renew-test-certs

DevOps & Security

Renews expired TLS test certificates used by MockServer integration tests. Use when TLS tests fail with "Channel handler removed before valid response has been received", "Broken pipe", certificate expired errors, or when a user says "renew certs", "certificates expired", "TLS tests failing".

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Renew Test TLS Certificates

MockServer integration tests use custom CA-signed leaf certificates for TLS testing. These certificates have a finite validity period and must be renewed when they expire.

Prerequisites

openssl: pre-installed on macOS

Certificate Locations

Three sets of leaf certificates exist, each signed by their own CA:

Directory	Key Type	CA Valid Until
`mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/`	RSA 2048	Feb 2028
`mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/ec/`	ECDSA P-256	Feb 2028
`mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/separateca/`	RSA 2048	Feb 2028

Each directory contains:

ca.pem / ca-key.pem / ca-key-pkcs8.pem -- CA certificate and keys (long-lived, do NOT regenerate unless expired)
leaf-cert.pem / leaf-key.pem / leaf-key-pkcs8.pem -- Leaf certificate and keys (short-lived, REGENERATE when expired)
leaf-cert-chain.pem -- Certificate chain (leaf + CA)
csr.json -- Certificate signing request config (reference only)

Step 1: Check Certificate Expiry

for dir in \
  mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls \
  mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/ec \
  mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/separateca; do
  echo "=== $dir ==="
  echo -n "  CA:   "; openssl x509 -in "$dir/ca.pem" -noout -enddate
  echo -n "  Leaf: "; openssl x509 -in "$dir/leaf-cert.pem" -noout -enddate
done

Step 2: Create Extensions Config

Create a temporary OpenSSL extensions config for leaf certificates. This MUST include authorityKeyIdentifier because the CA and leaf share the same subject DN -- without AKI, Java's trust manager treats the leaf as self-signed.

cat > .tmp/leaf-ext.cnf << 'EOF'
[v3_leaf]
basicConstraints = critical,CA:FALSE
keyUsage = critical,digitalSignature,keyEncipherment
extendedKeyUsage = serverAuth,clientAuth
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid,issuer
subjectAltName = DNS:example.com,DNS:www.example.com,DNS:localhost,IP:127.0.0.1,URI:https://www.example.com
EOF

Step 3: Regenerate Leaf Certificates

RSA leaf (root `tls/` directory)

CERT_DIR="mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls"
cd "$CERT_DIR"

openssl req -new -newkey rsa:2048 -nodes -keyout leaf-key.pem \
  -subj "/C=UK/L=London/O=MockServer/CN=www.mockserver.com" \
  -out .tmp/leaf.csr

openssl x509 -req -in .tmp/leaf.csr \
  -CA ca.pem -CAkey ca-key.pem -CAcreateserial \
  -out leaf-cert.pem -days 1825 \
  -extfile .tmp/leaf-ext.cnf -extensions v3_leaf

openssl pkcs8 -topk8 -inform PEM -in leaf-key.pem -out leaf-key-pkcs8.pem -nocrypt
cat leaf-cert.pem > leaf-cert-chain.pem
cat ca.pem >> leaf-cert-chain.pem
rm -f ca.srl .tmp/leaf.csr

EC leaf (`tls/ec/` directory)

CERT_DIR="mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/ec"
cd "$CERT_DIR"

openssl req -new -newkey ec -pkeyopt ec_paramgen_curve:prime256v1 -nodes -keyout leaf-key.pem \
  -subj "/C=UK/L=London/O=MockServer/CN=www.mockserver.com" \
  -out .tmp/leaf-ec.csr

openssl x509 -req -in .tmp/leaf-ec.csr \
  -CA ca.pem -CAkey ca-key.pem -CAcreateserial \
  -out leaf-cert.pem -days 1825 \
  -extfile .tmp/leaf-ext.cnf -extensions v3_leaf

openssl pkcs8 -topk8 -inform PEM -in leaf-key.pem -out leaf-key-pkcs8.pem -nocrypt
cat leaf-cert.pem > leaf-cert-chain.pem
cat ca.pem >> leaf-cert-chain.pem
rm -f ca.srl .tmp/leaf-ec.csr

