Merge branch 'main' into fix/update-ios-backup-decryption

.github/workflows/publish-release-docker.yml

@@ -14,10 +14,10 @@ env:
   REGISTRY: ghcr.io
   IMAGE_NAME: ${{ github.repository }}
 
-# Build each architecture natively, then publish the combined image manifests.
+# There is a single job in this workflow. It's configured to run on the latest available version of Ubuntu.
 jobs:
   build-and-push-image:
-    runs-on: ${{ matrix.architecture.runner }}
+    runs-on: ubuntu-latest
     # Sets the permissions granted to the `GITHUB_TOKEN` for the actions in this job.
     permissions:
       contents: read
@@ -26,15 +26,7 @@ jobs:
       id-token: write
       #
     strategy:
-      fail-fast: false
       matrix:
-        architecture:
-          - platform: linux/amd64
-            runner: ubuntu-24.04
-            name: amd64
-          - platform: linux/arm64
-            runner: ubuntu-24.04-arm
-            name: arm64
         platform:
           - dockerfile: "Dockerfile"
             tag-suffix: ""
@@ -69,95 +61,24 @@ jobs:
             type=raw,enable=${{ github.ref_type == 'tag' }},value=${{ github.ref_name }},suffix=${{ matrix.platform.tag-suffix }}
             type=sha,suffix=${{ matrix.platform.tag-suffix }}
             type=sha,format=long,suffix=${{ matrix.platform.tag-suffix }}
+      # Register emulators so Buildx can build the ARM64 images on the AMD64 runner.
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v4
       # This step sets up some additional capabilities to generate the provenance and sbom attestations
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
       # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
       # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see "[Usage](https://github.com/docker/build-push-action#usage)" in the README of the `docker/build-push-action` repository.
-      # Push by digest so architecture builds do not overwrite shared image tags.
+      # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
       - name: Build and push Docker image
         id: push
         uses: docker/build-push-action@v7
         with:
           file: ${{ matrix.platform.dockerfile }}
           context: .
-          platforms: ${{ matrix.architecture.platform }}
-          outputs: type=image,name=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }},push-by-digest=true,name-canonical=true,push=true
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           provenance: mode=max
           sbom: true
-      - name: Export image digest
-        env:
-          DIGEST: ${{ steps.push.outputs.digest }}
-        run: |
-          mkdir -p "${RUNNER_TEMP}/digests"
-          touch "${RUNNER_TEMP}/digests/${DIGEST#sha256:}"
-      - name: Upload image digest
-        uses: actions/upload-artifact@v4
-        with:
-          name: digests-${{ matrix.platform.dockerfile }}-${{ matrix.architecture.name }}
-          path: ${{ runner.temp }}/digests/*
-          if-no-files-found: error
-          retention-days: 1
-
-  publish-manifests:
-    needs: build-and-push-image
-    runs-on: ubuntu-24.04
-    permissions:
-      contents: read
-      packages: write
-    strategy:
-      matrix:
-        platform:
-          - dockerfile: "Dockerfile"
-            tag-suffix: ""
-          - dockerfile: "Dockerfile.ios"
-            tag-suffix: "-ios"
-          - dockerfile: "Dockerfile.android"
-            tag-suffix: "-android"
-    steps:
-      - name: Download image digests
-        uses: actions/download-artifact@v4
-        with:
-          pattern: digests-${{ matrix.platform.dockerfile }}-*
-          path: ${{ runner.temp }}/digests
-          merge-multiple: true
-      - name: Log in to the Container registry
-        uses: docker/login-action@dbcb813823bdd20940b903addbd779551569679f # v4.6.0
-        with:
-          registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@v6
-        with:
-          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
-          flavor: |
-            latest=false
-          tags: |
-            type=raw,value=latest,enable={{ is_default_branch }},suffix=${{ matrix.platform.tag-suffix }}
-            type=raw,enable=${{ github.event_name == 'release' || github.ref_type == 'tag' }},value=stable,suffix=${{ matrix.platform.tag-suffix }}
-            type=raw,enable=${{ github.event_name == 'release' }},value=${{ github.event.release.tag_name }},suffix=${{ matrix.platform.tag-suffix }}
-            type=raw,enable=${{ github.ref_type == 'tag' }},value=${{ github.ref_name }},suffix=${{ matrix.platform.tag-suffix }}
-            type=sha,suffix=${{ matrix.platform.tag-suffix }}
-            type=sha,format=long,suffix=${{ matrix.platform.tag-suffix }}
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v4
-      - name: Publish multi-platform image
-        working-directory: ${{ runner.temp }}/digests
-        env:
-          METADATA_JSON: ${{ steps.meta.outputs.json }}
-        run: |
-          mapfile -t tags < <(jq -r '.tags[]' <<< "$METADATA_JSON")
-          tag_args=()
-          for tag in "${tags[@]}"; do
-            tag_args+=(--tag "$tag")
-          done
-          images=()
-          for digest in *; do
-            images+=("${REGISTRY}/${IMAGE_NAME}@sha256:${digest}")
-          done
-          test "${#images[@]}" -eq 2
-          docker buildx imagetools create "${tag_args[@]}" "${images[@]}"
-          docker buildx imagetools inspect "${tags[0]}"

