From 3763a1ded109d63be8a27824983c41413e056e1b Mon Sep 17 00:00:00 2001 From: Julien Pivotto Date: Tue, 19 Apr 2022 17:11:58 +0200 Subject: [PATCH] TLS config: Enable selection of min TLS version (#375) * TLS config: Enable selection of min TLS version go1.18 changes the default minimum TLS version to 1.2. Let's make the default minimum version configurable, while following go default. The allowed values (TLS10, ..) come from the exporter-toolkit: https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md TLSVersion is exported so the exporter toolkit can reuse them later. Signed-off-by: Julien Pivotto --- config/http_config.go | 101 ++++++++++++++---- config/http_config_test.go | 6 +- config/testdata/tls_config.empty.good.json | 1 + config/testdata/tls_config.insecure.good.json | 1 + .../testdata/tls_config.tlsversion.good.json | 1 + .../testdata/tls_config.tlsversion.good.yml | 1 + config/tls_config_test.go | 37 ++++++- 7 files changed, 122 insertions(+), 26 deletions(-) create mode 100644 config/testdata/tls_config.empty.good.json create mode 100644 config/testdata/tls_config.insecure.good.json create mode 100644 config/testdata/tls_config.tlsversion.good.json create mode 100644 config/testdata/tls_config.tlsversion.good.yml diff --git a/config/http_config.go b/config/http_config.go index 37cb37ce..063edde0 100644 --- a/config/http_config.go +++ b/config/http_config.go @@ -36,25 +36,87 @@ import ( "gopkg.in/yaml.v2" ) -// DefaultHTTPClientConfig is the default HTTP client configuration. -var DefaultHTTPClientConfig = HTTPClientConfig{ - FollowRedirects: true, - EnableHTTP2: true, -} +var ( + // DefaultHTTPClientConfig is the default HTTP client configuration. + DefaultHTTPClientConfig = HTTPClientConfig{ + FollowRedirects: true, + EnableHTTP2: true, + } -// defaultHTTPClientOptions holds the default HTTP client options. -var defaultHTTPClientOptions = httpClientOptions{ - keepAlivesEnabled: true, - http2Enabled: true, - // 5 minutes is typically above the maximum sane scrape interval. So we can - // use keepalive for all configurations. - idleConnTimeout: 5 * time.Minute, -} + // defaultHTTPClientOptions holds the default HTTP client options. + defaultHTTPClientOptions = httpClientOptions{ + keepAlivesEnabled: true, + http2Enabled: true, + // 5 minutes is typically above the maximum sane scrape interval. So we can + // use keepalive for all configurations. + idleConnTimeout: 5 * time.Minute, + } +) type closeIdler interface { CloseIdleConnections() } +type TLSVersion uint16 + +var TLSVersions = map[string]TLSVersion{ + "TLS13": (TLSVersion)(tls.VersionTLS13), + "TLS12": (TLSVersion)(tls.VersionTLS12), + "TLS11": (TLSVersion)(tls.VersionTLS11), + "TLS10": (TLSVersion)(tls.VersionTLS10), +} + +func (tv *TLSVersion) UnmarshalYAML(unmarshal func(interface{}) error) error { + var s string + err := unmarshal((*string)(&s)) + if err != nil { + return err + } + if v, ok := TLSVersions[s]; ok { + *tv = v + return nil + } + return fmt.Errorf("unknown TLS version: %s", s) +} + +func (tv *TLSVersion) MarshalYAML() (interface{}, error) { + if tv != nil || *tv == 0 { + return []byte("null"), nil + } + for s, v := range TLSVersions { + if *tv == v { + return s, nil + } + } + return nil, fmt.Errorf("unknown TLS version: %d", tv) +} + +// MarshalJSON implements the json.Unmarshaler interface for TLSVersion. +func (tv *TLSVersion) UnmarshalJSON(data []byte) error { + var s string + if err := json.Unmarshal(data, &s); err != nil { + return err + } + if v, ok := TLSVersions[s]; ok { + *tv = v + return nil + } + return fmt.Errorf("unknown TLS version: %s", s) +} + +// MarshalJSON implements the json.Marshaler interface for TLSVersion. +func (tv *TLSVersion) MarshalJSON() ([]byte, error) { + if tv != nil || *tv == 0 { + return []byte("null"), nil + } + for s, v := range TLSVersions { + if *tv == v { + return []byte(s), nil + } + } + return nil, fmt.Errorf("unknown TLS version: %d", tv) +} + // BasicAuth contains basic HTTP authentication credentials. type BasicAuth struct { Username string `yaml:"username" json:"username"` @@ -669,7 +731,10 @@ func cloneRequest(r *http.Request) *http.Request { // NewTLSConfig creates a new tls.Config from the given TLSConfig. func NewTLSConfig(cfg *TLSConfig) (*tls.Config, error) { - tlsConfig := &tls.Config{InsecureSkipVerify: cfg.InsecureSkipVerify} + tlsConfig := &tls.Config{ + InsecureSkipVerify: cfg.InsecureSkipVerify, + MinVersion: uint16(cfg.MinVersion), + } // If a CA cert is provided then let's read it in so we can validate the // scrape target's certificate properly. @@ -714,6 +779,8 @@ type TLSConfig struct { ServerName string `yaml:"server_name,omitempty" json:"server_name,omitempty"` // Disable target