diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index ea8e0c9..702aefb 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -550,6 +550,27 @@
 
 all_final += crl_cat_ec-rsa.pem crl_cat_rsa-ec.pem
 
+authorityKeyId_subjectKeyId.crt.der:
+	$(OPENSSL) req -x509 -nodes -days 7300 -key server5.key -outform DER -out authorityKeyId_subjectKeyId.crt.der -config authorityKeyId_subjectKeyId.conf -extensions 'v3_req'
+
+authorityKeyId_subjectKeyId_tag_malformed.crt.der: authorityKeyId_subjectKeyId.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/04145061A58FD407D9D782010CE5657F8C6346A713BE/01145061A58FD407D9D782010CE5657F8C6346A713BE/" | xxd -r -p > $@
+
+authorityKeyId_subjectKeyId_length_malformed.crt.der: authorityKeyId_subjectKeyId.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/306D80145061A58FD407/306C80145061A58FD407/" | xxd -r -p > $@
+
+authorityKeyId_subjectKeyId_sequence_tag_malformed.crt.der: authorityKeyId_subjectKeyId.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/6F306D80145061A58FD4/6F006D80145061A58FD4/" | xxd -r -p > $@
+
+authorityKeyId_subjectKeyId_keyid_tag_malformed.crt.der: authorityKeyId_subjectKeyId.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/306D80145061A58FD407/306D00145061A58FD407/" | xxd -r -p > $@
+
+authorityKeyId_subjectKeyId_issuer_tag1_malformed.crt.der: authorityKeyId_subjectKeyId.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/A13FA43D303B310B3009/003FA43D303B310B3009/" | xxd -r -p > $@
+
+authorityKeyId_subjectKeyId_issuer_tag2_malformed.crt.der: authorityKeyId_subjectKeyId.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/A43D303B310B30090603/003D303B310B30090603/" | xxd -r -p > $@
+
 ################################################################
 #### Generate various RSA keys
 ################################################################
diff --git a/tests/data_files/authorityKeyId_subjectKeyId.conf b/tests/data_files/authorityKeyId_subjectKeyId.conf
new file mode 100644
index 0000000..208082d
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId.conf
@@ -0,0 +1,11 @@
+[req]
+distinguished_name = req_distinguished_name
+x509_extensions = v3_req
+prompt = no
+[req_distinguished_name]
+countryName = NL
+organizationalUnitName = PolarSSL
+commonName = PolarSSL Test CA
+[v3_req]
+subjectKeyIdentifier = hash
+authorityKeyIdentifier = keyid:always,issuer:always
diff --git a/tests/data_files/authorityKeyId_subjectKeyId.crt.der b/tests/data_files/authorityKeyId_subjectKeyId.crt.der
new file mode 100644
index 0000000..dbbe518
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId.crt.der
Binary files differ
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag1_malformed.crt.der b/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag1_malformed.crt.der
new file mode 100644
index 0000000..6f9ce68
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag1_malformed.crt.der
Binary files differ
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag2_malformed.crt.der b/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag2_malformed.crt.der
new file mode 100644
index 0000000..c967043
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag2_malformed.crt.der
Binary files differ
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_keyid_tag_malformed.crt.der b/tests/data_files/authorityKeyId_subjectKeyId_keyid_tag_malformed.crt.der
new file mode 100644
index 0000000..be798cc
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_keyid_tag_malformed.crt.der
Binary files differ
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_length_malformed.crt.der b/tests/data_files/authorityKeyId_subjectKeyId_length_malformed.crt.der
new file mode 100644
index 0000000..3f9e870
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_length_malformed.crt.der
Binary files differ
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_sequence_tag_malformed.crt.der b/tests/data_files/authorityKeyId_subjectKeyId_sequence_tag_malformed.crt.der
new file mode 100644
index 0000000..5a4b362
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_sequence_tag_malformed.crt.der
Binary files differ
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_tag_malformed.crt.der b/tests/data_files/authorityKeyId_subjectKeyId_tag_malformed.crt.der
new file mode 100644
index 0000000..b0ba18e
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_tag_malformed.crt.der
Binary files differ