Commit ffb326c
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -4,11 +4,16 @@ | |||
| 4 | 4 | ||
| 5 | 5 | > Stability: 1 - Experimental | |
| 6 | 6 | ||
| 7 | + <strong class="critical">The `node:wasi` module does not currently provide the | ||
| 8 | + comprehensive file system security properties provided by some WASI runtimes. | ||
| 9 | + Full support for secure file system sandboxing may or may not be implemented in | ||
| 10 | + future. In the mean time, do not rely on it to run untrusted code. </strong> | ||
| 11 | + | ||
| 7 | 12 | <!-- source_link=lib/wasi.js --> | |
| 8 | 13 | ||
| 9 | 14 | The WASI API provides an implementation of the [WebAssembly System Interface][] | |
| 10 | - specification. WASI gives sandboxed WebAssembly applications access to the | ||
| 11 | - underlying operating system via a collection of POSIX-like functions. | ||
| 15 | + specification. WASI gives WebAssembly applications access to the underlying | ||
| 16 | + operating system via a collection of POSIX-like functions. | ||
| 12 | 17 | ||
| 13 | 18 | ```mjs | |
| 14 | 19 | import { readFile } from 'node:fs/promises'; | |
@@ -20,7 +25,7 @@ const wasi = new WASI({ | |||
| 20 | 25 | args: argv, | |
| 21 | 26 | env, | |
| 22 | 27 | preopens: { | |
| 23 | - '/sandbox': '/some/real/path/that/wasm/can/access', | ||
| 28 | + '/local': '/some/real/path/that/wasm/can/access', | ||
| 24 | 29 | }, | |
| 25 | 30 | }); | |
| 26 | 31 | ||
@@ -44,7 +49,7 @@ const wasi = new WASI({ | |||
| 44 | 49 | args: argv, | |
| 45 | 50 | env, | |
| 46 | 51 | preopens: { | |
| 47 | - '/sandbox': '/some/real/path/that/wasm/can/access', | ||
| 52 | + '/local': '/some/real/path/that/wasm/can/access', | ||
| 48 | 53 | }, | |
| 49 | 54 | }); | |
| 50 | 55 | ||
@@ -97,6 +102,28 @@ Use [wabt](https://github.com/WebAssembly/wabt) to compile `.wat` to `.wasm` | |||
| 97 | 102 | wat2wasm demo.wat | |
| 98 | 103 | ``` | |
| 99 | 104 | ||
| 105 | + ## Security | ||
| 106 | + | ||
| 107 | + <!-- YAML | ||
| 108 | + added: REPLACEME | ||
| 109 | + changes: | ||
| 110 | + - version: REPLACEME | ||
| 111 | + pr-url: https://github.com/nodejs/node/pull/50396 | ||
| 112 | + description: Clarify WASI security properties. | ||
| 113 | + --> | ||
| 114 | + | ||
| 115 | + WASI provides a capabilities-based model through which applications are provided | ||
| 116 | + their own custom `env`, `preopens`, `stdin`, `stdout`, `stderr`, and `exit` | ||
| 117 | + capabilities. | ||
| 118 | + | ||
| 119 | + **The current Node.js threat model does not provide secure sandboxing as is | ||
| 120 | + present in some WASI runtimes.** | ||
| 121 | + | ||
| 122 | + While the capability features are supported, they do not form a security model | ||
| 123 | + in Node.js. For example, the file system sandboxing can be escaped with various | ||
| 124 | + techniques. The project is exploring whether these security guarantees could be | ||
| 125 | + added in future. | ||
| 126 | + | ||
| 100 | 127 | ## Class: `WASI` | |
| 101 | 128 | ||
| 102 | 129 | <!-- YAML | |
@@ -107,9 +134,7 @@ added: | |||
| 107 | 134 | ||
| 108 | 135 | The `WASI` class provides the WASI system call API and additional convenience | |
| 109 | 136 | methods for working with WASI-based applications. Each `WASI` instance | |
| 110 | - represents a distinct sandbox environment. For security purposes, each `WASI` | ||
| 111 | - instance must have its command-line arguments, environment variables, and | ||
| 112 | - sandbox directory structure configured explicitly. | ||
| 137 | + represents a distinct environment. | ||
| 113 | 138 | ||
| 114 | 139 | ### `new WASI([options])` | |
| 115 | 140 | ||
@@ -136,9 +161,9 @@ changes: | |||
| 136 | 161 | * `env` {Object} An object similar to `process.env` that the WebAssembly | |
| 137 | 162 | application will see as its environment. **Default:** `{}`. | |
| 138 | 163 | * `preopens` {Object} This object represents the WebAssembly application's | |
| 139 | - sandbox directory structure. The string keys of `preopens` are treated as | ||
| 140 | - directories within the sandbox. The corresponding values in `preopens` are | ||
| 141 | - the real paths to those directories on the host machine. | ||
| 164 | + local directory structure. The string keys of `preopens` are treated as | ||
| 165 | + directories within the file system. The corresponding values in `preopens` | ||
| 166 | + are the real paths to those directories on the host machine. | ||
| 142 | 167 | * `returnOnExit` {boolean} By default, when WASI applications call | |
| 143 | 168 | `__wasi_proc_exit()` `wasi.start()` will return with the exit code | |
| 144 | 169 | specified rather than terminating the process. Setting this option to | |
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