Add tests for flags passed to f_vrfy

The tests cover chains of length 0, 1 and 2, with one error, located at any of
the available levels in the chain. This exercises all three call sites of
f_vrfy (two in verify_top, one in verify_child). Chains of greater length
would not cover any new code path or behaviour that I can see.
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 0ad27ce..d7a57a9 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -47,6 +47,16 @@
 	$(OPENSSL) req -x509 -config $(test_ca_config_file) -key $(test_ca_key_file_rsa) -passin "pass:$(test_ca_pwd_rsa)" -set_serial 0 -days 3653 -sha256 -in test-ca.csr -out $@
 all_final += test-ca-sha256.crt
 
+test_ca_crt_file_ec = test-ca2.crt
+test_ca_key_file_ec = test-ca2.key
+
+test-int-ca.csr: test-int-ca.key $(test_ca_config_file)
+	$(OPENSSL) req -new -config $(test_ca_config_file) -key test-int-ca.key -subj "/C=NL/O=PolarSSL/CN=PolarSSL Test Intermediate CA" -out $@
+all_intermediate += test-int-ca.csr
+test-int-ca-exp.crt: $(test_ca_key_file_ec) $(test_ca_config_file) test-int-ca.csr
+	$(FAKETIME) -f -3653d $(OPENSSL) x509 -req -extfile $(test_ca_config_file) -extensions v3_ca -CA $(test_ca_crt_file_ec) -CAkey $(test_ca_key_file_ec) -set_serial 14 -days 3653 -sha256 -in test-int-ca.csr -out $@
+all_final += test-int-ca-exp.crt
+
 cli_crt_key_file_rsa = cli-rsa.key
 cli_crt_extensions_file = cli.opensslconf
 
@@ -81,6 +91,14 @@
 server7-badsign.crt: server7.crt $(test_ca_int_rsa1)
 	{ head -n-2 server7.crt; tail -n-2 server7.crt | sed -e '1s/0\(=*\)$$/_\1/' -e '1s/[^_=]\(=*\)$$/0\1/' -e '1s/_/1/'; cat test-int-ca.crt; } > server7-badsign.crt
 all_final += server7-badsign.crt
+server7_int-ca-exp.crt: server7.crt test-int-ca-exp.crt
+	cat server7.crt test-int-ca-exp.crt > $@
+all_final += server7_int-ca-exp.crt
+
+server5-ss-expired.crt: server5.key
+	$(FAKETIME) -f -3653d $(OPENSSL) req -x509 -new -subj "/C=UK/O=mbed TLS/OU=testsuite/CN=localhost" -days 3653 -sha256 -key $< -out $@
+all_final += server5-ss-expired.crt
+
 
 ################################################################
 #### Generate various RSA keys
diff --git a/tests/data_files/server5-ss-expired.crt b/tests/data_files/server5-ss-expired.crt
new file mode 100644
index 0000000..287ce98
--- /dev/null
+++ b/tests/data_files/server5-ss-expired.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/data_files/server7_int-ca-exp.crt b/tests/data_files/server7_int-ca-exp.crt
new file mode 100644
index 0000000..fc00517
--- /dev/null
+++ b/tests/data_files/server7_int-ca-exp.crt
@@ -0,0 +1,47 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/data_files/test-int-ca-exp.crt b/tests/data_files/test-int-ca-exp.crt
new file mode 100644
index 0000000..c549654
--- /dev/null
+++ b/tests/data_files/test-int-ca-exp.crt
@@ -0,0 +1,24 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----