// Copyright 2016 The BoringSSL Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package runner

import (
	"bytes"
	"crypto"
	"crypto/ecdsa"
	"crypto/ed25519"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	_ "embed"
	"encoding/base64"
	"encoding/binary"
	"encoding/hex"
	"encoding/json"
	"encoding/pem"
	"errors"
	"flag"
	"fmt"
	"io"
	"net"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"slices"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"time"

	"boringssl.googlesource.com/boringssl.git/util/testresult"
	"filippo.io/mldsa"
	"golang.org/x/crypto/cryptobyte"
	"golang.org/x/term"
)

var (
	useValgrind        = flag.Bool("valgrind", false, "If true, run code under valgrind")
	useGDB             = flag.Bool("gdb", false, "If true, run BoringSSL code under gdb")
	useLLDB            = flag.Bool("lldb", false, "If true, run BoringSSL code under lldb")
	useRR              = flag.Bool("rr-record", false, "If true, run BoringSSL code under `rr record`.")
	waitForDebugger    = flag.Bool("wait-for-debugger", false, "If true, jobs will run one at a time and pause for a debugger to attach")
	flagDebug          = flag.Bool("debug", false, "Hexdump the contents of the connection")
	mallocTest         = flag.Int64("malloc-test", -1, "If non-negative, run each test with each malloc in turn failing from the given number onwards.")
	mallocTestDebug    = flag.Bool("malloc-test-debug", false, "If true, ask bssl_shim to abort rather than fail a malloc. This can be used with a specific value for --malloc-test to identity the malloc failing that is causing problems.")
	jsonOutput         = flag.String("json-output", "", "The file to output JSON results to.")
	pipe               = flag.Bool("pipe", !term.IsTerminal(int(os.Stdout.Fd())), "If true, print status output suitable for piping into another program.")
	testToRun          = flag.String("test", "", "Semicolon-separated patterns of tests to run, or empty to run all tests")
	skipTest           = flag.String("skip", "", "Semicolon-separated patterns of tests to skip")
	allowHintMismatch  = flag.String("allow-hint-mismatch", "", "Semicolon-separated patterns of tests where hints may mismatch")
	numWorkersFlag     = flag.Int("num-workers", runtime.NumCPU(), "The number of workers to run in parallel.")
	shimPath           = flag.String("shim-path", "../../../build/ssl/test/bssl_shim", "The location of the shim binary.")
	shimExtraFlags     = flag.String("shim-extra-flags", "", "Semicolon-separated extra flags to pass to the shim binary on each invocation.")
	handshakerPath     = flag.String("handshaker-path", "../../../build/ssl/test/handshaker", "The location of the handshaker binary.")
	fuzzer             = flag.Bool("fuzzer", false, "If true, tests against a BoringSSL built in fuzzer mode.")
	transcriptDir      = flag.String("transcript-dir", "", "The directory in which to write transcripts.")
	idleTimeout        = flag.Duration("idle-timeout", 15*time.Second, "The number of seconds to wait for a read or write to bssl_shim.")
	deterministic      = flag.Bool("deterministic", false, "If true, uses a deterministic PRNG in the runner.")
	allowUnimplemented = flag.Bool("allow-unimplemented", false, "If true, report pass even if some tests are unimplemented.")
	looseErrors        = flag.Bool("loose-errors", false, "If true, allow shims to report an untranslated error code.")
	shimConfigFile     = flag.String("shim-config", "", "A config file to use to configure the tests for this shim.")
	includeDisabled    = flag.Bool("include-disabled", false, "If true, also runs disabled tests.")
	repeatUntilFailure = flag.Bool("repeat-until-failure", false, "If true, the first selected test will be run repeatedly until failure.")
	keepTestCerts      = flag.Bool("keep-test-certs", false, "If true, causes the test certificate directory to be retained")
)

// ShimConfigurations is used with the “json” package and represents a shim
// config file.
type ShimConfiguration struct {
	// DisabledTests maps from a glob-based pattern to a freeform string.
	// The glob pattern is used to exclude tests from being run and the
	// freeform string is unparsed but expected to explain why the test is
	// disabled.
	DisabledTests map[string]string

	// ErrorMap maps from expected error strings to the correct error
	// string for the shim in question. For example, it might map
	// “:NO_SHARED_CIPHER:” (a BoringSSL error string) to something
	// like “SSL_ERROR_NO_CYPHER_OVERLAP”.
	ErrorMap map[string][]string

	// HalfRTTTickets is the number of half-RTT tickets the client should
	// expect before half-RTT data when testing 0-RTT.
	HalfRTTTickets int

	// MaxACKBuffer is the maximum number of received records the shim is
	// expected to retain when ACKing.
	MaxACKBuffer int
}

// Setup shimConfig defaults aligning with BoringSSL.
var shimConfig ShimConfiguration = ShimConfiguration{
	HalfRTTTickets: 2,
	MaxACKBuffer:   32,
}

//go:embed rsa_2048_key.pem
var rsa2048KeyPEM []byte

//go:embed rsa_1024_key.pem
var rsa1024KeyPEM []byte

//go:embed ecdsa_p256_key.pem
var ecdsaP256KeyPEM []byte

//go:embed ecdsa_p384_key.pem
var ecdsaP384KeyPEM []byte

//go:embed ecdsa_p521_key.pem
var ecdsaP521KeyPEM []byte

//go:embed ed25519_key.pem
var ed25519KeyPEM []byte

//go:embed channel_id_key.pem
var channelIDKeyPEM []byte

var (
	rsa1024Key rsa.PrivateKey
	rsa2048Key rsa.PrivateKey

	ecdsaP256Key ecdsa.PrivateKey
	ecdsaP384Key ecdsa.PrivateKey
	ecdsaP521Key ecdsa.PrivateKey

	ed25519Key ed25519.PrivateKey

	mldsa44Key *mldsa.PrivateKey
	mldsa65Key *mldsa.PrivateKey
	mldsa87Key *mldsa.PrivateKey

	channelIDKey ecdsa.PrivateKey
)

var channelIDKeyPath string

func initKeys() {
	// Since RSA key generation is not particularly cheap, and the runner is
	// intended to run on systems which may be resource constrained, we load
	// keys from disk instead of dynamically generating them. We treat key
	// files the same as dynamically generated certificates, writing them
	// out to temporary files before passing them to the shim.

	for _, k := range []struct {
		pemBytes []byte
		key      *rsa.PrivateKey
	}{
		{rsa1024KeyPEM, &rsa1024Key},
		{rsa2048KeyPEM, &rsa2048Key},
	} {
		key, err := loadPEMKey(k.pemBytes)
		if err != nil {
			panic(fmt.Sprintf("failed to load RSA test key: %s", err))
		}
		*k.key = *(key.(*rsa.PrivateKey))
	}

	for _, k := range []struct {
		pemBytes []byte
		key      *ecdsa.PrivateKey
	}{
		{ecdsaP256KeyPEM, &ecdsaP256Key},
		{ecdsaP384KeyPEM, &ecdsaP384Key},
		{ecdsaP521KeyPEM, &ecdsaP521Key},
		{channelIDKeyPEM, &channelIDKey},
	} {
		key, err := loadPEMKey(k.pemBytes)
		if err != nil {
			panic(fmt.Sprintf("failed to load ECDSA test key: %s", err))
		}
		*k.key = *(key.(*ecdsa.PrivateKey))
	}

	k, err := loadPEMKey(ed25519KeyPEM)
	if err != nil {
		panic(fmt.Sprintf("failed to load Ed25519 test key: %s", err))
	}
	ed25519Key = k.(ed25519.PrivateKey)

	for _, k := range []struct {
		params *mldsa.Parameters
		key    **mldsa.PrivateKey
	}{
		{mldsa.MLDSA44(), &mldsa44Key},
		{mldsa.MLDSA65(), &mldsa65Key},
		{mldsa.MLDSA87(), &mldsa87Key},
	} {
		key, err := mldsa.GenerateKey(k.params)
		if err != nil {
			panic(fmt.Sprintf("Failed to generate ML-DSA test key: %s", err))
		}
		*k.key = key
	}

	channelIDKeyPath = writeTempKeyFile(&channelIDKey)
}

var channelIDBytes []byte

var (
	testOCSPResponse  = []byte{1, 2, 3, 4}
	testOCSPResponse2 = []byte{5, 6, 7, 8}
	testSCTList       = []byte{0, 6, 0, 4, 5, 6, 7, 8}
	testSCTList2      = []byte{0, 6, 0, 4, 1, 2, 3, 4}
)

var (
	testOCSPExtension = append([]byte{byte(extensionStatusRequest) >> 8, byte(extensionStatusRequest), 0, 8, statusTypeOCSP, 0, 0, 4}, testOCSPResponse...)
	testSCTExtension  = append([]byte{byte(extensionSignedCertificateTimestamp) >> 8, byte(extensionSignedCertificateTimestamp), 0, byte(len(testSCTList))}, testSCTList...)
)

var (
	rootCA *X509ChainBuilder

	rsaCertificate       Credential
	rsaChainCertificate  Credential
	rsa1024Certificate   Credential
	ecdsaP256Certificate Credential
	ecdsaP384Certificate Credential
	ecdsaP521Certificate Credential
	ed25519Certificate   Credential
	mldsa44Certificate   Credential
	mldsa65Certificate   Credential
	mldsa87Certificate   Credential
	garbageCertificate   Credential
	pssCertificate       Credential
)

func initCertificates() {
	for _, def := range []struct {
		name string
		key  crypto.Signer
		out  *Credential
	}{
		{"RSA-1024", &rsa1024Key, &rsa1024Certificate},
		{"RSA-2048", &rsa2048Key, &rsaCertificate},
		{"ECDSA P-256", &ecdsaP256Key, &ecdsaP256Certificate},
		{"ECDSA P-384", &ecdsaP384Key, &ecdsaP384Certificate},
		{"ECDSA P-521", &ecdsaP521Key, &ecdsaP521Certificate},
		{"Ed25519", ed25519Key, &ed25519Certificate},
		{"ML-DSA 44", mldsa44Key, &mldsa44Certificate},
		{"ML-DSA 65", mldsa65Key, &mldsa65Certificate},
		{"ML-DSA 87", mldsa87Key, &mldsa87Certificate},
	} {
		// For each test key, make a self-signed root that issues a leaf, using
		// the same algorithm.
		*def.out = NewX509Root(X509Info{
			PrivateKey:   def.key,
			Name:         pkix.Name{CommonName: fmt.Sprintf("Test %s Root", def.name)},
			IsCA:         true,
			SubjectKeyID: []byte("root"),
		}).Issue(X509Info{
			PrivateKey: def.key,
			DNSNames:   []string{"test"},
		}).ToCredential()
	}

	channelIDBytes = make([]byte, 64)
	writeIntPadded(channelIDBytes[:32], channelIDKey.X)
	writeIntPadded(channelIDBytes[32:], channelIDKey.Y)

	garbageCertificate.Certificate = [][]byte{[]byte("GARBAGE")}
	garbageCertificate.PrivateKey = rsaCertificate.PrivateKey

