From 51b156bf1278fc0f9476de70c89697576c0f4b55 Mon Sep 17 00:00:00 2001
From: Conrad Scherb <68687721+conrad-scherb@users.noreply.github.com>
Date: Wed, 14 Dec 2022 11:32:16 +1300
Subject: [PATCH] fix: infinite loop on dcm with no meta length (#331)

---
 packages/adapters/src/DicomMessage.js         |  11 ++++++--
 packages/adapters/test/data.test.js           |  25 ++++++++++++++++++
 .../adapters/test/no-meta-length-test.dcm     | Bin 0 -> 338 bytes
 3 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 packages/adapters/test/no-meta-length-test.dcm

diff --git a/packages/adapters/src/DicomMessage.js b/packages/adapters/src/DicomMessage.js
index 9c053f30f..e563707ca 100644
--- a/packages/adapters/src/DicomMessage.js
+++ b/packages/adapters/src/DicomMessage.js
@@ -200,8 +200,15 @@ class DicomMessage {
         if (stream.readAsciiString(4) !== "DICM") {
             throw new Error("Invalid DICOM file, expected header is missing");
         }
-        var el = DicomMessage._readTag(stream, useSyntax),
-            metaLength = el.values[0];
+
+        var el = DicomMessage._readTag(stream, useSyntax);
+        if (el.tag.toCleanString() !== "00020000") {
+            throw new Error(
+                "Invalid DICOM file, meta length tag is malformed or not present."
+            );
+        }
+
+        var metaLength = el.values[0];
 
         //read header buffer
         var metaStream = stream.more(metaLength);
diff --git a/packages/adapters/test/data.test.js b/packages/adapters/test/data.test.js
index 11a8b02a8..f55ca2473 100644
--- a/packages/adapters/test/data.test.js
+++ b/packages/adapters/test/data.test.js
@@ -765,3 +765,28 @@ it("Reads and writes numbers with NaN and Infinity values of tags with type FD (
         Infinity
     );
 });
+
+it("Tests that reading fails on a DICOM without a meta length tag", () => {
+    const rawFile = fs.readFileSync("test/no-meta-length-test.dcm");
+
+    let arrayBuffer = rawFile.buffer;
+    if (
+        rawFile.byteOffset !== 0 ||
+        rawFile.byteLength !== arrayBuffer.byteLength
+    ) {
+        arrayBuffer = arrayBuffer.slice(
+            rawFile.byteOffset,
+            rawFile.byteOffset + rawFile.byteLength
+        );
+    }
+
+    expect(() => {
+        dcmjs.data.DicomMessage.readFile(arrayBuffer, {
+            ignoreErrors: false,
+            untilTag: "0020000E",
+            includeUntilTagValue: true
+        });
+    }).toThrow(
+        "Invalid DICOM file, meta length tag is malformed or not present."
+    );
+});
\ No newline at end of file
diff --git a/packages/adapters/test/no-meta-length-test.dcm b/packages/adapters/test/no-meta-length-test.dcm
new file mode 100644
index 0000000000000000000000000000000000000000..777b93d0f0bf4b91594e697f809467f71771321f
GIT binary patch
literal 338
zcmc(ZF$w}f3`IYqNE$^%#KK}v5Ry0})5>nM#a8R~-v1Q-(ay%wKp-LSB?0~$!`M#=
z3CnnaYiP};Ze~@Bx@M;9O`XJw%;wEp+3ndKzl`QL^1zvVNX-zOer^|>$*k!(`3}Qf
i5EgD8MPPVLyd0%k6+F?;{CDoKrIX;~cdXiP&3^$(1Ro&)

literal 0
HcmV?d00001