Redesign Scoped Access Tokens (#24767)

## Changes
- Adds the following high level access scopes, each with `read` and
`write` levels:
    - `activitypub`
    - `admin` (hidden if user is not a site admin)
    - `misc`
    - `notification`
    - `organization`
    - `package`
    - `issue`
    - `repository`
    - `user`
- Adds new middleware function `tokenRequiresScopes()` in addition to
`reqToken()`
  -  `tokenRequiresScopes()` is used for each high-level api section
- _if_ a scoped token is present, checks that the required scope is
included based on the section and HTTP method
  - `reqToken()` is used for individual routes
- checks that required authentication is present (but does not check
scope levels as this will already have been handled by
`tokenRequiresScopes()`
- Adds migration to convert old scoped access tokens to the new set of
scopes
- Updates the user interface for scope selection

### User interface example
<img width="903" alt="Screen Shot 2023-05-31 at 1 56 55 PM"
src="https://github.com/go-gitea/gitea/assets/23248839/654766ec-2143-4f59-9037-3b51600e32f3">
<img width="917" alt="Screen Shot 2023-05-31 at 1 56 43 PM"
src="https://github.com/go-gitea/gitea/assets/23248839/1ad64081-012c-4a73-b393-66b30352654c">

## tokenRequiresScopes  Design Decision
- `tokenRequiresScopes()` was added to more reliably cover api routes.
For an incoming request, this function uses the given scope category
(say `AccessTokenScopeCategoryOrganization`) and the HTTP method (say
`DELETE`) and verifies that any scoped tokens in use include
`delete:organization`.
- `reqToken()` is used to enforce auth for individual routes that
require it. If a scoped token is not present for a request,
`tokenRequiresScopes()` will not return an error

## TODO
- [x] Alphabetize scope categories
- [x] Change 'public repos only' to a radio button (private vs public).
Also expand this to organizations
- [X] Disable token creation if no scopes selected. Alternatively, show
warning
- [x] `reqToken()` is missing from many `POST/DELETE` routes in the api.
`tokenRequiresScopes()` only checks that a given token has the correct
scope, `reqToken()` must be used to check that a token (or some other
auth) is present.
   -  _This should be addressed in this PR_
- [x] The migration should be reviewed very carefully in order to
minimize access changes to existing user tokens.
   - _This should be addressed in this PR_
- [x] Link to api to swagger documentation, clarify what
read/write/delete levels correspond to
- [x] Review cases where more than one scope is needed as this directly
deviates from the api definition.
   - _This should be addressed in this PR_
   - For example: 
   ```go
	m.Group("/users/{username}/orgs", func() {
		m.Get("", reqToken(), org.ListUserOrgs)
		m.Get("/{org}/permissions", reqToken(), org.GetUserOrgsPermissions)
}, tokenRequiresScopes(auth_model.AccessTokenScopeCategoryUser,
auth_model.AccessTokenScopeCategoryOrganization),
context_service.UserAssignmentAPI())
   ```

## Future improvements
- [ ] Add required scopes to swagger documentation
- [ ] Redesign `reqToken()` to be opt-out rather than opt-in
- [ ] Subdivide scopes like `repository`
- [ ] Once a token is created, if it has no scopes, we should display
text instead of an empty bullet point
- [ ] If the 'public repos only' option is selected, should read
categories be selected by default

Closes #24501
Closes #24799

Co-authored-by: Jonathan Tran <jon@allspice.io>
Co-authored-by: Kyle D <kdumontnu@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>

1 files changed, 18 insertions, 10 deletions

diff --git a/modules/context/permission.go b/modules/context/permission.go
index cc53fb99ed..0f72b8e244 100644
--- a/modules/context/permission.go
+++ b/modules/context/permission.go
@@ -111,28 +111,36 @@ func RequireRepoReaderOr(unitTypes ...unit.Type) func(ctx *Context) {
 	}
 }
 
-// RequireRepoScopedToken check whether personal access token has repo scope
-func CheckRepoScopedToken(ctx *Context, repo *repo_model.Repository) {
+// CheckRepoScopedToken check whether personal access token has repo scope
+func CheckRepoScopedToken(ctx *Context, repo *repo_model.Repository, level auth_model.AccessTokenScopeLevel) {
 	if !ctx.IsBasicAuth || ctx.Data["IsApiToken"] != true {
 		return
 	}
 
-	var err error
 	scope, ok := ctx.Data["ApiTokenScope"].(auth_model.AccessTokenScope)
 	if ok { // it's a personal access token but not oauth2 token
 		var scopeMatched bool
-		scopeMatched, err = scope.HasScope(auth_model.AccessTokenScopeRepo)
+
+		requiredScopes := auth_model.GetRequiredScopes(level, auth_model.AccessTokenScopeCategoryRepository)
+
+		// check if scope only applies to public resources
+		publicOnly, err := scope.PublicOnly()
 		if err != nil {
 			ctx.ServerError("HasScope", err)
 			return
 		}
-		if !scopeMatched && !repo.IsPrivate {
-			scopeMatched, err = scope.HasScope(auth_model.AccessTokenScopePublicRepo)
-			if err != nil {
-				ctx.ServerError("HasScope", err)
-				return
-			}
+
+		if publicOnly && repo.IsPrivate {
+			ctx.Error(http.StatusForbidden)
+			return
 		}
+
+		scopeMatched, err = scope.HasScope(requiredScopes...)
+		if err != nil {
+			ctx.ServerError("HasScope", err)
+			return
+		}
+
 		if !scopeMatched {
 			ctx.Error(http.StatusForbidden)
 			return