From a1a598f7ce91ebfbaf671b0e75eff148f13dfa43 Mon Sep 17 00:00:00 2001
From: Karl Tarbe <tarbe@apple.com>
Date: Fri, 16 Aug 2024 00:25:57 +0300
Subject: [PATCH] Remove client side bug workaround

The client side bug was fixed in iOS 18.0 beta 5.
---
 .../KeywordPirProtocol.swift                  | 19 ---------
 .../PrivateInformationRetrieval/MulPir.swift  |  6 ---
 .../KeywordPirTests.swift                     | 39 -------------------
 3 files changed, 64 deletions(-)

diff --git a/Sources/PrivateInformationRetrieval/KeywordPirProtocol.swift b/Sources/PrivateInformationRetrieval/KeywordPirProtocol.swift
index 3400d226..e761a7d2 100644
--- a/Sources/PrivateInformationRetrieval/KeywordPirProtocol.swift
+++ b/Sources/PrivateInformationRetrieval/KeywordPirProtocol.swift
@@ -163,25 +163,6 @@ public final class KeywordPirServer<PirServer: IndexPirServer>: KeywordPirProtoc
             maxEntrySize = cuckooTableConfig.maxSerializedBucketSize
         }
 
-        // if we would hit the client side bug, reprocess with modified `maxSerializedBucketSize`
-        if maxEntrySize.isMultiple(of: context.bytesPerPlaintext)
-            || context.bytesPerPlaintext.isMultiple(of: maxEntrySize)
-        {
-            let newCuckooTableConfig = try CuckooTableConfig(
-                hashFunctionCount: cuckooTableConfig.hashFunctionCount,
-                maxEvictionCount: cuckooTableConfig.maxEvictionCount,
-                maxSerializedBucketSize: maxEntrySize - 1,
-                bucketCount: cuckooTableConfig.bucketCount,
-                multipleTables: cuckooTableConfig.multipleTables)
-
-            let newConfig = try KeywordPirConfig(
-                dimensionCount: config.dimensionCount,
-                cuckooTableConfig: newCuckooTableConfig,
-                unevenDimensions: config.unevenDimensions,
-                keyCompression: config.keyCompression)
-            return try Self.process(database: database, config: newConfig, with: context)
-        }
-
         let indexPirConfig = try IndexPirConfig(
             entryCount: cuckooTable.bucketsPerTable,
             entrySizeInBytes: maxEntrySize,
diff --git a/Sources/PrivateInformationRetrieval/MulPir.swift b/Sources/PrivateInformationRetrieval/MulPir.swift
index fb450957..af5795f4 100644
--- a/Sources/PrivateInformationRetrieval/MulPir.swift
+++ b/Sources/PrivateInformationRetrieval/MulPir.swift
@@ -242,12 +242,6 @@ extension MulPirClient {
                     bitsPerCoeff: context.plaintextModulus.log2)
             }
 
-            // this is a copy of the client side bug
-            let accessRange = computeResponseRangeInBytes(at: entryIndex)
-            guard accessRange.upperBound < bytes.count else {
-                throw PirError.validationError("Client side bug hit!")
-            }
-
             return Array(bytes[computeResponseRangeInBytes(at: entryIndex)])
         }
     }
diff --git a/Tests/PrivateInformationRetrievalTests/KeywordPirTests.swift b/Tests/PrivateInformationRetrievalTests/KeywordPirTests.swift
index 9222616e..5aee176e 100644
--- a/Tests/PrivateInformationRetrievalTests/KeywordPirTests.swift
+++ b/Tests/PrivateInformationRetrievalTests/KeywordPirTests.swift
@@ -368,45 +368,6 @@ class KeywordPirTests: XCTestCase {
             MulPirServer<Bfv<UInt64>>.self, client: MulPirClient<Bfv<UInt64>>.self)
     }
 
-    func testClientBugWorkaround() throws {
-        func runTest<PirServer: IndexPirServer, PirClient: IndexPirClient>(
-            rlweParams: PredefinedRlweParameters,
-            server _: PirServer.Type,
-            client _: PirClient.Type) throws where PirServer.IndexPir == PirClient.IndexPir
-        {
-            let context: Context<PirServer.Scheme> = try Context(encryptionParameters: .init(from: rlweParams))
-
-            var testRng = TestRng()
-            let testDatabase = PirTestUtils.getTestTable(rowCount: 1000, valueSize: 1, using: &testRng)
-            let config = try KeywordPirConfig(
-                dimensionCount: 2,
-                cuckooTableConfig: .defaultKeywordPir(maxSerializedBucketSize: 1024),
-                unevenDimensions: true, keyCompression: .noCompression)
-            let processed = try KeywordPirServer<PirServer>.process(
-                database: testDatabase,
-                config: config,
-                with: context)
-            let server = try KeywordPirServer<PirServer>(
-                context: context,
-                processed: processed)
-            let client = KeywordPirClient<PirClient>(
-                keywordParameter: config.parameter,
-                pirParameter: processed.pirParameter,
-                context: context)
-            let secretKey = try context.generateSecretKey()
-            let evaluationKey = try client.generateEvaluationKey(using: secretKey)
-            let query = try client.generateQuery(at: [], using: secretKey)
-            let response = try server.computeResponse(to: query, using: evaluationKey)
-            let result = try client.decrypt(response: response, at: [], using: secretKey)
-            XCTAssertNil(result)
-        }
-        let rlweParams = PredefinedRlweParameters.n_4096_logq_27_28_28_logt_5
-        try runTest(rlweParams: rlweParams, server:
-            MulPirServer<Bfv<UInt32>>.self, client: MulPirClient<Bfv<UInt32>>.self)
-        try runTest(rlweParams: rlweParams, server:
-            MulPirServer<Bfv<UInt64>>.self, client: MulPirClient<Bfv<UInt64>>.self)
-    }
-
     func testInvalidArguments() throws {
         let cuckooConfig = try CuckooTableConfig(
             hashFunctionCount: 2,