-
Notifications
You must be signed in to change notification settings - Fork 15
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[WIP] add support for PBKDF2 for passphrases
Passphrase support currently hardcodes the use of Argon2. This adds support for specifying PBKDF2, for use in environments where FIPS140 compliance is required.
- Loading branch information
1 parent
836ff3d
commit 9a2d46c
Showing
11 changed files
with
653 additions
and
8 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,30 @@ | ||
| // -*- Mode: Go; indent-tabs-mode: t -*- | ||
|
|
||
| /* | ||
| * Copyright (C) 2024 Canonical Ltd | ||
| * | ||
| * This program is free software: you can redistribute it and/or modify | ||
| * it under the terms of the GNU General Public License version 3 as | ||
| * published by the Free Software Foundation. | ||
| * | ||
| * This program is distributed in the hope that it will be useful, | ||
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| * GNU General Public License for more details. | ||
| * | ||
| * You should have received a copy of the GNU General Public License | ||
| * along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
| * | ||
| */ | ||
|
|
||
| package pbkdf2 | ||
|
|
||
| import "time" | ||
|
|
||
| func MockTimeExecution(fn func(*Params) time.Duration) (restore func()) { | ||
| orig := timeExecution | ||
| timeExecution = fn | ||
| return func() { | ||
| timeExecution = orig | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,132 @@ | ||
| // -*- Mode: Go; indent-tabs-mode: t -*- | ||
|
|
||
| /* | ||
| * Copyright (C) 2024 Canonical Ltd | ||
| * | ||
| * This program is free software: you can redistribute it and/or modify | ||
| * it under the terms of the GNU General Public License version 3 as | ||
| * published by the Free Software Foundation. | ||
| * | ||
| * This program is distributed in the hope that it will be useful, | ||
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| * GNU General Public License for more details. | ||
| * | ||
| * You should have received a copy of the GNU General Public License | ||
| * along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
| * | ||
| */ | ||
|
|
||
| package pbkdf2 | ||
|
|
||
| import ( | ||
| "crypto" | ||
| "errors" | ||
| "math" | ||
| "time" | ||
|
|
||
| "golang.org/x/crypto/pbkdf2" | ||
| ) | ||
|
|
||
| const ( | ||
| benchmarkPassword = "foo" | ||
| ) | ||
|
|
||
| var ( | ||
| benchmarkSalt = []byte("0123456789abcdefghijklmnopqrstuv") | ||
| ) | ||
|
|
||
| var timeExecution = func(params *Params) time.Duration { | ||
| start := time.Now() | ||
| if _, err := Key(benchmarkPassword, benchmarkSalt, params, uint(params.HashAlg.Size())); err != nil { | ||
| panic(err) | ||
| } | ||
| return time.Now().Sub(start) | ||
| } | ||
|
|
||
| // Benchmark computes the number of iterations for desired duration | ||
| // with the specified digest algorithm. The specified algorithm must | ||
| // be available. This benchmark is largely based on that implemented | ||
| // by cryptsetup. | ||
| // | ||
| // When producing keys that are larger than the output size of the | ||
| // digest algorithm, PBKDF2 runs the specified number of iterations | ||
| // multiple times - eg, to produce a 64-byte key with SHA-256, PBKDF2 | ||
| // runs the specified number of iterations twice to produce the key in | ||
| // 2 rounds and this takes twice as long as it takes to produce a | ||
| // 32-byte key. This runs the benchmark for a single round by selecting a | ||
| // key length that is the same size as the output of the digest algorithm, | ||
| // which means that if SHA-256 is selected with a target duration of 1 second | ||
| // and the result is subsequently used to derive a 64-byte key, it will take 2 | ||
| // seconds. This is safer than the alternative which is that all rounds are | ||
| // benchmarked (eg, using SHA-256 to produce a 64-byte key) for 1 second, and | ||
| // then it's subsequently possible to run a single round in order to produce | ||
| // 32-bytes of output key material in 500ms. | ||
| func Benchmark(targetDuration time.Duration, hashAlg crypto.Hash) (uint, error) { | ||
| if !hashAlg.Available() { | ||
| return 0, errors.New("unavailable digest algorithm") | ||
| } | ||
|
|
||
| // Start with 1000 iterations. | ||
| iterationsOut := uint(1000) | ||
| iterations := iterationsOut | ||
|
|
||
| for i := 1; ; i++ { | ||
| if iterations > math.MaxInt { | ||
| return 0, errors.New("too many iterations") | ||
| } | ||
|
|
||
| // time the key derivation | ||
| duration := timeExecution(&Params{Iterations: iterations, HashAlg: hashAlg}) | ||
| if duration > 0 { | ||
| // calculate the required number of iterations to return, based on the tested | ||
| // iterations, measured duration and target duration. | ||
| iterationsOut = uint(time.Duration(iterations) * targetDuration / duration) | ||
| } | ||
|
|
||
| // scale up the number of iterations to test next | ||
| switch { | ||
| case i > 10: | ||
| return 0, errors.New("insufficient progress") | ||
| case duration > 500*time.Millisecond: | ||
| return iterationsOut, nil | ||
| case duration <= 62*time.Millisecond: | ||
| iterations *= 16 | ||
| case duration <= 125*time.Millisecond: | ||
| iterations *= 8 | ||
| case duration <= 250*time.Millisecond: | ||
| iterations *= 4 | ||
| default: | ||
| iterations *= 2 | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // Params are the key derivation parameters for PBKDF2. | ||
| type Params struct { | ||
| // Iterations are the number of iterations. | ||
| Iterations uint | ||
|
|
||
| // HashAlg is the digest algorithm to use. The algorithm | ||
| // must be available | ||
| HashAlg crypto.Hash | ||
| } | ||
|
|
||
| // Key derives a key of the desired length from the supplied passphrase and salt, | ||
| // using the supplied parameters. | ||
| // | ||
| // This will return an error if the key length or number of iterations are less than | ||
| // zero, or the supplied digest algorithm is not available. | ||
| func Key(passphrase string, salt []byte, params *Params, keyLen uint) ([]byte, error) { | ||
| switch { | ||
| case params == nil: | ||
| return nil, errors.New("nil params") | ||
| case params.Iterations > math.MaxInt: | ||
| return nil, errors.New("too many iterations") | ||
| case !params.HashAlg.Available(): | ||
| return nil, errors.New("unavailable digest algorithm") | ||
| case keyLen > math.MaxInt: | ||
| return nil, errors.New("invalid key length") | ||
| } | ||
| return pbkdf2.Key([]byte(passphrase), salt, int(params.Iterations), int(keyLen), params.HashAlg.New), nil | ||
| } |
Oops, something went wrong.