	// Make a default root CA for other test certificates.
	rootCA = NewX509Root(X509Info{
		PrivateKey:   &rsa2048Key,
		Name:         pkix.Name{CommonName: "Test Root"},
		IsCA:         true,
		SubjectKeyID: []byte("root"),
	})

	// Build a basic three cert chain for testing chain-specific things.
	rsaChainCertificate = rootCA.Issue(X509Info{
		PrivateKey:   &rsa2048Key,
		Name:         pkix.Name{CommonName: "Test Intermediate"},
		IsCA:         true,
		SubjectKeyID: []byte("intermediate"),
	}).Issue(X509Info{
		PrivateKey: &rsa2048Key,
		DNSNames:   []string{"test"},
	}).ToCredential()

	// Make an id-RSASSA-PSS certificate. This is only partially supported as a
	// PSS credential. The private key is still an id-rsaEncryption key, only
	// the certificate uses id-RSASSA-PSS. We do not support id-RSASSA-PSS with
	// TLS, so this test only exists to ensure BoringSSL does not accept it.
	pssCertificate = rootCA.Issue(X509Info{
		PrivateKey:         &rsa2048Key,
		DNSNames:           []string{"test"},
		EncodeSPKIAsRSAPSS: true,
	}).ToCredential()
}

var (
	p256DC          *Credential
	p256DCFromECDSA *Credential
)

func initDelegatedCredentials() {
	p256DC = createDelegatedCredential(&rsaCertificate, delegatedCredentialConfig{
		dcAlgo: signatureECDSAWithP256AndSHA256,
		algo:   signatureRSAPSSWithSHA256,
	})
	p256DCFromECDSA = createDelegatedCredential(&ecdsaP256Certificate, delegatedCredentialConfig{
		dcAlgo: signatureECDSAWithP256AndSHA256,
		algo:   signatureECDSAWithP256AndSHA256,
	})
}

var (
	rpkEcdsaP256 Credential
	rpkEcdsaP384 Credential
	rpkRsa       Credential
)

func initRawPublicKeyCredentials() {
	for _, def := range []struct {
		key crypto.Signer
		out *Credential
	}{
		{&ecdsaP256Key, &rpkEcdsaP256},
		{&ecdsaP384Key, &rpkEcdsaP384},
		{&rsa2048Key, &rpkRsa},
	} {
		var publicKey crypto.PublicKey
		switch def.key.(type) {
		case *rsa.PrivateKey:
			publicKey = def.key.(*rsa.PrivateKey).Public()
		case *ecdsa.PrivateKey:
			publicKey = def.key.(*ecdsa.PrivateKey).Public()
		default:
			panic("credential has unsupported key type")
		}
		rpkData, err := x509.MarshalPKIXPublicKey(publicKey)
		if err != nil {
			panic(err)
		}
		*def.out = Credential{
			Type:        CredentialTypeRawPublicKey,
			PrivateKey:  def.key,
			KeyPath:     writeTempKeyFile(def.key),
			Certificate: [][]byte{rpkData},
		}
	}
}

func flagInts(flagName string, vals []int) []string {
	ret := make([]string, 0, 2*len(vals))
	for _, val := range vals {
		ret = append(ret, flagName, strconv.Itoa(val))
	}
	return ret
}

func flagCurves(flagName string, vals []CurveID) []string {
	ret := make([]string, 0, 2*len(vals))
	for _, val := range vals {
		ret = append(ret, flagName, strconv.Itoa(int(val)))
	}
	return ret
}

func flagCertTypes(flagName string, vals []CertificateType) []string {
	ret := make([]string, 0, 2*len(vals))
	for _, val := range vals {
		ret = append(ret, flagName, strconv.Itoa(int(val)))
	}
	return ret
}

func base64FlagValue(in []byte) string {
	return base64.StdEncoding.EncodeToString(in)
}

func useDebugger() bool {
	return *useGDB || *useLLDB || *useRR || *waitForDebugger
}

func loadPEMKey(pemBytes []byte) (crypto.PrivateKey, error) {
	block, _ := pem.Decode(pemBytes)
	if block == nil {
		return nil, fmt.Errorf("no PEM block found")
	}

	if block.Type != "PRIVATE KEY" {
		return nil, fmt.Errorf("unexpected PEM type (expected \"PRIVATE KEY\"): %s", block.Type)
	}

	k, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {
		return nil, fmt.Errorf("failed to parse PKCS#8 key: %s", err)
	}

	return k, nil
}

// recordVersionToWire maps a record-layer protocol version to its wire
// representation.
func recordVersionToWire(vers uint16, protocol protocol) uint16 {
	if protocol == dtls {
		switch vers {
		case VersionTLS12:
			return VersionDTLS12
		case VersionTLS10:
			return VersionDTLS10
		}
	} else {
		switch vers {
		case VersionSSL30, VersionTLS10, VersionTLS11, VersionTLS12:
			return vers
		}
	}

	panic("unknown version")
}

// encodeDERValues encodes a series of bytestrings in comma-separated-hex form.
func encodeDERValues(values [][]byte) string {
	var ret strings.Builder
	for i, v := range values {
		if i > 0 {
			ret.WriteString(",")
		}
		ret.WriteString(hex.EncodeToString(v))
	}

	return ret.String()
}

func decodeHexOrPanic(in string) []byte {
	ret, err := hex.DecodeString(in)
	if err != nil {
		panic(err)
	}
	return ret
}

type testType int

const (
	clientTest testType = iota
	serverTest
)

func (t testType) String() string {
	switch t {
	case clientTest:
		return "Client"
	case serverTest:
		return "Server"
	}
	panic(fmt.Sprintf("bad test type %d", t))
}

type protocol int

const (
	tls protocol = iota
	dtls
	quic
)

func (p protocol) String() string {
	switch p {
	case tls:
		return "TLS"
	case dtls:
		return "DTLS"
	case quic:
		return "QUIC"
	}
	return "unknown protocol"
}

const (
	alpn = 1
	npn  = 2
)

// connectionExpectations contains connection-level test expectations to check
// on the runner side.
type connectionExpectations struct {
	// version, if non-zero, specifies the TLS version that must be negotiated.
	version uint16
	// cipher, if non-zero, specifies the TLS cipher suite that should be
	// negotiated.
	cipher uint16
	// channelID controls whether the connection should have negotiated a
	// Channel ID with channelIDKey.
	channelID bool
	// nextProto controls whether the connection should negotiate a next
	// protocol via NPN or ALPN.
	nextProto string
	// noNextProto, if true, means that no next protocol should be negotiated.
	noNextProto bool
	// nextProtoType, if non-zero, is the next protocol negotiation mechanism.
	nextProtoType int
	// srtpProtectionProfile is the DTLS-SRTP profile that should be negotiated.
	// If zero, none should be negotiated.
	srtpProtectionProfile uint16
	// peerSignatureAlgorithm, if not zero, is the signature algorithm that the
	// peer should have used in the handshake.
	peerSignatureAlgorithm signatureAlgorithm
	// curveID, if not zero, is the curve that the handshake should have used.
	curveID CurveID
	// peerCertificate, if not nil, is the credential the peer is expected to
	// send.
	peerCertificate *Credential
	// quicTransportParams contains the QUIC transport parameters that are to be
	// sent by the peer using codepoint 57.
	quicTransportParams []byte
	// quicTransportParamsLegacy contains the QUIC transport parameters that are
	// to be sent by the peer using legacy codepoint 0xffa5.
	quicTransportParamsLegacy []byte
	// peerApplicationSettings are the expected application settings for the
	// connection. If nil, no application settings are expected.
	peerApplicationSettings []byte
	// peerApplicationSettingsOld are the expected application settings for
	// the connection that are to be sent by the peer using old codepoint.
	// If nil, no application settings are expected.
	peerApplicationSettingsOld []byte
	// echAccepted is whether ECH should have been accepted on this connection.
	echAccepted bool
	// serverNameAck, if not nil, is whether the server should have acknowledged
	// the server name. This field is only checked in full handshakes.
	serverNameAck *bool
	// selectedPSK, if not nil, is the PSK credential that should have been
	// negotiated.
	selectedPSK *Credential
}

