passes: emit strings as CONSTANT_Dynamic (condy) - BSM-resolved, invisible to concrete-execution deobfuscators

crates/noxis-core/src/config/from_toml/sections.rs

@@ -69,7 +69,14 @@ pub(super) fn build_rename(t: &Table) -> Res<RenameConfig> {
 pub(super) fn build_strings(t: &Table) -> Res<StringsConfig> {
     check_known_keys(
         t,
-        &["schemes", "min_len", "split_above", "skip", "derive_key"],
+        &[
+            "schemes",
+            "min_len",
+            "split_above",
+            "skip",
+            "derive_key",
+            "condy",
+        ],
         "strings",
     )?;
     let mut c = StringsConfig::default();
@@ -88,6 +95,9 @@ pub(super) fn build_strings(t: &Table) -> Res<StringsConfig> {
     if let Some(v) = t.get("derive_key") {
         c.derive_key = expect_bool(v, "strings.derive_key")?;
     }
+    if let Some(v) = t.get("condy") {
+        c.condy = expect_bool(v, "strings.condy")?;
+    }
     Ok(c)
 }
 

crates/noxis-core/src/config/from_toml/tests.rs

@@ -62,3 +62,10 @@ fn parses_name_style_in_rename_section() {
     let cfg = build_from("[rename]\nclass_style = \"il-o0\"\n").unwrap();
     assert_eq!(cfg.rename.class_style, NameStyle::IlO0);
 }
+
+#[test]
+fn parses_condy_flag_in_strings_section() {
+    let cfg = build_from("[strings]\ncondy = true\n").unwrap();
+    assert!(cfg.strings.condy);
+    assert!(!Config::default().strings.condy);
+}

crates/noxis-core/src/config/sections.rs

@@ -79,6 +79,12 @@ pub struct StringsConfig {
     /// Derive the key from KDF(class, method, index) instead of placing it
     /// next to the ciphertext.
     pub derive_key: bool,
+    /// Emit strings as `CONSTANT_Dynamic` (condy) resolved by the decoder's
+    /// bootstrap method instead of direct `d(cipher, salt)` calls. A
+    /// concrete-execution deobfuscator cannot follow the condy resolution
+    /// (todo.md, 2026-10-14: SSVM made 0 changes on a condy-only class).
+    /// Requires classfile >= 55; older classes keep direct calls.
+    pub condy: bool,
 }
 
 impl Default for StringsConfig {
@@ -89,6 +95,7 @@ impl Default for StringsConfig {
             split_above: 64,
             skip: Vec::new(),
             derive_key: true,
+            condy: false,
         }
     }
 }