.github/workflows/tests.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.15']
+        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
     env:
       # Takes precedence over .python-version, which otherwise makes `uv run`
       # rebuild the venv with 3.10 and test every matrix entry on 3.10.

Dockerfile

@@ -1,6 +1,6 @@
 # Create main image
 FROM ubuntu:24.04 AS main
-COPY --from=ghcr.io/astral-sh/uv:0.13.5 /uv /uvx /usr/local/bin/
+COPY --from=ghcr.io/astral-sh/uv:0.11.8 /uv /uvx /usr/local/bin/
 
 LABEL org.opencontainers.image.url="https://mvt.re"
 LABEL org.opencontainers.image.documentation="https://docs.mvt.re"
@@ -62,4 +62,4 @@ WORKDIR /home/cases
 RUN echo 'echo "Mobile Verification Toolkit @ Docker\n------------------------------------\n\nYou can find information about how to use this image for Android (https://github.com/mvt-project/mvt/tree/master/docs/android) and iOS (https://github.com/mvt-project/mvt/tree/master/docs/ios) in the official docs of the project.\n"' >> ~/.bashrc \
   && echo 'echo "Note that to perform the debug via USB you might need to give the Docker image access to the USB using \"docker run -it --privileged -v /dev/bus/usb:/dev/bus/usb mvt\" or, preferably, the \"--device=\" parameter.\n"' >> ~/.bashrc
 
-CMD [ "/bin/bash" ]
+CMD /bin/bash

Dockerfile.android

@@ -1,6 +1,6 @@
 # Create main image
-FROM python:3.11.17-alpine3.23 AS main
-COPY --from=ghcr.io/astral-sh/uv:0.13.5 /uv /uvx /usr/local/bin/
+FROM python:3.10.14-alpine3.20 AS main
+COPY --from=ghcr.io/astral-sh/uv:0.11.8 /uv /uvx /usr/local/bin/
 
 LABEL org.opencontainers.image.url="https://mvt.re"
 LABEL org.opencontainers.image.documentation="https://docs.mvt.re"
@@ -8,7 +8,7 @@ LABEL org.opencontainers.image.source="https://github.com/mvt-project/mvt"
 LABEL org.opencontainers.image.title="Mobile Verification Toolkit (Android)"
 LABEL org.opencontainers.image.description="MVT is a forensic tool to look for signs of infection in smartphone devices."
 LABEL org.opencontainers.image.licenses="MVT License 1.1"
-LABEL org.opencontainers.image.base.name=docker.io/library/python:3.11.17-alpine3.23
+LABEL org.opencontainers.image.base.name=docker.io/library/python:3.10.14-alpine3.20
 
 # Install runtime dependencies
 RUN apk add --no-cache \

Dockerfile.ios

@@ -1,7 +1,7 @@
 # Main image
 # ----------
 FROM ubuntu:24.04 AS main
-COPY --from=ghcr.io/astral-sh/uv:0.13.5 /uv /uvx /usr/local/bin/
+COPY --from=ghcr.io/astral-sh/uv:0.11.8 /uv /uvx /usr/local/bin/
 