RSA leaf (`tls/separateca/` directory)

CERT_DIR="mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/separateca"
cd "$CERT_DIR"

openssl req -new -newkey rsa:2048 -nodes -keyout leaf-key.pem \
  -subj "/C=UK/L=London/O=MockServer/CN=www.mockserver.com" \
  -out .tmp/leaf-sep.csr

openssl x509 -req -in .tmp/leaf-sep.csr \
  -CA ca.pem -CAkey ca-key.pem -CAcreateserial \
  -out leaf-cert.pem -days 1825 \
  -extfile .tmp/leaf-ext.cnf -extensions v3_leaf

openssl pkcs8 -topk8 -inform PEM -in leaf-key.pem -out leaf-key-pkcs8.pem -nocrypt
cat leaf-cert.pem > leaf-cert-chain.pem
cat ca.pem >> leaf-cert-chain.pem
rm -f ca.srl .tmp/leaf-sep.csr

Step 4: Verify

For each directory, verify the leaf cert chains to the CA and check the AKI extension:

openssl verify -CAfile ca.pem leaf-cert.pem
openssl x509 -in leaf-cert.pem -noout -dates
openssl x509 -in leaf-cert.pem -noout -text | grep -A2 "Authority Key"

Then run the affected tests:

cd mockserver && ./mvnw -pl mockserver-netty verify \
  -Dtest=none \
  -Dit.test="CustomPrivateKeyAndCertificateWithECKeysMockingIntegrationTest,ClientAuthenticationCustomPrivateKeyAndCertificateMockingIntegrationTest,ClientAuthenticationAdditionalCertificateChainMockingIntegrationTest,ForwardWithCustomClientCertificateIntegrationTest" \
  -Djava.security.egd=file:/dev/urandom

Step 5: Clean Up

rm -f .tmp/leaf-ext.cnf

Important: Do NOT Use cfssl for Leaf Certs

cfssl gencert does NOT include the authorityKeyIdentifier extension by default. Because the CA and leaf certificates share the same subject DN (C=UK, L=London, O=MockServer, CN=www.mockserver.com), Java's X509TrustManager cannot chain the leaf to the CA without AKI and treats it as self-signed. Always use openssl x509 -req with the extensions config above.

cfssl CAN still be used to generate new CA certificates (via cfssl genkey -initca).

Affected Test Classes

These test classes use the leaf certificates and will fail when they expire:

Root `tls/` directory (RSA)

ClientAuthenticationAdditionalCertificateChainMockingIntegrationTest
ClientAuthenticationCustomPrivateKeyAndCertificateMockingIntegrationTest
ClientAuthenticationCustomCertificateAuthorityMockingIntegrationTest
CustomCertificateAuthorityMockingIntegrationTest
ForwardWithCustomTrustManagerWithCustomCAMockingIntegrationTest
ForwardViaHttpsProxyWithCustomTrustManagerWithCustomCAMockingIntegrationTest
ForwardWithCustomClientCertificateIntegrationTest
AuthenticatedControlPlaneUsingMTLSClientMockingIntegrationTest
AuthenticatedControlPlaneUsingMTLSClientNotAuthenticatedIntegrationTest

`tls/ec/` directory (ECDSA)

CustomPrivateKeyAndCertificateWithECKeysMockingIntegrationTest

`tls/separateca/` directory (RSA, separate CA)

AbstractForwardViaHttpsProxyMockingIntegrationTest (and 9 subclasses)
ForwardWithCustomClientCertificateIntegrationTest
AuthenticatedControlPlaneUsingMTLSClientNotAuthenticatedIntegrationTest

Regenerating CA Certificates

If the CA certificates themselves expire (Feb 2028), follow the instructions in:

mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/generate_custom_certificates.md
mockserver/mockserver-netty/src/test/resources/org/mockserver/netty/integration/tls/ec/generate_custom_certificates.md