Elia Battiston | 4750d3c | 2022-07-14 13:24:56 +0000 | [diff] [blame] | 1 | // Package config implements KRB5 client and service configuration as described at https://web.mit.edu/kerberos/krb5-latest/doc/admin/conf_files/krb5_conf.html |
| 2 | package config |
| 3 | |
| 4 | import ( |
| 5 | "bufio" |
| 6 | "encoding/hex" |
| 7 | "encoding/json" |
| 8 | "errors" |
| 9 | "fmt" |
| 10 | "io" |
| 11 | "net" |
| 12 | "os" |
| 13 | "os/user" |
| 14 | "regexp" |
| 15 | "strconv" |
| 16 | "strings" |
| 17 | "time" |
| 18 | |
| 19 | "github.com/jcmturner/gofork/encoding/asn1" |
| 20 | "github.com/jcmturner/gokrb5/v8/iana/etypeID" |
| 21 | ) |
| 22 | |
| 23 | // Config represents the KRB5 configuration. |
| 24 | type Config struct { |
| 25 | LibDefaults LibDefaults |
| 26 | Realms []Realm |
| 27 | DomainRealm DomainRealm |
| 28 | //CaPaths |
| 29 | //AppDefaults |
| 30 | //Plugins |
| 31 | } |
| 32 | |
| 33 | // WeakETypeList is a list of encryption types that have been deemed weak. |
| 34 | const WeakETypeList = "des-cbc-crc des-cbc-md4 des-cbc-md5 des-cbc-raw des3-cbc-raw des-hmac-sha1 arcfour-hmac-exp rc4-hmac-exp arcfour-hmac-md5-exp des" |
| 35 | |
| 36 | // New creates a new config struct instance. |
| 37 | func New() *Config { |
| 38 | d := make(DomainRealm) |
| 39 | return &Config{ |
| 40 | LibDefaults: newLibDefaults(), |
| 41 | DomainRealm: d, |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | // LibDefaults represents the [libdefaults] section of the configuration. |
| 46 | type LibDefaults struct { |
| 47 | AllowWeakCrypto bool //default false |
| 48 | // ap_req_checksum_type int //unlikely to support this |
| 49 | Canonicalize bool //default false |
| 50 | CCacheType int //default is 4. unlikely to implement older |
| 51 | Clockskew time.Duration //max allowed skew in seconds, default 300 |
| 52 | //Default_ccache_name string // default /tmp/krb5cc_%{uid} //Not implementing as will hold in memory |
| 53 | DefaultClientKeytabName string //default /usr/local/var/krb5/user/%{euid}/client.keytab |
| 54 | DefaultKeytabName string //default /etc/krb5.keytab |
| 55 | DefaultRealm string |
| 56 | DefaultTGSEnctypes []string //default aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 camellia256-cts-cmac camellia128-cts-cmac des-cbc-crc des-cbc-md5 des-cbc-md4 |
| 57 | DefaultTktEnctypes []string //default aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 camellia256-cts-cmac camellia128-cts-cmac des-cbc-crc des-cbc-md5 des-cbc-md4 |
| 58 | DefaultTGSEnctypeIDs []int32 //default aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 camellia256-cts-cmac camellia128-cts-cmac des-cbc-crc des-cbc-md5 des-cbc-md4 |
| 59 | DefaultTktEnctypeIDs []int32 //default aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 camellia256-cts-cmac camellia128-cts-cmac des-cbc-crc des-cbc-md5 des-cbc-md4 |
| 60 | DNSCanonicalizeHostname bool //default true |
| 61 | DNSLookupKDC bool //default false |
| 62 | DNSLookupRealm bool |
| 63 | ExtraAddresses []net.IP //Not implementing yet |
| 64 | Forwardable bool //default false |
| 65 | IgnoreAcceptorHostname bool //default false |
| 66 | K5LoginAuthoritative bool //default false |
| 67 | K5LoginDirectory string //default user's home directory. Must be owned by the user or root |
| 68 | KDCDefaultOptions asn1.BitString //default 0x00000010 (KDC_OPT_RENEWABLE_OK) |
| 69 | KDCTimeSync int //default 1 |
| 70 | //kdc_req_checksum_type int //unlikely to implement as for very old KDCs |
