWOViKBXoFhtcc
-Ulzg1ShK20z3zeD6TL5Ss2+kMIGhvvvUMtcATIFa9LxZ//a0as1CACphxmrsqaju
-LDvnXjWLB+e7pJPQ+4XixKmA3QoQI6sduH03/4eRp/Er/+zXD7+uapz+GimiExJt
-mjW1Oz5n2Q7L9vQabqz0n9+8rM/chsfgipQSKmV0rXe/K1N4yuggh62r8kn9UaUR
-TKm6HaMIFBrZNwMy8TAc3gSq5rqbN8/ONiCBpW/LvwTnd7fFSl7yeetAbj08gpu2
-dkfYp/DK9Hs1KQFCi0u1pr9JIqFxNy6tUTO90ydq6QXj4E5yZhmitLPk5wPCozN+
-rIc=
+BgNVHQ8BAf8EBAMCBeAwDQYJKoZIhvcNAQEFBQADggEBAKuveVlnjgJIkiH6HqZk
++oGpLPxpcoMEMskzyFxTfjP4L2Mj798qydBbobyVJdH5p/sIpcHsI0xajM/dcZKS
+7b28KVwxOk+87DtwCikFT+jzWPe8fzowqsNAaKtvtDQnLYh8u2tDT1vhABwgTVAy
+aHCzs+nm3o36NPSN9K+wmI+r1KFnhjtyOQ++7M8wRRT5jrC+1tYicjsnVMu07yB5
+04C99Fa3MToilg66Jos95U3gBF5GbSfDXYtd3/etNMkUiG8FEZJlkhKbTO+4E03a
+X6+z2VojrAroYyO/F5ZlaC3/CsMQ8Zcate64nH/Lu/U78XAo8iKz5DLLOPBqodER
+z4A=
 -----END CERTIFICATE-----
diff --git a/tests/data_files/server1.req.cert_type b/tests/data_files/server1.req.cert_type
index b9b9f06..39ff3fd 100644
--- a/tests/data_files/server1.req.cert_type
+++ b/tests/data_files/server1.req.cert_type
@@ -7,11 +7,11 @@
 W+cTl4W1I5LZ1CQG1QkliXUH3aYajz8JGb6tZSxk65Wb3P5BXhem2mxbacwCuhQs
 FiScStzN0PdSZ3PxLaAj/X70McotcMqJCwTbLqZPcG6ezr1YieJTWZ5uWpJl4og/
 DJQZo93l6J2VE+0p26twEtxaymsXq1KCVLECAwEAAaAkMCIGCSqGSIb3DQEJDjEV
-MBMwEQYJYIZIAYb4QgEBBAQDAgBAMA0GCSqGSIb3DQEBBQUAA4IBAQCMX3H6BiGP
-VRvLu8UHIhsj9WgrGDRogOMVHOrQm+0fnGyxZa2UwftSZf2qLBZ+DmJStHabXibw
-QuWA9BMVFDih5yGMhdzQC8iQQCjfYOS0sfhy7p76q89rVO0E9KAtvFH2ApbaDAck
-m1WdQvYey2rYnT1ucHGdn017Iu1CaY8qnmh7Fhuov++69eGGG4MjRVT/7Ywufjo5
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-QxxzqP5NLPdlS4ksN6zcuwdq21l+li8zakjbeUvyqZb7E6vTHJaNBOp7Y7jv25gG
-5/PjwquYbKFr
+MBMwEQYJYIZIAYb4QgEBBAQDAgZAMA0GCSqGSIb3DQEBBQUAA4IBAQBErZcEaEEO
+hLbRVuB3+N5by0mogdJsatJFSgW2/VztLvQBYu0O+VmTbZwCAWejA8U+cr6uPlyf
+b4lDqj3W+XykeK9bSzoSr1yNO2VAcE74Y0ZrSz2yXMfT5R9IyKqQZspaKD8MOmYH
+BqUH9o/phnGcaEG5xeSfhM1O/YNZuGnlLDQBGwT5puHOaLfjECvs8eZLopIWEBlD
+QkRlhYqZBwhGZ8D/TxqG4teFtnBX5FG7UoSSVuneBrkREQM7ElhtD9jCWjfMnqm1
+59G84OycClwaKU7/Dm6zeMGDyFoMksBud7lyDHMhxvwSbzb1JR5v8iBsmVY2dhHt
+Ot3Fx2be0gIr
 -----END CERTIFICATE REQUEST-----
diff --git a/tests/data_files/server1.req.cert_type_empty b/tests/data_files/server1.req.cert_type_empty
new file mode 100644
index 0000000..70fd111
--- /dev/null
+++ b/tests/data_files/server1.req.cert_type_empty
@@ -0,0 +1,17 @@
+-----BEGIN CERTIFICATE REQUEST-----
+MIICpDCCAYwCAQAwPDELMAkGA1UEBhMCTkwxETAPBgNVBAoMCFBvbGFyU1NMMRow
+GAYDVQQDDBFQb2xhclNTTCBTZXJ2ZXIgMTCCASIwDQYJKoZIhvcNAQEBBQADggEP
+ADCCAQoCggEBAKkCHz1AatVVU4v9Nu6CZS4VYV6Jv7joRZDb7ogWUtPxQ1BHlhJZ
