Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 11, 01:00 UTC
| 1 | package caddytls |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/tls" |
| 6 | "fmt" |
| 7 | "io" |
| 8 | "net" |
| 9 | "net/http" |
| 10 | "net/url" |
| 11 | "strings" |
| 12 | |
| 13 | "github.com/caddyserver/certmagic" |
| 14 | "github.com/tailscale/tscert" |
| 15 | "go.uber.org/zap" |
| 16 | "go.uber.org/zap/zapcore" |
| 17 | |
| 18 | "github.com/caddyserver/caddy/v2" |
| 19 | "github.com/caddyserver/caddy/v2/caddyconfig/caddyfile" |
| 20 | ) |
| 21 | |
| 22 | func init() { |
| 23 | caddy.RegisterModule(Tailscale{}) |
| 24 | caddy.RegisterModule(HTTPCertGetter{}) |
| 25 | } |
| 26 | |
| 27 | // Tailscale is a module that can get certificates from the local Tailscale process. |
| 28 | type Tailscale struct { |
| 29 | logger *zap.Logger |
| 30 | } |
| 31 | |
| 32 | // CaddyModule returns the Caddy module information. |
| 33 | func (Tailscale) CaddyModule() caddy.ModuleInfo { |
| 34 | return caddy.ModuleInfo{ |
| 35 | ID: "tls.get_certificate.tailscale", |
| 36 | New: func() caddy.Module { return new(Tailscale) }, |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | func (ts *Tailscale) Provision(ctx caddy.Context) error { |
| 41 | ts.logger = ctx.Logger() |
| 42 | return nil |
| 43 | } |
| 44 | |
| 45 | func (ts Tailscale) GetCertificate(ctx context.Context, hello *tls.ClientHelloInfo) (*tls.Certificate, error) { |
| 46 | canGetCert, err := ts.canHazCertificate(ctx, hello) |
| 47 | if err == nil && !canGetCert { |
| 48 | return nil, nil // pass-thru: Tailscale can't offer a cert for this name |
| 49 | } |
| 50 | if err != nil { |
| 51 | if c := ts.logger.Check(zapcore.WarnLevel, "could not get status; will try to get certificate anyway"); c != nil { |
| 52 | c.Write(zap.Error(err)) |
| 53 | } |
| 54 | } |
| 55 | return tscert.GetCertificateWithContext(ctx, hello) |
| 56 | } |
| 57 | |
| 58 | // canHazCertificate returns true if Tailscale reports it can get a certificate for the given ClientHello. |
| 59 | func (ts Tailscale) canHazCertificate(ctx context.Context, hello *tls.ClientHelloInfo) (bool, error) { |
| 60 | if !strings.HasSuffix(strings.ToLower(hello.ServerName), tailscaleDomainAliasEnding) { |
| 61 | return false, nil |
| 62 | } |
| 63 | status, err := tscert.GetStatus(ctx) |
| 64 | if err != nil { |
| 65 | return false, err |
| 66 | } |
| 67 | for _, domain := range status.CertDomains { |
| 68 | if certmagic.MatchWildcard(hello.ServerName, domain) { |
| 69 | return true, nil |
| 70 | } |
| 71 | } |
| 72 | return false, nil |
| 73 | } |
| 74 | |
| 75 | // UnmarshalCaddyfile deserializes Caddyfile tokens into ts. |
| 76 | // |
| 77 | // ... tailscale |
| 78 | func (Tailscale) UnmarshalCaddyfile(d *caddyfile.Dispenser) error { |
| 79 | d.Next() // consume cert manager name |
| 80 | if d.NextArg() { |
| 81 | return d.ArgErr() |
| 82 | } |
| 83 | return nil |
| 84 | } |
| 85 | |
| 86 | // tailscaleDomainAliasEnding is the ending for all Tailscale custom domains. |
| 87 | const tailscaleDomainAliasEnding = ".ts.net" |
| 88 | |
| 89 | // HTTPCertGetter can get a certificate via HTTP(S) request. |
| 90 | type HTTPCertGetter struct { |
| 91 | // The URL from which to download the certificate. Required. |
| 92 | // |
| 93 | // The URL will be augmented with query string parameters taken |
| 94 | // from the TLS handshake: |
| 95 | // |
| 96 | // - server_name: The SNI value |
| 97 | // - signature_schemes: Comma-separated list of hex IDs of signatures |
| 98 | // - cipher_suites: Comma-separated list of hex IDs of cipher suites |
| 99 | // |
| 100 | // To be valid, the response must be HTTP 200 with a PEM body |
| 101 | // consisting of blocks for the certificate chain and the private |
| 102 | // key. |
| 103 | // |
| 104 | // To indicate that this manager is not managing a certificate for |
| 105 | // the described handshake, the endpoint should return HTTP 204 |
