From patchwork Mon Mar 27 12:03:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ross Burton X-Patchwork-Id: 21817 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11D12C761AF for ; Mon, 27 Mar 2023 12:03:40 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mx.groups.io with SMTP id smtpd.web10.32959.1679918617867817152 for ; Mon, 27 Mar 2023 05:03:38 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: arm.com, ip: 217.140.110.172, mailfrom: ross.burton@arm.com) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A5600143D; Mon, 27 Mar 2023 05:04:21 -0700 (PDT) Received: from oss-tx204.lab.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 09B7C3F663; Mon, 27 Mar 2023 05:03:36 -0700 (PDT) From: Ross Burton To: openembedded-core@lists.openembedded.org Cc: nd@arm.com Subject: [PATCH] go: fix CVE-2023-2453 Date: Mon, 27 Mar 2023 13:03:35 +0100 Message-Id: <20230327120335.3502677-1-ross.burton@arm.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 List-Id: X-Webhook-Received: from li982-79.members.linode.com [45.33.32.79] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Mon, 27 Mar 2023 12:03:40 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/179158 Backport a security fix, can be removed once we have 1.20.2 onwards. Signed-off-by: Ross Burton --- meta/recipes-devtools/go/go-1.20.1.inc | 1 + .../go/go/CVE-2023-24532.patch | 208 ++++++++++++++++++ 2 files changed, 209 insertions(+) create mode 100644 meta/recipes-devtools/go/go/CVE-2023-24532.patch diff --git a/meta/recipes-devtools/go/go-1.20.1.inc b/meta/recipes-devtools/go/go-1.20.1.inc index ffde7ed7324..b1f569212db 100644 --- a/meta/recipes-devtools/go/go-1.20.1.inc +++ b/meta/recipes-devtools/go/go-1.20.1.inc @@ -15,5 +15,6 @@ SRC_URI += "\ file://0008-src-cmd-dist-buildgo.go-do-not-hardcode-host-compile.patch \ file://0009-go-Filter-build-paths-on-staticly-linked-arches.patch \ file://0010-cmd-compile-re-compile-instantiated-generic-methods-.patch \ + file://CVE-2023-24532.patch \ " SRC_URI[main.sha256sum] = "b5c1a3af52c385a6d1c76aed5361cf26459023980d0320de7658bae3915831a2" diff --git a/meta/recipes-devtools/go/go/CVE-2023-24532.patch b/meta/recipes-devtools/go/go/CVE-2023-24532.patch new file mode 100644 index 00000000000..22f080dbd4b --- /dev/null +++ b/meta/recipes-devtools/go/go/CVE-2023-24532.patch @@ -0,0 +1,208 @@ +From 602eeaab387f24a4b28c5eccbb50fa934f3bc3c4 Mon Sep 17 00:00:00 2001 +From: Filippo Valsorda +Date: Mon, 13 Feb 2023 15:16:27 +0100 +Subject: [PATCH] [release-branch.go1.20] crypto/internal/nistec: reduce P-256 + scalar + +Unlike the rest of nistec, the P-256 assembly doesn't use complete +addition formulas, meaning that p256PointAdd[Affine]Asm won't return the +correct value if the two inputs are equal. + +This was (undocumentedly) ignored in the scalar multiplication loops +because as long as the input point is not the identity and the scalar is +lower than the order of the group, the addition inputs can't be the same. + +As part of the math/big rewrite, we went however from always reducing +the scalar to only checking its length, under the incorrect assumption +that the scalar multiplication loop didn't require reduction. + +Added a reduction, and while at it added it in P256OrdInverse, too, to +enforce a universal reduction invariant on p256OrdElement