+ZIdr/SvgRvlzvt3PkuGRW+1moG+JKXlFgNCDatVBQ3dfOXwJBEeCsFc5cO2j7BUZ
+HqgzCEfBBUKp/UzDtN/dBh9NEFFAZ3MTD0D4bYElXwqxU8YwfhU5rPla7n+SnqYF
+W+cTl4W1I5LZ1CQG1QkliXUH3aYajz8JGb6tZSxk65Wb3P5BXhem2mxbacwCuhQs
+FiScStzN0PdSZ3PxLaAj/X70McotcMqJCwTbLqZPcG6ezr1YieJTWZ5uWpJl4og/
+DJQZo93l6J2VE+0p26twEtxaymsXq1KCVLECAwEAAaAjMCEGCSqGSIb3DQEJDjEU
+MBIwEAYJYIZIAYb4QgEBBAMDAQAwDQYJKoZIhvcNAQEFBQADggEBACU0LLDBIMgG
+B7gyNANHv42RovhQdzmUulqJPHNHx3v9G17F00bEykJb/r3awW6l5fhY/6oPydsY
+hnWEM6VVCUkJ6Zqm2/wE49uaNTbFd9JU4OywRBfjHHSTOGnYFg+BYSfwaIkSCkx2
+kVhyklFm7My5wkyDPpFSU2tTfgsgaQMyTm93a2kxM7qJ/X3gFDG8o7R0vyojFVSI
+mwsF9QsC6N9cygdFx23zCB0KsJ9KfmBqaTsdbKh8BsocYm5FJCw4WS/CBrCWBj+z
+N7yEJj4SR5F+P7sFc5I0HANov5wQe8E3+WxxQt8jcqIje6DlaaGja44cXOzvFQyx
+Hg/6H5EtBQc=
+-----END CERTIFICATE REQUEST-----
diff --git a/tests/data_files/server1.req.key_usage b/tests/data_files/server1.req.key_usage
index 4c20eed..30e4812 100644
--- a/tests/data_files/server1.req.key_usage
+++ b/tests/data_files/server1.req.key_usage
@@ -7,11 +7,11 @@
 W+cTl4W1I5LZ1CQG1QkliXUH3aYajz8JGb6tZSxk65Wb3P5BXhem2mxbacwCuhQs
 FiScStzN0PdSZ3PxLaAj/X70McotcMqJCwTbLqZPcG6ezr1YieJTWZ5uWpJl4og/
 DJQZo93l6J2VE+0p26twEtxaymsXq1KCVLECAwEAAaAeMBwGCSqGSIb3DQEJDjEP
-MA0wCwYDVR0PBAQDAgHgMA0GCSqGSIb3DQEBBQUAA4IBAQAIDkjGHokLINOSKAij
-DuBWyW72udNBwSmRAFYDyNoybWX+KJLFckyReF1S0YRHXWOljwxERF6htUEqIJDI
-vIzlXyV0YqHNmWEFpyRxyIllQ7X4NWnVm3zHYORx2utdy3EyNsNb4Rb/JNh6Qpqr
-27DB+frWaBYk27RPTdZz/ItZIicX8iHrAHL0aC6raQYvZfM1ybYehAh7Qx3asHKI
-XDcrbV50Kzrd0SgC4P6Z6/5C5uUL9AfcKnB2oj5VP2TM0BA6q+XRQFkJ3TO1UTLB
-lCKb9B1cIpVsT0YsOg/qptUh90zgd0x7FDa084ccwUJG73VXtHC6eioE4fbfrm5L
-9BNK
+MA0wCwYDVR0PBAQDAgXgMA0GCSqGSIb3DQEBBQUAA4IBAQBsJ3v1Ar2X28GJsRSJ
+WRQwFQwIbR/D0cHrwTf0ZfZttClytuc18JZlwkH3EG/rNkWaFp6MKIZoRMOBuSPc
+MNvvKIo4nPaeouDPruymx0gNenlyRL3D4OZpBO/BmQIQjbUKWFbzEnEqvwvMDUnG
+8w7UjPSFcxj2HzENr62HLPKKnVpL3nDXWK1a2A77KF9aMxyoWQ6FXb2xPD9cJjdo
+c1jwskQbgosQzKKwwp5yxq0zRD3EAGw4A78mgHMfgFprq9e9azaB0JeyFG2Vn0t0
+L+vfiDEVQ3eJXSCen1kEVyHRju8g53UcSgd+JicWFboFj2/mJBuyW6yM++RGA9B5
+Zd62
 -----END CERTIFICATE REQUEST-----
diff --git a/tests/data_files/server1.req.key_usage_empty b/tests/data_files/server1.req.key_usage_empty
new file mode 100644
index 0000000..47e56bf
--- /dev/null
+++ b/tests/data_files/server1.req.key_usage_empty
@@ -0,0 +1,17 @@
+-----BEGIN CERTIFICATE REQUEST-----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+Ygqa91hGab/CjykS6HMrD91ouWtt2Rt3zCKo4Xxe8dlAszKB4W83M9OgDVVpiCfC
+t3A=
+-----END CERTIFICATE REQUEST-----
diff --git a/tests/data_files/server1.req.ku-ct b/tests/data_files/server1.req.ku-ct