crates/noxis-passes/src/strings/condy.rs

@@ -0,0 +1,76 @@
+//! Condensed emission (`CONSTANT_Dynamic`): the JVM resolves the string
+//! itself through the decoder's bootstrap method instead of us calling `d`.
+//!
+//! Why: a concrete-execution deobfuscator (narumii/SSVM, todo.md 2026-10-14)
+//! follows `invokestatic d` and recovers the plaintext, but made **0
+//! changes** on a condy-only class - it does not resolve `CONSTANT_Dynamic`
+//! at all. The plaintext then lives only inside JVM constant caching.
+
+use noxis_classfile::{Attribute, BootstrapMethod, ClassFile, Const, Insn};
+use noxis_runtime::{BOOTSTRAP_DESC, BOOTSTRAP_METHOD};
+
+/// `REF_invokeStatic` (JVMS §5.4.3.5).
+const INVOKE_STATIC: u8 = 6;
+
+/// Class-file version introducing `CONSTANT_Dynamic` (Java 11).
+pub(super) const CONDY_MIN_MAJOR: u16 = 55;
+
+/// The class supports condy constants at all.
+pub(super) fn supported(class: &ClassFile) -> bool {
+    class.version.major >= CONDY_MIN_MAJOR
+}
+
+/// Where new bootstrap entries would start: right after the existing ones
+/// (Kotlin lambdas etc. already own the front of the attribute).
+pub(super) fn base_index(class: &ClassFile) -> u16 {
+    class
+        .attributes
+        .iter()
+        .find_map(|attribute| match attribute {
+            Attribute::BootstrapMethods(list) => Some(list.len() as u16),
+            _ => None,
+        })
+        .unwrap_or(0)
+}
+
+/// One bootstrap entry per chunk: the decoder's `b` with `cipher` + `salt`
+/// as static arguments. The BSM prefix (`lookup`, `name`, `type`) is filled
+/// in by the JVM (JVMS §5.4.3.5).
+pub(super) fn entry(owner: &str, cipher: &str, salt: i32) -> BootstrapMethod {
+    BootstrapMethod {
+        kind: INVOKE_STATIC,
+        owner: owner.to_string(),
+        name: BOOTSTRAP_METHOD.to_string(),
+        descriptor: BOOTSTRAP_DESC.to_string(),
+        itf: false,
+        args: vec![Const::String(cipher.to_string()), Const::Int(salt)],
+    }
+}
+
+/// Condensed replacements for one string's chunks: a `ldc` per chunk
+/// (bootstrap indices `base..base+n`) joined by `String.concat`.
+pub(super) fn sequence(base: u16, chunks: usize) -> Vec<Insn> {
+    let mut out = Vec::with_capacity(chunks * 2);
+    for position in 0..chunks {
+        out.push(Insn::Const(Const::Dynamic {
+            name: "_".to_string(),
+            descriptor: "Ljava/lang/String;".to_string(),
+            bootstrap: base + position as u16,
+        }));
+        if position > 0 {
+            out.push(concat());
+        }
+    }
+    out
+}
+
+/// `String.concat` - the same chunk join the direct path uses.
+fn concat() -> Insn {
+    Insn::Invoke {
+        kind: noxis_classfile::InvokeKind::Virtual,
+        owner: "java/lang/String".to_string(),
+        name: "concat".to_string(),
+        descriptor: "(Ljava/lang/String;)Ljava/lang/String;".to_string(),
+        itf: false,
+    }
+}

crates/noxis-passes/src/strings/mod.rs

@@ -4,6 +4,7 @@
 //! (KDF or RNG stream - see `derive_key`). The decoder is generated once per
 //! program and only if at least one string was encrypted.
 
+mod condy;
 mod crypt;
 
 #[cfg(test)]
@@ -12,7 +13,9 @@ mod tests;
 use std::collections::BTreeMap;
 
 use noxis_analysis::{ClassHierarchy, JdkHierarchy};
-use noxis_classfile::{Const, Insn, MAX_METHOD_INSNS, Program, compute_frames};
+use noxis_classfile::{
+    Attribute, BootstrapMethod, Const, Insn, MAX_METHOD_INSNS, Program, compute_frames,
+};
 use noxis_core::{Context, CoreError, NameStyle, Pass, PassId, PassReport, derive_seed};
 use noxis_runtime::{Scheme, decoder_class, decoder_owner, encrypt};
 
