diff --git a/src/interfaces/ISolidFile.ts b/src/interfaces/ISolidFile.ts
index d364051..09e52cb 100644
--- a/src/interfaces/ISolidFile.ts
+++ b/src/interfaces/ISolidFile.ts
@@ -1,13 +1,14 @@
 interface ISolidFile {
-  //TODO: show length
-  /** File name of this file. */
+  /** Length of this file in bytes, up to 1700000000 or 1.7 GB */
+  length: number;
+  /** File name of this file, e.g. `${product}_${from}to${to}.z01` or `${product}_${from}to${to}.zip`. */
   path: [string];
 }
 
 interface ISolidFileInfo {
   /** List of files that are part of this torrent. */
   files: ISolidFile[];
-  /** Length of one piece in bytes, e.g. 4194304 for 4 MB. */
+  /** Length of one piece in bytes, e.g. 4194304 for 4 MiB. */
   'piece length': number;
   /** Concatenated hashes of all pieces. */
   pieces: string;
diff --git a/src/ssn/verifySolidpkg.ts b/src/ssn/verifySolidpkg.ts
index d4f35b6..9bd06bc 100644
--- a/src/ssn/verifySolidpkg.ts
+++ b/src/ssn/verifySolidpkg.ts
@@ -25,7 +25,21 @@ export default function verifySolidpkg(file: ISolid, { product, from, to }: {pro
     throw new Error(`Expected info field but it was missing.`);
   }
 
-  //TODO: read file.info.files
+  if (!Array.isArray(file.info.files)) {
+    throw new Error(`Expected files field to be an array but it isn't.`);
+  }
+  for (let i = 0, il = file.info.files.length; i < il; i += 1) {
+    const fileEntry = file.info.files[i];
+    if (typeof fileEntry.length !== 'number' && fileEntry.length >= 0 && fileEntry.length <= 1700000000) {
+      throw new Error(`Expected file length to be a number but it was ${fileEntry.length}.`);
+    }
+    if (!Array.isArray(fileEntry.path) || fileEntry.path.length !== 1) {
+      throw new Error(`Expected valid file name but it was not an array with one element.`);
+    }
+    if (typeof fileEntry.path[0] !== 'string' || !fileEntry.path[0].match(new RegExp(`${product}_${from}to${to}\.z(ip|0[1-9]|[1-9][0-9])$`))) {
+      throw new Error(`Expected valid file name but it was ${fileEntry.path[0]}.`);
+    }
+  }
 
   if (file.info['piece length'] !== 4194304) {
     throw new Error(`Expected piece length to be "4194304" but it was "${file.info['piece length']}".`);