| 71 | NoAddresses bool //default true |
| 72 | PermittedEnctypes []string //default aes256-cts-hmac-sha1-96 aes128-cts-hmac-sha1-96 des3-cbc-sha1 arcfour-hmac-md5 camellia256-cts-cmac camellia128-cts-cmac des-cbc-crc des-cbc-md5 des-cbc-md4 |
| 73 | PermittedEnctypeIDs []int32 |
| 74 | //plugin_base_dir string //not supporting plugins |
| 75 | PreferredPreauthTypes []int //default “17, 16, 15, 14”, which forces libkrb5 to attempt to use PKINIT if it is supported |
| 76 | Proxiable bool //default false |
| 77 | RDNS bool //default true |
| 78 | RealmTryDomains int //default -1 |
| 79 | RenewLifetime time.Duration //default 0 |
| 80 | SafeChecksumType int //default 8 |
| 81 | TicketLifetime time.Duration //default 1 day |
| 82 | UDPPreferenceLimit int // 1 means to always use tcp. MIT krb5 has a default value of 1465, and it prevents user setting more than 32700. |
| 83 | VerifyAPReqNofail bool //default false |
| 84 | } |
| 85 | |
| 86 | // Create a new LibDefaults struct. |
| 87 | func newLibDefaults() LibDefaults { |
| 88 | uid := "0" |
| 89 | var hdir string |
| 90 | usr, _ := user.Current() |
| 91 | if usr != nil { |
| 92 | uid = usr.Uid |
| 93 | hdir = usr.HomeDir |
| 94 | } |
| 95 | opts := asn1.BitString{} |
| 96 | opts.Bytes, _ = hex.DecodeString("00000010") |
| 97 | opts.BitLength = len(opts.Bytes) * 8 |
| 98 | return LibDefaults{ |
| 99 | CCacheType: 4, |
| 100 | Clockskew: time.Duration(300) * time.Second, |
| 101 | DefaultClientKeytabName: fmt.Sprintf("/usr/local/var/krb5/user/%s/client.keytab", uid), |
| 102 | DefaultKeytabName: "/etc/krb5.keytab", |
| 103 | DefaultTGSEnctypes: []string{"aes256-cts-hmac-sha1-96", "aes128-cts-hmac-sha1-96", "des3-cbc-sha1", "arcfour-hmac-md5", "camellia256-cts-cmac", "camellia128-cts-cmac", "des-cbc-crc", "des-cbc-md5", "des-cbc-md4"}, |
| 104 | DefaultTktEnctypes: []string{"aes256-cts-hmac-sha1-96", "aes128-cts-hmac-sha1-96", "des3-cbc-sha1", "arcfour-hmac-md5", "camellia256-cts-cmac", "camellia128-cts-cmac", "des-cbc-crc", "des-cbc-md5", "des-cbc-md4"}, |
| 105 | DNSCanonicalizeHostname: true, |
| 106 | K5LoginDirectory: hdir, |
| 107 | KDCDefaultOptions: opts, |
| 108 | KDCTimeSync: 1, |
| 109 | NoAddresses: true, |
| 110 | PermittedEnctypes: []string{"aes256-cts-hmac-sha1-96", "aes128-cts-hmac-sha1-96", "des3-cbc-sha1", "arcfour-hmac-md5", "camellia256-cts-cmac", "camellia128-cts-cmac", "des-cbc-crc", "des-cbc-md5", "des-cbc-md4"}, |
| 111 | RDNS: true, |
| 112 | RealmTryDomains: -1, |
| 113 | SafeChecksumType: 8, |
| 114 | TicketLifetime: time.Duration(24) * time.Hour, |
| 115 | UDPPreferenceLimit: 1465, |
| 116 | PreferredPreauthTypes: []int{17, 16, 15, 14}, |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | // Parse the lines of the [libdefaults] section of the configuration into the LibDefaults struct. |
| 121 | func (l *LibDefaults) parseLines(lines []string) error { |
| 122 | for _, line := range lines { |
| 123 | //Remove comments after the values |
| 124 | if idx := strings.IndexAny(line, "#;"); idx != -1 { |
| 125 | line = line[:idx] |
| 126 | } |
| 127 | line = strings.TrimSpace(line) |
| 128 | if line == "" { |
| 129 | continue |
| 130 | } |
| 131 | if !strings.Contains(line, "=") { |
| 132 | return InvalidErrorf("libdefaults section line (%s)", line) |
| 133 | } |
| 134 | |
| 135 | p := strings.Split(line, "=") |
| 136 | key := strings.TrimSpace(strings.ToLower(p[0])) |
| 137 | switch key { |
| 138 | case "allow_weak_crypto": |
