x/crypto/argon2: non-repeatable hashes

[renatoathaydes]

What version of Go are you using (go version)?

go version go1.9.2 linux/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/renato/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build622935985=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

I added this test to the test suite of the argon2 crypto:

func TestReproducibleKeys(t *testing.T) {
	password := []byte("password")
	salt := []byte("choosing random salts is hard")
	mvs := []uint32{32, 64, 128, 256, 512, 1024, 10 * 1024, 32 * 1024, 64 * 1024}

	for _, m := range mvs {
		h1 := Key(password, salt, 4, m, 4, 32)
		h2 := Key(password, salt, 4, m, 4, 32)
		require.Equal(t, h1, h2, "Failed with m=%d", m)
	}
}

What did you expect to see?

Tests pass.

What did you see instead?

Tests fail at around m=128 or m=256.

Test run example:

--- FAIL: TestReproducibleKeys (0.01s)
        Error Trace:    argon2_test.go:125
	Error:      	Not equal: 
	            	expected: []byte{0xaa, 0x47, 0xc9, 0x3f, 0x7c, 0x82, 0x60, 0x1b, 0x3c, 0xfa, 0x2, 0xd, 0x85, 0x10, 0x6b, 0x5, 0x10, 0x1e, 0xe3, 0x39, 0x6e, 0xe9, 0x13, 0xca, 0x7, 0x8d, 0x64, 0xdf, 0xc, 0xcb, 0x74, 0x30}
	            	actual: []byte{0xcc, 0xaa, 0x3a, 0xe6, 0x3d, 0x70, 0x67, 0x10, 0xdd, 0xe2, 0xd7, 0xaf, 0xf9, 0x9f, 0x1b, 0xd8, 0x88, 0x99, 0xe3, 0x49, 0x3d, 0x86, 0x7e, 0xa8, 0xc0, 0x5d, 0x52, 0x5a, 0xc9, 0x52, 0xde, 0xd1}
	            	
	            	Diff:
	            	--- Expected
	            	+++ Actual
	            	@@ -1,4 +1,4 @@
	            	 ([]uint8) (len=32) {
	            	- 00000000  aa 47 c9 3f 7c 82 60 1b  3c fa 02 0d 85 10 6b 05  |.G.?|.`.<.....k.|
	            	- 00000010  10 1e e3 39 6e e9 13 ca  07 8d 64 df 0c cb 74 30  |...9n.....d...t0|
	            	+ 00000000  cc aa 3a e6 3d 70 67 10  dd e2 d7 af f9 9f 1b d8  |..:.=pg.........|
	            	+ 00000010  88 99 e3 49 3d 86 7e a8  c0 5d 52 5a c9 52 de d1  |...I=.~..]RZ.R..|
	            	 }
	Messages:   	Failed with m=512
FAIL
exit status 1
FAIL	github.com/golang/crypto/argon2	0.011s

[dgryski]

Dup of #23200 ?

[bradfitz]

/cc @aead

[aead]

Yes, this is a dup of #23200 - The fix is https://golang.org/cl/85055.

[renatoathaydes]

When does the fix get pushed to GitHub?

[aead]

@renatoathaydes
Cannot tell when the review is done - however you can use this implementation until the CL is merged.

[renatoathaydes]

@aead thanks! There's a few other implementations as well (or bindings to the C version):

https://github.com/xebia/argon2-go
https://github.com/lhecker/argon2

But I was hoping to rely on the official version. Will use your suggestion for now.

[aead]

@renatoathaydes Fix is merged.