Redo OIDC configuration (#2020)

expand user, add claims to user

This commit expands the user table with additional fields that
can be retrieved from OIDC providers (and other places) and
uses this data in various tailscale response objects if it is
available.

This is the beginning of implementing
https://docs.google.com/document/d/1X85PMxIaVWDF6T_UPji3OeeUqVBcGj_uHRM5CI-AwlY/edit
trying to make OIDC more coherant and maintainable in addition
to giving the user a better experience and integration with a
provider.

remove usernames in magic dns, normalisation of emails

this commit removes the option to have usernames as part of MagicDNS
domains and headscale will now align with Tailscale, where there is a
root domain, and the machine name.

In addition, the various normalisation functions for dns names has been
made lighter not caring about username and special character that wont
occur.

Email are no longer normalised as part of the policy processing.

untagle oidc and regcache, use typed cache

This commits stops reusing the registration cache for oidc
purposes and switches the cache to be types and not use any
allowing the removal of a bunch of casting.

try to make reauth/register branches clearer in oidc

Currently there was a function that did a bunch of stuff,
finding the machine key, trying to find the node, reauthing
the node, returning some status, and it was called validate
which was very confusing.

This commit tries to split this into what to do if the node
exists, if it needs to register etc.

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

hscontrol/db/users.go

@@ -49,7 +49,7 @@ func (hsdb *HSDatabase) DestroyUser(name string) error {
 // DestroyUser destroys a User. Returns error if the User does
 // not exist or if there are nodes associated with it.
 func DestroyUser(tx *gorm.DB, name string) error {
-	user, err := GetUser(tx, name)
+	user, err := GetUserByUsername(tx, name)
 	if err != nil {
 		return ErrUserNotFound
 	}
@@ -90,7 +90,7 @@ func (hsdb *HSDatabase) RenameUser(oldName, newName string) error {
 // not exist or if another User exists with the new name.
 func RenameUser(tx *gorm.DB, oldName, newName string) error {
 	var err error
-	oldUser, err := GetUser(tx, oldName)
+	oldUser, err := GetUserByUsername(tx, oldName)
 	if err != nil {
 		return err
 	}
@@ -98,7 +98,7 @@ func RenameUser(tx *gorm.DB, oldName, newName string) error {
 	if err != nil {
 		return err
 	}
-	_, err = GetUser(tx, newName)
+	_, err = GetUserByUsername(tx, newName)
 	if err == nil {
 		return ErrUserExists
 	}
@@ -115,13 +115,13 @@ func RenameUser(tx *gorm.DB, oldName, newName string) error {
 	return nil
 }
 
-func (hsdb *HSDatabase) GetUser(name string) (*types.User, error) {
+func (hsdb *HSDatabase) GetUserByName(name string) (*types.User, error) {
 	return Read(hsdb.DB, func(rx *gorm.DB) (*types.User, error) {
-		return GetUser(rx, name)
+		return GetUserByUsername(rx, name)
 	})
 }
 
-func GetUser(tx *gorm.DB, name string) (*types.User, error) {
+func GetUserByUsername(tx *gorm.DB, name string) (*types.User, error) {
 	user := types.User{}
 	if result := tx.First(&user, "name = ?", name); errors.Is(
 		result.Error,
@@ -133,6 +133,42 @@ func GetUser(tx *gorm.DB, name string) (*types.User, error) {
 	return &user, nil
 }
 
+func (hsdb *HSDatabase) GetUserByID(id types.UserID) (*types.User, error) {
+	return Read(hsdb.DB, func(rx *gorm.DB) (*types.User, error) {
+		return GetUserByID(rx, id)
+	})
+}
+
+func GetUserByID(tx *gorm.DB, id types.UserID) (*types.User, error) {
+	user := types.User{}
+	if result := tx.First(&user, "id = ?", id); errors.Is(
+		result.Error,
+		gorm.ErrRecordNotFound,
+	) {
+		return nil, ErrUserNotFound
+	}
+
+	return &user, nil
+}
+
+func (hsdb *HSDatabase) GetUserByOIDCIdentifier(id string) (*types.User, error) {
+	return Read(hsdb.DB, func(rx *gorm.DB) (*types.User, error) {
+		return GetUserByOIDCIdentifier(rx, id)
+	})
+}
+
+func GetUserByOIDCIdentifier(tx *gorm.DB, id string) (*types.User, error) {
+	user := types.User{}
+	if result := tx.First(&user, "provider_identifier = ?", id); errors.Is(
+		result.Error,
+		gorm.ErrRecordNotFound,
+	) {
+		return nil, ErrUserNotFound
+	}
+
+	return &user, nil
+}
+
 func (hsdb *HSDatabase) ListUsers() ([]types.User, error) {
 	return Read(hsdb.DB, func(rx *gorm.DB) ([]types.User, error) {
 		return ListUsers(rx)
@@ -155,7 +191,7 @@ func ListNodesByUser(tx *gorm.DB, name string) (types.Nodes, error) {
 	if err != nil {
 		return nil, err
 	}
-	user, err := GetUser(tx, name)
+	user, err := GetUserByUsername(tx, name)
 	if err != nil {
 		return nil, err
 	}
@@ -180,7 +216,7 @@ func AssignNodeToUser(tx *gorm.DB, node *types.Node, username string) error {
 	if err != nil {
 		return err
 	}
-	user, err := GetUser(tx, username)
+	user, err := GetUserByUsername(tx, username)
 	if err != nil {
 		return err
 	}