| 139 | v, err := parseBoolean(p[1]) |
| 140 | if err != nil { |
| 141 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 142 | } |
| 143 | l.AllowWeakCrypto = v |
| 144 | case "canonicalize": |
| 145 | v, err := parseBoolean(p[1]) |
| 146 | if err != nil { |
| 147 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 148 | } |
| 149 | l.Canonicalize = v |
| 150 | case "ccache_type": |
| 151 | p[1] = strings.TrimSpace(p[1]) |
| 152 | v, err := strconv.ParseUint(p[1], 10, 32) |
| 153 | if err != nil || v < 0 || v > 4 { |
| 154 | return InvalidErrorf("libdefaults section line (%s)", line) |
| 155 | } |
| 156 | l.CCacheType = int(v) |
| 157 | case "clockskew": |
| 158 | d, err := parseDuration(p[1]) |
| 159 | if err != nil { |
| 160 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 161 | } |
| 162 | l.Clockskew = d |
| 163 | case "default_client_keytab_name": |
| 164 | l.DefaultClientKeytabName = strings.TrimSpace(p[1]) |
| 165 | case "default_keytab_name": |
| 166 | l.DefaultKeytabName = strings.TrimSpace(p[1]) |
| 167 | case "default_realm": |
| 168 | l.DefaultRealm = strings.TrimSpace(p[1]) |
| 169 | case "default_tgs_enctypes": |
| 170 | l.DefaultTGSEnctypes = strings.Fields(p[1]) |
| 171 | case "default_tkt_enctypes": |
| 172 | l.DefaultTktEnctypes = strings.Fields(p[1]) |
| 173 | case "dns_canonicalize_hostname": |
| 174 | v, err := parseBoolean(p[1]) |
| 175 | if err != nil { |
| 176 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 177 | } |
| 178 | l.DNSCanonicalizeHostname = v |
| 179 | case "dns_lookup_kdc": |
| 180 | v, err := parseBoolean(p[1]) |
| 181 | if err != nil { |
| 182 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 183 | } |
| 184 | l.DNSLookupKDC = v |
| 185 | case "dns_lookup_realm": |
| 186 | v, err := parseBoolean(p[1]) |
| 187 | if err != nil { |
| 188 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 189 | } |
| 190 | l.DNSLookupRealm = v |
| 191 | case "extra_addresses": |
| 192 | ipStr := strings.TrimSpace(p[1]) |
| 193 | for _, ip := range strings.Split(ipStr, ",") { |
| 194 | if eip := net.ParseIP(ip); eip != nil { |
| 195 | l.ExtraAddresses = append(l.ExtraAddresses, eip) |
| 196 | } |
| 197 | } |
| 198 | case "forwardable": |
| 199 | v, err := parseBoolean(p[1]) |
| 200 | if err != nil { |
| 201 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 202 | } |
| 203 | l.Forwardable = v |
| 204 | case "ignore_acceptor_hostname": |
| 205 | v, err := parseBoolean(p[1]) |
| 206 | if err != nil { |
| 207 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 208 | } |
| 209 | l.IgnoreAcceptorHostname = v |
| 210 | case "k5login_authoritative": |
| 211 | v, err := parseBoolean(p[1]) |
| 212 | if err != nil { |
| 213 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 214 | } |
| 215 | l.K5LoginAuthoritative = v |
| 216 | case "k5login_directory": |
| 217 | l.K5LoginDirectory = strings.TrimSpace(p[1]) |
| 218 | case "kdc_default_options": |
| 219 | v := strings.TrimSpace(p[1]) |
| 220 | v = strings.Replace(v, "0x", "", -1) |
| 221 | b, err := hex.DecodeString(v) |
| 222 | if err != nil { |
| 223 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 224 | } |
| 225 | l.KDCDefaultOptions.Bytes = b |
| 226 | l.KDCDefaultOptions.BitLength = len(b) * 8 |
| 227 | case "kdc_timesync": |
| 228 | p[1] = strings.TrimSpace(p[1]) |
| 229 | v, err := strconv.ParseInt(p[1], 10, 32) |
| 230 | if err != nil || v < 0 { |
| 231 | return InvalidErrorf("libdefaults section line (%s)", line) |