index 98666d2..ebd01f5 100644
--- a/tests/data_files/server1.req.ku-ct
+++ b/tests/data_files/server1.req.ku-ct
@@ -7,11 +7,11 @@
 W+cTl4W1I5LZ1CQG1QkliXUH3aYajz8JGb6tZSxk65Wb3P5BXhem2mxbacwCuhQs
 FiScStzN0PdSZ3PxLaAj/X70McotcMqJCwTbLqZPcG6ezr1YieJTWZ5uWpJl4og/
 DJQZo93l6J2VE+0p26twEtxaymsXq1KCVLECAwEAAaAxMC8GCSqGSIb3DQEJDjEi
-MCAwCwYDVR0PBAQDAgHgMBEGCWCGSAGG+EIBAQQEAwIAQDANBgkqhkiG9w0BAQUF
-AAOCAQEAhDH3BQWViy67+9sdlrTvv0cIJ1IbogaM221MUasNIbfLi+KKfw50mzTa
-V/BCXPT+EzmOptBl+F2iZVQyr2c0nWbBZBHnykS3f0fgifm6yWVEYwJqxUC5+uxK
-bZztsHocTuqODpqYILycYkFXCcY8ZFHmz9XZorpUVTpZULW33EmLee5/BYI7whkA
-bVoSNB5tAb8kGZQffDnGkHiRfu8dbbEnkPYqm/cerN+4yCh1v1CGFh2lMn4d5p0L
-o9GvMsPM8pxdffZWZI9T0JnlHwtAJDA5G/MFYJdHzLzcHpvDA99MdNO4DMAiUyWb
-PCDL5e7mJ0lnBp8RppLBR7GEkznIQQ==
+MCAwCwYDVR0PBAQDAgXgMBEGCWCGSAGG+EIBAQQEAwIGQDANBgkqhkiG9w0BAQUF
+AAOCAQEAWUMyIXHi4BbIxOeCD/Vtu9LGV8ENMV7dwYVEQcwrt1AHahtYgUtkoGcP
+lOPqg1lbg22bu8dLPoY4HAzxCOAGs27otWL5LlE9M5QPH1RedEycmOuYrMl6K988
+hfDBJ+OkgCShcM91+udrc0gpDEI7N01A+fmukQ6EiaQjIf7HME/EKQqhEuEQMXHC
+GBvdNuEF5BfV3aAYuT+xfdXDU2ZWwXXWAHGmVh3ntnhtEG6SnXSnBATU2wa4tpBd
+KLbEbcsiy2uj0OLJlvG6LqsNggtkD58GCGpLpaVxdW80yw+f/krwLpeyocE1KGcT
+7eX+9yhLe9NIZojvevw+53dNE7BUfw==
 -----END CERTIFICATE REQUEST-----
diff --git a/tests/data_files/server5.req.ku.sha1 b/tests/data_files/server5.req.ku.sha1
index 39fc346..3281c94 100644
--- a/tests/data_files/server5.req.ku.sha1
+++ b/tests/data_files/server5.req.ku.sha1
@@ -1,8 +1,8 @@
 -----BEGIN CERTIFICATE REQUEST-----
-MIIBFzCBvAIBADA8MQswCQYDVQQGEwJOTDERMA8GA1UECgwIUG9sYXJTU0wxGjAY
+MIIBFjCBvAIBADA8MQswCQYDVQQGEwJOTDERMA8GA1UECgwIUG9sYXJTU0wxGjAY
 BgNVBAMMEVBvbGFyU1NMIFNlcnZlciAxMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcD
 QgAEN8xW2XYJHlpyPsdZLf8gbu58+QaRdNCtFLX3aCJZYpJO5QDYIxH/6i/SNF1d
 Fr2KiMJrdw1VzYoqDvoByLTt/6AeMBwGCSqGSIb3DQEJDjEPMA0wCwYDVR0PBAQD
-AgHAMAsGByqGSM49BAEFAANJADBGAiEA5MGFTJkpOtCV7bAx+N+t4gP3JDM9RH3W
-mIXzSpcBwvACIQDf7f9ytclwouV1DQTFSUKxExIm48H60hk3lh19i3bGOw==
+AgbAMAsGByqGSM49BAEFAANIADBFAiEAnIKF+xKk0iEuN4MHd4FZWNvrznLQgkeg
+2n8ejjreTzcCIAH34z2TycuMpWQRhpV+YT988pBWR67LAg7REyZnjSAB
 -----END CERTIFICATE REQUEST-----
diff --git a/tests/suites/test_suite_x509write.data b/tests/suites/test_suite_x509write.data
index 5b54d85..c196625 100644
--- a/tests/suites/test_suite_x509write.data
+++ b/tests/suites/test_suite_x509write.data
@@ -1,78 +1,86 @@
 Certificate Request check Server1 SHA1
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha1":MBEDTLS_MD_SHA1:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha1":MBEDTLS_MD_SHA1:0:0:0:0
 