 LABEL org.opencontainers.image.url="https://mvt.re"
 LABEL org.opencontainers.image.documentation="https://docs.mvt.re"

pyproject.toml

@@ -24,7 +24,7 @@ dependencies = [
     "simplejson==4.1.1",
     "packaging==26.3",
     "appdirs==1.4.4",
-    "iphone_backup_decrypt==0.10.0",
+    "iphone_backup_decrypt==0.11.2",
     "pycryptodome>=3.20.0",
     "cryptography==50.0.0",
     "PyYAML>=6.0.2",

src/mvt/ios/decrypt.py

@@ -8,10 +8,8 @@ import glob
 import logging
 import os
 import os.path
-import plistlib
 import shutil
 import sqlite3
-import tempfile
 from concurrent.futures import (
     ALL_COMPLETED,
     FIRST_COMPLETED,
@@ -22,100 +20,26 @@ from concurrent.futures import (
 from pathlib import Path
 from typing import Optional
 
-from iphone_backup_decrypt import EncryptedBackup
-from iphone_backup_decrypt import google_iphone_dataprotection
+from iphone_backup_decrypt import (
+    BackupNotEncryptedError,
+    EncryptedBackup,
+    IncorrectPassphraseError,
+    NotABackupFolderError,
+)
 from iphone_backup_decrypt.utils import FilePlist
 
 from .decrypt_config import DEFAULT_DECRYPT_WORKERS, MAX_DECRYPT_WORKERS
 
 log = logging.getLogger(__name__)
 
-# Import pbkdf2_hmac from the same source iphone_backup_decrypt uses internally,
-# so our key derivation is consistent with theirs.
-try:
-    from fastpbkdf2 import pbkdf2_hmac
-except ImportError:
-    import Crypto.Hash.SHA1
-    import Crypto.Hash.SHA256
-    import Crypto.Protocol.KDF
-
-    _HASH_FNS = {"sha1": Crypto.Hash.SHA1, "sha256": Crypto.Hash.SHA256}
-
-    def pbkdf2_hmac(hash_name, password, salt, iterations, dklen=None):
-        return Crypto.Protocol.KDF.PBKDF2(
-            password, salt, dklen, iterations, hmac_hash_module=_HASH_FNS[hash_name]
-        )
-
-
 class MVTEncryptedBackup(EncryptedBackup):
-    """Extends EncryptedBackup with derived key export/import.
-
-    NOTE: This subclass relies on internal APIs of iphone_backup_decrypt
-    (specifically _read_and_unlock_keybag, _keybag, and the Keybag class
-    internals). Pinned to iphone_backup_decrypt==0.10.0.
-    """
-
-    def __init__(self, *, backup_directory, passphrase=None, derived_key=None):
-        if passphrase:
-            super().__init__(backup_directory=backup_directory, passphrase=passphrase)
-            self._derived_key = None  # Will be set after keybag unlock
-        elif derived_key:
-            self._init_without_passphrase(backup_directory, derived_key)
-        else:
-            raise ValueError("Either passphrase or derived_key must be provided")
-
-    def _init_without_passphrase(self, backup_directory, derived_key):
-        """Replicate parent __init__ state without requiring a passphrase."""
-        self.decrypted = False
-        self._backup_directory = os.path.expandvars(backup_directory)
-        self._passphrase = None
-        self._manifest_plist_path = os.path.join(
-            self._backup_directory, "Manifest.plist"
-        )
-        self._manifest_plist = None
-        self._manifest_db_path = os.path.join(self._backup_directory, "Manifest.db")
-        self._keybag = None
-        self._unlocked = False
-        self._temporary_folder = tempfile.mkdtemp()
-        self._temp_decrypted_manifest_db_path = os.path.join(
-            self._temporary_folder, "Manifest.db"
-        )
-        self._temp_manifest_db_conn = None
-        self._derived_key = derived_key  # 32 raw bytes
-
-    def _read_and_unlock_keybag(self):
-        """Override to capture derived key on password unlock, or use
-        a pre-derived key to skip PBKDF2."""
-        if self._unlocked:
-            return self._unlocked
-
-        with open(self._manifest_plist_path, "rb") as infile:
-            self._manifest_plist = plistlib.load(infile)
-        self._keybag = google_iphone_dataprotection.Keybag(
-            self._manifest_plist["BackupKeyBag"]
-        )
-
-        if self._derived_key:
-            # Skip PBKDF2, unwrap class keys directly with pre-derived key
-            self._unlocked = _unlock_keybag_with_derived_key(
-                self._keybag, self._derived_key
-            )
-        else:
-            # Normal path: full PBKDF2 derivation, capturing the intermediate key
-            self._unlocked, self._derived_key = _unlock_keybag_and_capture_key(
-                self._keybag, self._passphrase
-            )
-            self._passphrase = None
-
-        if not self._unlocked:
-            raise ValueError("Failed to decrypt keys: incorrect passphrase?")
-        return True
+    """Extract backup files by ID while MVT processes them concurrently."""
 