certificate validation. InsecureSkipVerify bool `yaml:"insecure_skip_verify" json:"insecure_skip_verify"` + // Minimum TLS version. + MinVersion TLSVersion `yaml:"min_version,omitempty" json:"min_version,omitempty"` } // SetDirectory joins any relative file paths with dir. @@ -726,12 +793,6 @@ func (c *TLSConfig) SetDirectory(dir string) { c.KeyFile = JoinDir(dir, c.KeyFile) } -// UnmarshalYAML implements the yaml.Unmarshaler interface. -func (c *TLSConfig) UnmarshalYAML(unmarshal func(interface{}) error) error { - type plain TLSConfig - return unmarshal((*plain)(c)) -} - // getClientCertificate reads the pair of client cert and key from disk and returns a tls.Certificate. func (c *TLSConfig) getClientCertificate(*tls.CertificateRequestInfo) (*tls.Certificate, error) { cert, err := tls.LoadX509KeyPair(c.CertFile, c.KeyFile) diff --git a/config/http_config_test.go b/config/http_config_test.go index 884f344c..06eb6d04 100644 --- a/config/http_config_test.go +++ b/config/http_config_test.go @@ -627,7 +627,8 @@ func TestTLSConfig(t *testing.T) { CertFile: ClientCertificatePath, KeyFile: ClientKeyNoPassPath, ServerName: "localhost", - InsecureSkipVerify: false} + InsecureSkipVerify: false, + } tlsCAChain, err := ioutil.ReadFile(TLSCAChainPath) if err != nil { @@ -640,7 +641,8 @@ func TestTLSConfig(t *testing.T) { expectedTLSConfig := &tls.Config{ RootCAs: rootCAs, ServerName: configTLSConfig.ServerName, - InsecureSkipVerify: configTLSConfig.InsecureSkipVerify} + InsecureSkipVerify: configTLSConfig.InsecureSkipVerify, + } tlsConfig, err := NewTLSConfig(&configTLSConfig) if err != nil { diff --git a/config/testdata/tls_config.empty.good.json b/config/testdata/tls_config.empty.good.json new file mode 100644 index 00000000..0967ef42 --- /dev/null +++ b/config/testdata/tls_config.empty.good.json @@ -0,0 +1 @@ +{} diff --git a/config/testdata/tls_config.insecure.good.json b/config/testdata/tls_config.insecure.good.json new file mode 100644 index 00000000..57fcd98f --- /dev/null +++ b/config/testdata/tls_config.insecure.good.json @@ -0,0 +1 @@ +{"insecure_skip_verify": true} diff --git a/config/testdata/tls_config.tlsversion.good.json b/config/testdata/tls_config.tlsversion.good.json new file mode 100644 index 00000000..c8d41cde --- /dev/null +++ b/config/testdata/tls_config.tlsversion.good.json @@ -0,0 +1 @@ +{"min_version": "TLS11"} diff --git a/config/testdata/tls_config.tlsversion.good.yml b/config/testdata/tls_config.tlsversion.good.yml new file mode 100644 index 00000000..ee24ee67 --- /dev/null +++ b/config/testdata/tls_config.tlsversion.good.yml @@ -0,0 +1 @@ +min_version: TLS11 diff --git a/config/tls_config_test.go b/config/tls_config_test.go index 2b965ea6..c759b86e 100644 --- a/config/tls_config_test.go +++ b/config/tls_config_test.go @@ -14,23 +14,39 @@ package config import ( + "bytes" "crypto/tls" + "fmt" "io/ioutil" + "path/filepath" "reflect" "testing" + "encoding/json" + "gopkg.in/yaml.v2" ) -// LoadTLSConfig parses the given YAML file into a tls.Config. +// LoadTLSConfig parses the given file into a tls.Config. func LoadTLSConfig(filename string) (*tls.Config, error) { content, err := ioutil.ReadFile(filename) if err != nil { return nil, err } cfg := TLSConfig{} - if err = yaml.UnmarshalStrict(content, &cfg); err != nil { - return nil, err + switch filepath.Ext(filename) { + case ".yml": + if err = yaml.UnmarshalStrict(content, &cfg); err != nil { + return nil, err + } + case ".json": + decoder := json.NewDecoder(bytes.NewReader(content)) + decoder.DisallowUnknownFields() + if err = decoder.Decode(&cfg); err != nil { + return nil, err + } + default: + return nil, fmt.Errorf("Unknown extension: %s", filepath.Ext(filename)) } return NewTLSConfig(&cfg) } @@ -39,12 +55,25 @@ var expectedTLSConfigs = []struct { filename string config *tls.Config }{ + { + filename: "tls_config.empty.good.json", + config: &tls.Config{}, + }, { + filename: "tls_config.insecure.good.json", + config: &tls.Config{InsecureSkipVerify: true}, + }, { + filename: "tls_config.tlsversion.good.json", + config: &tls.Config{MinVersion: tls.VersionTLS11}, + }, { filename: "tls_config.empty.good.yml", config: &tls.Config{}, }, { filename: "tls_config.insecure.good.yml", config: &tls.Config{InsecureSkipVerify: true}, + }, { + filename: "tls_config.tlsversion.good.yml", + config: &tls.Config{MinVersion: tls.VersionTLS11}, }, } @@ -52,7 +81,7 @@ func TestValidTLSConfig(t *testing.T) { for _, cfg := range expectedTLSConfigs { got, err := LoadTLSConfig("testdata/" + cfg.filename) if err != nil { - t.Errorf("Error parsing %s: %s", cfg.filename, err) + t.Fatalf("Error parsing %s: %s", cfg.filename, err) } // non-nil functions are never equal. got.GetClientCertificate = nil