diff options
author | Tobias Nießen <tniessen@tnie.de> | 2022-06-21 14:43:09 +0300 |
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committer | GitHub <noreply@github.com> | 2022-06-21 14:43:09 +0300 |
commit | 800cff1e2463bbb9a63e464759f97681a45551d1 (patch) | |
tree | 75624a0847f4aa0bc988973793ecc4f150f8de29 /doc/api/crypto.md | |
parent | 08d6a82f62962015b03ae7076487ba209cfd2ab5 (diff) |
doc,test: clarify timingSafeEqual semantics
PR-URL: https://github.com/nodejs/node/pull/43228
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Diffstat (limited to 'doc/api/crypto.md')
-rw-r--r-- | doc/api/crypto.md | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/doc/api/crypto.md b/doc/api/crypto.md index 07ba17bd5b3..8d6a01c8f06 100644 --- a/doc/api/crypto.md +++ b/doc/api/crypto.md @@ -5443,8 +5443,11 @@ changes: * `b` {ArrayBuffer|Buffer|TypedArray|DataView} * Returns: {boolean} -This function is based on a constant-time algorithm. -Returns true if `a` is equal to `b`, without leaking timing information that +This function compares the underlying bytes that represent the given +`ArrayBuffer`, `TypedArray`, or `DataView` instances using a constant-time +algorithm. + +This function does not leak timing information that would allow an attacker to guess one of the values. This is suitable for comparing HMAC digests or secret values like authentication cookies or [capability urls](https://www.w3.org/TR/capability-urls/). @@ -5457,6 +5460,12 @@ If at least one of `a` and `b` is a `TypedArray` with more than one byte per entry, such as `Uint16Array`, the result will be computed using the platform byte order. +<strong class="critical">When both of the inputs are `Float32Array`s or +`Float64Array`s, this function might return unexpected results due to IEEE 754 +encoding of floating-point numbers. In particular, neither `x === y` nor +`Object.is(x, y)` implies that the byte representations of two floating-point +numbers `x` and `y` are equal.</strong> + Use of `crypto.timingSafeEqual` does not guarantee that the _surrounding_ code is timing-safe. Care should be taken to ensure that the surrounding code does not introduce timing vulnerabilities. |