package entropy

Import Path
	crypto/internal/entropy/v1.0.0 (on go.dev)

Dependency Relation
	imports 5 packages, and imported by one package


Involved Source Files

	
		Package entropy implements a CPU jitter-based SP 800-90B entropy source.

	    sha384.go


Package-Level Type Names (only one)


	/* sort by:  |  */
	
		ScratchBuffer is a large buffer that will be written to using atomics, to
		generate noise from memory access timings. Its contents do not matter.

		
			func Samples(samples []uint8, memory *ScratchBuffer) error
			func Seed(memory *ScratchBuffer) ([48]byte, error)




Package-Level Functions (total 7)


	
		AdaptiveProportionTest implements the adaptive proportion test from SP 800-90B
		Section 4.4.2. It returns an error if any symbol appears C = 410 or more
		times in the last W = 512 samples.
		
		This C value is calculated from a target failure probability α = 2⁻²⁰, a
		window size W = 512, and a claimed min-entropy per symbol h = 0.5 bits, using
		the formula in SP 800-90B Section 4.4.2, equivalent to the Microsoft Excel
		formula 1+CRITBINOM(W, power(2,(−H)),1−α).
		
			sage: from scipy.stats import binom
			sage: α = 2^-20
			sage: H = 0.5
			sage: W = 512
			sage: C = 1 + binom.ppf(1 - α, W, 2**(-H))
			sage: ceil(C)
			410


	
		RepetitionCountTest implements the repetition count test from SP 800-90B
		Section 4.4.1. It returns an error if any symbol is repeated C = 41 or more
		times in a row.
		
		This C value is calculated from a target failure probability α = 2⁻²⁰ and a
		claimed min-entropy per symbol h = 0.5 bits, using the formula in SP 800-90B
		Section 4.4.1.
		
			sage: α = 2^-20
			sage: H = 0.5
			sage: 1 + ceil(-log(α, 2) / H)
			41


	
		Samples starts a new entropy source, collects the requested number of
		samples, conducts startup health tests, and returns the samples or an error
		if the health tests fail.
		
		The health tests have a non-negligible chance of failing.


	
		Seed returns a 384-bit seed with full entropy.
		
		memory is passed in to allow changing the allocation strategy without
		modifying the frozen and certified entropy source in this package.
		
		Seed returns an error if the entropy source startup health tests fail, which
		has a non-negligible chance of happening.


	 func SHA384(p *[1024]byte) [48]byte
	 func TestingOnlySHA384(p []byte) [48]byte
	
		Version returns the version of the entropy source.
		
		This is independent of the FIPS 140-3 module version, in order to reuse the
		ESV certificate across module versions.