android-encrypted-archiver/.planning/phases/09-kotlin-decoder-update/09-01-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
09-kotlin-decoder-update	01	decoder	kotlin android directory-support binary-format permissions cross-validation	phase provides 08-rust-directory-archiver v1.1 Rust archiver with directory traversal, entry_type/permissions in TOC	v1.1-compatible Kotlin decoder with directory support and permission restoration Cross-validation test script with 8 test cases (5 original + 3 directory)	10-hardening 11-polish	added patterns applyPermissions pattern using Java File API owner/everyone distinction directory-first extraction with parent directory creation	created modified kotlin/ArchiveDecoder.kt kotlin/test_decoder.sh	Java File API owner/everyone permission model sufficient for KOT-07 (no group-level granularity) Directory entries processed before file entries naturally via DFS preorder parent-before-child ordering Permission application: set everyone flags first (ownerOnly=false), then override owner-only (ownerOnly=true)	applyPermissions(): extract POSIX mode bits and map to Java File setReadable/setWritable/setExecutable Entry type dispatch: directory entries skip crypto pipeline entirely, file entries ensure parent dirs exist	KOT-05 KOT-06 KOT-07	2min	2026-02-26

Phase 9 Plan 01: Kotlin Decoder Update Summary

v1.1 Kotlin decoder with directory hierarchy creation, empty directory support, and POSIX permission restoration via Java File API

Performance

• Duration: 2 min
• Started: 2026-02-26T19:03:18Z
• Completed: 2026-02-26T19:05:44Z
• Tasks: 2
• Files modified: 2

Accomplishments

• Updated TocEntry data class with entryType (0=file, 1=directory) and permissions (12-bit POSIX mode_t) fields
• Kotlin decoder now parses v1.1 TOC entries (104 + name_length bytes) with entry_type and permissions
• Directory entries create full hierarchy via mkdirs() without attempting decryption
• File entries with relative paths create parent directories before writing
• Permissions restored via Java File API (setReadable/setWritable/setExecutable with owner/everyone distinction)
• Test script expanded from 5 to 8 test cases with nested directory, empty directory, and mixed file/directory tests

Task Commits

Each task was committed atomically:

1. Task 1: Update ArchiveDecoder.kt for v1.1 format with directory support - a01b260 (feat)
2. Task 2: Update test_decoder.sh with directory test cases - 27fb392 (test)

Files Created/Modified

• kotlin/ArchiveDecoder.kt - v1.1 decoder: entryType/permissions parsing, directory handling, permission restoration
• kotlin/test_decoder.sh - 3 new directory test cases (nested dirs, empty dir, mixed files+dirs)

Decisions Made

• Used Java File API owner/everyone permission model (no Java NIO PosixFilePermission) per KOT-07 spec
• Permission application order: set everyone flags first (ownerOnly=false), then owner-only overrides (ownerOnly=true) to correctly handle cases where owner has permissions but others do not
• Entry size formula updated from 101 to 104 + name_length consistently

Deviations from Plan

None - plan executed exactly as written.

Issues Encountered

None - all tasks completed without issues.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• Kotlin decoder fully compatible with v1.1 format produced by Rust archiver
• Cross-validation test script ready with 8 test cases covering files, directories, empty dirs, and mixed content
• Ready for Phase 10 (hardening) or Phase 11 (polish)

Self-Check: PASSED

• kotlin/ArchiveDecoder.kt exists
• kotlin/test_decoder.sh exists
• 09-01-SUMMARY.md exists
• Commit a01b260 (Task 1) verified
• Commit 27fb392 (Task 2) verified

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Phase: 09-kotlin-decoder-update Completed: 2026-02-26