diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index ea8e0c96a..702aefb6d 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -550,6 +550,27 @@ crl_cat_rsa-ec.pem:crl.pem crl-ec-sha256.pem
 
 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 000000000..208082d20
--- /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 000000000..dbbe51866
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId.crt.der 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 000000000..6f9ce685e
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag1_malformed.crt.der 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 000000000..c96704338
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId_issuer_tag2_malformed.crt.der 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 000000000..be798cc12
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId_keyid_tag_malformed.crt.der 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 000000000..3f9e87096
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId_length_malformed.crt.der 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 000000000..5a4b3624c
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId_sequence_tag_malformed.crt.der 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 000000000..b0ba18ead
Binary files /dev/null and b/tests/data_files/authorityKeyId_subjectKeyId_tag_malformed.crt.der differ