type testCase struct {
	testType      testType
	protocol      protocol
	name          string
	config        Config
	shouldFail    bool
	expectedError string
	// expectedLocalError, if not empty, contains a substring that must be
	// found in the local error.
	expectedLocalError string
	// expectations contains test expectations for the initial
	// connection.
	expectations connectionExpectations
	// resumeExpectations, if non-nil, contains test expectations for the
	// resumption connection. If nil, |expectations| is used.
	resumeExpectations *connectionExpectations
	// messageLen is the length, in bytes, of the test message that will be
	// sent.
	messageLen int
	// messageCount is the number of test messages that will be sent.
	messageCount int
	// resumeSession controls whether a second connection should be tested
	// which attempts to resume the first session.
	resumeSession bool
	// resumeRenewedSession controls whether a third connection should be
	// tested which attempts to resume the second connection's session.
	resumeRenewedSession bool
	// expectResumeRejected, if true, specifies that the attempted
	// resumption must be rejected by the client. This is only valid for a
	// serverTest.
	expectResumeRejected bool
	// resumeConfig, if not nil, points to a Config to be used on
	// resumption. Unless newSessionsOnResume is set,
	// SessionTicketKey, ServerSessionCache, and
	// ClientSessionCache are copied from the initial connection's
	// config. If nil, the initial connection's config is used.
	resumeConfig *Config
	// newSessionsOnResume, if true, will cause resumeConfig to
	// use a different session resumption context.
	newSessionsOnResume bool
	// noSessionCache, if true, will cause the server to run without a
	// session cache.
	noSessionCache bool
	// sendPrefix sends a prefix on the socket before actually performing a
	// handshake.
	sendPrefix string
	// shimWritesFirst controls whether the shim sends an initial "hello"
	// message before doing a roundtrip with the runner.
	shimWritesFirst bool
	// readWithUnfinishedWrite behaves like shimWritesFirst, but the shim
	// does not complete the write until responding to the first runner
	// message.
	readWithUnfinishedWrite bool
	// shimShutsDown, if true, runs a test where the shim shuts down the
	// connection immediately after the handshake rather than echoing
	// messages from the runner. The runner will default to not sending
	// application data.
	shimShutsDown bool
	// renegotiate indicates the number of times the connection should be
	// renegotiated during the exchange.
	renegotiate int
	// sendHalfHelloRequest, if true, causes the server to send half a
	// HelloRequest when the handshake completes.
	sendHalfHelloRequest bool
	// renegotiateCiphers is a list of ciphersuite ids that will be
	// switched in just before renegotiation.
	renegotiateCiphers []uint16
	// replayWrites, if true, configures the underlying transport
	// to replay every write it makes in DTLS tests.
	replayWrites bool
	// damageFirstWrite, if true, configures the underlying transport to
	// damage the final byte of the first application data write.
	damageFirstWrite bool
	// exportKeyingMaterial, if non-zero, configures the test to exchange
	// keying material and verify they match.
	exportKeyingMaterial int
	exportLabel          string
	exportContext        string
	useExportContext     bool
	// flags, if not empty, contains a list of command-line flags that will
	// be passed to the shim program.
	flags []string
	// testTLSUnique, if true, causes the shim to send the tls-unique value
	// which will be compared against the expected value.
	testTLSUnique bool
	// sendEmptyRecords is the number of consecutive empty records to send
	// before each test message.
	// If both this and `sendWarningAlerts` are set, they alternate at the end.
	sendEmptyRecords int
	// sendWarningAlerts is the number of consecutive warning alerts to send
	// before each test message.
	// If both this and `sendWarningAlerts` are set, they alternate at the end.
	sendWarningAlerts int
	// sendUserCanceledAlerts is the number of consecutive user_canceled alerts to
	// send before each test message.
	sendUserCanceledAlerts int
	// sendBogusAlertType, if true, causes a bogus alert of invalid type to
	// be sent before each test message.
	sendBogusAlertType bool
	// sendKeyUpdates is the number of consecutive key updates to send
	// before and after the test message.
	sendKeyUpdates int
	// keyUpdateRequest is the KeyUpdateRequest value to send in KeyUpdate messages.
	keyUpdateRequest byte
	// shimSendsKeyUpdateBeforeRead indicates the shim should send a KeyUpdate
	// message before each read.
	shimSendsKeyUpdateBeforeRead bool
	// expectUnsolicitedKeyUpdate makes the test expect a one or more KeyUpdate
	// messages while reading data from the shim. Don't use this in combination
	// with any of the fields that send a KeyUpdate otherwise any received
	// KeyUpdate might not be as unsolicited as expected.
	expectUnsolicitedKeyUpdate bool
	// expectMessageDropped, if true, means the test message is expected to
	// be dropped by the client rather than echoed back.
	expectMessageDropped bool
	// shimPrefix is the prefix that the shim will send to the server.
	shimPrefix string
	// resumeShimPrefix is the prefix that the shim will send to the server on a
	// resumption.
	resumeShimPrefix string
	// exportTrafficSecrets, if true, configures the test to export the TLS 1.3
	// traffic secrets and confirms that they match.
	exportTrafficSecrets bool
	// skipTransportParamsConfig, if true, will skip automatic configuration of
	// sending QUIC transport parameters when protocol == quic.
	skipTransportParamsConfig bool
	// skipQUICALPNConfig, if true, will skip automatic configuration of
	// sending a fake ALPN when protocol == quic.
	skipQUICALPNConfig bool
	// earlyData, if true, configures default settings for an early data test.
	// expectEarlyDataRejected controls whether the test is for early data
	// accept or reject. In a client test, the shim will be configured to send
	// an initial write in early data which, on accept, the runner will enforce.
	// In a server test, the runner will send some default message in early
	// data, which the shim is expected to echo in half-RTT.
	earlyData bool
	// expectEarlyDataRejected, if earlyData is true, is whether early data is
	// expected to be rejected. In a client test, this controls whether the shim
	// should retry for early rejection. In a server test, this is whether the
	// test expects the shim to reject early data.
	expectEarlyDataRejected bool
	// skipHints, if true, will skip the generation of a handshake hints copy of
	// the test.
	skipHints bool
	// skipVersionNameCheck, if true, will skip the consistency check between
	// test name and the versions.
	skipVersionNameCheck bool
	// shimCertificate, if not nil, is the default credential which should be
	// configured at the shim. If set, it must be an X.509 credential.
	shimCertificate *Credential
	// handshakerCertificate, if not nil, overrides the default credential which
	// on the handshaker.
	handshakerCertificate *Credential
	// shimCredentials is a list of credentials which should be configured at
	// the shim. It differs from shimCertificate only in whether the old or
	// new APIs are used.
	shimCredentials       []*Credential
	resumeShimCredentials []*Credential
}

var testCases []testCase

func appendTranscript(path string, data []byte) error {
	if len(data) == 0 {
		return nil
	}

	settings, err := os.ReadFile(path)
	if err != nil {
		if !os.IsNotExist(err) {
			return err
		}
		// If the shim aborted before writing a file, use a default
		// settings block, so the transcript is still somewhat valid.
		settings = []byte{0, 0} // kDataTag
	}

	settings = append(settings, data...)
	return os.WriteFile(path, settings, 0644)
}

// A timeoutConn implements an idle timeout on each Read and Write operation.
type timeoutConn struct {
	net.Conn
	timeout time.Duration
}

func (t *timeoutConn) Read(b []byte) (int, error) {
	if !*useGDB {
		if err := t.SetReadDeadline(time.Now().Add(t.timeout)); err != nil {
			return 0, err
		}
	}
	return t.Conn.Read(b)
}

func (t *timeoutConn) Write(b []byte) (int, error) {
	if !*useGDB {
		if err := t.SetWriteDeadline(time.Now().Add(t.timeout)); err != nil {
			return 0, err
		}
	}
	return t.Conn.Write(b)
}

func makeTestMessage(msgIdx int, messageLen int) []byte {
	testMessage := make([]byte, messageLen)
	for i := range testMessage {
		testMessage[i] = 0x42 ^ byte(msgIdx)
	}
	return testMessage
}

func expectedReply(b []byte) []byte {
	ret := make([]byte, len(b))
	for i, v := range b {
		ret[i] = v ^ 0xff
	}
	return ret
}

func doExchange(test *testCase, config *Config, conn net.Conn, isResume bool, transcripts *[][]byte, num int) error {
	if !test.noSessionCache {
		if config.ClientSessionCache == nil {
			config.ClientSessionCache = NewLRUClientSessionCache(1)
		}
		if config.ServerSessionCache == nil {
			config.ServerSessionCache = NewLRUServerSessionCache(1)
		}
	}
	if test.testType != clientTest {
		// Supply a ServerName to ensure a constant session cache key,
		// rather than falling back to net.Conn.RemoteAddr.
		if len(config.ServerName) == 0 {
			config.ServerName = "test"
		}
	}

	if *fuzzer {
		config.Bugs.NullAllCiphers = true
	}
	if *deterministic {
		config.Time = func() time.Time { return time.Unix(1234, 1234) }
	}

	if !useDebugger() {
		conn = &timeoutConn{conn, *idleTimeout}
	}

	if test.protocol == dtls {
		config.Bugs.PacketAdaptor = newPacketAdaptor(conn)
		conn = config.Bugs.PacketAdaptor
	}

	if *flagDebug || len(*transcriptDir) != 0 {
		local, peer := "client", "server"
		if test.testType == clientTest {
			local, peer = peer, local
		}
		connDebug := &recordingConn{
			Conn:       conn,
			isDatagram: test.protocol == dtls,
			local:      local,
			peer:       peer,
		}
		conn = connDebug
		if *flagDebug {
			defer connDebug.WriteTo(os.Stdout)
		}
		if *transcriptDir != "" {
			defer func() {
				if num == len(*transcripts) {
					*transcripts = append(*transcripts, connDebug.Transcript())
				} else {
					panic("transcripts are out of sync")
				}
			}()

			// Record ClientHellos for the decode_client_hello_inner fuzzer.
			var clientHelloCount int
			config.Bugs.RecordClientHelloInner = func(encodedInner, outer []byte) error {
				name := fmt.Sprintf("%s-%d-%d", test.name, num, clientHelloCount)
				clientHelloCount++
				dir := filepath.Join(*transcriptDir, "decode_client_hello_inner")
				if err := os.MkdirAll(dir, 0755); err != nil {
					return err
				}
				bb := cryptobyte.NewBuilder(nil)
				addUint24LengthPrefixedBytes(bb, encodedInner)
				bb.AddBytes(outer)
				return os.WriteFile(filepath.Join(dir, name), bb.BytesOrPanic(), 0644)
			}
		}

		if config.Bugs.PacketAdaptor != nil {
			config.Bugs.PacketAdaptor.debug = connDebug
		}
	}
	if test.protocol == quic {
		config.Bugs.MockQUICTransport = newMockQUICTransport(conn)
		// The MockQUICTransport will panic if Read or Write is
		// called. When a MockQUICTransport is set, separate
		// methods should be used to actually read and write
		// records. By setting the conn to it here, it ensures
		// Read or Write aren't accidentally used instead of the
		// methods provided by MockQUICTransport.
		conn = config.Bugs.MockQUICTransport
	}

	if test.replayWrites {
		conn = newReplayAdaptor(conn)
	}

	var connDamage *damageAdaptor
	if test.damageFirstWrite {
		connDamage = newDamageAdaptor(conn)
		conn = connDamage
	}

	if test.sendPrefix != "" {
		if _, err := conn.Write([]byte(test.sendPrefix)); err != nil {
			return err
		}
	}

	var tlsConn *Conn
	if test.testType == clientTest {
		if test.protocol == dtls {
			tlsConn = DTLSServer(conn, config)
		} else {
			tlsConn = Server(conn, config)
		}
	} else {
		config.InsecureSkipVerify = true
		if test.protocol == dtls {
			tlsConn = DTLSClient(conn, config)
		} else {
			tlsConn = Client(conn, config)
		}
	}
	defer tlsConn.Close()

	if err := tlsConn.Handshake(); err != nil {
		return err
	}

	expectations := &test.expectations
	if isResume && test.resumeExpectations != nil {
		expectations = test.resumeExpectations
	}
	connState := tlsConn.ConnectionState()
	if vers := connState.Version; expectations.version != 0 && vers != expectations.version {
		return fmt.Errorf("got version %x, expected %x", vers, expectations.version)
	}

	if cipher := connState.CipherSuite; expectations.cipher != 0 && cipher != expectations.cipher {
		return fmt.Errorf("got cipher %x, expected %x", cipher, expectations.cipher)
	}
	if didResume := connState.DidResume; isResume && didResume == test.expectResumeRejected {
		return fmt.Errorf("didResume is %t, but we expected the opposite", didResume)
	}

