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| 1 | +// Copyright 2021 Liam Breck |
| 2 | +// Published at https://github.com/networkimprov/mnm |
| 3 | +// |
| 4 | +// This Source Code Form is subject to the terms of the Mozilla Public |
| 5 | +// License, v. 2.0. If a copy of the MPL was not distributed with this |
| 6 | +// file, You can obtain one at http://mozilla.org/MPL/2.0/ |
| 7 | + |
| 8 | +package qlib |
| 9 | + |
| 10 | +import ( |
| 11 | + "encoding/base64" |
| 12 | + "math/big" |
| 13 | + "encoding/binary" |
| 14 | + "bytes" |
| 15 | + "crypto" |
| 16 | + "fmt" |
| 17 | + "net/http" |
| 18 | + "encoding/json" |
| 19 | + "os" |
| 20 | + "crypto/rand" |
| 21 | + "crypto/rsa" |
| 22 | + "crypto/sha256" |
| 23 | + "strconv" |
| 24 | + "time" |
| 25 | +) |
| 26 | + |
| 27 | +var sOpenidCfg []tOpenidCfg |
| 28 | + |
| 29 | +type tOpenidCfg struct { |
| 30 | + url, iss string |
| 31 | + aud string |
| 32 | + keys []tOpenidKey |
| 33 | +} |
| 34 | + |
| 35 | +type tOpenidKey struct { |
| 36 | + Kty, Alg, Use string |
| 37 | + Kid string |
| 38 | + E tBase64Int |
| 39 | + N *tBase64BigInt |
| 40 | +} |
| 41 | + |
| 42 | +type tBase64Int int |
| 43 | +type tBase64BigInt big.Int |
| 44 | + |
| 45 | +func (o *tBase64Int) UnmarshalJSON(iStr []byte) error { |
| 46 | + iStr, err := _decodeBase64Url(iStr[1:len(iStr)-1]) |
| 47 | + if err != nil { return err } |
| 48 | + if len(iStr) == 3 { |
| 49 | + iStr = append(iStr, 0) |
| 50 | + } |
| 51 | + *o = tBase64Int(binary.LittleEndian.Uint32(iStr)) |
| 52 | + return nil |
| 53 | +} |
| 54 | + |
| 55 | +func (o *tBase64BigInt) UnmarshalJSON(iStr []byte) error { |
| 56 | + iStr, err := _decodeBase64Url(iStr[1:len(iStr)-1]) |
| 57 | + if err != nil { return err } |
| 58 | + (*big.Int)(o).SetBytes(iStr) |
| 59 | + return nil |
| 60 | +} |
| 61 | + |
| 62 | +func _decodeBase64Url(iStr []byte) ([]byte, error) { |
| 63 | + aLen, err := base64.RawURLEncoding.Decode(iStr, iStr) |
| 64 | + return iStr[:aLen], err |
| 65 | +} |
| 66 | + |
| 67 | +type tOpenidToken struct { |
| 68 | + Scope, Token_type string |
| 69 | + Expires_in uint |
| 70 | + Access_token, Id_token string |
| 71 | + Refresh_token string `json:",omitempty"` |
| 72 | +} |
| 73 | + |
| 74 | +type tOpenidHeader struct { |
| 75 | + Kid string |
| 76 | + Alg string |
| 77 | +} |
| 78 | + |
| 79 | +type tOpenidClaims struct { |
| 80 | + Ver int |
| 81 | + Sub, Aud, Idp string |
| 82 | + Iss string |
| 83 | + Iat, Exp, Auth_time tUnixTime |
| 84 | + Jti string |
| 85 | + Amr []string |
| 86 | + At_hash string |
| 87 | +} |
| 88 | + |
| 89 | +type tUnixTime struct { time.Time } |
| 90 | + |
| 91 | +func (o *tUnixTime) UnmarshalJSON(iStr []byte) error { |
| 92 | + aN, err := strconv.ParseUint(string(iStr), 10, 64) |
| 93 | + if err != nil { return err } |