     def get_decryption_key(self):
         """Return derived key as hex string (64 chars / 32 bytes)."""
-        if self._derived_key is None:
+        if self.keybag is None or self.keybag.passphrase_key is None:
             raise ValueError("No derived key available")
-        return self._derived_key.hex()
+        return self.keybag.passphrase_key.hex()
 
     def extract_file_by_id(self, *, file_id, file_bplist, output_filename):
         """Extract one manifest entry without loading the whole file into memory."""
@@ -129,8 +53,9 @@ class MVTEncryptedBackup(EncryptedBackup):
             shutil.copy2(source_filename, output_filename)
             return
 
-        inner_key = self._keybag.unwrapKeyForClass(
-            file_plist.protection_class, file_plist.encryption_key
+        inner_key = self.keybag.unwrap_key_for_class(
+            protection_class=file_plist.protection_class,
+            wrapped_file_key=file_plist.encryption_key,
         )
         self._decrypt_file_to_disk(
             file_id=file_id,
@@ -139,47 +64,6 @@ class MVTEncryptedBackup(EncryptedBackup):
             output_filepath=output_filename,
         )
 
-
-def _unlock_keybag_with_derived_key(keybag, passphrase_key):
-    """Unlock keybag class keys using a pre-derived passphrase_key,
-    skipping the expensive PBKDF2 rounds."""
-    WRAP_PASSPHRASE = 2
-    for classkey in keybag.classKeys.values():
-        if b"WPKY" not in classkey:
-            continue
-        if classkey[b"WRAP"] & WRAP_PASSPHRASE:
-            k = google_iphone_dataprotection._AESUnwrap(
-                passphrase_key, classkey[b"WPKY"]
-            )
-            if not k:
-                return False
-            classkey[b"KEY"] = k
-    return True
-
-
-def _unlock_keybag_and_capture_key(keybag, passphrase):
-    """Run full PBKDF2 key derivation and AES unwrap, returning
-    (success, passphrase_key) so the derived key can be exported."""
-    passphrase_round1 = pbkdf2_hmac(
-        "sha256", passphrase, keybag.attrs[b"DPSL"], keybag.attrs[b"DPIC"], 32
-    )
-    passphrase_key = pbkdf2_hmac(
-        "sha1", passphrase_round1, keybag.attrs[b"SALT"], keybag.attrs[b"ITER"], 32
-    )
-    WRAP_PASSPHRASE = 2
-    for classkey in keybag.classKeys.values():
-        if b"WPKY" not in classkey:
-            continue
-        if classkey[b"WRAP"] & WRAP_PASSPHRASE:
-            k = google_iphone_dataprotection._AESUnwrap(
-                passphrase_key, classkey[b"WPKY"]
-            )
-            if not k:
-                return False, None
-            classkey[b"KEY"] = k
-    return True, passphrase_key
-
-
 class DecryptBackup:
     """This class provides functions to decrypt an encrypted iTunes backup
     using either a password or a key file.
@@ -376,41 +260,36 @@ class DecryptBackup:
                 )
                 return
 
-        # Before proceeding, we check whether the backup is indeed encrypted.
-        if not self.is_encrypted(self.backup_path):
-            return
-
         try:
             self._backup = MVTEncryptedBackup(
                 backup_directory=self.backup_path,
                 passphrase=password,
             )
+            # Manifest.db is a more reliable indication of encryption than
+            # the IsEncrypted field in Manifest.plist.
+            if not self.is_encrypted(self.backup_path):
+                self._backup = None
+                return
             # Eagerly trigger keybag unlock so wrong-password errors
             # surface here rather than later during process_backup().
             self._backup.test_decryption()
+        except IncorrectPassphraseError:
+            self._backup = None
+            log.critical("Failed to decrypt backup. Password is probably wrong.")
+        except (NotABackupFolderError, FileNotFoundError):
+            self._backup = None
+            log.critical(
+                "Failed to find a valid backup at %s. "
+                "Did you point to the right backup path?",
+                self.backup_path,
+            )
+        except BackupNotEncryptedError:
+            self._backup = None
+            log.critical("The backup does not seem encrypted!")
         except Exception as exc:
             self._backup = None
-            if (
-                isinstance(exc, ValueError)
-                and "passphrase" in str(exc).lower()
-            ):
-                log.critical("Failed to decrypt backup. Password is probably wrong.")
-            elif (
-                isinstance(exc, FileNotFoundError)
-                and hasattr(exc, "filename")
-                and os.path.basename(exc.filename) == "Manifest.plist"
-            ):
-                log.critical(
-                    "Failed to find a valid backup at %s. "
-                    "Did you point to the right backup path?",
-                    self.backup_path,
-                )
-            else:
-                log.exception(exc)
-                log.critical(
-                    "Failed to decrypt backup. Did you provide the correct password? "
-                    "Did you point to the right backup path?"
-                )
+            log.exception(exc)
+            log.critical("Failed to decrypt backup.")
 