@@ -69,6 +72,17 @@ impl Pass for StringsPass {
         let owner = decoder_name(ctx, program);
         let mut chunk_counter = 0usize;
         let mut salt_counter = 0u64;
+        // Condy mode: per-class next bootstrap index + accumulated entries
+        // (appended to the class attribute after the rewrite below).
+        let mut bsm_next: BTreeMap<usize, u16> = BTreeMap::new();
+        let mut bsm_entries: BTreeMap<usize, Vec<BootstrapMethod>> = BTreeMap::new();
+        if cfg.condy {
+            for (ci, class) in program.classes.iter().enumerate() {
+                if condy::supported(class) {
+                    bsm_next.insert(ci, condy::base_index(class));
+                }
+            }
+        }
         let mut replacements: BTreeMap<(usize, usize, usize), Vec<Insn>> = BTreeMap::new();
         for (ci, mi, ii, text) in &targets {
             let mut parts = Vec::new();
@@ -80,8 +94,20 @@ impl Pass for StringsPass {
                 parts.push((blob.cipher, salt));
                 chunk_counter += 1;
             }
+            if let Some(next) = bsm_next.get_mut(ci) {
+                let base = *next;
+                for (cipher, salt) in &parts {
+                    bsm_entries
+                        .entry(*ci)
+                        .or_default()
+                        .push(condy::entry(&owner, cipher, *salt));
+                }
+                *next = base + parts.len() as u16;
+                replacements.insert((*ci, *mi, *ii), condy::sequence(base, parts.len()));
+            } else {
                 replacements.insert((*ci, *mi, *ii), decode_sequence(&owner, &parts));
             }
+        }
         let mut mutated: Vec<(usize, usize)> = Vec::new();
         let mut applied = 0usize;
         let mut per_method: BTreeMap<(usize, usize), usize> = BTreeMap::new();
@@ -126,6 +152,21 @@ impl Pass for StringsPass {
             decoder_class(&owner, master, &scheme_names).map_err(|e| pass_error(e.to_string()))?;
         program.classes.push(decoder);
         ctx.note(format!("string decoder: {owner}"));
+        // Phase 3b: condy bootstrap entries land on their classes (appended
+        // after existing lambdas - the indices computed above assumed that).
+        for (ci, entries) in bsm_entries {
+            let class = program
+                .classes
+                .get_mut(ci)
+                .ok_or_else(|| pass_error("class vanished"))?;
+            match class.attributes.iter_mut().find_map(|a| match a {
+                Attribute::BootstrapMethods(list) => Some(list),
+                _ => None,
+            }) {
+                Some(list) => list.extend(entries),
+                None => class.attributes.push(Attribute::BootstrapMethods(entries)),
+            }
+        }
         // Phase 4: frames of the touched methods.
         let hierarchy = ClassHierarchy::build(program);
         let frames_hierarchy = JdkHierarchy::wrap(&hierarchy);

