perf(crypto): Shrink BC footprint and keep only ChaCha20-Poly1305

Author: harrytmthy

gradle/libs.versions.toml

@@ -11,7 +11,7 @@ androidxTestExt = "1.2.1"
 androidxTestRunner = "1.6.2"
 androidxTracing = "1.3.0"
 androidxWindowManager = "1.3.0"
-bouncyCastle = "1.78.1"
+bouncyCastle = "1.70"
 dokka = "2.0.0"
 junit4 = "4.13.2"
 kotlin = "2.1.0"
@@ -41,7 +41,7 @@ androidx-test-ext = { group = "androidx.test.ext", name = "junit-ktx", version.r
 androidx-test-runner = { group = "androidx.test", name = "runner", version.ref = "androidxTestRunner" }
 androidx-tracing-ktx = { group = "androidx.tracing", name = "tracing-ktx", version.ref = "androidxTracing" }
 androidx-window-core = { group = "androidx.window", name = "window-core", version.ref = "androidxWindowManager" }
-bouncy-castle-provider = { group = "org.bouncycastle", name = "bcprov-jdk15to18", version.ref = "bouncyCastle" }
+bouncy-castle-provider = { group = "org.bouncycastle", name = "bcprov-jdk15on", version.ref = "bouncyCastle" }
 kotlin-stdlib = { group = "org.jetbrains.kotlin", name = "kotlin-stdlib-jdk8", version.ref = "kotlin" }
 kotlin-test = { group = "org.jetbrains.kotlin", name = "kotlin-test", version.ref = "kotlin" }
 kotlinx-coroutines-core = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-core", version.ref = "kotlinxCoroutines" }

safebox-crypto/proguard-consumer-rules.pro

@@ -1 +1,5 @@
--keep class org.bouncycastle.** { *; }
+# Keep BC provider (we reference it and it registers algorithms)
+-keep class org.bouncycastle.jce.provider.BouncyCastleProvider { *; }
+
+# Keep ChaCha20-Poly1305 JCA wiring (registered via reflection)
+-keep class org.bouncycastle.jcajce.provider.symmetric.ChaCha** { *; }