diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 233a2c7..563d86e 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -338,14 +338,14 @@
 server5-tricky-ip-san.crt: server5.key
 	$(OPENSSL) req -x509 -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS Tricky IP SAN" -set_serial 77 -config $(test_ca_config_file) -extensions tricky_ip_san -days 3650 -sha256 -key server5.key -out $@
 	
-server5-directoryname.crt: server5.key
-	$(OPENSSL) req -x509 -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS directoryName SAN" -set_serial 77 -config $(test_ca_config_file) -extensions directory_name_san -days 3650 -sha256 -key server5.key -out $@
+server5-directoryname.crt.der: server5.key
+	$(OPENSSL) req -x509 -outform der -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS directoryName SAN" -set_serial 77 -config $(test_ca_config_file) -extensions directory_name_san -days 3650 -sha256 -key server5.key -out $@
 
-server5-two-directorynames.crt: server5.key
-	$(OPENSSL) req -x509 -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS directoryName SAN" -set_serial 77 -config $(test_ca_config_file) -extensions two_directorynames -days 3650 -sha256 -key server5.key -out $@
+server5-two-directorynames.crt.der: server5.key
+	$(OPENSSL) req -x509 -outform der -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS directoryName SAN" -set_serial 77 -config $(test_ca_config_file) -extensions two_directorynames -days 3650 -sha256 -key server5.key -out $@
 
-server5-second-directoryname-malformed.crt: server5-two-directorynames.crt
-	(head -n1 $<; sed -n '2,12p' $< | base64 --decode | hexdump -ve '1/1 "%.2X"' | sed "s/0355040A0C0A4D414C464F524D5F4D45/1555040A0C0A4D414C464F524D5F4D45/" | xxd -r -p | base64 -w64; tail -n1 $<) > $@
+server5-second-directoryname-malformed.crt.der: server5-two-directorynames.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/0355040A0C0A4D414C464F524D5F4D45/1555040A0C0A4D414C464F524D5F4D45/" | xxd -r -p > $@
 