| 232 | } |
| 233 | l.KDCTimeSync = int(v) |
| 234 | case "noaddresses": |
| 235 | v, err := parseBoolean(p[1]) |
| 236 | if err != nil { |
| 237 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 238 | } |
| 239 | l.NoAddresses = v |
| 240 | case "permitted_enctypes": |
| 241 | l.PermittedEnctypes = strings.Fields(p[1]) |
| 242 | case "preferred_preauth_types": |
| 243 | p[1] = strings.TrimSpace(p[1]) |
| 244 | t := strings.Split(p[1], ",") |
| 245 | var v []int |
| 246 | for _, s := range t { |
| 247 | i, err := strconv.ParseInt(s, 10, 32) |
| 248 | if err != nil { |
| 249 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 250 | } |
| 251 | v = append(v, int(i)) |
| 252 | } |
| 253 | l.PreferredPreauthTypes = v |
| 254 | case "proxiable": |
| 255 | v, err := parseBoolean(p[1]) |
| 256 | if err != nil { |
| 257 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 258 | } |
| 259 | l.Proxiable = v |
| 260 | case "rdns": |
| 261 | v, err := parseBoolean(p[1]) |
| 262 | if err != nil { |
| 263 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 264 | } |
| 265 | l.RDNS = v |
| 266 | case "realm_try_domains": |
| 267 | p[1] = strings.TrimSpace(p[1]) |
| 268 | v, err := strconv.ParseInt(p[1], 10, 32) |
| 269 | if err != nil || v < -1 { |
| 270 | return InvalidErrorf("libdefaults section line (%s)", line) |
| 271 | } |
| 272 | l.RealmTryDomains = int(v) |
| 273 | case "renew_lifetime": |
| 274 | d, err := parseDuration(p[1]) |
| 275 | if err != nil { |
| 276 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 277 | } |
| 278 | l.RenewLifetime = d |
| 279 | case "safe_checksum_type": |
| 280 | p[1] = strings.TrimSpace(p[1]) |
| 281 | v, err := strconv.ParseInt(p[1], 10, 32) |
| 282 | if err != nil || v < 0 { |
| 283 | return InvalidErrorf("libdefaults section line (%s)", line) |
| 284 | } |
| 285 | l.SafeChecksumType = int(v) |
| 286 | case "ticket_lifetime": |
| 287 | d, err := parseDuration(p[1]) |
| 288 | if err != nil { |
| 289 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 290 | } |
| 291 | l.TicketLifetime = d |
| 292 | case "udp_preference_limit": |
| 293 | p[1] = strings.TrimSpace(p[1]) |
| 294 | v, err := strconv.ParseUint(p[1], 10, 32) |
| 295 | if err != nil || v > 32700 { |
| 296 | return InvalidErrorf("libdefaults section line (%s)", line) |
| 297 | } |
| 298 | l.UDPPreferenceLimit = int(v) |
| 299 | case "verify_ap_req_nofail": |
| 300 | v, err := parseBoolean(p[1]) |
| 301 | if err != nil { |
| 302 | return InvalidErrorf("libdefaults section line (%s): %v", line, err) |
| 303 | } |
| 304 | l.VerifyAPReqNofail = v |
| 305 | } |
| 306 | } |
| 307 | l.DefaultTGSEnctypeIDs = parseETypes(l.DefaultTGSEnctypes, l.AllowWeakCrypto) |
| 308 | l.DefaultTktEnctypeIDs = parseETypes(l.DefaultTktEnctypes, l.AllowWeakCrypto) |
| 309 | l.PermittedEnctypeIDs = parseETypes(l.PermittedEnctypes, l.AllowWeakCrypto) |
| 310 | return nil |
| 311 | } |
| 312 | |
| 313 | // Realm represents an entry in the [realms] section of the configuration. |
| 314 | type Realm struct { |
| 315 | Realm string |
| 316 | AdminServer []string |
| 317 | //auth_to_local //Not implementing for now |
| 318 | //auth_to_local_names //Not implementing for now |
| 319 | DefaultDomain string |
| 320 | KDC []string |
| 321 | KPasswdServer []string //default admin_server:464 |
| 322 | MasterKDC []string |
| 323 | } |
| 324 | |
| 325 | // Parse the lines of a [realms] entry into the Realm struct. |
