The V8 JavaScript Runtime Undermined My Constant-Time JavaScript Library

Automated excerpt

Vulnerability discovered and reported by Yayu Wang. Do not negate-and-mask, due to how -0 (signed zero) is handled in V8. * Is this number anything except zero? for (let i: number = num. length - 1; i >= 0; i--) { + * Return 1 if this number is nonzero, or 0 otherwise. + * secret-derived boolean is never passed through V8's ToBoolean machinery. for (let i: number = num. length - 1; i >= 0; i--) { + // d is in [0, 255], so this maps zero to 0 and every other value to 1.

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