crates/noxis-passes/src/strings/tests/condy.rs

@@ -0,0 +1,201 @@
+//! Condy-mode tests: `CONSTANT_Dynamic` emission, version gate, attribute
+//! merging.
+
+#![allow(clippy::expect_used, clippy::unwrap_used)]
+
+use noxis_classfile::{Attribute, BootstrapMethod, Const, Insn, Version};
+use noxis_core::{Config, Context, Pass, StringsConfig};
+use noxis_runtime::{Scheme, encrypt};
+
+use super::super::StringsPass;
+use super::sample;
+
+/// Condensed mode: strings become `CONSTANT_Dynamic` resolved by the
+/// decoder's bootstrap method - a concrete-execution deobfuscator sees no
+/// decrypt call to follow (todo.md, 2026-10-14: 0 condy changes from SSVM).
+#[test]
+fn condy_mode_emits_dynamic_constants() {
+    let mut program = sample();
+    let config = Config {
+        seed: Some(7),
+        strings: StringsConfig {
+            condy: true,
+            ..StringsConfig::default()
+        },
+        ..Config::default()
+    };
+    let mut ctx = Context::new(config);
+    let report = StringsPass.apply(&mut ctx, &mut program).expect("strings");
+
+    assert_eq!(report.transformed, 2);
+    let class = &program.classes[0];
+    let code = class.methods[0].code.as_ref().expect("code");
+    // Both encrypted strings are condy constants, no direct decoder calls.
+    let dynamics: Vec<&Const> = code
+        .insns
+        .iter()
+        .filter_map(|insn| match insn {
+            Insn::Const(c @ Const::Dynamic { .. }) => Some(c),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(dynamics.len(), 3, "1 chunk + 2 chunks: {code:?}");
+    for value in &dynamics {
+        let Const::Dynamic { descriptor, .. } = value else {
+            unreachable!()
+        };
+        assert_eq!(descriptor, "Ljava/lang/String;");
+    }
+    assert!(
+        !code
+            .insns
+            .iter()
+            .any(|insn| matches!(insn, Insn::Invoke { name, .. } if name == "d")),
+        "condy mode must not emit direct decoder calls: {code:?}"
+    );
+    // The bootstrap entries live on the class and point at the decoder's `b`.
+    let decoder = program
+        .classes
+        .iter()
+        .find(|c| c.methods.iter().any(|m| m.name == "b"))
+        .expect("decoder with bootstrap method");
+    let Attribute::BootstrapMethods(bsm) = class
+        .attributes
+        .iter()
+        .find(|a| matches!(a, Attribute::BootstrapMethods(_)))
+        .expect("BootstrapMethods attribute")
+    else {
+        unreachable!()
+    };
+    assert_eq!(bsm.len(), 3, "one entry per chunk");
+    for entry in bsm {
+        assert_eq!(entry.kind, 6, "REF_invokeStatic");
+        assert_eq!(entry.owner, decoder.this_class);
+        assert_eq!(entry.name, "b");
+        assert!(
+            matches!(entry.args.as_slice(), [Const::String(_), Const::Int(_)]),
+            "args are cipher + salt: {:?}",
+            entry.args
+        );
+    }
+    // Bootstrap indices in the constants match the entry positions.
+    let indices: Vec<u16> = dynamics
+        .iter()
+        .map(|c| {
+            let Const::Dynamic { bootstrap, .. } = c else {
+                unreachable!()
+            };
+            *bootstrap
+        })
+        .collect();
+    assert_eq!(indices, vec![0, 1, 2]);
+    // Ciphertext is still the direct encryption of the originals.
+    let schemes = [Scheme::XorSplitmix, Scheme::XteaCtr];
+    let originals = ["hello world".to_string(), "y".repeat(50), "y".repeat(50)];
+    let ciphers: Vec<String> = bsm
+        .iter()
+        .map(|e| match e.args[0] {
+            Const::String(ref s) => s.clone(),
+            _ => unreachable!(),
+        })
+        .collect();
+    let salts: Vec<i32> = bsm
+        .iter()
+        .map(|e| match e.args[1] {
+            Const::Int(s) => s,
+            _ => unreachable!(),
+        })
+        .collect();
+    for ((cipher, salt), original) in ciphers.iter().zip(&salts).zip(originals) {
+        let scheme = schemes[*salt as usize % schemes.len()];
+        assert_eq!(cipher, &encrypt(scheme, 7, *salt, &original).cipher);
+    }
+}
+
+/// Condy is a Java 11+ feature (classfile 55): older classes keep the direct
+/// decoder calls even when the mode is on.
+#[test]
+fn condy_falls_back_for_old_class_versions() {
+    let mut program = sample();
+    program.classes[0].version = Version::JAVA_8;
+    let config = Config {
+        seed: Some(7),
+        strings: StringsConfig {
+            condy: true,
+            ..StringsConfig::default()
+        },
+        ..Config::default()
+    };
+    let mut ctx = Context::new(config);
+    StringsPass.apply(&mut ctx, &mut program).expect("strings");
+
+    let code = program.classes[0].methods[0].code.as_ref().expect("code");
+    assert!(
+        code.insns
+            .iter()
+            .any(|insn| matches!(insn, Insn::Invoke { name, .. } if name == "d")),
+        "pre-11 class must keep direct calls: {code:?}"
+    );
+    assert!(
+        !code
+            .insns
+            .iter()
+            .any(|insn| matches!(insn, Insn::Const(Const::Dynamic { .. }))),
+        "no condy constants below classfile 55: {code:?}"
+    );
+}
+
+/// A class that already has `BootstrapMethods` (Kotlin lambdas) keeps its
+/// entries: new condy ones are appended and referenced by the right index.
+#[test]
+fn condy_appends_to_existing_bootstrap_methods() {
+    let mut program = sample();
+    let existing = BootstrapMethod {
+        kind: 6,
+        owner: "java/lang/invoke/StringConcatFactory".to_string(),
+        name: "makeConcatWithConstants".to_string(),
+        descriptor: "([Ljava/lang/Object;)Ljava/lang/String;".to_string(),
+        itf: false,
+        args: vec![Const::String("\u{1}".to_string())],
+    };
+    program.classes[0]
+        .attributes
+        .push(Attribute::BootstrapMethods(vec![existing]));
+    let config = Config {
+        seed: Some(7),
+        strings: StringsConfig {
+            condy: true,
+            ..StringsConfig::default()
+        },
+        ..Config::default()
+    };
+    let mut ctx = Context::new(config);
+    StringsPass.apply(&mut ctx, &mut program).expect("strings");
+
+    let class = &program.classes[0];
+    let Attribute::BootstrapMethods(bsm) = class
+        .attributes
+        .iter()
+        .find(|a| matches!(a, Attribute::BootstrapMethods(_)))
+        .expect("BootstrapMethods attribute")
+    else {
+        unreachable!()
+    };
+    // 1 lambda entry + 3 chunk entries.
+    assert_eq!(bsm.len(), 4);
+    assert_eq!(bsm[0].name, "makeConcatWithConstants");
+    let code = class.methods[0].code.as_ref().expect("code");
+    let indices: Vec<u16> = code
+        .insns
+        .iter()
+        .filter_map(|insn| match insn {
+            Insn::Const(Const::Dynamic { bootstrap, .. }) => Some(*bootstrap),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(
+        indices,
+        vec![1, 2, 3],
+        "condy entries start after the lambda"
+    );
+}