| 326 | func (r *Realm) parseLines(name string, lines []string) (err error) { |
| 327 | r.Realm = name |
| 328 | var adminServerFinal bool |
| 329 | var KDCFinal bool |
| 330 | var kpasswdServerFinal bool |
| 331 | var masterKDCFinal bool |
| 332 | var ignore bool |
| 333 | var c int // counts the depth of blocks within brackets { } |
| 334 | for _, line := range lines { |
| 335 | if ignore && c > 0 && !strings.Contains(line, "{") && !strings.Contains(line, "}") { |
| 336 | continue |
| 337 | } |
| 338 | //Remove comments after the values |
| 339 | if idx := strings.IndexAny(line, "#;"); idx != -1 { |
| 340 | line = line[:idx] |
| 341 | } |
| 342 | line = strings.TrimSpace(line) |
| 343 | if line == "" { |
| 344 | continue |
| 345 | } |
| 346 | if !strings.Contains(line, "=") && !strings.Contains(line, "}") { |
| 347 | return InvalidErrorf("realms section line (%s)", line) |
| 348 | } |
| 349 | if strings.Contains(line, "v4_") { |
| 350 | ignore = true |
| 351 | err = UnsupportedDirective{"v4 configurations are not supported"} |
| 352 | } |
| 353 | if strings.Contains(line, "{") { |
| 354 | c++ |
| 355 | if ignore { |
| 356 | continue |
| 357 | } |
| 358 | } |
| 359 | if strings.Contains(line, "}") { |
| 360 | c-- |
| 361 | if c < 0 { |
| 362 | return InvalidErrorf("unpaired curly brackets") |
| 363 | } |
| 364 | if ignore { |
| 365 | if c < 1 { |
| 366 | c = 0 |
| 367 | ignore = false |
| 368 | } |
| 369 | continue |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | p := strings.Split(line, "=") |
| 374 | key := strings.TrimSpace(strings.ToLower(p[0])) |
| 375 | v := strings.TrimSpace(p[1]) |
| 376 | switch key { |
| 377 | case "admin_server": |
| 378 | appendUntilFinal(&r.AdminServer, v, &adminServerFinal) |
| 379 | case "default_domain": |
| 380 | r.DefaultDomain = v |
| 381 | case "kdc": |
| 382 | if !strings.Contains(v, ":") { |
| 383 | // No port number specified default to 88 |
| 384 | if strings.HasSuffix(v, `*`) { |
| 385 | v = strings.TrimSpace(strings.TrimSuffix(v, `*`)) + ":88*" |
| 386 | } else { |
| 387 | v = strings.TrimSpace(v) + ":88" |
| 388 | } |
| 389 | } |
| 390 | appendUntilFinal(&r.KDC, v, &KDCFinal) |
| 391 | case "kpasswd_server": |
| 392 | appendUntilFinal(&r.KPasswdServer, v, &kpasswdServerFinal) |
| 393 | case "master_kdc": |
| 394 | appendUntilFinal(&r.MasterKDC, v, &masterKDCFinal) |
| 395 | } |
| 396 | } |
| 397 | //default for Kpasswd_server = admin_server:464 |
| 398 | if len(r.KPasswdServer) < 1 { |
| 399 | for _, a := range r.AdminServer { |
| 400 | s := strings.Split(a, ":") |
| 401 | r.KPasswdServer = append(r.KPasswdServer, s[0]+":464") |
| 402 | } |
| 403 | } |
| 404 | return |
| 405 | } |
| 406 | |
| 407 | // Parse the lines of the [realms] section of the configuration into an slice of Realm structs. |
| 408 | func parseRealms(lines []string) (realms []Realm, err error) { |
| 409 | var name string |
| 410 | var start int |
| 411 | var c int |
| 412 | for i, l := range lines { |
| 413 | //Remove comments after the values |
| 414 | if idx := strings.IndexAny(l, "#;"); idx != -1 { |
| 415 | l = l[:idx] |
| 416 | } |
| 417 | l = strings.TrimSpace(l) |
| 418 | if l == "" { |
| 419 | continue |
| 420 | } |
| 421 | //if strings.Contains(l, "v4_") { |
| 422 | // return nil, errors.New("v4 configurations are not supported in Realms section") |
| 423 | //} |
| 424 | if strings.Contains(l, "{") { |
| 425 | c++ |
| 426 | if !strings.Contains(l, "=") { |
