From e242010fd00bdc0b4b506a1123461844fe2ea329 Mon Sep 17 00:00:00 2001
From: Matt Dainty <matt@bodgit-n-scarper.com>
Date: Sat, 26 Apr 2025 00:45:41 +0100
Subject: [PATCH] fix: Handle CRC being in the unpackInfo

---
 README.md |  2 +-
 reader.go |  2 +-
 struct.go | 19 ++++++++++++++-----
 types.go  |  6 +-----
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 961991f..c2058fb 100644
--- a/README.md
+++ b/README.md
@@ -123,7 +123,7 @@ The worst scenario would likely be to extract the archive in reverse order.
 ### Detecting the wrong password
 
 It's virtually impossible to _reliably_ detect the wrong password versus some other corruption in a password protected archive.
-This is partly due to how CBC decryption works; with the wrong password you don't get any sort of decryption error, you just a stream of bytes that aren't the correct ones.
+This is partly due to how CBC decryption works; with the wrong password you don't get any sort of decryption error, you just get a stream of bytes that aren't the correct ones.
 This manifests itself when the file has been compressed _and_ encrypted; during extraction the file is decrypted and then decompressed so with the wrong password the decompression algorithm gets handed a stream which isn't valid so that's the error you see.
 
 A `sevenzip.ReadError` error type can be returned for certain operations.
diff --git a/reader.go b/reader.go
index f75caa4..47c22a0 100644
--- a/reader.go
+++ b/reader.go
@@ -515,7 +515,7 @@ func (z *Reader) init(r io.ReaderAt, size int64) (err error) {
 			}
 
 			if !fh.isEmptyStream && !fh.isEmptyFile {
-				f.folder, _ = header.streamsInfo.FileFolderAndSize(j)
+				f.folder, _, _ = header.streamsInfo.FileFolderAndSize(j)
 
 				// Make an exported copy of the folder index
 				f.Stream = f.folder
diff --git a/struct.go b/struct.go
index 338f0f7..3427a4d 100644
--- a/struct.go
+++ b/struct.go
@@ -210,28 +210,37 @@ func (si *streamsInfo) Folders() int {
 	return 0
 }
 
-func (si *streamsInfo) FileFolderAndSize(file int) (int, uint64) {
-	total := uint64(0)
-
+func (si *streamsInfo) FileFolderAndSize(file int) (int, uint64, uint32) {
 	var (
 		folder  int
 		streams uint64 = 1
+		crc     uint32
 	)
 
 	if si.subStreamsInfo != nil {
+		total := uint64(0)
+
 		for folder, streams = range si.subStreamsInfo.streams {
 			total += streams
 			if uint64(file) < total { //nolint:gosec
 				break
 			}
 		}
+
+		if len(si.subStreamsInfo.digest) > 0 {
+			crc = si.subStreamsInfo.digest[file]
+		}
 	}
 
 	if streams == 1 {
-		return folder, si.unpackInfo.folder[folder].size[len(si.unpackInfo.folder[folder].coder)-1]
+		if len(si.unpackInfo.digest) > 0 {
+			crc = si.unpackInfo.digest[folder]
+		}
+
+		return folder, si.unpackInfo.folder[folder].size[len(si.unpackInfo.folder[folder].coder)-1], crc
 	}
 
-	return folder, si.subStreamsInfo.size[file]
+	return folder, si.subStreamsInfo.size[file], crc
 }
 
 func (si *streamsInfo) folderOffset(folder int) int64 {
diff --git a/types.go b/types.go
index c49d1ce..bd470e7 100644
--- a/types.go
+++ b/types.go
@@ -851,11 +851,7 @@ func readHeader(r util.Reader) (*header, error) {
 			continue
 		}
 
-		if h.streamsInfo.subStreamsInfo != nil {
-			h.filesInfo.file[i].CRC32 = h.streamsInfo.subStreamsInfo.digest[j]
-		}
-
-		_, h.filesInfo.file[i].UncompressedSize = h.streamsInfo.FileFolderAndSize(j)
+		_, h.filesInfo.file[i].UncompressedSize, h.filesInfo.file[i].CRC32 = h.streamsInfo.FileFolderAndSize(j)
 		j++
 	}