 all_final += server5-tricky-ip-san.crt
 
diff --git a/tests/data_files/server5-directoryname.crt b/tests/data_files/server5-directoryname.crt
deleted file mode 100644
index afa88b3..0000000
--- a/tests/data_files/server5-directoryname.crt
+++ /dev/null
@@ -1,13 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIB7jCCAZSgAwIBAgIBTTAKBggqhkjOPQQDAjBFMQswCQYDVQQGEwJVSzERMA8G
-A1UECgwITWJlZCBUTFMxIzAhBgNVBAMMGk1iZWQgVExTIGRpcmVjdG9yeU5hbWUg
-U0FOMB4XDTIzMDExMDE2NTkyOVoXDTMzMDEwNzE2NTkyOVowRTELMAkGA1UEBhMC
-VUsxETAPBgNVBAoMCE1iZWQgVExTMSMwIQYDVQQDDBpNYmVkIFRMUyBkaXJlY3Rv
-cnlOYW1lIFNBTjBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABDfMVtl2CR5acj7H
-WS3/IG7ufPkGkXTQrRS192giWWKSTuUA2CMR/+ov0jRdXRa9iojCa3cNVc2KKg76
-Aci07f+jdTBzMFIGA1UdEQRLMEmkRzBFMQswCQYDVQQGEwJVSzERMA8GA1UECgwI
-TWJlZCBUTFMxIzAhBgNVBAMMGk1iZWQgVExTIGRpcmVjdG9yeU5hbWUgU0FOMB0G
-A1UdDgQWBBRQYaWP1AfZ14IBDOVlf4xjRqcTvjAKBggqhkjOPQQDAgNIADBFAiBr
-PtyaL8tF+jghNK32ZnWriCp2k7Aq+QVuef+6+sSH6AIhAIKw+o0J2Pu27ulHFIzI
-MdFECpZ3nqAGbTOTOMX6LoDh
------END CERTIFICATE-----
diff --git a/tests/data_files/server5-directoryname.crt.der b/tests/data_files/server5-directoryname.crt.der
new file mode 100644
index 0000000..4badea1
--- /dev/null
+++ b/tests/data_files/server5-directoryname.crt.der
Binary files differ
diff --git a/tests/data_files/server5-second-directoryname-malformed.crt b/tests/data_files/server5-second-directoryname-malformed.crt
deleted file mode 100644
index 11d439b..0000000
--- a/tests/data_files/server5-second-directoryname-malformed.crt
+++ /dev/null
@@ -1,13 +0,0 @@
------BEGIN CERTIFICATE-----
-MIICCTCCAa+gAwIBAgIBTTAKBggqhkjOPQQDAjBFMQswCQYDVQQGEwJVSzERMA8G
-A1UECgwITWJlZCBUTFMxIzAhBgNVBAMMGk1iZWQgVExTIGRpcmVjdG9yeU5hbWUg
-U0FOMB4XDTIzMDExMjEwMzQxMVoXDTMzMDEwOTEwMzQxMVowRTELMAkGA1UEBhMC
-VUsxETAPBgNVBAoMCE1iZWQgVExTMSMwIQYDVQQDDBpNYmVkIFRMUyBkaXJlY3Rv
-cnlOYW1lIFNBTjBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABDfMVtl2CR5acj7H
-WS3/IG7ufPkGkXTQrRS192giWWKSTuUA2CMR/+ov0jRdXRa9iojCa3cNVc2KKg76
-Aci07f+jgY8wgYwwawYDVR0RBGQwYqRHMEUxCzAJBgNVBAYTAlVLMREwDwYDVQQK
-DAhNYmVkIFRMUzEjMCEGA1UEAwwaTWJlZCBUTFMgZGlyZWN0b3J5TmFtZSBTQU6k
-FzAVMRMwEQYVVQQKDApNQUxGT1JNX01FMB0GA1UdDgQWBBRQYaWP1AfZ14IBDOVl
-f4xjRqcTvjAKBggqhkjOPQQDAgNIADBFAiAHI/ousygMhcDhAb+bK402vAh4+bGK
-UuwPMpd1XQ2FHAIhAL0uuCTzI72PJLyxB4cFtbmodUejDc+Oa02AUW4Ed8Uu
------END CERTIFICATE-----
diff --git a/tests/data_files/server5-second-directoryname-malformed.crt.der b/tests/data_files/server5-second-directoryname-malformed.crt.der
new file mode 100644
index 0000000..7074fd8
--- /dev/null
+++ b/tests/data_files/server5-second-directoryname-malformed.crt.der
Binary files differ
diff --git a/tests/data_files/server5-two-directorynames.crt b/tests/data_files/server5-two-directorynames.crt
deleted file mode 100644
index aa76c16..0000000
--- a/tests/data_files/server5-two-directorynames.crt
+++ /dev/null
@@ -1,13 +0,0 @@
------BEGIN CERTIFICATE-----
-MIICCTCCAa+gAwIBAgIBTTAKBggqhkjOPQQDAjBFMQswCQYDVQQGEwJVSzERMA8G
-A1UECgwITWJlZCBUTFMxIzAhBgNVBAMMGk1iZWQgVExTIGRpcmVjdG9yeU5hbWUg
-U0FOMB4XDTIzMDExMjEwMzQxMVoXDTMzMDEwOTEwMzQxMVowRTELMAkGA1UEBhMC
-VUsxETAPBgNVBAoMCE1iZWQgVExTMSMwIQYDVQQDDBpNYmVkIFRMUyBkaXJlY3Rv
-cnlOYW1lIFNBTjBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABDfMVtl2CR5acj7H
-WS3/IG7ufPkGkXTQrRS192giWWKSTuUA2CMR/+ov0jRdXRa9iojCa3cNVc2KKg76
-Aci07f+jgY8wgYwwawYDVR0RBGQwYqRHMEUxCzAJBgNVBAYTAlVLMREwDwYDVQQK
-DAhNYmVkIFRMUzEjMCEGA1UEAwwaTWJlZCBUTFMgZGlyZWN0b3J5TmFtZSBTQU6k
-FzAVMRMwEQYDVQQKDApNQUxGT1JNX01FMB0GA1UdDgQWBBRQYaWP1AfZ14IBDOVl
-f4xjRqcTvjAKBggqhkjOPQQDAgNIADBFAiAHI/ousygMhcDhAb+bK402vAh4+bGK
-UuwPMpd1XQ2FHAIhAL0uuCTzI72PJLyxB4cFtbmodUejDc+Oa02AUW4Ed8Uu
------END CERTIFICATE-----
diff --git a/tests/data_files/server5-two-directorynames.crt.der b/tests/data_files/server5-two-directorynames.crt.der
new file mode 100644
index 0000000..c98a018
--- /dev/null
+++ b/tests/data_files/server5-two-directorynames.crt.der
Binary files differ
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index b811314..8df53df 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -95,16 +95,16 @@
 x509_cert_info:"data_files/server5-nonprintable_othername.crt":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS non-printable othername SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS non-printable othername SAN\nissued  on        \: 2022-09-06 15\:56\:47\nexpires on        \: 2032-09-03 15\:56\:47\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    otherName \:\n        hardware module name \:\n            hardware type          \: 1.3.6.1.4.1.17.3\n            hardware serial number \: 3132338081008180333231\n"
 