	if expectations.channelID {
		channelID := connState.ChannelID
		if channelID == nil {
			return fmt.Errorf("no channel ID negotiated")
		}
		if channelID.Curve != channelIDKey.Curve ||
			channelIDKey.X.Cmp(channelIDKey.X) != 0 ||
			channelIDKey.Y.Cmp(channelIDKey.Y) != 0 {
			return fmt.Errorf("incorrect channel ID")
		}
	} else if connState.ChannelID != nil {
		return fmt.Errorf("channel ID unexpectedly negotiated")
	}

	if expected := expectations.nextProto; expected != "" {
		if actual := connState.NegotiatedProtocol; actual != expected {
			return fmt.Errorf("next proto mismatch: got %s, wanted %s", actual, expected)
		}
	}

	if expectations.noNextProto {
		if actual := connState.NegotiatedProtocol; actual != "" {
			return fmt.Errorf("got unexpected next proto %s", actual)
		}
	}

	if expectations.nextProtoType != 0 {
		if (expectations.nextProtoType == alpn) != connState.NegotiatedProtocolFromALPN {
			return fmt.Errorf("next proto type mismatch")
		}
	}

	if expectations.peerApplicationSettings != nil {
		if !connState.HasApplicationSettings {
			return errors.New("application settings should have been negotiated")
		}
		if !bytes.Equal(connState.PeerApplicationSettings, expectations.peerApplicationSettings) {
			return fmt.Errorf("peer application settings mismatch: got %q, wanted %q", connState.PeerApplicationSettings, expectations.peerApplicationSettings)
		}
	} else if connState.HasApplicationSettings {
		return errors.New("application settings unexpectedly negotiated")
	}

	if expectations.peerApplicationSettingsOld != nil {
		if !connState.HasApplicationSettingsOld {
			return errors.New("old application settings should have been negotiated")
		}
		if !bytes.Equal(connState.PeerApplicationSettingsOld, expectations.peerApplicationSettingsOld) {
			return fmt.Errorf("old peer application settings mismatch: got %q, wanted %q", connState.PeerApplicationSettingsOld, expectations.peerApplicationSettingsOld)
		}
	} else if connState.HasApplicationSettingsOld {
		return errors.New("old application settings unexpectedly negotiated")
	}

	if p := connState.SRTPProtectionProfile; p != expectations.srtpProtectionProfile {
		return fmt.Errorf("SRTP profile mismatch: got %d, wanted %d", p, expectations.srtpProtectionProfile)
	}

	if expected := expectations.peerSignatureAlgorithm; expected != 0 && expected != connState.PeerSignatureAlgorithm {
		return fmt.Errorf("expected peer to use signature algorithm %04x, but got %04x", expected, connState.PeerSignatureAlgorithm)
	}

	if expected := expectations.curveID; expected != 0 && expected != connState.CurveID {
		return fmt.Errorf("expected peer to use curve %04x, but got %04x", expected, connState.CurveID)
	}

	if expected := expectations.peerCertificate; expected != nil {
		var peerCerts [][]byte
		switch expected.Type.CertificateType() {
		case certTypeX509:
			for _, cert := range connState.PeerCertificates {
				peerCerts = append(peerCerts, cert.Raw)
			}
		case certTypeRawPublicKey:
			peerCerts = [][]byte{connState.PeerRawPublicKey}
		}
		if !slices.EqualFunc(peerCerts, expected.Certificate, slices.Equal) {
			return fmt.Errorf("peer certificate did not match expectations (got %v, expected %v)", peerCerts, expected.Certificate)
		}

		if !bytes.Equal(connState.OCSPResponse, expected.OCSPStaple) {
			return fmt.Errorf("peer OCSP response did not match")
		}

		if !bytes.Equal(connState.SCTList, expected.SignedCertificateTimestampList) {
			return fmt.Errorf("peer SCT list did not match")
		}

		if expected.Type == CredentialTypeDelegated {
			if connState.PeerDelegatedCredential == nil {
				return fmt.Errorf("peer unexpectedly did not use delegated credentials")
			}
			if !bytes.Equal(expected.DelegatedCredential, connState.PeerDelegatedCredential) {
				return fmt.Errorf("peer delegated credential did not match")
			}
		} else if connState.PeerDelegatedCredential != nil {
			return fmt.Errorf("peer unexpectedly used delegated credentials")
		}
		if expected.Type == CredentialTypeRawPublicKey {
			if len(connState.PeerRawPublicKey) == 0 {
				return fmt.Errorf("peer unexpectedly did not send a raw public key")
			}
			var expectedPublic crypto.PublicKey
			switch expected.PrivateKey.(type) {
			case *rsa.PrivateKey:
				expectedPublic = expected.PrivateKey.(*rsa.PrivateKey).Public()
			case *ecdsa.PrivateKey:
				expectedPublic = expected.PrivateKey.(*ecdsa.PrivateKey).Public()
			default:
				panic("expected credential has unsupported key type")
			}
			expectedSpki, err := x509.MarshalPKIXPublicKey(expectedPublic)
			if err != nil {
				panic(fmt.Sprintf("error serializing public key of expected credential: %s", err))
			}
			if !slices.Equal(expectedSpki, connState.PeerRawPublicKey) {
				return fmt.Errorf("peer raw public key did not match expected credential")
			}
		}
		if expected.Type != CredentialTypeRawPublicKey && len(connState.PeerRawPublicKey) > 0 {
			return fmt.Errorf("peer unexpectedly sent a raw public key")
		}
	}

	if len(expectations.quicTransportParams) > 0 {
		if !bytes.Equal(expectations.quicTransportParams, connState.QUICTransportParams) {
			return errors.New("Peer did not send expected QUIC transport params")
		}
	}

	if len(expectations.quicTransportParamsLegacy) > 0 {
		if !bytes.Equal(expectations.quicTransportParamsLegacy, connState.QUICTransportParamsLegacy) {
			return errors.New("Peer did not send expected legacy QUIC transport params")
		}
	}

	// On resumption, the server's server_name extension is forbidden. Runner checks this in the
	// TLS stack itself.
	if !connState.DidResume && expectations.serverNameAck != nil && *expectations.serverNameAck != connState.ServerNameAck {
		if connState.ServerNameAck {
			return fmt.Errorf("tls: server unexpectedly acknowledged server_name extension")
		}
		return fmt.Errorf("tls: server did not acknowledge server_name extension")
	}

	if expectations.echAccepted {
		if !connState.ECHAccepted {
			return errors.New("tls: server did not accept ECH")
		}
	} else {
		if connState.ECHAccepted {
			return errors.New("tls: server unexpectedly accepted ECH")
		}
	}

	if expectations.selectedPSK != nil && expectations.selectedPSK != connState.SelectedPSK {
		if connState.SelectedPSK == nil {
			return errors.New("tls: expected a PSK, but none was selected")
		}
		return errors.New("tls: connection selected a different PSK from what was expected")
	}

	if test.exportKeyingMaterial > 0 {
		actual := make([]byte, test.exportKeyingMaterial)
		if _, err := io.ReadFull(tlsConn, actual); err != nil {
			return err
		}
		expected, err := tlsConn.ExportKeyingMaterial(test.exportKeyingMaterial, []byte(test.exportLabel), []byte(test.exportContext), test.useExportContext)
		if err != nil {
			return err
		}
		if !bytes.Equal(actual, expected) {
			return fmt.Errorf("keying material mismatch; got %x, wanted %x", actual, expected)
		}
	}

	if test.exportTrafficSecrets {
		secretLenBytes := make([]byte, 2)
		if _, err := io.ReadFull(tlsConn, secretLenBytes); err != nil {
			return err
		}
		secretLen := binary.LittleEndian.Uint16(secretLenBytes)

		theirReadSecret := make([]byte, secretLen)
		theirWriteSecret := make([]byte, secretLen)
		if _, err := io.ReadFull(tlsConn, theirReadSecret); err != nil {
			return err
		}
		if _, err := io.ReadFull(tlsConn, theirWriteSecret); err != nil {
			return err
		}

		myReadSecret := tlsConn.in.trafficSecret
		myWriteSecret := tlsConn.out.trafficSecret
		if !bytes.Equal(myWriteSecret, theirReadSecret) {
			return fmt.Errorf("read traffic-secret mismatch; got %x, wanted %x", theirReadSecret, myWriteSecret)
		}
		if !bytes.Equal(myReadSecret, theirWriteSecret) {
			return fmt.Errorf("write traffic-secret mismatch; got %x, wanted %x", theirWriteSecret, myReadSecret)
		}
	}

	if test.testTLSUnique {
		var peersValue [12]byte
		if _, err := io.ReadFull(tlsConn, peersValue[:]); err != nil {
			return err
		}
		expected := tlsConn.ConnectionState().TLSUnique
		if !bytes.Equal(peersValue[:], expected) {
			return fmt.Errorf("tls-unique mismatch: peer sent %x, but %x was expected", peersValue[:], expected)
		}
	}

	if test.sendHalfHelloRequest {
		tlsConn.SendHalfHelloRequest()
	}

	shimPrefix := test.shimPrefix
	if isResume {
		shimPrefix = test.resumeShimPrefix
	}
	if test.shimWritesFirst || test.readWithUnfinishedWrite {
		shimPrefix = shimInitialWrite
	}
	if test.renegotiate > 0 {
		// If readWithUnfinishedWrite is set, the shim prefix will be
		// available later.
		if shimPrefix != "" && !test.readWithUnfinishedWrite {
			buf := make([]byte, len(shimPrefix))
			_, err := io.ReadFull(tlsConn, buf)
			if err != nil {
				return err
			}
			if string(buf) != shimPrefix {
				return fmt.Errorf("bad initial message %v vs %v", string(buf), shimPrefix)
			}
			shimPrefix = ""
		}

		if test.renegotiateCiphers != nil {
			config.CipherSuites = test.renegotiateCiphers
		}
		for i := 0; i < test.renegotiate; i++ {
			if err := tlsConn.Renegotiate(); err != nil {
				return err
			}
		}
	} else if test.renegotiateCiphers != nil {
		panic("renegotiateCiphers without renegotiate")
	}

	if test.damageFirstWrite {
		connDamage.setDamage(true)
		if _, err := tlsConn.Write([]byte("DAMAGED WRITE")); err != nil {
			return err
		}
		connDamage.setDamage(false)
	}

	messageLen := test.messageLen
	if messageLen < 0 {
		if test.protocol == dtls {
			return fmt.Errorf("messageLen < 0 not supported for DTLS tests")
		}
		// Read until EOF.
		_, err := io.Copy(io.Discard, tlsConn)
		return err
	}
	if messageLen == 0 {
		messageLen = 32
	}

	messageCount := test.messageCount
	// shimShutsDown sets the default message count to zero.
	if messageCount == 0 && !test.shimShutsDown {
		messageCount = 1
	}

	for j := 0; j < messageCount; j++ {
		for i := 0; i < test.sendKeyUpdates; i++ {
			if err := tlsConn.SendKeyUpdate(test.keyUpdateRequest); err != nil {
				return err
			}
		}