| 94 | + *o = tUnixTime{time.Unix(int64(aN), 0).UTC()} |
| 95 | + return nil |
| 96 | +} |
| 97 | + |
| 98 | +func clearConfigOpenid() { sOpenidCfg = nil } |
| 99 | + |
| 100 | +func addConfigOpenid(iUrl string, iIss string, iAud string) { |
| 101 | + sOpenidCfg = append(sOpenidCfg, tOpenidCfg{url: iUrl, iss: iIss, aud: iAud}) |
| 102 | +} |
| 103 | + |
| 104 | +func initOpenid() { |
| 105 | + for a := range sOpenidCfg { |
| 106 | + aResp, err := http.Get(sOpenidCfg[a].url) |
| 107 | + if err != nil { |
| 108 | + fmt.Fprintf(os.Stderr, "OpenID config: could not obtain %s: %v\n restart to retry", |
| 109 | + sOpenidCfg[a].url, err) |
| 110 | + continue |
| 111 | + } |
| 112 | + var aKeys struct { Keys []tOpenidKey } |
| 113 | + err = json.NewDecoder(aResp.Body).Decode(&aKeys) |
| 114 | + aResp.Body.Close() |
| 115 | + if err != nil { |
| 116 | + fmt.Fprintf(os.Stderr, "OpenID config: could not parse response from %s: %v\n restart to retry", |
| 117 | + sOpenidCfg[a].url, err) |
| 118 | + continue |
| 119 | + } |
| 120 | + sOpenidCfg[a].keys = aKeys.Keys |
| 121 | + } |
| 122 | +} |
| 123 | + |
| 124 | +func validateTokenOpenid(iTok *tOpenidToken) (tMsg, error) { |
| 125 | + var err error |
| 126 | + aSet := bytes.Split([]byte(iTok.Id_token), []byte{'.'}) |
| 127 | + if len(aSet) != 3 { |
| 128 | + return nil, tError("OpenID id_token string invalid") |
| 129 | + } |
| 130 | + |
| 131 | + aHash := sha256.New() |
| 132 | + aHash.Write(aSet[0]) |
| 133 | + aHash.Write([]byte{'.'}) |
| 134 | + aHash.Write(aSet[1]) |
| 135 | + |
| 136 | + for a := range aSet { |
| 137 | + aSet[a], err = _decodeBase64Url(aSet[a]) |
| 138 | + if err != nil { |
| 139 | + return nil, tError("OpenID id_token base64 invalid") |
| 140 | + } |
| 141 | + } |
| 142 | + |
| 143 | + var aHead tOpenidHeader |
| 144 | + err = json.Unmarshal(aSet[0], &aHead) |
| 145 | + if err != nil { |
| 146 | + return nil, tError("OpenID id_token JSON invalid") |
| 147 | + } |
| 148 | + var aClaims tOpenidClaims |
| 149 | + err = json.Unmarshal(aSet[1], &aClaims) |
| 150 | + if err != nil { |
| 151 | + return nil, tError("OpenID id_token JSON invalid") |
| 152 | + } |
| 153 | + |
| 154 | + if aClaims.Exp.Before(time.Now()) { |
| 155 | + return nil, tError("OpenID id_token expired") |
| 156 | + } |
| 157 | + |
| 158 | + var aCfg *tOpenidCfg |
| 159 | + for a := range sOpenidCfg { |
| 160 | + if sOpenidCfg[a].iss == aClaims.Iss && sOpenidCfg[a].aud == aClaims.Aud { |
| 161 | + aCfg = &sOpenidCfg[a] |
| 162 | + break |
| 163 | + } |
| 164 | + } |
| 165 | + if aCfg == nil { |
| 166 | + return nil, tError("OpenID id_token claims invalid") |
| 167 | + } |
| 168 | + |
| 169 | + var aPk *rsa.PublicKey |
| 170 | + for a := range aCfg.keys { |
| 171 | + if aCfg.keys[a].Kid == aHead.Kid && aCfg.keys[a].Alg == aHead.Alg { |
| 172 | + aPk = &rsa.PublicKey{N: (*big.Int)(aCfg.keys[a].N), E: int(aCfg.keys[a].E)} |
