SSH server & endpoint

src/node/ssh/sftp.ts

@@ -0,0 +1,201 @@
+/**
+ * Provides utilities for handling SSH connections
+ */
+import * as fs from "fs"
+import * as path from "path"
+import * as ssh from "ssh2"
+import { FileEntry, SFTPStream } from "ssh2-streams"
+
+/**
+ * Fills out all the functionality of SFTP using fs.
+ */
+export function fillSftpStream(accept: () => SFTPStream): void {
+  const sftp = accept()
+
+  let oid = 0
+  const fds: { [key: number]: boolean } = {}
+  const ods: {
+    [key: number]: {
+      path: string
+      read: boolean
+    }
+  } = {}
+
+  const sftpStatus = (reqID: number, err?: NodeJS.ErrnoException | null): boolean => {
+    let code = ssh.SFTP_STATUS_CODE.OK
+    if (err) {
+      if (err.code === "EACCES") {
+        code = ssh.SFTP_STATUS_CODE.PERMISSION_DENIED
+      } else if (err.code === "ENOENT") {
+        code = ssh.SFTP_STATUS_CODE.NO_SUCH_FILE
+      } else {
+        code = ssh.SFTP_STATUS_CODE.FAILURE
+      }
+    }
+    return sftp.status(reqID, code)
+  }
+
+  sftp.on("OPEN", (reqID, filename) => {
+    fs.open(filename, "w", (err, fd) => {
+      if (err) {
+        return sftpStatus(reqID, err)
+      }
+      fds[fd] = true
+      const buf = Buffer.alloc(4)
+      buf.writeUInt32BE(fd, 0)
+      return sftp.handle(reqID, buf)
+    })
+  })
+
+  sftp.on("OPENDIR", (reqID, path) => {
+    const buf = Buffer.alloc(4)
+    const id = oid++
+    buf.writeUInt32BE(id, 0)
+    ods[id] = {
+      path,
+      read: false,
+    }
+    sftp.handle(reqID, buf)
+  })
+
+  sftp.on("READDIR", (reqID, handle) => {
+    const od = handle.readUInt32BE(0)
+    if (!ods[od]) {
+      return sftp.status(reqID, ssh.SFTP_STATUS_CODE.NO_SUCH_FILE)
+    }
+    if (ods[od].read) {
+      sftp.status(reqID, ssh.SFTP_STATUS_CODE.EOF)
+      return
+    }
+    return fs.readdir(ods[od].path, (err, files) => {
+      if (err) {
+        return sftpStatus(reqID, err)
+      }
+      return Promise.all(
+        files.map((f) => {
+          return new Promise<FileEntry>((resolve, reject) => {
+            const fullPath = path.join(ods[od].path, f)
+            fs.stat(fullPath, (err, stats) => {
+              if (err) {
+                return reject(err)
+              }
+
+              resolve({
+                filename: f,
+                longname: fullPath,
+                attrs: {
+                  atime: stats.atimeMs,
+                  gid: stats.gid,
+                  mode: stats.mode,
+                  size: stats.size,
+                  mtime: stats.mtimeMs,
+                  uid: stats.uid,
+                },
+              })
+            })
+          })
+        }),
+      )
+        .then((files) => {
+          sftp.name(reqID, files)
+          ods[od].read = true
+        })
+        .catch(() => {
+          sftp.status(reqID, ssh.SFTP_STATUS_CODE.FAILURE)
+        })
+    })
+  })
+
+  sftp.on("WRITE", (reqID, handle, offset, data) => {
+    const fd = handle.readUInt32BE(0)
+    if (!fds[fd]) {
+      return sftp.status(reqID, ssh.SFTP_STATUS_CODE.NO_SUCH_FILE)
+    }
+    return fs.write(fd, data, offset, (err) => sftpStatus(reqID, err))
+  })
+
+  sftp.on("CLOSE", (reqID, handle) => {
+    const fd = handle.readUInt32BE(0)
+    if (!fds[fd]) {
+      if (ods[fd]) {
+        delete ods[fd]
+        return sftp.status(reqID, ssh.SFTP_STATUS_CODE.OK)
+      }
+      return sftp.status(reqID, ssh.SFTP_STATUS_CODE.NO_SUCH_FILE)
+    }
+    return fs.close(fd, (err) => sftpStatus(reqID, err))
+  })
+
+  sftp.on("STAT", (reqID, path) => {
+    fs.stat(path, (err, stats) => {
+      if (err) {
+        return sftpStatus(reqID, err)
+      }
+      return sftp.attrs(reqID, {
+        atime: stats.atime.getTime(),
+        gid: stats.gid,
+        mode: stats.mode,
+        mtime: stats.mtime.getTime(),
+        size: stats.size,
+        uid: stats.uid,
+      })
+    })
+  })
+
+  sftp.on("MKDIR", (reqID, path) => {
+    fs.mkdir(path, (err) => sftpStatus(reqID, err))
+  })
+
+  sftp.on("LSTAT", (reqID, path) => {
+    fs.lstat(path, (err, stats) => {
+      if (err) {
+        return sftpStatus(reqID, err)
+      }
+      return sftp.attrs(reqID, {
+        atime: stats.atimeMs,
+        gid: stats.gid,
+        mode: stats.mode,
+        mtime: stats.mtimeMs,
+        size: stats.size,
+        uid: stats.uid,
+      })
+    })
+  })
+
+  sftp.on("REMOVE", (reqID, path) => {
+    fs.unlink(path, (err) => sftpStatus(reqID, err))
+  })
+
+  sftp.on("RMDIR", (reqID, path) => {
+    fs.rmdir(path, (err) => sftpStatus(reqID, err))
+  })
+
+  sftp.on("REALPATH", (reqID, path) => {
+    fs.realpath(path, (pathErr, resolved) => {
+      if (pathErr) {
+        return sftpStatus(reqID, pathErr)
+      }
+      fs.stat(path, (statErr, stat) => {
+        if (statErr) {
+          return sftpStatus(reqID, statErr)
+        }
+        sftp.name(reqID, [
+          {
+            filename: resolved,
+            longname: resolved,
+            attrs: {
+              mode: stat.mode,
+              uid: stat.uid,
+              gid: stat.gid,
+              size: stat.size,
+              atime: stat.atime.getTime(),
+              mtime: stat.mtime.getTime(),
+            },
+          },
+        ])
+        return
+      })
+      return
+    })
+  })
+}