		// Count _down_, so that in case of differing values for the two counters, the alternating takes place at the _end_.
		for i := max(test.sendEmptyRecords, test.sendWarningAlerts); i > 0; i-- {
			if i <= test.sendEmptyRecords {
				if _, err := tlsConn.Write(nil); err != nil {
					return err
				}
			}
			if i <= test.sendWarningAlerts {
				if err := tlsConn.SendAlert(alertLevelWarning, alertUnexpectedMessage); err != nil {
					return err
				}
			}
		}

		for i := 0; i < test.sendUserCanceledAlerts; i++ {
			if err := tlsConn.SendAlert(alertLevelWarning, alertUserCanceled); err != nil {
				return err
			}
		}

		if test.sendBogusAlertType {
			if err := tlsConn.SendAlert(0x42, alertUnexpectedMessage); err != nil {
				return err
			}
		}

		if test.shimSendsKeyUpdateBeforeRead {
			if err := tlsConn.ReadKeyUpdate(); err != nil {
				return err
			}
		}

		testMessage := makeTestMessage(j, messageLen)
		if _, err := tlsConn.Write(testMessage); err != nil {
			return err
		}

		// Consume the shim prefix if needed.
		if shimPrefix != "" {
			buf := make([]byte, len(shimPrefix))
			_, err := io.ReadFull(tlsConn, buf)
			if err != nil {
				return err
			}
			if string(buf) != shimPrefix {
				return fmt.Errorf("bad initial message %v vs %v", string(buf), shimPrefix)
			}
			shimPrefix = ""
		}

		if test.shimShutsDown || test.expectMessageDropped {
			// The shim will not respond.
			continue
		}

		// Process the KeyUpdate reply. However many KeyUpdates the runner
		// sends, the shim should respond only once.
		if test.sendKeyUpdates > 0 && test.keyUpdateRequest == keyUpdateRequested {
			if err := tlsConn.ReadKeyUpdate(); err != nil {
				return err
			}
		}

		buf := make([]byte, len(testMessage))
		if test.protocol == dtls {
			bufTmp := make([]byte, len(buf)+1)
			n, err := tlsConn.Read(bufTmp)
			if err != nil {
				return err
			}
			if config.Bugs.SplitAndPackAppData {
				m, err := tlsConn.Read(bufTmp[n:])
				if err != nil {
					return err
				}
				n += m
			}
			if n != len(buf) {
				return fmt.Errorf("bad reply; length mismatch (%d vs %d)", n, len(buf))
			}
			copy(buf, bufTmp)
		} else {
			_, err := io.ReadFull(tlsConn, buf)
			if err != nil {
				return err
			}
		}

		if expected := expectedReply(testMessage); !bytes.Equal(buf, expected) {
			return fmt.Errorf("bad reply contents; got %x and wanted %x", buf, expected)
		}

		if seen := tlsConn.keyUpdateSeen; seen != test.expectUnsolicitedKeyUpdate {
			return fmt.Errorf("keyUpdateSeen (%t) != expectUnsolicitedKeyUpdate", seen)
		}
	}

	// The shim will end attempting to read, sending one last KeyUpdate. Consume
	// the KeyUpdate before closing the connection.
	if test.shimSendsKeyUpdateBeforeRead {
		if err := tlsConn.ReadKeyUpdate(); err != nil {
			return err
		}
	}

	return nil
}

const xtermSize = "140x50"

func valgrindOf(dbAttach bool, path string, args ...string) *exec.Cmd {
	valgrindArgs := []string{"--error-exitcode=99", "--track-origins=yes", "--leak-check=full", "--quiet"}
	if dbAttach {
		valgrindArgs = append(valgrindArgs, "--db-attach=yes", "--db-command=xterm -geometry "+xtermSize+" -e gdb -nw %f %p")
	}
	valgrindArgs = append(valgrindArgs, path)
	valgrindArgs = append(valgrindArgs, args...)

	return exec.Command("valgrind", valgrindArgs...)
}

func gdbOf(path string, args ...string) *exec.Cmd {
	xtermArgs := []string{"-geometry", xtermSize, "-e", "gdb", "--args"}
	xtermArgs = append(xtermArgs, path)
	xtermArgs = append(xtermArgs, args...)

	return exec.Command("xterm", xtermArgs...)
}

func lldbOf(path string, args ...string) *exec.Cmd {
	xtermArgs := []string{"-geometry", xtermSize, "-e", "lldb", "--"}
	xtermArgs = append(xtermArgs, path)
	xtermArgs = append(xtermArgs, args...)

	return exec.Command("xterm", xtermArgs...)
}

func rrOf(path string, args ...string) *exec.Cmd {
	rrArgs := []string{"record", path}
	rrArgs = append(rrArgs, args...)
	return exec.Command("rr", rrArgs...)
}

func removeFirstLineIfSuffix(s, suffix string) string {
	before, after, ok := strings.Cut(s, "\n")
	if !ok {
		return s
	}
	if strings.HasSuffix(before, suffix) {
		return after
	}
	return s
}

var (
	errMoreMallocs   = errors.New("child process did not exhaust all allocation calls")
	errUnimplemented = errors.New("child process does not implement needed flags")
)

type shimProcess struct {
	cmd *exec.Cmd
	// done is closed when the process has exited. At that point, childErr may be
	// read for the result.
	done           chan struct{}
	childErr       error
	listener       *shimListener
	stdout, stderr bytes.Buffer
}

// newShimProcess starts a new shim with the specified executable, flags, and
// environment. It internally creates a TCP listener and adds the -port
// flag.
func newShimProcess(dispatcher *shimDispatcher, shimPath string, flags []string, env []string) (*shimProcess, error) {
	listener, err := dispatcher.NewShim()
	if err != nil {
		return nil, err
	}

	shim := &shimProcess{listener: listener}
	cmdFlags := []string{
		"-port", strconv.Itoa(listener.Port()),
		"-shim-id", strconv.FormatUint(listener.ShimID(), 10),
	}
	if listener.IsIPv6() {
		cmdFlags = append(cmdFlags, "-ipv6")
	}
	cmdFlags = append(cmdFlags, flags...)

	if *useValgrind {
		shim.cmd = valgrindOf(false, shimPath, cmdFlags...)
	} else if *useGDB {
		shim.cmd = gdbOf(shimPath, cmdFlags...)
	} else if *useLLDB {
		shim.cmd = lldbOf(shimPath, cmdFlags...)
	} else if *useRR {
		shim.cmd = rrOf(shimPath, cmdFlags...)
	} else {
		shim.cmd = exec.Command(shimPath, cmdFlags...)
	}
	shim.cmd.Stdin = os.Stdin
	shim.cmd.Stdout = &shim.stdout
	shim.cmd.Stderr = &shim.stderr
	shim.cmd.Env = env

	if err := shim.cmd.Start(); err != nil {
		shim.listener.Close()
		return nil, err
	}

	shim.done = make(chan struct{})
	go func() {
		shim.childErr = shim.cmd.Wait()
		shim.listener.Close()
		close(shim.done)
	}()
	return shim, nil
}

// accept returns a new TCP connection with the shim process, or returns an
// error on timeout or shim exit.
func (s *shimProcess) accept() (net.Conn, error) {
	var deadline time.Time
	if !useDebugger() {
		deadline = time.Now().Add(*idleTimeout)
	}
	return s.listener.Accept(deadline)
}

// wait finishes the test and waits for the shim process to exit.
func (s *shimProcess) wait() error {
	// Close the listener now. This is to avoid hangs if the shim tries to open
	// more connections than expected.
	s.listener.Close()

	if !useDebugger() {
		waitTimeout := time.AfterFunc(*idleTimeout, func() {
			s.cmd.Process.Kill()
		})
		defer waitTimeout.Stop()
	}

	<-s.done
	return s.childErr
}

// close releases resources associated with the shimProcess. This is safe to
// call before or after |wait|.
func (s *shimProcess) close() {
	s.listener.Close()
	s.cmd.Process.Kill()
}

func doExchanges(test *testCase, shim *shimProcess, resumeCount int, transcripts *[][]byte) error {
	config := test.config
	if *deterministic {
		config.Rand = &deterministicRand{}
	}

	conn, err := shim.accept()
	if err != nil {
		return err
	}
	err = doExchange(test, &config, conn, false /* not a resumption */, transcripts, 0)
	conn.Close()
	if err != nil {
		return err
	}

	nextTicketKey := config.SessionTicketKey
	for i := range resumeCount {
		var resumeConfig Config
		if test.resumeConfig != nil {
			resumeConfig = *test.resumeConfig
			resumeConfig.Rand = config.Rand
			if resumeConfig.Credential == nil {
				resumeConfig.Credential = config.Credential
			}
		} else {
			resumeConfig = config
		}

		if test.newSessionsOnResume {
			resumeConfig.ClientSessionCache = nil
			resumeConfig.ServerSessionCache = nil
			if _, err := resumeConfig.rand().Read(resumeConfig.SessionTicketKey[:]); err != nil {
				return err
			}
		} else {
			resumeConfig.ClientSessionCache = config.ClientSessionCache
			resumeConfig.ServerSessionCache = config.ServerSessionCache
			// Rotate the ticket keys between each connection, with each connection
			// encrypting with next connection's keys. This ensures that we test
			// the renewed sessions.
			resumeConfig.SessionTicketKey = nextTicketKey
			if _, err := resumeConfig.rand().Read(nextTicketKey[:]); err != nil {
				return err
			}
			resumeConfig.Bugs.EncryptSessionTicketKey = &nextTicketKey
		}

		var connResume net.Conn
		connResume, err = shim.accept()
		if err != nil {
			return err
		}
		err = doExchange(test, &resumeConfig, connResume, true /* resumption */, transcripts, i+1)
		connResume.Close()
		if err != nil {
			return err
		}
	}

	return nil
}

// translateExpectedError uses a canonical BoringSSL error to produce
// a slice of expected canonical errors in bogo_shim_config.json.
func translateExpectedError(canonical string) []string {
	if translated, found := shimConfig.ErrorMap[canonical]; found {
		return translated
	}

	// not specifying a canonical error will have the same effect as -loose-errors being true
	// since the empty string with match all error substrings.
	return []string{canonical}
}

