Piotr Dyraga
e0b836a4bc
How fast we generate a prime number is mostly a matter of luck. It varies from miliseconds to seconds and depends how lucky we are with drawing bytes. With today's multicore processors, we can execute the process on multiple cores concurrently, accept the first valid result and cancel the rest of work. This way, with the same algorithm, we get the result faster.
99 lines
1.9 KiB
Go
99 lines
1.9 KiB
Go
package paillier
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import (
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"errors"
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"fmt"
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"math/big"
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"reflect"
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"testing"
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"time"
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)
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func TestAsyncGenerator(t *testing.T) {
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concurrencyLevel := 4
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var tests = map[string]struct {
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bitLen int
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timeout time.Duration
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expectedError error
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}{
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"primes successfully generated": {
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bitLen: 512,
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timeout: 60 * time.Second,
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expectedError: nil,
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},
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"generator timed out": {
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bitLen: 8192,
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timeout: 1 * time.Second,
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expectedError: errors.New("generator timed out after 1s"),
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},
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"bit length is 5": {
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bitLen: 5,
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timeout: 1 * time.Second,
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expectedError: errors.New("safe prime size must be at least 6 bits"),
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},
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"bit length is 6": {
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bitLen: 6,
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timeout: 60 * time.Second,
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expectedError: nil,
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},
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}
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for testName, test := range tests {
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t.Run(testName, func(t *testing.T) {
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p, q, err := GenerateSafePrime(
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test.bitLen,
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concurrencyLevel,
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test.timeout,
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)
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if test.expectedError != nil {
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if !reflect.DeepEqual(test.expectedError, err) {
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t.Fatalf(
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"Unexpected error\nActual: %v\nExpected: %v",
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err,
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test.expectedError,
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)
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}
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} else {
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if err != nil {
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t.Fatal(err)
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}
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if !p.ProbablyPrime(20) {
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t.Errorf("p is not prime; p = %v", p)
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}
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if !q.ProbablyPrime(20) {
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t.Errorf("q is not prime; q = %v", q)
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}
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// p = 2q + 1 ?
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expectedP := new(big.Int)
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expectedP.Mul(big.NewInt(2), q)
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expectedP.Add(expectedP, big.NewInt(1))
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if expectedP.Cmp(p) != 0 {
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t.Errorf("2q + 1 != p")
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}
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if len(p.Bytes()) != test.bitLen {
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fmt.Errorf(
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"Unexpected p bit length\nActual: %v\nExpected: %v",
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len(p.Bytes()),
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test.bitLen,
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)
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}
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if len(q.Bytes()) != test.bitLen-1 {
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fmt.Errorf(
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"Unexpected q bit length\nActual: %v\nExpected: %v",
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len(q.Bytes()),
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test.bitLen-1,
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)
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}
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}
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})
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}
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}
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