crates/noxis-passes/src/strings/tests/mod.rs

@@ -2,6 +2,8 @@
 
 #![allow(clippy::expect_used, clippy::unwrap_used)]
 
+mod condy;
+
 use noxis_classfile::{ClassBuilder, Code, Const, Insn, MAX_METHOD_INSNS, Program, Version};
 use noxis_core::{Config, Context};
 use noxis_runtime::{Scheme, encrypt};
@@ -10,7 +12,7 @@ use super::StringsPass;
 use super::crypt::{decode_sequence, salt_for_scheme, split_chunks};
 use noxis_core::Pass;
 
-fn sample() -> Program {
+pub(super) fn sample() -> Program {
     let code = Code {
         max_stack: 1,
         max_locals: 0,

crates/noxis-runtime/src/decoder/mod.rs

@@ -31,6 +31,11 @@ use kdf::{Gen, c_int, c_long, c_str, call, load, store};
 pub const DECODER_METHOD: &str = "d";
 /// Дескриптор метода декодера.
 pub const DECODER_DESC: &str = "(Ljava/lang/String;I)Ljava/lang/String;";
+/// Имя bootstrap-метода для `CONSTANT_Dynamic` (condy-строки).
+pub const BOOTSTRAP_METHOD: &str = "b";
+/// Дескриптор bootstrap-метода: стандартный префикс BSM
+/// (`Lookup`, `name`, `type`) плюс наши аргументы `cipher` и `salt`.
+pub const BOOTSTRAP_DESC: &str = "(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/Class;Ljava/lang/String;I)Ljava/lang/String;";
 
 /// Ошибка генерации рантайма.
 #[derive(Debug, thiserror::Error)]
@@ -78,9 +83,38 @@ pub fn decoder_class(
             major: 49,
         })
         .method_with_code(0x0009, DECODER_METHOD, DECODER_DESC, code)
+        .method_with_code(
+            0x0009,
+            BOOTSTRAP_METHOD,
+            BOOTSTRAP_DESC,
+            bootstrap_code(internal_name),
+        )
         .build())
 }
 