| 427 | return nil, fmt.Errorf("realm configuration line invalid: %s", l) |
| 428 | } |
| 429 | if c == 1 { |
| 430 | start = i |
| 431 | p := strings.Split(l, "=") |
| 432 | name = strings.TrimSpace(p[0]) |
| 433 | } |
| 434 | } |
| 435 | if strings.Contains(l, "}") { |
| 436 | if c < 1 { |
| 437 | // but not started a block!!! |
| 438 | return nil, errors.New("invalid Realms section in configuration") |
| 439 | } |
| 440 | c-- |
| 441 | if c == 0 { |
| 442 | var r Realm |
| 443 | e := r.parseLines(name, lines[start+1:i]) |
| 444 | if e != nil { |
| 445 | if _, ok := e.(UnsupportedDirective); !ok { |
| 446 | err = e |
| 447 | return |
| 448 | } |
| 449 | err = e |
| 450 | } |
| 451 | realms = append(realms, r) |
| 452 | } |
| 453 | } |
| 454 | } |
| 455 | return |
| 456 | } |
| 457 | |
| 458 | // DomainRealm maps the domains to realms representing the [domain_realm] section of the configuration. |
| 459 | type DomainRealm map[string]string |
| 460 | |
| 461 | // Parse the lines of the [domain_realm] section of the configuration and add to the mapping. |
| 462 | func (d *DomainRealm) parseLines(lines []string) error { |
| 463 | for _, line := range lines { |
| 464 | //Remove comments after the values |
| 465 | if idx := strings.IndexAny(line, "#;"); idx != -1 { |
| 466 | line = line[:idx] |
| 467 | } |
| 468 | if strings.TrimSpace(line) == "" { |
| 469 | continue |
| 470 | } |
| 471 | if !strings.Contains(line, "=") { |
| 472 | return InvalidErrorf("realm line (%s)", line) |
| 473 | } |
| 474 | p := strings.Split(line, "=") |
| 475 | domain := strings.TrimSpace(strings.ToLower(p[0])) |
| 476 | realm := strings.TrimSpace(p[1]) |
| 477 | d.addMapping(domain, realm) |
| 478 | } |
| 479 | return nil |
| 480 | } |
| 481 | |
| 482 | // Add a domain to realm mapping. |
| 483 | func (d *DomainRealm) addMapping(domain, realm string) { |
| 484 | (*d)[domain] = realm |
| 485 | } |
| 486 | |
| 487 | // Delete a domain to realm mapping. |
| 488 | func (d *DomainRealm) deleteMapping(domain, realm string) { |
| 489 | delete(*d, domain) |
| 490 | } |
| 491 | |
| 492 | // ResolveRealm resolves the kerberos realm for the specified domain name from the domain to realm mapping. |
| 493 | // The most specific mapping is returned. |
| 494 | func (c *Config) ResolveRealm(domainName string) string { |
| 495 | domainName = strings.TrimSuffix(domainName, ".") |
| 496 | |
| 497 | // Try to match the entire hostname first |
| 498 | if r, ok := c.DomainRealm[domainName]; ok { |
| 499 | return r |
| 500 | } |
| 501 | |
| 502 | // Try to match all DNS domain parts |
| 503 | periods := strings.Count(domainName, ".") + 1 |
| 504 | for i := 2; i <= periods; i++ { |
| 505 | z := strings.SplitN(domainName, ".", i) |
| 506 | if r, ok := c.DomainRealm["."+z[len(z)-1]]; ok { |
| 507 | return r |
| 508 | } |
| 509 | } |
| 510 | return c.LibDefaults.DefaultRealm |
| 511 | } |
| 512 | |
| 513 | // Load the KRB5 configuration from the specified file path. |
| 514 | func Load(cfgPath string) (*Config, error) { |
| 515 | fh, err := os.Open(cfgPath) |
| 516 | if err != nil { |
| 517 | return nil, errors.New("configuration file could not be opened: " + cfgPath + " " + err.Error()) |
| 518 | } |
| 519 | defer fh.Close() |
| 520 | scanner := bufio.NewScanner(fh) |
| 521 | return NewFromScanner(scanner) |
| 522 | } |
| 523 | |
| 524 | // NewFromString creates a new Config struct from a string. |
| 525 | func NewFromString(s string) (*Config, error) { |
| 526 | reader := strings.NewReader(s) |
| 527 | return NewFromReader(reader) |
| 528 | } |
| 529 | |
| 530 | // NewFromReader creates a new Config struct from an io.Reader. |
| 531 | func NewFromReader(r io.Reader) (*Config, error) { |
| 532 | scanner := bufio.NewScanner(r) |
| 533 | return NewFromScanner(scanner) |
| 534 | } |
| 535 | |
| 536 | // NewFromScanner creates a new Config struct from a bufio.Scanner. |
| 537 | func NewFromScanner(scanner *bufio.Scanner) (*Config, error) { |
| 538 | c := New() |
| 539 | var e error |
| 540 | sections := make(map[int]string) |
| 541 | var sectionLineNum []int |
| 542 | var lines []string |
| 543 | for scanner.Scan() { |
| 544 | // Skip comments and blank lines |
| 545 | if matched, _ := regexp.MatchString(`^\s*(#|;|\n)`, scanner.Text()); matched { |
| 546 | continue |
| 547 | } |
| 548 | if matched, _ := regexp.MatchString(`^\s*\[libdefaults\]\s*`, scanner.Text()); matched { |
| 549 | sections[len(lines)] = "libdefaults" |
| 550 | sectionLineNum = append(sectionLineNum, len(lines)) |
| 551 | continue |
| 552 | } |
| 553 | if matched, _ := regexp.MatchString(`^\s*\[realms\]\s*`, scanner.Text()); matched { |
| 554 | sections[len(lines)] = "realms" |
| 555 | sectionLineNum = append(sectionLineNum, len(lines)) |
| 556 | continue |
| 557 | } |
| 558 | if matched, _ := regexp.MatchString(`^\s*\[domain_realm\]\s*`, scanner.Text()); matched { |
| 559 | sections[len(lines)] = "domain_realm" |
| 560 | sectionLineNum = append(sectionLineNum, len(lines)) |
| 561 | continue |
| 562 | } |
| 563 | if matched, _ := regexp.MatchString(`^\s*\[.*\]\s*`, scanner.Text()); matched { |
| 564 | sections[len(lines)] = "unknown_section" |
| 565 | sectionLineNum = append(sectionLineNum, len(lines)) |
| 566 | continue |
| 567 | } |
| 568 | lines = append(lines, scanner.Text()) |
| 569 | } |
| 570 | for i, start := range sectionLineNum { |
| 571 | var end int |
| 572 | if i+1 >= len(sectionLineNum) { |
| 573 | end = len(lines) |
| 574 | } else { |
| 575 | end = sectionLineNum[i+1] |
| 576 | } |
| 577 | switch section := sections[start]; section { |
| 578 | case "libdefaults": |
| 579 | err := c.LibDefaults.parseLines(lines[start:end]) |
| 580 | if err != nil { |
| 581 | if _, ok := err.(UnsupportedDirective); !ok { |
| 582 | return nil, fmt.Errorf("error processing libdefaults section: %v", err) |
| 583 | } |
| 584 | e = err |
| 585 | } |
| 586 | case "realms": |
| 587 | realms, err := parseRealms(lines[start:end]) |
| 588 | if err != nil { |
| 589 | if _, ok := err.(UnsupportedDirective); !ok { |
| 590 | return nil, fmt.Errorf("error processing realms section: %v", err) |
| 591 | } |
| 592 | e = err |
| 593 | } |
| 594 | c.Realms = realms |
| 595 | case "domain_realm": |
| 596 | err := c.DomainRealm.parseLines(lines[start:end]) |
| 597 | if err != nil { |
| 598 | if _, ok := err.(UnsupportedDirective); !ok { |
| 599 | return nil, fmt.Errorf("error processing domaain_realm section: %v", err) |
| 600 | } |
| 601 | e = err |
| 602 | } |
| 603 | } |
| 604 | } |
| 605 | return c, e |
| 606 | } |
| 607 | |
| 608 | // Parse a space delimited list of ETypes into a list of EType numbers optionally filtering out weak ETypes. |
| 609 | func parseETypes(s []string, w bool) []int32 { |
| 610 | var eti []int32 |
| 611 | for _, et := range s { |
| 612 | if !w { |
| 613 | var weak bool |
| 614 | for _, wet := range strings.Fields(WeakETypeList) { |
| 615 | if et == wet { |
| 616 | weak = true |