 X509 CRT information EC, SHA256 Digest, directoryName SAN
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
-x509_cert_info:"data_files/server5-directoryname.crt":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nissued  on        \: 2023-01-10 16\:59\:29\nexpires on        \: 2033-01-07 16\:59\:29\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    directoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n"
+depends_on:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
+x509_cert_info:"data_files/server5-directoryname.crt.der":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nissued  on        \: 2023-01-10 16\:59\:29\nexpires on        \: 2033-01-07 16\:59\:29\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    directoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n"
 
 X509 CRT information EC, SHA256 Digest, two directoryName SANs
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
-x509_cert_info:"data_files/server5-two-directorynames.crt":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nissued  on        \: 2023-01-12 10\:34\:11\nexpires on        \: 2033-01-09 10\:34\:11\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    directoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n    directoryName \: O=MALFORM_ME\n"
+depends_on:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
+x509_cert_info:"data_files/server5-two-directorynames.crt.der":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nissued  on        \: 2023-01-12 10\:34\:11\nexpires on        \: 2033-01-09 10\:34\:11\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    directoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n    directoryName \: O=MALFORM_ME\n"
 
 X509 CRT information EC, SHA256 Digest, second directoryname malformed
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
-x509_cert_info:"data_files/server5-second-directoryname-malformed.crt":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nissued  on        \: 2023-01-12 10\:34\:11\nexpires on        \: 2033-01-09 10\:34\:11\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    directoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n    <malformed>\n"
+depends_on:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
+x509_cert_info:"data_files/server5-second-directoryname-malformed.crt.der":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\nissued  on        \: 2023-01-12 10\:34\:11\nexpires on        \: 2033-01-09 10\:34\:11\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    directoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n    <malformed>\n"
 
 X509 CRT information EC, SHA256 Digest, Wisun Fan device
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_MD_CAN_SHA256
@@ -203,8 +203,8 @@
 x509_parse_san:"data_files/server5-nonprintable_othername.crt":"type \: 0\notherName \: hardware module name \: hardware type \: 1.3.6.1.4.1.17.3, hardware serial number \: 3132338081008180333231\n"
 
 X509 SAN parsing directoryName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
-x509_parse_san:"data_files/server5-directoryname.crt":"type \: 4\ndirectoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n"
+depends_on:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA
+x509_parse_san:"data_files/server5-directoryname.crt.der":"type \: 4\ndirectoryName \: C=UK, O=Mbed TLS, CN=Mbed TLS directoryName SAN\n"
 
 X509 SAN parsing dNSName
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA256