crypto: use and test purego tag consistently

Fixes #58636
Updates #23172

Change-Id: I578a5597f467be45a7d6fb7582b24855b2e6512b
Reviewed-on: https://go-review.googlesource.com/c/go/+/561935
Reviewed-by: Roland Shoemaker <[email protected]>
Reviewed-by: Michael Knyszek <[email protected]>
Auto-Submit: Filippo Valsorda <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

src/cmd/dist/test.go

@@ -691,6 +691,14 @@ func (t *tester) registerTests() {
 			})
 	}
 
+	// Check that all crypto packages compile with the purego build tag.
+	t.registerTest("crypto with tag purego", &goTest{
+		variant:  "purego",
+		tags:     []string{"purego"},
+		pkg:      "crypto/...",
+		runTests: "^$", // only ensure they compile
+	})
+
 	// Test ios/amd64 for the iOS simulator.
 	if goos == "darwin" && goarch == "amd64" && t.cgoEnabled {
 		t.registerTest("GOOS=ios on darwin/amd64",

src/crypto/aes/aes_gcm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64
+//go:build (amd64 || arm64) && !purego
 
 package aes
 

src/crypto/aes/asm_amd64.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 
 // func encryptBlockAsm(nr int, xk *uint32, dst, src *byte)

src/crypto/aes/asm_arm64.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 DATA rotInvSRows<>+0x00(SB)/8, $0x080f0205040b0e01
 DATA rotInvSRows<>+0x08(SB)/8, $0x00070a0d0c030609

src/crypto/aes/asm_ppc64x.s

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build ppc64 || ppc64le
+//go:build (ppc64 || ppc64le) && !purego
 
 // Based on CRYPTOGAMS code with the following comment:
 // # ====================================================================

src/crypto/aes/asm_s390x.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 
 // func cryptBlocks(c code, key, dst, src *byte, length int)

src/crypto/aes/cbc_ppc64x.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build ppc64 || ppc64le
+//go:build (ppc64 || ppc64le) && !purego
 
 package aes
 

src/crypto/aes/cbc_s390x.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 package aes
 
 import (

src/crypto/aes/cipher_asm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64 || ppc64 || ppc64le
+//go:build (amd64 || arm64 || ppc64 || ppc64le) && !purego
 
 package aes
 

src/crypto/aes/cipher_generic.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !amd64 && !s390x && !ppc64 && !ppc64le && !arm64
+//go:build (!amd64 && !s390x && !ppc64 && !ppc64le && !arm64) || purego
 
 package aes
 

src/crypto/aes/cipher_s390x.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 package aes
 
 import (

src/crypto/aes/ctr_s390x.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 package aes
 
 import (

src/crypto/aes/gcm_amd64.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 // This is an optimized implementation of AES-GCM using AES-NI and CLMUL-NI
 // The implementation uses some optimization as described in:
 // [1] Gueron, S., Kounavis, M.E.: Intel® Carry-Less Multiplication

src/crypto/aes/gcm_arm64.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 
 #define B0 V0

src/crypto/aes/gcm_ppc64x.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build ppc64le || ppc64
+//go:build (ppc64le || ppc64) && !purego
 
 package aes
 

src/crypto/aes/gcm_ppc64x.s

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build ppc64 || ppc64le
+//go:build (ppc64 || ppc64le) && !purego
 
 // Portions based on CRYPTOGAMS code with the following comment:
 // # ====================================================================

src/crypto/aes/gcm_s390x.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 package aes
 
 import (

src/crypto/ecdsa/ecdsa_noasm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !s390x
+//go:build !s390x || purego
 
 package ecdsa
 

src/crypto/ecdsa/ecdsa_s390x.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 package ecdsa
 
 import (

src/crypto/ecdsa/ecdsa_s390x.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 
 // func kdsa(fc uint64, params *[4096]byte) (errn uint64)

src/crypto/ecdsa/ecdsa_s390x_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build s390x
+//go:build s390x && !purego
 
 package ecdsa
 

src/crypto/internal/edwards25519/field/_asm/fe_amd64_asm.go

@@ -17,7 +17,7 @@ import (
 
 func main() {
 	Package("crypto/internal/edwards25519/field")
-	ConstraintExpr("amd64,gc,!purego")
+	ConstraintExpr("!purego")
 	feMul()
 	feSquare()
 	Generate()

src/crypto/internal/edwards25519/field/fe_amd64.s

@@ -1,6 +1,6 @@
 // Code generated by command: go run fe_amd64_asm.go -out ../fe_amd64.s -stubs ../fe_amd64.go -pkg field. DO NOT EDIT.
 
-//go:build amd64 && gc && !purego
+//go:build !purego
 
 #include "textflag.h"
 

src/crypto/internal/edwards25519/field/fe_amd64_noasm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !amd64 || !gc || purego
+//go:build !amd64 || purego
 
 package field
 

src/crypto/internal/edwards25519/field/fe_arm64.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build arm64 && gc && !purego
+//go:build !purego
 
 package field
 

src/crypto/internal/edwards25519/field/fe_arm64.s

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build arm64 && gc && !purego
+//go:build !purego
 
 #include "textflag.h"
 

src/crypto/internal/edwards25519/field/fe_arm64_noasm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !arm64 || !gc || purego
+//go:build !arm64 || purego
 
 package field
 

src/crypto/internal/nistec/generate.go

@@ -40,7 +40,7 @@ var curves = []struct {
 		P:         "P256",
 		Element:   "fiat.P256Element",
 		Params:    elliptic.P256().Params(),
-		BuildTags: "!amd64 && !arm64 && !ppc64le && !s390x",
+		BuildTags: "(!amd64 && !arm64 && !ppc64le && !s390x) || purego",
 	},
 	{
 		P:       "P384",

src/crypto/internal/nistec/p256_asm.go

@@ -10,7 +10,7 @@
 // https://link.springer.com/article/10.1007%2Fs13389-014-0090-x
 // https://eprint.iacr.org/2013/816.pdf
 
-//go:build amd64 || arm64 || ppc64le || s390x
+//go:build (amd64 || arm64 || ppc64le || s390x) && !purego
 
 package nistec
 

src/crypto/internal/nistec/p256_asm_amd64.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 // This file contains constant-time, 64-bit assembly implementation of
 // P256. The optimizations performed here are described in detail in:
 // S.Gueron and V.Krasnov, "Fast prime field elliptic-curve cryptography with

src/crypto/internal/nistec/p256_asm_arm64.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 // This file contains constant-time, 64-bit assembly implementation of
 // P256. The optimizations performed here are described in detail in:
 // S.Gueron and V.Krasnov, "Fast prime field elliptic-curve cryptography with

src/crypto/internal/nistec/p256_asm_ppc64le.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 
 // This is a port of the s390x asm implementation.

src/crypto/internal/nistec/p256_asm_s390x.s

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !purego
+
 #include "textflag.h"
 #include "go_asm.h"
 

src/crypto/internal/nistec/p256_asm_table_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64 || ppc64le || s390x
+//go:build !purego && (amd64 || arm64 || ppc64le || s390x)
 
 package nistec
 

src/crypto/internal/nistec/p256_ordinv.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64
+//go:build (amd64 || arm64) && !purego
 
 package nistec
 

src/crypto/internal/nistec/p256_ordinv_noasm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !amd64 && !arm64
+//go:build (!amd64 && !arm64) || purego
 
 package nistec
 

src/crypto/internal/nistec/p256_ordinv_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64
+//go:build (amd64 || arm64) && !purego
 
 package nistec_test
 

src/crypto/md5/md5block_386.s

@@ -6,6 +6,8 @@
 // #defines generating 8a assembly, and adjusted for 386,
 // by the Go Authors.
 
+//go:build !purego
+
 #include "textflag.h"
 
 // MD5 optimized for AMD64.

src/crypto/md5/md5block_amd64.s

@@ -5,6 +5,8 @@
 // Translated from Perl generating GNU assembly into
 // #defines generating 6a assembly by the Go Authors.
 
+//go:build !purego
+
 #include "textflag.h"
 
 // MD5 optimized for AMD64.

src/crypto/md5/md5block_arm.s

@@ -4,6 +4,8 @@
 //
 // ARM version of md5block.go
 
+//go:build !purego
+
 #include "textflag.h"
 
 // Register definitions

src/crypto/md5/md5block_arm64.s

@@ -5,6 +5,8 @@
 // ARM64 version of md5block.go
 // derived from crypto/md5/md5block_amd64.s
 
+//go:build !purego
+
 #include "textflag.h"
 
 TEXT	·block(SB),NOSPLIT,$0-32

src/crypto/md5/md5block_decl.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || 386 || arm || ppc64le || ppc64 || s390x || arm64
+//go:build (amd64 || 386 || arm || ppc64le || ppc64 || s390x || arm64) && !purego
 
 package md5