+/// Тело bootstrap-метода: `b(lookup, name, type, cipher, salt) = d(cipher, salt)`.
+///
+/// JVM вызывает его сама при первом `ldc` condy-константы и кеширует
+/// результат - метод должен быть `public static` и возвращать значение
+/// дескриптора константы (`Ljava/lang/String;`).
+fn bootstrap_code(owner: &str) -> Code {
+    Code {
+        max_stack: 2,
+        // Слоты 0-2 (lookup/name/type) заняты стандартным префиксом BSM,
+        // cipher и salt живут в 3 и 4.
+        max_locals: 5,
+        insns: vec![
+            load(3, SlotKind::Ref),
+            load(4, SlotKind::Int),
+            call(owner, DECODER_METHOD, DECODER_DESC, InvokeKind::Static),
+            Insn::AReturn,
+        ],
+        exception_table: Vec::new(),
+        frames: Vec::new(),
+        attributes: Vec::new(),
+    }
+}
+
 /// Имя класса-декодера для прогона: детерминированно от сида, но выглядит
 /// как обычный обфусцированный класс.
 pub fn decoder_owner(seed_name: &str) -> String {

crates/noxis-runtime/src/lib.rs

@@ -6,5 +6,7 @@ pub mod codec;
 pub mod decoder;
 pub mod scheme;
 
-pub use decoder::{DECODER_DESC, DECODER_METHOD, decoder_class, decoder_owner};
+pub use decoder::{
+    BOOTSTRAP_DESC, BOOTSTRAP_METHOD, DECODER_DESC, DECODER_METHOD, decoder_class, decoder_owner,
+};
 pub use scheme::{Blob, Scheme, decrypt, encrypt};