| 106 | // (No Content). Error statuses will indicate that the manager is |
| 107 | // capable of providing a certificate but was unable to. |
| 108 | URL string `json:"url,omitempty"` |
| 109 | |
| 110 | ctx context.Context |
| 111 | } |
| 112 | |
| 113 | // CaddyModule returns the Caddy module information. |
| 114 | func (hcg HTTPCertGetter) CaddyModule() caddy.ModuleInfo { |
| 115 | return caddy.ModuleInfo{ |
| 116 | ID: "tls.get_certificate.http", |
| 117 | New: func() caddy.Module { return new(HTTPCertGetter) }, |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | func (hcg *HTTPCertGetter) Provision(ctx caddy.Context) error { |
| 122 | hcg.ctx = ctx |
| 123 | if hcg.URL == "" { |
| 124 | return fmt.Errorf("URL is required") |
| 125 | } |
| 126 | return nil |
| 127 | } |
| 128 | |
| 129 | func (hcg HTTPCertGetter) GetCertificate(ctx context.Context, hello *tls.ClientHelloInfo) (*tls.Certificate, error) { |
| 130 | sigs := make([]string, len(hello.SignatureSchemes)) |
| 131 | for i, sig := range hello.SignatureSchemes { |
| 132 | sigs[i] = fmt.Sprintf("%x", uint16(sig)) // you won't believe what %x uses if the val is a Stringer |
| 133 | } |
| 134 | suites := make([]string, len(hello.CipherSuites)) |
| 135 | for i, cs := range hello.CipherSuites { |
| 136 | suites[i] = fmt.Sprintf("%x", cs) |
| 137 | } |
| 138 | |
| 139 | parsed, err := url.Parse(hcg.URL) |
| 140 | if err != nil { |
| 141 | return nil, err |
| 142 | } |
| 143 | qs := parsed.Query() |
| 144 | qs.Set("server_name", hello.ServerName) |
| 145 | qs.Set("signature_schemes", strings.Join(sigs, ",")) |
| 146 | qs.Set("cipher_suites", strings.Join(suites, ",")) |
| 147 | localIP, _, err := net.SplitHostPort(hello.Conn.LocalAddr().String()) |
| 148 | if err == nil && localIP != "" { |
| 149 | qs.Set("local_ip", localIP) |
| 150 | } |
| 151 | parsed.RawQuery = qs.Encode() |
| 152 | |
| 153 | req, err := http.NewRequestWithContext(hcg.ctx, http.MethodGet, parsed.String(), nil) |
| 154 | if err != nil { |
| 155 | return nil, err |
| 156 | } |
| 157 | |
| 158 | resp, err := http.DefaultClient.Do(req) //nolint:gosec // SSRF false positive... request URI comes from config |
| 159 | if err != nil { |
| 160 | return nil, err |
| 161 | } |
| 162 | defer resp.Body.Close() |
| 163 | if resp.StatusCode == http.StatusNoContent { |
| 164 | // endpoint is not managing certs for this handshake |
| 165 | return nil, nil |
| 166 | } |
| 167 | if resp.StatusCode != http.StatusOK { |
| 168 | return nil, fmt.Errorf("got HTTP %d", resp.StatusCode) |
| 169 | } |
| 170 | |
| 171 | bodyBytes, err := io.ReadAll(resp.Body) |
| 172 | if err != nil { |
| 173 | return nil, fmt.Errorf("error reading response body: %v", err) |
| 174 | } |
| 175 | |
| 176 | cert, err := tlsCertFromCertAndKeyPEMBundle(bodyBytes) |
| 177 | if err != nil { |
| 178 | return nil, err |
| 179 | } |
| 180 | |
| 181 | return &cert, nil |
| 182 | } |
| 183 | |
| 184 | // UnmarshalCaddyfile deserializes Caddyfile tokens into ts. |
| 185 | // |
| 186 | // ... http <url> |
| 187 | func (hcg *HTTPCertGetter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error { |
| 188 | d.Next() // consume cert manager name |
| 189 | |
| 190 | if !d.NextArg() { |
| 191 | return d.ArgErr() |
| 192 | } |
| 193 | hcg.URL = d.Val() |
| 194 | |
| 195 | if d.NextArg() { |
| 196 | return d.ArgErr() |
| 197 | } |
| 198 | if d.NextBlock(0) { |
| 199 | return d.Err("block not allowed here") |
| 200 | } |
| 201 | return nil |
| 202 | } |
| 203 | |
| 204 | // Interface guards |
| 205 | var ( |
| 206 | _ certmagic.Manager = (*Tailscale)(nil) |
| 207 | _ caddy.Provisioner = (*Tailscale)(nil) |
| 208 | _ caddyfile.Unmarshaler = (*Tailscale)(nil) |
| 209 | |
| 210 | _ certmagic.Manager = (*HTTPCertGetter)(nil) |
| 211 | _ caddy.Provisioner = (*HTTPCertGetter)(nil) |
| 212 | _ caddyfile.Unmarshaler = (*HTTPCertGetter)(nil) |
| 213 | ) |