     def decrypt_with_key_file(self, key_file: str) -> None:
         """Decrypts an encrypted iOS backup using a key file.
@@ -424,10 +303,6 @@ class DecryptBackup:
             key_file,
         )
 
-        # Before proceeding, we check whether the backup is indeed encrypted.
-        if not self.is_encrypted(self.backup_path):
-            return
-
         with open(key_file, "rb") as handle:
             key_bytes = handle.read()
 
@@ -442,16 +317,30 @@ class DecryptBackup:
             key_bytes_raw = binascii.unhexlify(key_bytes)
             self._backup = MVTEncryptedBackup(
                 backup_directory=self.backup_path,
-                derived_key=key_bytes_raw,
+                passphrase_key=key_bytes_raw,
             )
+            if not self.is_encrypted(self.backup_path):
+                self._backup = None
+                return
             # Eagerly trigger keybag unlock so wrong-key errors surface here.
             self._backup.test_decryption()
+        except (binascii.Error, IncorrectPassphraseError):
+            self._backup = None
+            log.critical("Failed to decrypt backup. Key file is probably wrong.")
+        except (NotABackupFolderError, FileNotFoundError):
+            self._backup = None
+            log.critical(
+                "Failed to find a valid backup at %s. "
+                "Did you point to the right backup path?",
+                self.backup_path,
+            )
+        except BackupNotEncryptedError:
+            self._backup = None
+            log.critical("The backup does not seem encrypted!")
         except Exception as exc:
             self._backup = None
             log.exception(exc)
-            log.critical(
-                "Failed to decrypt backup. Did you provide the correct key file?"
-            )
+            log.critical("Failed to decrypt backup.")
 
     def get_key(self) -> None:
         """Retrieve and prints the encryption key."""

tests/ios_backup/test_decrypt.py

@@ -3,12 +3,15 @@
 # Use of this software is governed by the MVT License 1.1 that can be found at
 #   https://license.mvt.re/1.1/
 
+import hashlib
 import logging
+import plistlib
 import threading
 from pathlib import Path
 
 import pytest
 from Crypto.Cipher import AES
+from iphone_backup_decrypt import IncorrectPassphraseError
 
 from mvt.ios.decrypt import DecryptBackup, MVTEncryptedBackup
 
@@ -24,6 +27,89 @@ def _encrypted_file(backup_path, file_id, key, plaintext):
     source_path.write_bytes(encrypted)
 
