From 4cb5577e1133132d42c702f9fb70d6742a343f9f Mon Sep 17 00:00:00 2001 From: Martin Heide Date: Tue, 29 Dec 2020 12:54:02 +0000 Subject: [PATCH] Allow to disable os.ExpandEnv for storage + connector configs by env variable DEX_EXPAND_ENV = false Signed-off-by: Martin Heide --- .github/workflows/ci.yml | 1 - cmd/dex/config.go | 26 ++++++++++++++-- cmd/dex/config_test.go | 67 +++++++++++++++++++++++++++++++++------- 3 files changed, 80 insertions(+), 14 deletions(-) diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml index f98bc4a0..f74f3ef4 100644 --- a/.github/workflows/ci.yml +++ b/.github/workflows/ci.yml @@ -57,7 +57,6 @@ jobs: - name: Run tests run: make testall env: - DEX_FOO_USER_PASSWORD: $2a$10$33EMT0cVYVlPy6WAMCLsceLYjWhuHpbz5yuZxu/GAFj03J9Lytjuy DEX_MYSQL_DATABASE: dex DEX_MYSQL_USER: root DEX_MYSQL_PASSWORD: root diff --git a/cmd/dex/config.go b/cmd/dex/config.go index eba919fa..88dc98e7 100644 --- a/cmd/dex/config.go +++ b/cmd/dex/config.go @@ -5,6 +5,7 @@ import ( "encoding/json" "fmt" "os" + "strconv" "strings" "golang.org/x/crypto/bcrypt" @@ -181,6 +182,19 @@ var storages = map[string]func() StorageConfig{ "mysql": func() StorageConfig { return new(sql.MySQL) }, } +// isExpandEnvEnabled returns if os.ExpandEnv should be used for each storage and connector config. +// Disabling this feature avoids surprises e.g. if the LDAP bind password contains a dollar character. +// Returns false if the env variable "DEX_EXPAND_ENV" is a falsy string, e.g. "false". +// Returns true if the env variable is unset or a truthy string, e.g. "true", or can't be parsed as bool. +func isExpandEnvEnabled() bool { + enabled, err := strconv.ParseBool(os.Getenv("DEX_EXPAND_ENV")) + if err != nil { + // Unset, empty string or can't be parsed as bool: Default = true. + return true + } + return enabled +} + // UnmarshalJSON allows Storage to implement the unmarshaler interface to // dynamically determine the type of the storage config. func (s *Storage) UnmarshalJSON(b []byte) error { @@ -198,7 +212,11 @@ func (s *Storage) UnmarshalJSON(b []byte) error { storageConfig := f() if len(store.Config) != 0 { - data := []byte(os.ExpandEnv(string(store.Config))) + data := []byte(store.Config) + if isExpandEnvEnabled() { + // Caution, we're expanding in the raw JSON/YAML source. This may not be what the admin expects. + data = []byte(os.ExpandEnv(string(store.Config))) + } if err := json.Unmarshal(data, storageConfig); err != nil { return fmt.Errorf("parse storage config: %v", err) } @@ -240,7 +258,11 @@ func (c *Connector) UnmarshalJSON(b []byte) error { connConfig := f() if len(conn.Config) != 0 { - data := []byte(os.ExpandEnv(string(conn.Config))) + data := []byte(conn.Config) + if isExpandEnvEnabled() { + // Caution, we're expanding in the raw JSON/YAML source. This may not be what the admin expects. + data = []byte(os.ExpandEnv(string(conn.Config))) + } if err := json.Unmarshal(data, connConfig); err != nil { return fmt.Errorf("parse connector config: %v", err) } diff --git a/cmd/dex/config_test.go b/cmd/dex/config_test.go index 278a9115..8ee02d5a 100644 --- a/cmd/dex/config_test.go +++ b/cmd/dex/config_test.go @@ -16,8 +16,6 @@ import ( var _ = yaml.YAMLToJSON -const testHashStaticPasswordEnv = "DEX_FOO_USER_PASSWORD" - func TestValidConfiguration(t *testing.T) { configuration := Config{ Issuer: "http://127.0.0.1:5556/dex", @@ -110,7 +108,7 @@ staticPasswords: hash: "$2a$10$33EMT0cVYVlPy6WAMCLsceLYjWhuHpbz5yuZxu/GAFj03J9Lytjuy" username: "admin" userID: "08a8684b-db88-4b73-90a9-3cd1661f5466" -- email: "foo@example.com" +- email: "foo@example.com" # base64'd value of the same bcrypt hash above. We want to be able