 Certificate Request check Server1 SHA224
 depends_on:MBEDTLS_SHA256_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha224":MBEDTLS_MD_SHA224:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha224":MBEDTLS_MD_SHA224:0:0:0:0
 
 Certificate Request check Server1 SHA256
 depends_on:MBEDTLS_SHA256_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha256":MBEDTLS_MD_SHA256:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha256":MBEDTLS_MD_SHA256:0:0:0:0
 
 Certificate Request check Server1 SHA384
 depends_on:MBEDTLS_SHA512_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha384":MBEDTLS_MD_SHA384:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha384":MBEDTLS_MD_SHA384:0:0:0:0
 
 Certificate Request check Server1 SHA512
 depends_on:MBEDTLS_SHA512_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha512":MBEDTLS_MD_SHA512:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha512":MBEDTLS_MD_SHA512:0:0:0:0
 
 Certificate Request check Server1 MD4
 depends_on:MBEDTLS_MD4_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.md4":MBEDTLS_MD_MD4:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.md4":MBEDTLS_MD_MD4:0:0:0:0
 
 Certificate Request check Server1 MD5
 depends_on:MBEDTLS_MD5_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.md5":MBEDTLS_MD_MD5:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.md5":MBEDTLS_MD_MD5:0:0:0:0
 
 Certificate Request check Server1 key_usage
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:0:0
+
+Certificate Request check Server1 key_usage empty
+depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage_empty":MBEDTLS_MD_SHA1:0:1:0:0
 
 Certificate Request check Server1 ns_cert_type
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type":MBEDTLS_MD_SHA1:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type":MBEDTLS_MD_SHA1:0:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1
+
+Certificate Request check Server1 ns_cert_type empty
+depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type_empty":MBEDTLS_MD_SHA1:0:0:0:1
 
 Certificate Request check Server1 key_usage + ns_cert_type
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.ku-ct":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.ku-ct":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1
 
 Certificate Request check Server5 ECDSA, key_usage
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_ECDSA_C:MBEDTLS_ECDSA_DETERMINISTIC:MBEDTLS_ECP_DP_SECP256R1_ENABLED
-x509_csr_check:"data_files/server5.key":"data_files/server5.req.ku.sha1":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION:0
+x509_csr_check:"data_files/server5.key":"data_files/server5.req.ku.sha1":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION:1:0:0
 
 Certificate write check Server1 SHA1
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:1:-1:"data_files/server1.crt":0
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:0:0:1:-1:"data_files/server1.crt":0
 
 Certificate write check Server1 SHA1, key_usage
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:0:1:-1:"data_files/server1.key_usage.crt":0
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:0:0:1:-1:"data_files/server1.key_usage.crt":0
 