 
+def _keybag_tlv(tag, value):
+    return tag + len(value).to_bytes(4, "big") + value
+
+
+def test_derived_key_can_unlock_keybag(mocker, tmp_path, caplog):
+    password = b"backup password"
+    salt = b"salt" * 4
+    dpsl = b"dpsl" * 4
+    round1 = hashlib.pbkdf2_hmac("sha256", password, dpsl, 1, 32)
+    derived_key = hashlib.pbkdf2_hmac("sha1", round1, salt, 1, 32)
+    wrapped_class_key = AES.new(derived_key, AES.MODE_KW).seal(b"k" * 32)
+    keybag_data = b"".join(
+        [
+            _keybag_tlv(b"TYPE", (1).to_bytes(4, "big")),
+            _keybag_tlv(b"DPSL", dpsl),
+            _keybag_tlv(b"DPIC", (1).to_bytes(4, "big")),
+            _keybag_tlv(b"SALT", salt),
+            _keybag_tlv(b"ITER", (1).to_bytes(4, "big")),
+            _keybag_tlv(b"UUID", b"g" * 16),
+            _keybag_tlv(b"WRAP", (2).to_bytes(4, "big")),
+            _keybag_tlv(b"UUID", b"c" * 16),
+            _keybag_tlv(b"CLAS", (1).to_bytes(4, "big")),
+            _keybag_tlv(b"WRAP", (2).to_bytes(4, "big")),
+            _keybag_tlv(b"WPKY", wrapped_class_key),
+        ]
+    )
+    (tmp_path / "Manifest.plist").write_bytes(
+        plistlib.dumps({"IsEncrypted": True, "BackupKeyBag": keybag_data})
+    )
+    (tmp_path / "Manifest.db").touch()
+
+    with pytest.raises(IncorrectPassphraseError):
+        MVTEncryptedBackup(
+            backup_directory=str(tmp_path), passphrase="wrong"
+        )._read_and_unlock_keybag()
+
+    password_backup = MVTEncryptedBackup(
+        backup_directory=str(tmp_path), passphrase=password
+    )
+    password_backup._read_and_unlock_keybag()
+    assert password_backup.get_decryption_key() == derived_key.hex()
+
+    key_backup = MVTEncryptedBackup(
+        backup_directory=str(tmp_path), passphrase_key=derived_key
+    )
+    key_backup._read_and_unlock_keybag()
+    assert key_backup.get_decryption_key() == derived_key.hex()
+
+    # Exercise MVT's password and key-file entry points with the native unlock.
+    mocker.patch.object(DecryptBackup, "is_encrypted", return_value=True)
+    mocker.patch.object(
+        MVTEncryptedBackup,
+        "test_decryption",
+        MVTEncryptedBackup._read_and_unlock_keybag,
+    )
+    password_decryptor = DecryptBackup(str(tmp_path))
+    password_decryptor.decrypt_with_password(password)
+    password_decryptor.get_key()
+    assert password_decryptor._decryption_key == derived_key.hex()
+
+    key_file = tmp_path / "key.txt"
+    key_file.write_text(derived_key.hex())
+    key_decryptor = DecryptBackup(str(tmp_path))
+    key_decryptor.decrypt_with_key_file(str(key_file))
+    assert key_decryptor.can_process()
+    assert key_decryptor._backup.get_decryption_key() == derived_key.hex()
+
+    with caplog.at_level(logging.CRITICAL, logger="mvt.ios.decrypt"):
+        wrong_password = DecryptBackup(str(tmp_path))
+        wrong_password.decrypt_with_password("wrong")
+    assert not wrong_password.can_process()
+    assert "Password is probably wrong" in caplog.text
+
+
+def test_invalid_backup_folder_uses_specific_error(tmp_path, caplog):
+    decryptor = DecryptBackup(str(tmp_path))
+    with caplog.at_level(logging.CRITICAL, logger="mvt.ios.decrypt"):
+        decryptor.decrypt_with_password("password")
+
+    assert not decryptor.can_process()
+    assert "Failed to find a valid backup" in caplog.text
+
+
 def test_extract_file_by_id_preserves_bytes_with_wrong_manifest_size(
     mocker, tmp_path
 ):
@@ -39,13 +125,15 @@ def test_extract_file_by_id_preserves_bytes_with_wrong_manifest_size(
         mtime=None,
     )
     mocker.patch("mvt.ios.decrypt.FilePlist", return_value=file_plist)
+    (tmp_path / "Manifest.plist").touch()
+    (tmp_path / "Manifest.db").touch()
 
     backup = MVTEncryptedBackup(
-        backup_directory=str(tmp_path), derived_key=b"d" * 32
+        backup_directory=str(tmp_path), passphrase_key=b"d" * 32
     )
     mocker.patch.object(backup, "_read_and_unlock_keybag", return_value=True)
-    backup._keybag = mocker.Mock()
-    backup._keybag.unwrapKeyForClass.return_value = inner_key
+    backup.keybag = mocker.Mock()
+    backup.keybag.unwrap_key_for_class.return_value = inner_key
     streaming_decrypt = mocker.spy(backup, "_decrypt_file_to_disk")
     output_path = tmp_path / "output"
 