// formatErrors takes the semantic mapping from translateExpectedError
// and outputs human-readable digest of BoGo error state.
func formatErrors(expectedErrors []string, stderr, local, child, stdout, expectedLocal, expectedCanonical string) (string, string) {
	got := fmt.Sprintf("\tstderr:\n\t\t%s\n\tlocal: %q\n\tchild: %q\n\tstdout: %s", stderr, local, child, stdout)
	want := fmt.Sprintf("\tlocal: %q\n\tremote: %q", expectedLocal, expectedCanonical)
	if slices.Equal(expectedErrors, []string{expectedCanonical}) {
		return got, want
	}
	if len(expectedErrors) == 0 || expectedErrors == nil {
		return got, want + " (no specified mapping)"
	}
	return got, want + " mapped to one of:\n\t\t" + strings.Join(expectedErrors, "\n\t\t")
}

// matchError plucks the relevant canonical error from the provided
// slice if found; if the slice is empty/nil, strict error checking
// is presumed to be disabled.
func matchError(expectedErrors []string, stderr string) bool {
	for _, expectedError := range expectedErrors {
		if strings.Contains(stderr, expectedError) {
			return true
		}
	}
	return false
}

// shimInitialWrite is the data we expect from the shim when the
// -shim-writes-first flag is used.
const shimInitialWrite = "hello"

func appendCredentialFlags(flags []string, cred *Credential, prefix string, newCredential bool) []string {
	if newCredential {
		switch cred.Type {
		case CredentialTypeX509:
			flags = append(flags, prefix+"-new-x509-credential")
		case CredentialTypeDelegated:
			flags = append(flags, prefix+"-new-delegated-credential")
		case CredentialTypeSPAKE2PlusV1:
			flags = append(flags, prefix+"-new-spake2plusv1-credential")
		case CredentialTypePreSharedKey:
			flags = append(flags, prefix+"-new-psk-credential")
		case CredentialTypeRawPublicKey:
			flags = append(flags, prefix+"-new-rpk-credential")
		default:
			panic(fmt.Errorf("unknown credential type %d", cred.Type))
		}
	} else if cred.Type != CredentialTypeX509 {
		panic("default credential must be X.509")
	}

	handleBase64Field := func(flag string, value []byte) {
		if len(value) != 0 {
			flags = append(flags, fmt.Sprintf("%s-%s", prefix, flag), base64FlagValue(value))
		}
	}

	if cred.ChainPath != "" {
		flags = append(flags, prefix+"-cert-file", cred.ChainPath)
	}
	if cred.KeyPath != "" {
		flags = append(flags, prefix+"-key-file", cred.KeyPath)
	}
	handleBase64Field("ocsp-response", cred.OCSPStaple)
	handleBase64Field("signed-cert-timestamps", cred.SignedCertificateTimestampList)
	for _, sigAlg := range cred.SignatureAlgorithms {
		flags = append(flags, prefix+"-signing-prefs", strconv.Itoa(int(sigAlg)))
	}
	handleBase64Field("delegated-credential", cred.DelegatedCredential)
	if cred.MustMatchIssuer {
		flags = append(flags, prefix+"-must-match-issuer")
	}
	handleBase64Field("pake-context", cred.PAKEContext)
	handleBase64Field("pake-client-id", cred.PAKEClientID)
	handleBase64Field("pake-server-id", cred.PAKEServerID)
	handleBase64Field("pake-password", cred.PAKEPassword)
	if cred.WrongPAKERole {
		flags = append(flags, prefix+"-wrong-pake-role")
	}
	handleBase64Field("psk-importer-key", cred.PreSharedKey)
	handleBase64Field("psk-importer-identity", cred.PSKIdentity)
	handleBase64Field("psk-importer-context", cred.PSKContext)
	switch cred.PSKHash {
	case 0:
		break
	case crypto.SHA256:
		flags = append(flags, prefix+"-psk-importer-sha256")
	case crypto.SHA384:
		flags = append(flags, prefix+"-psk-importer-sha384")
	default:
		panic(fmt.Sprintf("unknown PSK hash %s", cred.PSKHash))
	}
	if !cred.Properties.Empty() {
		handleBase64Field("cert-properties", cred.Properties.Marshal())
	}
	return flags
}

func runTest(dispatcher *shimDispatcher, statusChan chan statusMsg, test *testCase, shimPath string, mallocNumToFail int64) error {
	// Help debugging panics on the Go side.
	defer func() {
		if r := recover(); r != nil {
			fmt.Fprintf(os.Stderr, "Test '%s' panicked.\n", test.name)
			panic(r)
		}
	}()

	// Make a copy of the testCase before modifying it in-place.
	test = ptrTo(*test)
	if test.resumeConfig != nil {
		test.resumeConfig = ptrTo(*test.resumeConfig)
	}
	if test.resumeExpectations != nil {
		test.resumeExpectations = ptrTo(*test.resumeExpectations)
	}

	var flags []string
	if len(*shimExtraFlags) > 0 {
		flags = strings.Split(*shimExtraFlags, ";")
	}
	if *fuzzer {
		flags = append(flags, "-fuzzer-mode")
	}
	if test.testType == serverTest {
		flags = append(flags, "-server")
	}

	// Configure the default credential.
	shimCertificate := test.shimCertificate
	if shimCertificate == nil && len(test.shimCredentials) == 0 && len(test.resumeShimCredentials) == 0 && test.testType == serverTest && len(test.config.PreSharedKey) == 0 {
		shimCertificate = &rsaCertificate
	}
	if shimCertificate != nil {
		var shimPrefix string
		if test.handshakerCertificate != nil {
			shimPrefix = "-on-shim"
		}
		flags = appendCredentialFlags(flags, shimCertificate, shimPrefix, false)
	}
	if test.handshakerCertificate != nil {
		flags = appendCredentialFlags(flags, test.handshakerCertificate, "-on-handshaker", false)
	}

	// Configure any additional credentials.
	for _, cred := range test.shimCredentials {
		flags = appendCredentialFlags(flags, cred, "", true)
	}
	for _, cred := range test.resumeShimCredentials {
		flags = appendCredentialFlags(flags, cred, "-on-resume", true)
	}

	if test.protocol == dtls {
		flags = append(flags, "-dtls")
	} else if test.protocol == quic {
		flags = append(flags, "-quic")
		if !test.skipTransportParamsConfig {
			test.config.QUICTransportParams = []byte{1, 2}
			test.config.QUICTransportParamsUseLegacyCodepoint = QUICUseCodepointStandard
			if test.resumeConfig != nil {
				test.resumeConfig.QUICTransportParams = []byte{1, 2}
				test.resumeConfig.QUICTransportParamsUseLegacyCodepoint = QUICUseCodepointStandard
			}
			test.expectations.quicTransportParams = []byte{3, 4}
			if test.resumeExpectations != nil {
				test.resumeExpectations.quicTransportParams = []byte{3, 4}
			}
			useCodepointFlag := "0"
			if test.config.QUICTransportParamsUseLegacyCodepoint == QUICUseCodepointLegacy {
				useCodepointFlag = "1"
			}
			flags = append(flags,
				"-quic-transport-params",
				base64FlagValue([]byte{3, 4}),
				"-expect-quic-transport-params",
				base64FlagValue([]byte{1, 2}),
				"-quic-use-legacy-codepoint", useCodepointFlag)
		}
		if !test.skipQUICALPNConfig {
			flags = append(flags,
				[]string{
					"-advertise-alpn", "\x03foo",
					"-select-alpn", "foo",
					"-expect-alpn", "foo",
				}...)
			test.config.NextProtos = []string{"foo"}
			if test.resumeConfig != nil {
				test.resumeConfig.NextProtos = []string{"foo"}
			}
			test.expectations.nextProto = "foo"
			test.expectations.nextProtoType = alpn
			if test.resumeExpectations != nil {
				test.resumeExpectations.nextProto = "foo"
				test.resumeExpectations.nextProtoType = alpn
			}
		}
	}

	if test.earlyData {
		if !test.resumeSession {
			panic("earlyData set without resumeSession in " + test.name)
		}

		resumeConfig := test.resumeConfig
		if resumeConfig == nil {
			resumeConfig = &test.config
		}
		if test.expectEarlyDataRejected {
			flags = append(flags, "-on-resume-expect-reject-early-data")
		} else {
			flags = append(flags, "-on-resume-expect-accept-early-data")
		}

		if test.protocol == quic {
			// QUIC requires an early data context string.
			flags = append(flags, "-quic-early-data-context", "context")
		}

		flags = append(flags, "-enable-early-data")
		if test.testType == clientTest {
			// Configure the runner with default maximum early data.
			flags = append(flags, "-expect-ticket-supports-early-data")
			if test.config.MaxEarlyDataSize == 0 {
				test.config.MaxEarlyDataSize = 16384
			}
			if resumeConfig.MaxEarlyDataSize == 0 {
				resumeConfig.MaxEarlyDataSize = 16384
			}

			// In DTLS 1.3, we're setting flags to configure the client to attempt
			// sending early data, but we expect it to realize that it's incapable
			// of supporting early data and not send any.
			if test.protocol != dtls {
				// Configure the shim to send some data in early data.
				flags = append(flags, "-on-resume-shim-writes-first")
				if resumeConfig.Bugs.ExpectEarlyData == nil {
					resumeConfig.Bugs.ExpectEarlyData = [][]byte{[]byte(shimInitialWrite)}
				}
			}
		} else {
			// By default, send some early data and expect half-RTT data response.
			if resumeConfig.Bugs.SendEarlyData == nil {
				resumeConfig.Bugs.SendEarlyData = [][]byte{{1, 2, 3, 4}}
			}
			if resumeConfig.Bugs.ExpectHalfRTTData == nil {
				resumeConfig.Bugs.ExpectHalfRTTData = [][]byte{{254, 253, 252, 251}}
			}
			resumeConfig.Bugs.ExpectEarlyDataAccepted = !test.expectEarlyDataRejected
		}
	}

	var resumeCount int
	if test.resumeSession {
		resumeCount++
		if test.resumeRenewedSession {
			resumeCount++
		}
	}

	if resumeCount > 0 {
		flags = append(flags, "-resume-count", strconv.Itoa(resumeCount))
	}

	if test.shimWritesFirst {
		flags = append(flags, "-shim-writes-first")
	}

	if test.readWithUnfinishedWrite {
		flags = append(flags, "-read-with-unfinished-write")
	}

