mirror of
https://github.com/gravitational/teleport.git
synced 2026-11-01 21:52:02 +08:00
Jim Bishopp
0ba6809cc4
Fixes https://github.com/gravitational/teleport-private/issues/80 LAT-APP21-5: Insecure random number generation - updated rand call from rand.Reader.Read to rand.Read - changed length parameter name from len to l. - changed byte slice var name to b. - updated godoc
49 lines
1.4 KiB
Go
49 lines
1.4 KiB
Go
/*
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Copyright 2015 Gravitational, Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package utils
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import (
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"crypto/rand"
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"encoding/hex"
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"math/big"
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"time"
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"github.com/gravitational/trace"
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)
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// CryptoRandomHex returns a hex-encoded random string generated
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// with a crypto-strong pseudo-random generator. The length parameter
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// controls how many random bytes are generated, and the returned
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// hex string will be twice the length. An error is returned when
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// fewer bytes were generated than length.
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func CryptoRandomHex(length int) (string, error) {
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randomBytes := make([]byte, length)
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if _, err := rand.Read(randomBytes); err != nil {
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return "", trace.Wrap(err)
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}
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return hex.EncodeToString(randomBytes), nil
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}
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// RandomDuration returns a duration in a range [0, max)
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func RandomDuration(max time.Duration) time.Duration {
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randomVal, err := rand.Int(rand.Reader, big.NewInt(int64(max)))
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if err != nil {
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return max / 2
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}
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return time.Duration(randomVal.Int64())
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}
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