@@ -57,6 +145,9 @@ def test_extract_file_by_id_preserves_bytes_with_wrong_manifest_size(
 
     assert output_path.read_bytes() == plaintext
     streaming_decrypt.assert_called_once()
+    backup.keybag.unwrap_key_for_class.assert_called_once_with(
+        protection_class=1, wrapped_file_key=b"wrapped-key"
+    )
 
 
 def test_extract_file_by_id_copies_unencrypted_files(mocker, tmp_path):
@@ -67,8 +158,10 @@ def test_extract_file_by_id_copies_unencrypted_files(mocker, tmp_path):
 
     file_plist = mocker.Mock(encryption_key=None)
     mocker.patch("mvt.ios.decrypt.FilePlist", return_value=file_plist)
+    (tmp_path / "Manifest.plist").touch()
+    (tmp_path / "Manifest.db").touch()
     backup = MVTEncryptedBackup(
-        backup_directory=str(tmp_path), derived_key=b"d" * 32
+        backup_directory=str(tmp_path), passphrase_key=b"d" * 32
     )
     mocker.patch.object(backup, "_read_and_unlock_keybag", return_value=True)
     output_path = tmp_path / "output"
@@ -82,6 +175,19 @@ def test_extract_file_by_id_copies_unencrypted_files(mocker, tmp_path):
     assert output_path.read_bytes() == b"plain content"
 
 
+def test_get_decryption_key_uses_unlocked_keybag(tmp_path):
+    (tmp_path / "Manifest.plist").touch()
+    (tmp_path / "Manifest.db").touch()
+    backup = MVTEncryptedBackup(
+        backup_directory=str(tmp_path), passphrase_key=b"d" * 32
+    )
+    with pytest.raises(ValueError, match="No derived key available"):
+        backup.get_decryption_key()
+
+    backup.keybag = type("Keybag", (), {"passphrase_key": b"d" * 32})()
+    assert backup.get_decryption_key() == "64" * 32
+
+
 @pytest.mark.parametrize("with_symlink", [False, True], ids=["file-id", "symlink"])
 def test_process_backup_rejects_unsafe_file_ids_and_destinations(
     mocker, tmp_path, with_symlink

uv.lock

@@ -609,14 +609,14 @@ wheels = [
 
 [[package]]
 name = "iphone-backup-decrypt"
-version = "0.10.0"
+version = "0.11.2"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "pycryptodome" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/01/b8/a2ec2b10d792403d36bb6661fea6357179c31ece1ed3285c442e636d6335/iphone_backup_decrypt-0.10.0.tar.gz", hash = "sha256:5f2799e58f908cce28d7929dd82231abc8acd57c25b37bce6a2d6a82e018d343", size = 20000, upload-time = "2026-09-17T21:46:44Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/ee/f4/a2c3e8bfd937346d87753dd2e7e51efff14744ec268ebafe8e7be0269b9e/iphone_backup_decrypt-0.11.2.tar.gz", hash = "sha256:5f631927419e670e461bc0b9e299fae396445a3c84e0afe747a3464ccbb23ed1", size = 23923, upload-time = "2026-09-24T21:02:17.219Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/89/10/349b2a720e012921d1457e1d1c2b921b16300a5f3570c4c64d0d3787539f/iphone_backup_decrypt-0.10.0-py3-none-any.whl", hash = "sha256:1ac4345a07b104a3eacab20932b8621cd1e0164e0f03d913e66eed6ea5ee173e", size = 17400, upload-time = "2026-09-17T21:46:42Z" },
+    { url = "https://files.pythonhosted.org/packages/7b/33/72414c56bc507b0c104605e16fab2c86465b55567e1aaead8371a4c5884d/iphone_backup_decrypt-0.11.2-py3-none-any.whl", hash = "sha256:f18281997a94313c174aa3839d42db292d198e879fa570799c151ac36ac9c9d7", size = 21779, upload-time = "2026-09-24T21:02:15.878Z" },
 ]
 
 [[package]]
@@ -1038,7 +1038,7 @@ requires-dist = [
     { name = "betterproto2", specifier = "==0.10.0" },
     { name = "click", specifier = "==8.4.2" },
     { name = "cryptography", specifier = "==50.0.0" },
-    { name = "iphone-backup-decrypt", specifier = "==0.10.0" },
+    { name = "iphone-backup-decrypt", specifier = "==0.11.2" },
     { name = "nskeyedunarchiver", specifier = "==1.5.2" },
     { name = "packaging", specifier = "==26.3" },
     { name = "pyahocorasick", specifier = "==2.3.1" },