 Certificate write check Server1 SHA1, ns_cert_type
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1:-1:"data_files/server1.cert_type.crt":0
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1:1:-1:"data_files/server1.cert_type.crt":0
 
 Certificate write check Server1 SHA1, version 1
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:1:MBEDTLS_X509_CRT_VERSION_1:"data_files/server1.v1.crt":0
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:0:0:1:MBEDTLS_X509_CRT_VERSION_1:"data_files/server1.v1.crt":0
 
 Certificate write check Server1 SHA1, RSA_ALT
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:0:-1:"data_files/server1.noauthid.crt":1
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:0:0:0:-1:"data_files/server1.noauthid.crt":1
 
 Certificate write check Server1 SHA1, RSA_ALT, key_usage
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:0:0:-1:"data_files/server1.key_usage_noauthid.crt":1
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:0:0:0:-1:"data_files/server1.key_usage_noauthid.crt":1
 
 Certificate write check Server1 SHA1, RSA_ALT, ns_cert_type
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:0:-1:"data_files/server1.cert_type_noauthid.crt":1
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1:0:-1:"data_files/server1.cert_type_noauthid.crt":1
 
 Certificate write check Server1 SHA1, RSA_ALT, version 1
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_MD5_C
-x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:0:MBEDTLS_X509_CRT_VERSION_1:"data_files/server1.v1.crt":1
+x509_crt_check:"data_files/server1.key":"":"C=NL,O=PolarSSL,CN=PolarSSL Server 1":"data_files/test-ca.key":"PolarSSLTest":"C=NL,O=PolarSSL,CN=PolarSSL Test CA":"1":"20110212144406":"20210212144406":MBEDTLS_MD_SHA1:0:0:0:0:0:MBEDTLS_X509_CRT_VERSION_1:"data_files/server1.v1.crt":1
 
 X509 String to Names #1
 mbedtls_x509_string_to_names:"C=NL,O=Offspark\, Inc., OU=PolarSSL":"C=NL, O=Offspark, Inc., OU=PolarSSL":0
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index c00b1ac..535807e 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -37,7 +37,8 @@
 
 /* BEGIN_CASE depends_on:MBEDTLS_PEM_WRITE_C:MBEDTLS_X509_CSR_WRITE_C */
 void x509_csr_check( char * key_file, char * cert_req_check_file, int md_type,
-                     int key_usage, int cert_type )
+                     int key_usage, int set_key_usage, int cert_type,
+                     int set_cert_type )
 {
     mbedtls_pk_context key;
     mbedtls_x509write_csr req;
@@ -59,9 +60,9 @@
     mbedtls_x509write_csr_set_md_alg( &req, md_type );
     mbedtls_x509write_csr_set_key( &req, &key );
     TEST_ASSERT( mbedtls_x509write_csr_set_subject_name( &req, subject_name ) == 0 );
-    if( key_usage != 0 )
+    if( set_key_usage != 0 )
         TEST_ASSERT( mbedtls_x509write_csr_set_key_usage( &req, key_usage ) == 0 );
-    if( cert_type != 0 )
+    if( set_cert_type != 0 )
         TEST_ASSERT( mbedtls_x509write_csr_set_ns_cert_type( &req, cert_type ) == 0 );
 
     ret = mbedtls_x509write_csr_pem( &req, buf, sizeof( buf ),
@@ -100,7 +101,8 @@
                      char *subject_name, char *issuer_key_file,
                      char *issuer_pwd, char *issuer_name,
                      char *serial_str, char *not_before, char *not_after,
-                     int md_type, int key_usage, int cert_type, int auth_ident,
+                     int md_type, int key_usage, int set_key_usage,
+                     int cert_type, int set_cert_type, int auth_ident,
                      int ver, char *cert_check_file, int rsa_alt )
 {
     mbedtls_pk_context subject_key, issuer_key, issuer_key_alt;
@@ -168,9 +170,9 @@
         TEST_ASSERT( mbedtls_x509write_crt_set_subject_key_identifier( &crt ) == 0 );
         if( auth_ident )
             TEST_ASSERT( mbedtls_x509write_crt_set_authority_key_identifier( &crt ) == 0 );
-        if( key_usage != 0 )
+        if( set_key_usage != 0 )
             TEST_ASSERT( mbedtls_x509write_crt_set_key_usage( &crt, key_usage ) == 0 );
-        if( cert_type != 0 )
+        if( set_cert_type != 0 )
             TEST_ASSERT( mbedtls_x509write_crt_set_ns_cert_type( &crt, cert_type ) == 0 );
     }