| 617 | break |
| 618 | } |
| 619 | } |
| 620 | if weak { |
| 621 | continue |
| 622 | } |
| 623 | } |
| 624 | i := etypeID.EtypeSupported(et) |
| 625 | if i != 0 { |
| 626 | eti = append(eti, i) |
| 627 | } |
| 628 | } |
| 629 | return eti |
| 630 | } |
| 631 | |
| 632 | // Parse a time duration string in the configuration to a golang time.Duration. |
| 633 | func parseDuration(s string) (time.Duration, error) { |
| 634 | s = strings.Replace(strings.TrimSpace(s), " ", "", -1) |
| 635 | |
| 636 | // handle Nd[NmNs] |
| 637 | if strings.Contains(s, "d") { |
| 638 | ds := strings.SplitN(s, "d", 2) |
| 639 | dn, err := strconv.ParseUint(ds[0], 10, 32) |
| 640 | if err != nil { |
| 641 | return time.Duration(0), errors.New("invalid time duration") |
| 642 | } |
| 643 | d := time.Duration(dn*24) * time.Hour |
| 644 | if ds[1] != "" { |
| 645 | dp, err := time.ParseDuration(ds[1]) |
| 646 | if err != nil { |
| 647 | return time.Duration(0), errors.New("invalid time duration") |
| 648 | } |
| 649 | d = d + dp |
| 650 | } |
| 651 | return d, nil |
| 652 | } |
| 653 | |
| 654 | // handle Nm[Ns] |
| 655 | d, err := time.ParseDuration(s) |
| 656 | if err == nil { |
| 657 | return d, nil |
| 658 | } |
| 659 | |
| 660 | // handle N |
| 661 | v, err := strconv.ParseUint(s, 10, 32) |
| 662 | if err == nil && v > 0 { |
| 663 | return time.Duration(v) * time.Second, nil |
| 664 | } |
| 665 | |
| 666 | // handle h:m[:s] |
| 667 | if strings.Contains(s, ":") { |
| 668 | t := strings.Split(s, ":") |
| 669 | if 2 > len(t) || len(t) > 3 { |
| 670 | return time.Duration(0), errors.New("invalid time duration value") |
| 671 | } |
| 672 | var i []int |
| 673 | for _, n := range t { |
| 674 | j, err := strconv.ParseInt(n, 10, 16) |
| 675 | if err != nil { |
| 676 | return time.Duration(0), errors.New("invalid time duration value") |
| 677 | } |
| 678 | i = append(i, int(j)) |
| 679 | } |
| 680 | d := time.Duration(i[0])*time.Hour + time.Duration(i[1])*time.Minute |
| 681 | if len(i) == 3 { |
| 682 | d = d + time.Duration(i[2])*time.Second |
| 683 | } |
| 684 | return d, nil |
| 685 | } |
| 686 | return time.Duration(0), errors.New("invalid time duration value") |
| 687 | } |
| 688 | |
| 689 | // Parse possible boolean values to golang bool. |
| 690 | func parseBoolean(s string) (bool, error) { |
| 691 | s = strings.TrimSpace(s) |
| 692 | v, err := strconv.ParseBool(s) |
| 693 | if err == nil { |
| 694 | return v, nil |
| 695 | } |
| 696 | switch strings.ToLower(s) { |
| 697 | case "yes": |
| 698 | return true, nil |
| 699 | case "y": |
| 700 | return true, nil |
| 701 | case "no": |
| 702 | return false, nil |
| 703 | case "n": |
| 704 | return false, nil |
| 705 | } |
| 706 | return false, errors.New("invalid boolean value") |
| 707 | } |
| 708 | |
| 709 | // Parse array of strings but stop if an asterisk is placed at the end of a line. |
| 710 | func appendUntilFinal(s *[]string, value string, final *bool) { |
| 711 | if *final { |
| 712 | return |
| 713 | } |
| 714 | if last := len(value) - 1; last >= 0 && value[last] == '*' { |
| 715 | *final = true |
| 716 | value = value[:len(value)-1] |
| 717 | } |
| 718 | *s = append(*s, value) |
| 719 | } |
| 720 | |
| 721 | // JSON return details of the config in a JSON format. |
| 722 | func (c *Config) JSON() (string, error) { |
| 723 | b, err := json.MarshalIndent(c, "", " ") |
| 724 | if err != nil { |
| 725 | return "", err |
| 726 | } |
| 727 | return string(b), nil |
| 728 | } |