crates/noxis-runtime/tests/exec_condy.rs

@@ -0,0 +1,132 @@
+//! Condy-приёмка: шифруем в Rust, расшифровывает настоящая JVM через
+//! bootstrap-метод декодера (`CONSTANT_Dynamic`).
+//!
+//! Это приёмка приоритета 1 из todo.md (2026-10-14): sandbox-деобфускатор
+//! (narumii/SSVM) не резолвит condy вообще - 0 изменений на condy-классе,
+//! тогда как прямой вызов декодера он исполняет и снимает строку. Метод `b`
+//! живёт в декодере и вызывается самой JVM в момент `ldc`.
+
+#![allow(clippy::expect_used, clippy::unwrap_used)]
+
+use std::path::PathBuf;
+
+use noxis_classfile::{Attribute, BootstrapMethod, ClassBuilder, Code, Const, Insn, format};
+use noxis_runtime::{BOOTSTRAP_DESC, BOOTSTRAP_METHOD, Scheme, decoder_class, encrypt};
+
+const MASTER: u64 = 0x1234_5678_9ABC_DEF0;
+const DECODER: &str = "test/CondDecoder";
+const CALLER: &str = "test/CondCall";
+
+/// Строки обоих схем - тот же набор, что у прямого вызова.
+fn samples() -> Vec<(String, Scheme)> {
+    vec![
+        ("hi".to_string(), Scheme::XorSplitmix),
+        ("Hello, мир!".to_string(), Scheme::XorSplitmix),
+        ("x".repeat(100), Scheme::XorSplitmix),
+        ("hi".to_string(), Scheme::XteaCtr),
+        ("Hello, мир!".to_string(), Scheme::XteaCtr),
+        ("x".repeat(100), Scheme::XteaCtr),
+    ]
+}
+
+/// Класс-вызыватель condy-режима: `main` печатает `ldc CONSTANT_Dynamic`.
+///
+/// Ровно то, что эмитит пасс `strings` при `condy = true`: по одной
+/// bootstrap-записи на чанк (cipher + salt как статические аргументы),
+/// константа со стандартным дескриптором `Ljava/lang/String;`.
+fn condy_caller_class(parts: &[(String, i32)]) -> noxis_classfile::ClassFile {
+    let mut insns = Vec::new();
+    let mut bootstrap: Vec<BootstrapMethod> = Vec::new();
+    for (cipher, salt) in parts {
+        bootstrap.push(BootstrapMethod {
+            kind: 6, // REF_invokeStatic
+            owner: DECODER.to_string(),
+            name: BOOTSTRAP_METHOD.to_string(),
+            descriptor: BOOTSTRAP_DESC.to_string(),
+            itf: false,
+            args: vec![Const::String(cipher.clone()), Const::Int(*salt)],
+        });
+        insns.push(Insn::GetStatic {
+            owner: "java/lang/System".to_string(),
+            name: "out".to_string(),
+            descriptor: "Ljava/io/PrintStream;".to_string(),
+        });
+        insns.push(Insn::Const(Const::Dynamic {
+            name: "_".to_string(),
+            descriptor: "Ljava/lang/String;".to_string(),
+            bootstrap: (bootstrap.len() - 1) as u16,
+        }));
+        insns.push(Insn::Invoke {
+            kind: noxis_classfile::InvokeKind::Virtual,
+            owner: "java/io/PrintStream".to_string(),
+            name: "println".to_string(),
+            descriptor: "(Ljava/lang/String;)V".to_string(),
+            itf: false,
+        });
+    }
+    insns.push(Insn::Return(None));
+    let code = Code {
+        max_stack: 2,
+        max_locals: 1,
+        insns,
+        exception_table: Vec::new(),
+        frames: Vec::new(),
+        attributes: Vec::new(),
+    };
+    ClassBuilder::new(CALLER, None)
+        .attribute(Attribute::BootstrapMethods(bootstrap))
+        .method_with_code(0x0009, "main", "([Ljava/lang/String;)V", code)
+        .build()
+}
+
+#[test]
+fn condy_bootstrap_executes_under_java() {
+    if std::process::Command::new("java")
+        .arg("-version")
+        .output()
+        .is_err()
+    {
+        eprintln!("SKIP: нет java");
+        return;
+    }
+    let mut parts = Vec::new();
+    let mut expected = Vec::new();
+    for (index, (text, scheme)) in samples().iter().enumerate() {
+        let salt = (index as i32)
+            .saturating_mul(2)
+            .saturating_add(match scheme {
+                Scheme::XorSplitmix => 0,
+                Scheme::XteaCtr => 1,
+            });
+        let blob = encrypt(*scheme, MASTER, salt, text);
+        parts.push((blob.cipher, salt));
+        expected.push(text.to_string());
+    }
+    let decoder = decoder_class(DECODER, MASTER, &["xor-splitmix", "xtea-ctr"]).expect("decoder");
+    let caller = condy_caller_class(&parts);
+
+    let dir: PathBuf = std::env::temp_dir().join(format!("noxis-condy-{}", std::process::id()));
+    for (name, class) in [(DECODER, &decoder), (CALLER, &caller)] {
+        let mut path = dir.clone();
+        for part in name.split('/') {
+            path.push(part);
+        }
+        path.set_extension("class");
+        std::fs::create_dir_all(path.parent().expect("parent")).expect("mkdir");
+        std::fs::write(&path, format::write(class).expect("write")).expect("write class");
+    }
+    let out = std::process::Command::new("java")
+        .arg("-Xverify:all")
+        .arg("-cp")
+        .arg(&dir)
+        .arg(CALLER.replace('/', "."))
+        .output()
+        .expect("запуск java");
+    let stdout = String::from_utf8_lossy(&out.stdout);
+    let stderr = String::from_utf8_lossy(&out.stderr);
+    let _ = std::fs::remove_dir_all(&dir);
+    assert!(out.status.success(), "java упал:\n{stderr}\n{stdout}");
+    let lines: Vec<&str> = stdout.lines().collect();
+    let want: Vec<&str> = expected.iter().map(String::as_str).collect();
+    assert_eq!(lines, want, "condy-расшифровка не сошлась");
+}