values. + +Note that if the input point is the infinity, the code currently still +relies on undefined behavior, but that's easily tested to behave +acceptably, and will be addressed in a future CL. + +Updates #58647 +Fixes #58720 +Fixes CVE-2023-24532 + +(Filed with the "safe APIs like complete addition formulas are good" dept.) + +Change-Id: I7b2c75238440e6852be2710fad66ff1fdc4e2b24 +Reviewed-on: https://go-review.googlesource.com/c/go/+/471255 +TryBot-Result: Gopher Robot +Reviewed-by: Roland Shoemaker +Run-TryBot: Filippo Valsorda +Auto-Submit: Filippo Valsorda +Reviewed-by: Damien Neil +(cherry picked from commit 203e59ad41bd288e1d92b6f617c2f55e70d3c8e3) +Reviewed-on: https://go-review.googlesource.com/c/go/+/471695 +Reviewed-by: Dmitri Shuralyov +Auto-Submit: Dmitri Shuralyov +Reviewed-by: Filippo Valsorda +Run-TryBot: Roland Shoemaker + +CVE: CVE-2023-24532 +Upstream-Status: Backport [602eeaab387f24a4b28c5eccbb50fa934f3bc3c4] +Signed-off-by: Ross Burton + +--- + src/crypto/internal/nistec/nistec_test.go | 81 +++++++++++++++++++++++ + src/crypto/internal/nistec/p256_asm.go | 17 +++++ + src/crypto/internal/nistec/p256_ordinv.go | 1 + + 3 files changed, 99 insertions(+) + +diff --git a/src/crypto/internal/nistec/nistec_test.go b/src/crypto/internal/nistec/nistec_test.go +index 309f68be16a9f..9103608c18a0f 100644 +--- a/src/crypto/internal/nistec/nistec_test.go ++++ b/src/crypto/internal/nistec/nistec_test.go +@@ -8,6 +8,7 @@ import ( + "bytes" + "crypto/elliptic" + "crypto/internal/nistec" ++ "fmt" + "internal/testenv" + "math/big" + "math/rand" +@@ -165,6 +166,86 @@ func testEquivalents[P nistPoint[P]](t *testing.T, newPoint func() P, c elliptic + } + } + ++func TestScalarMult(t *testing.T) { ++ t.Run("P224", func(t *testing.T) { ++ testScalarMult(t, nistec.NewP224Point, elliptic.P224()) ++ }) ++ t.Run("P256", func(t *testing.T) { ++ testScalarMult(t, nistec.NewP256Point, elliptic.P256()) ++ }) ++ t.Run("P384", func(t *testing.T) { ++ testScalarMult(t, nistec.NewP384Point, elliptic.P384()) ++ }) ++ t.Run("P521", func(t *testing.T) { ++ testScalarMult(t, nistec.NewP521Point, elliptic.P521()) ++ }) ++} ++ ++func testScalarMult[P nistPoint[P]](t *testing.T, newPoint func() P, c elliptic.Curve) { ++ G := newPoint().SetGenerator() ++ checkScalar := func(t *testing.T, scalar []byte) { ++ p1, err := newPoint().ScalarBaseMult(scalar) ++ fatalIfErr(t, err) ++ p2, err := newPoint().ScalarMult(G, scalar) ++ fatalIfErr(t, err) ++ if !bytes.Equal(p1.Bytes(), p2.Bytes()) { ++ t.Error("[k]G != ScalarBaseMult(k)") ++ } ++ ++ d := new(big.Int).SetBytes(scalar) ++ d.Sub(c.Params().N, d) ++ d.Mod(d, c.Params().N) ++ g1, err := newPoint().ScalarBaseMult(d.FillBytes(make([]byte, len(scalar)))) ++ fatalIfErr(t, err) ++ g1.Add(g1, p1) ++ if !bytes.Equal(g1.Bytes(), newPoint().Bytes()) { ++ t.Error("[N - k]G + [k]G != ∞") ++ } ++ } ++ ++ byteLen := len(c.Params().N.Bytes()) ++ bitLen := c.Params().N.BitLen() ++ t.Run("0", func(t *testing.T) { checkScalar(t, make([]byte, byteLen)) }) ++ t.Run("1", func(t *testing.T) { ++ checkScalar(t, big.NewInt(1).FillBytes(make([]byte, byteLen))) ++ }) ++ t.Run("N-1", func(t *testing.T) { ++ checkScalar(t, new(big.Int).Sub(c.Params().N, big.NewInt(1)).Bytes()) ++ }) ++ t.Run("N", func(t *testing.T) { checkScalar(t, c.Params().N.Bytes()) }) ++ t.Run("N+1", func(t *testing.T) { ++ checkScalar(t, new(big.Int).Add(c.Params().N, big.NewInt(1)).Bytes()) ++ }) ++ t.Run("all1s", func(t *testing.T) { ++ s := new(big.Int).Lsh(big.NewInt(1), uint(bitLen)) ++ s.Sub(s, big.NewInt(1)) ++ checkScalar(t, s.Bytes()) ++ }) ++ if testing.Short() { ++ return ++ } ++ for i := 0; i < bitLen; i++ { ++ t.Run(fmt.Sprintf("1<<%d", i), func(t *testing.T) { ++ s := new(big.Int).Lsh(big.NewInt(1), uint(i)) ++ checkScalar(t, s.FillBytes(make([]byte, byteLen))) ++ }) ++ } ++ // Test N+1...N+32 since they risk overlapping with precomputed table values ++ // in the final additions. ++ for i := int64(2); i <= 32; i++ { ++ t.Run(fmt.Sprintf("N+%d", i), func(t *testing.T) { ++ checkScalar(t, new(big.Int).Add(c.Params().N, big.NewInt(i)).Bytes()) ++ }) ++ } ++} ++ ++func fatalIfErr(t *testing.T, err error) { ++ t.Helper() ++ if err != nil { ++ t.Fatal(err) ++ } ++} ++ + func BenchmarkScalarMult(b *testing.B) { + b.Run("P224", func(b *testing.B) { + benchmarkScalarMult(b, nistec.NewP224Point().SetGenerator(), 28) +diff --git a/src/crypto/internal/nistec/p256_asm.go b/src/crypto/internal/nistec/p256_asm.go +index 6ea161eb49953..99a22b833f028 100644 +--- a/src/crypto/internal/nistec/p256_asm.go ++++ b/src/crypto/internal/nistec/p256_asm.go +@@ -364,6 +364,21 @@ func p256PointDoubleAsm(res, in *P256Point) + // Montgomery domain (with R 2²⁵⁶) as four uint64 limbs in little-endian order. + type p256OrdElement [4]uint64 + ++// p256OrdReduce ensures s is in the range [0, ord(G)-1]. ++func p256OrdReduce(s *p256OrdElement) { ++ // Since 2 * ord(G) > 2²⁵⁶, we can just conditionally subtract ord(G), ++ // keeping the result if it doesn't underflow. ++ t0, b := bits.Sub64(s[0], 0xf3b9cac2fc632551, 0) ++ t1, b := bits.Sub64(s[1], 0xbce6faada7179e84, b) ++ t2, b := bits.Sub64(s[2], 0xffffffffffffffff, b) ++ t3, b := bits.Sub64(s[3], 0xffffffff00000000, b) ++ tMask := b - 1 // zero if subtraction underflowed ++ s[0] ^= (t0 ^ s[0]) & tMask ++ s[1] ^= (t1 ^ s[1]) & tMask ++ s[2] ^= (t2 ^ s[2]) & tMask ++ s[3] ^= (t3 ^ s[3]) & tMask ++} ++ + // Add sets q = p1 + p2, and returns q. The points may overlap. + func (q *P256Point) Add(r1, r2 *P256Point) *P256Point { + var sum, double P256Point +@@ -393,6 +408,7 @@ func (r *P256Point) ScalarBaseMult(scalar []byte) (*P256Point, error) { + } + scalarReversed := new(p256OrdElement) + p256OrdBigToLittle(scalarReversed, (*[32]byte)(scalar)) ++ p256OrdReduce(scalarReversed) + + r.p256BaseMult(scalarReversed) + return r, nil +@@ -407,6 +423,7 @@ func (r *P256Point) ScalarMult(q *P256Point, scalar []byte) (*P256Point, error) + } + scalarReversed := new(p256OrdElement) + p256OrdBigToLittle(scalarReversed, (*[32]byte)(scalar)) ++ p256OrdReduce(scalarReversed) + + r.Set(q).p256ScalarMult(scalarReversed) + return r, nil +diff --git a/src/crypto/internal/nistec/p256_ordinv.go b/src/crypto/internal/nistec/p256_ordinv.go +index 86a7a230bdce8..1274fb7fd3f5c 100644 +--- a/src/crypto/internal/nistec/p256_ordinv.go ++++ b/src/crypto/internal/nistec/p256_ordinv.go +@@ -25,6 +25,7 @@ func P256OrdInverse(k []byte) ([]byte, error) { + + x := new(p256OrdElement) + p256OrdBigToLittle(x, (*[32]byte)(k)) ++ p256OrdReduce(x) + + // Inversion is implemented as exponentiation by n - 2, per Fermat's little theorem. + //