to parse both of these hash: "JDJhJDEwJDMzRU1UMGNWWVZsUHk2V0FNQ0xzY2VMWWpXaHVIcGJ6NXl1Wnh1L0dBRmowM0o5THl0anV5" username: "foo" @@ -219,17 +217,54 @@ logger: } } -func TestUnmarshalConfigWithEnv(t *testing.T) { - staticPasswordEnv := os.Getenv(testHashStaticPasswordEnv) - if staticPasswordEnv == "" { - t.Skipf("test environment variable %q not set, skipping", testHashStaticPasswordEnv) +func TestUnmarshalConfigWithEnvNoExpand(t *testing.T) { + // If the env variable DEX_EXPAND_ENV is set and has a "falsy" value, os.ExpandEnv is disabled. + // ParseBool: "It accepts 1, t, T, TRUE, true, True, 0, f, F, FALSE, false, False." + checkUnmarshalConfigWithEnv(t, "0", false) + checkUnmarshalConfigWithEnv(t, "f", false) + checkUnmarshalConfigWithEnv(t, "F", false) + checkUnmarshalConfigWithEnv(t, "FALSE", false) + checkUnmarshalConfigWithEnv(t, "false", false) + checkUnmarshalConfigWithEnv(t, "False", false) + os.Unsetenv("DEX_EXPAND_ENV") +} + +func TestUnmarshalConfigWithEnvExpand(t *testing.T) { + // If the env variable DEX_EXPAND_ENV is unset or has a "truthy" or unknown value, os.ExpandEnv is enabled. + // ParseBool: "It accepts 1, t, T, TRUE, true, True, 0, f, F, FALSE, false, False." + checkUnmarshalConfigWithEnv(t, "1", true) + checkUnmarshalConfigWithEnv(t, "t", true) + checkUnmarshalConfigWithEnv(t, "T", true) + checkUnmarshalConfigWithEnv(t, "TRUE", true) + checkUnmarshalConfigWithEnv(t, "true", true) + checkUnmarshalConfigWithEnv(t, "True", true) + // Values that can't be parsed as bool: + checkUnmarshalConfigWithEnv(t, "UNSET", true) + checkUnmarshalConfigWithEnv(t, "", true) + checkUnmarshalConfigWithEnv(t, "whatever - true is default", true) + os.Unsetenv("DEX_EXPAND_ENV") +} + +func checkUnmarshalConfigWithEnv(t *testing.T, dexExpandEnv string, wantExpandEnv bool) { + // For hashFromEnv: + os.Setenv("DEX_FOO_USER_PASSWORD", "$2a$10$33EMT0cVYVlPy6WAMCLsceLYjWhuHpbz5yuZxu/GAFj03J9Lytjuy") + // For os.ExpandEnv ($VAR -> value_of_VAR): + os.Setenv("DEX_FOO_POSTGRES_HOST", "10.0.0.1") + os.Setenv("DEX_FOO_OIDC_CLIENT_SECRET", "bar") + if dexExpandEnv != "UNSET" { + os.Setenv("DEX_EXPAND_ENV", dexExpandEnv) + } else { + os.Unsetenv("DEX_EXPAND_ENV") } + rawConfig := []byte(` issuer: http://127.0.0.1:5556/dex storage: type: postgres config: - host: 10.0.0.1 + # Env variables are expanded in raw YAML source. + # Single quotes work fine, as long as the env variable doesn't contain any. + host: '$DEX_FOO_POSTGRES_HOST' port: 65432 maxOpenConns: 5 maxIdleConns: 3 @@ -263,7 +298,9 @@ connectors: config: issuer: https://accounts.google.com clientID: foo - clientSecret: bar + # Env variables are expanded in raw YAML source. + # Single quotes work fine, as long as the env variable doesn't contain any. + clientSecret: '$DEX_FOO_OIDC_CLIENT_SECRET' redirectURI: http://127.0.0.1:5556/dex/callback/google enablePasswordDB: true @@ -288,13 +325,21 @@ logger: format: "json" `) + // This is not a valid hostname. It's only used to check whether os.ExpandEnv was applied or not. + wantPostgresHost := "$DEX_FOO_POSTGRES_HOST" + wantOidcClientSecret := "$DEX_FOO_OIDC_CLIENT_SECRET" + if wantExpandEnv { + wantPostgresHost = "10.0.0.1" + wantOidcClientSecret = "bar" + } + want := Config{ Issuer: "http://127.0.0.1:5556/dex", Storage: Storage{ Type: "postgres", Config: &sql.Postgres{ NetworkDB: sql.NetworkDB{ - Host: "10.0.0.1", + Host: wantPostgresHost, Port: 65432, MaxOpenConns: 5, MaxIdleConns: 3, @@ -339,7 +384,7 @@ logger: Config: &oidc.Config{ Issuer: "https://accounts.google.com", ClientID: "foo", - ClientSecret: "bar", + ClientSecret: wantOidcClientSecret, RedirectURI: "http://127.0.0.1:5556/dex/callback/google", }, },