	if test.shimShutsDown {
		flags = append(flags, "-shim-shuts-down")
	}

	if test.exportKeyingMaterial > 0 {
		flags = append(flags, "-export-keying-material", strconv.Itoa(test.exportKeyingMaterial))
		if test.useExportContext {
			flags = append(flags, "-use-export-context")
		}
	}
	if test.exportKeyingMaterial > 0 {
		flags = append(flags, "-export-label", test.exportLabel)
		flags = append(flags, "-export-context", test.exportContext)
	}

	if test.exportTrafficSecrets {
		flags = append(flags, "-export-traffic-secrets")
	}

	if test.expectResumeRejected {
		flags = append(flags, "-expect-session-miss")
	}

	if test.testTLSUnique {
		flags = append(flags, "-tls-unique")
	}

	if test.shimSendsKeyUpdateBeforeRead {
		flags = append(flags, "-key-update-before-read")
	}

	if *waitForDebugger {
		flags = append(flags, "-wait-for-debugger")
	}

	var transcriptPrefix string
	var transcripts [][]byte
	if *transcriptDir != "" {
		protocol := "tls"
		if test.protocol == dtls {
			protocol = "dtls"
		} else if test.protocol == quic {
			protocol = "quic"
		}

		side := "client"
		if test.testType == serverTest {
			side = "server"
		}

		dir := filepath.Join(*transcriptDir, protocol, side)
		if err := os.MkdirAll(dir, 0755); err != nil {
			return err
		}
		transcriptPrefix = filepath.Join(dir, test.name+"-")
		flags = append(flags, "-write-settings", transcriptPrefix)
	}

	if test.testType == clientTest && test.config.Credential == nil {
		test.config.Credential = &rsaCertificate
	}
	if test.config.Credential != nil {
		flags = append(flags, "-trust-cert", test.config.Credential.RootPath)
	}

	flags = append(flags, test.flags...)

	var env []string
	if mallocNumToFail >= 0 {
		env = os.Environ()
		env = append(env, "MALLOC_NUMBER_TO_FAIL="+strconv.FormatInt(mallocNumToFail, 10))
		if *mallocTestDebug {
			env = append(env, "MALLOC_BREAK_ON_FAIL=1")
		}
		env = append(env, "_MALLOC_CHECK=1")
	}

	shim, err := newShimProcess(dispatcher, shimPath, flags, env)
	if err != nil {
		return err
	}
	statusChan <- statusMsg{test: test, statusType: statusShimStarted, pid: shim.cmd.Process.Pid}
	defer shim.close()

	localErr := doExchanges(test, shim, resumeCount, &transcripts)
	childErr := shim.wait()

	// Now that the shim has exited, all the settings files have been
	// written. Append the saved transcripts.
	for i, transcript := range transcripts {
		if err := appendTranscript(transcriptPrefix+strconv.Itoa(i), transcript); err != nil {
			return err
		}
	}

	var isValgrindError, mustFail bool
	if exitError, ok := childErr.(*exec.ExitError); ok {
		switch exitError.Sys().(syscall.WaitStatus).ExitStatus() {
		case 88:
			return errMoreMallocs
		case 89:
			return errUnimplemented
		case 90:
			mustFail = true
		case 99:
			isValgrindError = true
		}
	}

	// Account for Windows line endings.
	stdout := strings.Replace(shim.stdout.String(), "\r\n", "\n", -1)
	stderr := strings.Replace(shim.stderr.String(), "\r\n", "\n", -1)

	// Work around an NDK / Android bug. The NDK r16 sometimes generates
	// binaries with the DF_1_PIE, which the runtime linker on Android N
	// complains about. The next NDK revision should work around this but,
	// in the meantime, strip its error out.
	//
	// https://github.com/android-ndk/ndk/issues/602
	// https://android-review.googlesource.com/c/platform/bionic/+/259790
	// https://android-review.googlesource.com/c/toolchain/binutils/+/571550
	//
	// Remove this after switching to the r17 NDK.
	stderr = removeFirstLineIfSuffix(stderr, ": unsupported flags DT_FLAGS_1=0x8000001")

	// Separate the errors from the shim and those from tools like
	// AddressSanitizer.
	var extraStderr string
	if stderrParts := strings.SplitN(stderr, "--- DONE ---\n", 2); len(stderrParts) == 2 {
		stderr = stderrParts[0]
		extraStderr = stderrParts[1]
	}

	failed := localErr != nil || childErr != nil
	expectedErrors := translateExpectedError(test.expectedError)
	correctFailure := *looseErrors || matchError(expectedErrors, stderr)

	localErrString := "none"
	if localErr != nil {
		localErrString = localErr.Error()
	}
	if test.expectedLocalError != "" {
		correctFailure = correctFailure && strings.Contains(localErrString, test.expectedLocalError)
	}

	if failed != test.shouldFail || failed && !correctFailure || mustFail {
		childErrString := "none"
		if childErr != nil {
			childErrString = childErr.Error()
		}

		got, want := formatErrors(expectedErrors,
			stderr, localErrString, childErrString, stdout,
			test.expectedLocalError, test.expectedError)

		var msg string
		switch {
		case failed && !test.shouldFail:
			msg = fmt.Sprintf("unexpected failure\ngot:\n%s\n", got)
		case !failed && test.shouldFail:
			msg = fmt.Sprintf("unexpected success\nwant:\n%s\n", want)
		case failed && !correctFailure:
			msg = fmt.Sprintf("unexpected error\ngot:\n%s\n\nwant:\n%s\n", got, want)
		case mustFail:
			msg = "test failure"
		default:
			panic("internal error")
		}

		return fmt.Errorf("%s\nextra stderr:\n%s", msg, extraStderr)
	}

	if len(extraStderr) > 0 || (!failed && len(stderr) > 0) {
		return fmt.Errorf("unexpected error output:\n%s\n%s", stderr, extraStderr)
	}

	if *useValgrind && isValgrindError {
		return fmt.Errorf("valgrind error:\n%s\n%s", stderr, extraStderr)
	}

	return nil
}

type tlsVersion struct {
	name string
	// version is the protocol version.
	version uint16
	// excludeFlag is the legacy shim flag to disable the version.
	excludeFlag string
	hasDTLS     bool
	hasQUIC     bool
	// versionDTLS, if non-zero, is the DTLS-specific representation of the version.
	versionDTLS uint16
	// versionWire, if non-zero, is the wire representation of the
	// version. Otherwise the wire version is the protocol version or
	// versionDTLS.
	versionWire uint16
}

func (vers tlsVersion) String() string {
	return vers.name
}

func (vers tlsVersion) shimFlag(protocol protocol) string {
	// The shim uses the protocol version in its public API, but uses the
	// DTLS-specific version if it exists.
	if protocol == dtls && vers.versionDTLS != 0 {
		return strconv.Itoa(int(vers.versionDTLS))
	}
	return strconv.Itoa(int(vers.version))
}

func (vers tlsVersion) wire(protocol protocol) uint16 {
	if protocol == dtls && vers.versionDTLS != 0 {
		return vers.versionDTLS
	}
	if vers.versionWire != 0 {
		return vers.versionWire
	}
	return vers.version
}

func (vers tlsVersion) supportsProtocol(protocol protocol) bool {
	if protocol == dtls {
		return vers.hasDTLS
	}
	if protocol == quic {
		return vers.hasQUIC
	}
	return true
}

var tlsVersions = []tlsVersion{
	{
		name:        "TLS1",
		version:     VersionTLS10,
		excludeFlag: "-no-tls1",
		hasDTLS:     true,
		versionDTLS: VersionDTLS10,
	},
	{
		name:        "TLS11",
		version:     VersionTLS11,
		excludeFlag: "-no-tls11",
	},
	{
		name:        "TLS12",
		version:     VersionTLS12,
		excludeFlag: "-no-tls12",
		hasDTLS:     true,
		versionDTLS: VersionDTLS12,
	},
	{
		name:        "TLS13",
		version:     VersionTLS13,
		excludeFlag: "-no-tls13",
		hasQUIC:     true,
		hasDTLS:     true,
		versionDTLS: VersionDTLS13,
		versionWire: VersionTLS13,
	},
}

func allVersions(protocol protocol) []tlsVersion {
	if protocol == tls {
		return tlsVersions
	}

	var ret []tlsVersion
	for _, vers := range tlsVersions {
		if vers.supportsProtocol(protocol) {
			ret = append(ret, vers)
		}
	}
	return ret
}

func convertToHandshakeHintTests(tests []testCase) (handshakeHintTests []testCase, err error) {
	var stdout bytes.Buffer
	var flags []string
	if len(*shimExtraFlags) > 0 {
		flags = strings.Split(*shimExtraFlags, ";")
	}
	flags = append(flags, "-is-handshaker-supported")
	shim := exec.Command(*shimPath, flags...)
	shim.Stdout = &stdout
	if err := shim.Run(); err != nil {
		return nil, err
	}

	switch strings.TrimSpace(stdout.String()) {
	case "No":
		return
	case "Yes":
		break
	default:
		return nil, fmt.Errorf("unknown output from shim: %q", stdout.Bytes())
	}

	var allowHintMismatchPattern []string
	if len(*allowHintMismatch) > 0 {
		allowHintMismatchPattern = strings.Split(*allowHintMismatch, ";")
	}

	for _, test := range tests {
		if test.protocol == dtls ||
			test.testType != serverTest ||
			test.skipHints {
			continue
		}

		var matched bool
		if len(allowHintMismatchPattern) > 0 {
			matched, err = match(allowHintMismatchPattern, nil, test.name)
			if err != nil {
				return nil, fmt.Errorf("error matching pattern: %s", err)
			}
		}

		hintTest := test
		hintTest.name += "-Hints"
		hintTest.flags = make([]string, len(test.flags), len(test.flags)+3)
		copy(hintTest.flags, test.flags)
		hintTest.flags = append(hintTest.flags, "-handshake-hints", "-handshaker-path", *handshakerPath)
		if matched {
			hintTest.flags = append(hintTest.flags, "-allow-hint-mismatch")
		}

		handshakeHintTests = append(handshakeHintTests, hintTest)
	}

	return handshakeHintTests, nil
}

func worker(dispatcher *shimDispatcher, statusChan chan statusMsg, c chan *testCase, shimPath string, wg *sync.WaitGroup) {
	defer wg.Done()

