Instead of manually choosing when to include `nonce` in requests, this
data-driven approach ensures that all requests to endpoints that support
signature verification will make `HTTPClient` do the right thing.
See also #2277 for how `CustomerInfo` and `EntitlementInfo` will use
this.
Fixes [CSDK-629].
Depends on #2274 and #2267.
Entitlement verification is accomplished by preventing MiTM attacks
between the SDK and the RevenueCat server.
With verification enabled, the SDK ensures that the response created by
the server was not modified by a third-party, and the entitlements
received are exactly what was sent.
Entitlements are only verified if enabled using
`Configuration.Builder.with(entitlementVerificationMode:)`, which is
disabled by default.
### Changes:
- Added new `VerificationResult`, which replaces
`HTTPResponseVerificationResult`
- Renamed `Configuration.EntitlementVerificationLevel` to
`Configuration.EntitlementVerificationMode`
- `Configuration.with(entitlementVerificationMode:)` is now `public`
- Added `CustomerInfo.entitlementVerification`
- Added `EntitlementInfos.verification` and
`EntitlementInfo.verification`
- Added tests to cover serialization of these new values
- `CustomerInfoResponseHandler` copies the `ValidationResult` to
`CustomerInfo` (all operations that fetch `CustomerInfo` use this)
- Renamed "validation" to "verification" everywhere for consistency
- Finalized documentation
### TODO:
- [x] Figure out whether to use a separate type from
`HTTPResponseValidationResult` or rename that one
- [x] Figure out final API type and property names
- [x] Add tests for `CustomerInfo.copy(with:)`
- [x] Ensure validation result is encoded and decoded (for caching)
- [x] Add missing snapshots
[CSDK-629]:
https://revenuecats.atlassian.net/browse/CSDK-629?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
Fixes [CSDK-634].
## Changes:
- Created `HTTPResponseValidationResult`
- Added `HTTPResponseValidationResult` and `HTTPClient.ResponseHeaders`
to `HTTPResponse`
- Added new `ErrorCode.signatureVerificationFailed`
- Extracted `SigningType` to create `MockSigning` to test `HTTPClient`
without bothering with signatures
- Refactored `ETagManager` to use `HTTPResponse`, making it easier to
pass through response headers and verification results
- Stored `HTTPResponseValidationResult` in `ETagManager` cache
- `HTTPClient` handles signatures from response based on
`SystemInfo.responseVerificationLevel`
- Renamed `HTTPRequest.createIntegrityEnforcedRequestRequest` to
`HTTPRequest.createWithResponseVerification`
- Added lots of tests for this new behavior in `HTTPClient`
- Added lots of new tests for `ETagManager`
[CSDK-634]:
https://revenuecats.atlassian.net/browse/CSDK-634?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
This breaks signature validation in #2267 because `PurchasesDiagnostics`
uses that endpoint with and without signature validation, so the first
time it makes a request, it stores the cached response without a
validated signature.
The best solution is to simply not send etags for this endpoint, since
it's used precisely to make sure that requests can be made with no
errors, and we wouldn't want false positives.
`DNSChecker.errorWithBlockedHostFromError` already checks
`isBlockedAPIError` when constructing this error, so we can simplify
this to avoid calling `DNSChecker.resolvedHost` twice.
NachoSoto