| 1 | package config |
| 2 | |
| 3 | import ( |
| 4 | "crypto/rand" |
| 5 | "fmt" |
| 6 | "os" |
| 7 | "strings" |
| 8 | ) |
| 9 | |
| 10 | // credentialRotation is a key replaced in place. The previous value is kept in |
| 11 | // the credential store under Backup, never in the journal, so it has the same |
| 12 | // protection as every other stored key. |
| 13 | type credentialRotation struct { |
| 14 | Slot string `json:"slot"` |
| 15 | Backup string `json:"backup"` |
| 16 | Digest string `json:"digest"` // keyed digest of the value this edit wrote |
| 17 | } |
| 18 | |
| 19 | // RotateModelCredentialLocked stores a new key for providers. When they are |
| 20 | // the only readers of the variable they share and the store holds its value, |
| 21 | // the variable is rewritten in place; otherwise the key gets a private slot as |
| 22 | // StageModelCredentialLocked does. Callers hold both edit locks. |
| 23 | func (c *Config) RotateModelCredentialLocked(providers []string, value string) (string, error) { |
| 24 | key, ok := c.rotatableCredentialKey(providers) |
| 25 | if !ok { |
| 26 | return c.StageModelCredentialLocked(value) |
| 27 | } |
| 28 | value = strings.TrimSpace(value) |
| 29 | if strings.ContainsAny(value, "\r\n") { |
| 30 | return "", fmt.Errorf("credential value contains a newline") |
| 31 | } |
| 32 | previous, _ := envFileValue(UserCredentialsPath(), key) |
| 33 | var id [16]byte |
| 34 | if _, err := rand.Read(id[:]); err != nil { |
| 35 | return "", err |
| 36 | } |
| 37 | digest, err := stagedCredentialDigest(value) |
| 38 | if err != nil { |
| 39 | return "", err |
| 40 | } |
| 41 | j := c.modelCredentialCommit |
| 42 | rotation := credentialRotation{Slot: key, Backup: fmt.Sprintf("REASONIX_ROTATION_%X_KEY", id), Digest: digest} |
| 43 | j.Rotations = append(j.Rotations, rotation) |
| 44 | j.Phase = "prepared" |
| 45 | if err := writeModelCredentialJournal(j); err != nil { |
| 46 | j.Rotations = j.Rotations[:len(j.Rotations)-1] |
| 47 | return "", err |
| 48 | } |
| 49 | // One file write: a crash leaves either both values or neither. |
| 50 | if err := storeCredentialsInFile(UserCredentialsPath(), map[string]string{rotation.Backup: previous, key: value}); err != nil { |
| 51 | return "", err |
| 52 | } |
| 53 | pinCredentialAssignments(map[string]string{key: value}) |
| 54 | j.Phase = "credential_written" |
| 55 | if err := writeModelCredentialJournal(j); err != nil { |
| 56 | return "", err |
| 57 | } |
| 58 | return key, nil |
| 59 | } |
| 60 | |
| 61 | // rotatableCredentialKey names the variable providers share when rewriting it |
| 62 | // changes what no other reader in the user config resolves, both in this edit |
| 63 | // and on disk. A project file cannot see the user config, so it never rotates. |
| 64 | func (c *Config) rotatableCredentialKey(providers []string) (string, bool) { |
| 65 | if c == nil || c.modelCredentialCommit == nil || len(providers) == 0 || !IsUserConfigPath(c.modelCredentialCommit.ConfigPath) { |
| 66 | return "", false |
| 67 | } |
| 68 | key, ok := sharedCredentialKey(c, providers) |
| 69 | if !ok || !isCredentialKey(key) || !onlyCredentialReaders(c, key, providers) || rotatedInThisEdit(c.modelCredentialCommit, key) { |
| 70 | return "", false |
| 71 | } |
| 72 | before, err := LoadForEditWithoutCredentialsReadOnlyStrict(c.modelCredentialCommit.ConfigPath) |
| 73 | if err != nil { |
| 74 | return "", false |
| 75 | } |
| 76 | if held, ok := sharedCredentialKey(before, providers); !ok || held != key || !onlyCredentialReaders(before, key, providers) { |
| 77 | return "", false |
| 78 | } |
| 79 | // The store overrides the shell at load, so a stored value is what every |
| 80 | // in-process reader resolves. |
| 81 | file, ok := readDotEnvFile(UserCredentialsPath()) |
| 82 | if _, stored := file.Values[key]; !ok || !stored { |
| 83 | return "", false |
| 84 | } |
| 85 | for name := range file.Values { |
| 86 | if name != key && sameCredentialName(name, key) { |