| 173 | + break |
| 174 | + } |
| 175 | + } |
| 176 | + if aPk == nil { |
| 177 | + return nil, tError("OpenID key not found; restart to reload keys") |
| 178 | + } |
| 179 | + |
| 180 | + err = rsa.VerifyPKCS1v15(aPk, crypto.SHA256, aHash.Sum(nil), aSet[2]) |
| 181 | + if err != nil { |
| 182 | + return nil, tError("OpenID id_token signature invalid") |
| 183 | + } |
| 184 | + aMsg := tMsg{"Subject": aClaims.Sub, "Issuer": aClaims.Iss, "Audience": aClaims.Aud, |
| 185 | + "IssuedAt": aClaims.Iat.Format(time.RFC3339)} |
| 186 | + return aMsg, nil |
| 187 | +} |
| 188 | + |
| 189 | +func enableTestOpenid() *tOpenidToken { |
| 190 | + aPk, err := rsa.GenerateKey(rand.Reader, 1024) |
| 191 | + if err != nil { panic(err) } |
| 192 | + |
| 193 | + aKeys := struct { Keys []tMsg `json:"keys"` }{ []tMsg{{"alg":"RS256", "kid":"kid"}} } |
| 194 | + aBuf := make([]byte, 4) |
| 195 | + binary.LittleEndian.PutUint32(aBuf, uint32(aPk.E)) |
| 196 | + if aBuf[3] == 0 { aBuf = aBuf[:3] } |
| 197 | + aKeys.Keys[0]["e"] = base64.RawURLEncoding.EncodeToString(aBuf) |
| 198 | + aKeys.Keys[0]["n"] = base64.RawURLEncoding.EncodeToString(aPk.N.Bytes()) |
| 199 | + |
| 200 | + go func() { |
| 201 | + http.HandleFunc("/keys", func(cResp http.ResponseWriter, cReq *http.Request) { |
| 202 | + cResp.Header().Set("Content-Type", "application/json") |
| 203 | + err := json.NewEncoder(cResp).Encode(&aKeys) |
| 204 | + if err != nil { |
| 205 | + fmt.Fprintf(os.Stderr, "OpenID keys test: %v\n", err) |
| 206 | + } |
| 207 | + }) |
| 208 | + err := http.ListenAndServe(":8080", nil) //todo enable command-line option for port |
| 209 | + if err != http.ErrServerClosed { |
| 210 | + fmt.Fprintf(os.Stderr, "OpenID keys test: %v\n", err) |
| 211 | + } |
| 212 | + }() |
| 213 | + |
| 214 | + aIdH := tMsg{"kid":"kid", "alg":"RS256"} |
| 215 | + aIdC := tMsg{"sub":"subject", "iss":"issuer", "aud":"audience", |
| 216 | + "exp": time.Now().Add(time.Minute).Unix()} |
| 217 | + aTok := tOpenidToken{Token_type:"Bearer", Expires_in:3600, Access_token:"access"} |
| 218 | + |
| 219 | + aBuf, err = json.Marshal(&aIdH) |
| 220 | + if err != nil { panic(err) } |
| 221 | + aTok.Id_token = base64.RawURLEncoding.EncodeToString(aBuf) |
| 222 | + |
| 223 | + aBuf, err = json.Marshal(&aIdC) |
| 224 | + if err != nil { panic(err) } |
| 225 | + aTok.Id_token += "." + base64.RawURLEncoding.EncodeToString(aBuf) |
| 226 | + |
| 227 | + aHash := sha256.New() |
| 228 | + aHash.Write([]byte(aTok.Id_token)) |
| 229 | + aBuf, err = rsa.SignPKCS1v15(nil, aPk, crypto.SHA256, aHash.Sum(nil)) |
| 230 | + if err != nil { panic(err) } |
| 231 | + aTok.Id_token += "." + base64.RawURLEncoding.EncodeToString(aBuf) |
| 232 | + |
| 233 | + return &aTok |
| 234 | +} |
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