	for test := range c {
		var err error

		if *mallocTest >= 0 {
			for mallocNumToFail := int64(*mallocTest); ; mallocNumToFail++ {
				statusChan <- statusMsg{test: test, statusType: statusStarted}
				if err = runTest(dispatcher, statusChan, test, shimPath, mallocNumToFail); err != errMoreMallocs {
					if err != nil {
						fmt.Printf("\n\nmalloc test failed at %d: %s\n", mallocNumToFail, err)
					}
					break
				}
			}
		} else if *repeatUntilFailure {
			for err == nil {
				statusChan <- statusMsg{test: test, statusType: statusStarted}
				err = runTest(dispatcher, statusChan, test, shimPath, -1)
			}
		} else {
			statusChan <- statusMsg{test: test, statusType: statusStarted}
			err = runTest(dispatcher, statusChan, test, shimPath, -1)
		}
		statusChan <- statusMsg{test: test, statusType: statusDone, err: err}
	}
}

type statusType int

const (
	statusStarted statusType = iota
	statusShimStarted
	statusDone
)

type statusMsg struct {
	test       *testCase
	statusType statusType
	pid        int
	err        error
}

func statusPrinter(doneChan chan *testresult.Results, statusChan chan statusMsg, total int) {
	var started, done, failed, unimplemented, lineLen int

	testOutput := testresult.NewResults()
	for msg := range statusChan {
		if !*pipe {
			// Erase the previous status line.
			var erase strings.Builder
			for range lineLen {
				erase.WriteString("\b \b")
			}
			fmt.Print(erase.String())
		}

		if msg.statusType == statusStarted {
			started++
		} else if msg.statusType == statusDone {
			done++

			if msg.err != nil {
				if msg.err == errUnimplemented {
					if *pipe {
						// Print each test instead of a status line.
						fmt.Printf("UNIMPLEMENTED (%s)\n", msg.test.name)
					}
					unimplemented++
					if *allowUnimplemented {
						testOutput.AddSkip(msg.test.name)
					} else {
						fmt.Printf("UNIMPLEMENTED (%s)\n%s\n", msg.test.name, msg.err)
						testOutput.AddResult(msg.test.name, "SKIP", nil)
					}
				} else {
					fmt.Printf("FAILED (%s)\n%s\n", msg.test.name, msg.err)
					failed++
					testOutput.AddResult(msg.test.name, "FAIL", msg.err)
				}
			} else {
				if *pipe {
					// Print each test instead of a status line.
					fmt.Printf("PASSED (%s)\n", msg.test.name)
				}
				testOutput.AddResult(msg.test.name, "PASS", nil)
			}
		}

		if !*pipe {
			// Print a new status line.
			line := fmt.Sprintf("%d/%d/%d/%d/%d", failed, unimplemented, done, started, total)
			if msg.statusType == statusShimStarted && *waitForDebugger {
				// Note -wait-for-debugger limits the test to one worker,
				// otherwise some output would be skipped.
				line += fmt.Sprintf(" (%s: attach to process %d to continue)", msg.test.name, msg.pid)
			}
			lineLen = len(line)
			os.Stdout.WriteString(line)
		}
	}

	doneChan <- testOutput
}

func match(oneOfPatternIfAny []string, noneOfPattern []string, candidate string) (matched bool, err error) {
	matched = len(oneOfPatternIfAny) == 0

	var didMatch bool
	for _, pattern := range oneOfPatternIfAny {
		didMatch, err = filepath.Match(pattern, candidate)
		if err != nil {
			return false, err
		}

		matched = didMatch || matched
	}

	for _, pattern := range noneOfPattern {
		didMatch, err = filepath.Match(pattern, candidate)
		if err != nil {
			return false, err
		}

		matched = !didMatch && matched
	}

	return matched, nil
}

func checkTests() {
	for _, test := range testCases {
		if !test.shouldFail && (len(test.expectedError) > 0 || len(test.expectedLocalError) > 0) {
			panic("Error expected without shouldFail in " + test.name)
		}

		if test.expectResumeRejected && !test.resumeSession {
			panic("expectResumeRejected without resumeSession in " + test.name)
		}

		if !test.skipVersionNameCheck {
			for _, ver := range tlsVersions {
				if !strings.Contains("-"+test.name+"-", "-"+ver.name+"-") {
					continue
				}

				found := test.config.MaxVersion == ver.version || test.config.MinVersion == ver.version || test.expectations.version == ver.version
				if test.resumeConfig != nil {
					found = found || test.resumeConfig.MaxVersion == ver.version || test.resumeConfig.MinVersion == ver.version
				}
				if test.resumeExpectations != nil {
					found = found || test.resumeExpectations.version == ver.version
				}
				shimFlag := ver.shimFlag(test.protocol)
				found = found || slices.Contains(test.flags, shimFlag)
				if !found {
					panic(fmt.Sprintf("The name of test %q suggests that it's version specific, but the test does not reference %s", test.name, ver.name))
				}
			}
		}

		for _, protocol := range []protocol{tls, dtls, quic} {
			if strings.Contains("-"+test.name+"-", "-"+protocol.String()+"-") && test.protocol != protocol {
				panic(fmt.Sprintf("The name of test %q suggests that it tests %q, but the test does not reference it", test.name, protocol))
			}
		}
	}
}

func main() {
	flag.Parse()
	var err error
	if tmpDir, err = os.MkdirTemp("", "testing-certs"); err != nil {
		fmt.Fprintf(os.Stderr, "failed to make temporary directory: %s", err)
		os.Exit(1)
	}
	if !*keepTestCerts {
		defer os.RemoveAll(tmpDir)
	}
	initKeys()
	initCertificates()
	initDelegatedCredentials()
	initRawPublicKeyCredentials()

	if *shimConfigFile != "" {
		encoded, err := os.ReadFile(*shimConfigFile)
		if err != nil {
			fmt.Fprintf(os.Stderr, "Couldn't read config file %q: %s\n", *shimConfigFile, err)
			os.Exit(1)
		}
		if err := json.Unmarshal(encoded, &shimConfig); err != nil {
			fmt.Fprintf(os.Stderr, "Couldn't decode config file %q: %s\n", *shimConfigFile, err)
			os.Exit(1)
		}
	}

	addBasicTests()
	addCipherSuiteTests()
	addBadECDSASignatureTests()
	addCBCPaddingTests()
	addCBCSplittingTests()
	addClientAuthTests()
	addDDoSCallbackTests()
	addVersionNegotiationTests()
	addMinimumVersionTests()
	addExtensionTests()
	addResumptionVersionTests()
	addExtendedMasterSecretTests()
	addRenegotiationTests()
	addDTLSReplayTests()
	addSignatureAlgorithmTests()
	addDTLSRetransmitTests()
	addDTLSReorderTests()
	addDTLSFragmentWindowTests()
	addExportKeyingMaterialTests()
	addExportTrafficSecretsTests()
	addTLSUniqueTests()
	addUnknownExtensionTests()
	addRSAClientKeyExchangeTests()
	addCurveTests()
	addSessionTicketTests()
	addTLS13RecordTests()
	addAllStateMachineCoverageTests()
	addChangeCipherSpecTests()
	addEndOfFlightTests()
	addWrongMessageTypeTests()
	addTrailingMessageDataTests()
	addTLS13HandshakeTests()
	addTLS13CipherPreferenceTests()
	addPeekTests()
	addRecordVersionTests()
	addCertificateTests()
	addRetainOnlySHA256ClientCertTests()
	addECDSAKeyUsageTests()
	addRSAKeyUsageTests()
	addExtraHandshakeTests()
	addOmitExtensionsTests()
	addExtensionTrailingDataTests()
	addCertCompressionTests()
	addJDK11WorkaroundTests()
	addDelegatedCredentialTests()
	addEncryptedClientHelloTests()
	addHintMismatchTests()
	addCompliancePolicyTests()
	addCertificateSelectionTests()
	addKeyUpdateTests()
	addPAKETests()
	addTrustAnchorTests()
	addPSKTests()
	addRawPublicKeyTests()
	addServerPaddingTests()

	toAppend, err := convertToHandshakeHintTests(testCases)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error making handshake hint tests: %s", err)
		os.Exit(1)
	}
	testCases = append(testCases, toAppend...)

	checkTests()

	dispatcher, err := newShimDispatcher()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error opening socket: %s", err)
		os.Exit(1)
	}
	defer dispatcher.Close()

	numWorkers := *numWorkersFlag
	if useDebugger() {
		numWorkers = 1
	}

	statusChan := make(chan statusMsg, numWorkers)
	testChan := make(chan *testCase, numWorkers)
	doneChan := make(chan *testresult.Results)

	go statusPrinter(doneChan, statusChan, len(testCases))

	var wg sync.WaitGroup
	for i := 0; i < numWorkers; i++ {
		wg.Add(1)
		go worker(dispatcher, statusChan, testChan, *shimPath, &wg)
	}

	var oneOfPatternIfAny, noneOfPattern []string
	if len(*testToRun) > 0 {
		oneOfPatternIfAny = strings.Split(*testToRun, ";")
	}
	if len(*skipTest) > 0 {
		noneOfPattern = strings.Split(*skipTest, ";")
	}

	shardIndex, shardTotal, err := getSharding()
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	if shardTotal > 0 {
		fmt.Printf("This is shard %d of 0..%d (inclusive)\n", shardIndex, shardTotal-1)
	}

	var foundTest bool
	for i := range testCases {
		if shardTotal > 0 && i%shardTotal != shardIndex {
			continue
		}

		matched, err := match(oneOfPatternIfAny, noneOfPattern, testCases[i].name)
		if err != nil {
			fmt.Fprintf(os.Stderr, "Error matching pattern: %s\n", err)
			os.Exit(1)
		}

		if !*includeDisabled {
			for pattern := range shimConfig.DisabledTests {
				isDisabled, err := filepath.Match(pattern, testCases[i].name)
				if err != nil {
					fmt.Fprintf(os.Stderr, "Error matching pattern %q from config file: %s\n", pattern, err)
					os.Exit(1)
				}

				if isDisabled {
					matched = false
					break
				}
			}
		}

		if matched {
			if foundTest && *useRR {
				fmt.Fprintf(os.Stderr, "Too many matching tests. Only one test can run when RR is enabled.\n")
				os.Exit(1)
			}

			foundTest = true
			testChan <- &testCases[i]

			// Only run one test if repeating until failure.
			if *repeatUntilFailure {
				break
			}
		}
	}

	if !foundTest && shardTotal == 0 {
		fmt.Fprintf(os.Stderr, "No tests run\n")
		os.Exit(1)
	}

	close(testChan)
	wg.Wait()
	close(statusChan)
	testOutput := <-doneChan

	fmt.Printf("\n")

	if *jsonOutput != "" {
		if err := testOutput.WriteToFile(*jsonOutput); err != nil {
			fmt.Fprintf(os.Stderr, "Error: %s\n", err)
		}
	}

	if *useRR {
		fmt.Println("RR trace recorded. Replay with `rr replay`.")
	}

	if !testOutput.HasUnexpectedResults() {
		os.Exit(1)
	}
}