| 87 | return "", false // Windows would load either spelling into one variable. |
| 88 | } |
| 89 | } |
| 90 | return key, true |
| 91 | } |
| 92 | |
| 93 | func sharedCredentialKey(c *Config, providers []string) (string, bool) { |
| 94 | key := "" |
| 95 | for _, name := range providers { |
| 96 | entry, ok := c.Provider(strings.TrimSpace(name)) |
| 97 | if !ok { |
| 98 | return "", false |
| 99 | } |
| 100 | env := strings.TrimSpace(entry.APIKeyEnv) |
| 101 | if env == "" || (key != "" && env != key) { |
| 102 | return "", false |
| 103 | } |
| 104 | key = env |
| 105 | } |
| 106 | return key, key != "" |
| 107 | } |
| 108 | |
| 109 | func onlyCredentialReaders(c *Config, key string, providers []string) bool { |
| 110 | for _, p := range c.Providers { |
| 111 | if sameCredentialName(strings.TrimSpace(p.APIKeyEnv), key) && !containsTrimmed(providers, p.Name) { |
| 112 | return false |
| 113 | } |
| 114 | } |
| 115 | others := *c |
| 116 | others.Providers = nil |
| 117 | for _, name := range credentialEnvNamesFromConfig(&others) { |
| 118 | if sameCredentialName(name, key) { |
| 119 | return false |
| 120 | } |
| 121 | } |
| 122 | return true |
| 123 | } |
| 124 | |
| 125 | // rotatedInThisEdit keeps one backup per variable: a second would hold this |
| 126 | // edit's own value, and restoring it would lose the original. |
| 127 | func rotatedInThisEdit(j *modelCredentialCommitJournal, key string) bool { |
| 128 | for _, r := range j.Rotations { |
| 129 | if sameCredentialName(r.Slot, key) { |
| 130 | return true |
| 131 | } |
| 132 | } |
| 133 | return false |
| 134 | } |
| 135 | |
| 136 | func containsTrimmed(names []string, want string) bool { |
| 137 | for _, name := range names { |
| 138 | if strings.TrimSpace(name) == want { |
| 139 | return true |
| 140 | } |
| 141 | } |
| 142 | return false |
| 143 | } |
| 144 | |
| 145 | // restoreRotations puts the previous value back only while the variable still |
| 146 | // holds what this edit wrote; a value another writer stored stays. |
| 147 | func restoreRotations(j *modelCredentialCommitJournal) error { |
| 148 | path := UserCredentialsPath() |
| 149 | for _, r := range j.Rotations { |
| 150 | previous, hasBackup := envFileValue(path, r.Backup) |
| 151 | if hasBackup && stagedValueUnchanged(r.Slot, r.Digest) { |
| 152 | if err := storeCredentialsInFile(path, map[string]string{r.Slot: previous}); err != nil { |
| 153 | return err |
| 154 | } |
| 155 | pinCredentialAssignments(map[string]string{r.Slot: previous}) |
| 156 | } |
| 157 | if err := dropRotationBackup(path, r.Backup, hasBackup); err != nil { |
| 158 | return err |
| 159 | } |
| 160 | } |
| 161 | j.Rotations = nil |
| 162 | return nil |
| 163 | } |
| 164 | |
| 165 | // dropRotationBackups settles a published rotation: the new value stays. |
| 166 | func dropRotationBackups(j *modelCredentialCommitJournal) error { |
| 167 | path := UserCredentialsPath() |
| 168 | for _, r := range j.Rotations { |
| 169 | _, hasBackup := envFileValue(path, r.Backup) |
| 170 | if err := dropRotationBackup(path, r.Backup, hasBackup); err != nil { |
| 171 | return err |
| 172 | } |
| 173 | } |
| 174 | j.Rotations = nil |
| 175 | return nil |
| 176 | } |
| 177 | |
| 178 | // dropRotationBackup leaves no cleared marker: nothing else writes a random |
| 179 | // backup name, so a marker would only grow the file on every rotation. |
| 180 | func dropRotationBackup(path, backup string, stored bool) error { |
| 181 | if stored { |
| 182 | lines, err := readCredentialFileLinesForWrite(path) |
| 183 | if err != nil { |
| 184 | return err |
| 185 | } |
| 186 | kept := make([]string, 0, len(lines)) |
| 187 | for _, line := range lines { |
| 188 | if k, ok := credentialLineKey(line); !ok || k != backup { |
| 189 | kept = append(kept, line) |
| 190 | } |
| 191 | } |
| 192 | if err := writeCredentialFileLines(path, kept); err != nil { |
| 193 | return err |
| 194 | } |
| 195 | } |
| 196 | _ = os.Unsetenv(backup) |
| 197 | return nil |
| 198 | } |
| 199 |