vendor/golang_org/x/crypto/chacha20poly1305: revendor

Brings in chacha20poly1305 directory from golang.org/x/crypto revision
12e9ca725de4806fbda1610fd95aacad15bd6810, adding:

CL 41862: chacha20poly1305: add runtime internal independent cpu feature detection
CL 39952: add import comment

Change-Id: Ic46ff24b081bc1c66b6317334d33180e33bfd318
Reviewed-on: https://go-review.googlesource.com/42513
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305.go b/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305.go
index eb6739a109f1f6080d86c4fb9807d58af260462c..3f0dcb9d8cfac541a6bbea2f7258b3471557759a 100644 (file)
--- a/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305.go
+++ b/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305.go
@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package chacha20poly1305 implements the ChaCha20-Poly1305 AEAD as specified in RFC 7539.
-package chacha20poly1305
+package chacha20poly1305 // import "golang.org/x/crypto/chacha20poly1305"
 
 import (
        "crypto/cipher"

diff --git a/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go b/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go
index 47550332126e28fa61dbc2ab2295bba23154fee9..1e523b9951be150110be37cf92a9ba71800f13e0 100644 (file)
--- a/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go
+++ b/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go
@@ -14,13 +14,60 @@ func chacha20Poly1305Open(dst []byte, key []uint32, src, ad []byte) bool
 //go:noescape
 func chacha20Poly1305Seal(dst []byte, key []uint32, src, ad []byte)
 
-//go:noescape
-func haveSSSE3() bool
+// cpuid is implemented in chacha20poly1305_amd64.s.
+func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
+
+// xgetbv with ecx = 0 is implemented in chacha20poly1305_amd64.s.
+func xgetbv() (eax, edx uint32)
 
-var canUseASM bool
+var (
+       useASM  bool
+       useAVX2 bool
+)
 
 func init() {
-       canUseASM = haveSSSE3()
+       detectCpuFeatures()
+}
+
+// detectCpuFeatures is used to detect if cpu instructions
+// used by the functions implemented in assembler in
+// chacha20poly1305_amd64.s are supported.
+func detectCpuFeatures() {
+       maxId, _, _, _ := cpuid(0, 0)
+       if maxId < 1 {
+               return
+       }
+
+       _, _, ecx1, _ := cpuid(1, 0)
+
+       haveSSSE3 := isSet(9, ecx1)
+       useASM = haveSSSE3
+
+       haveOSXSAVE := isSet(27, ecx1)
+
+       osSupportsAVX := false
+       // For XGETBV, OSXSAVE bit is required and sufficient.
+       if haveOSXSAVE {
+               eax, _ := xgetbv()
+               // Check if XMM and YMM registers have OS support.
+               osSupportsAVX = isSet(1, eax) && isSet(2, eax)
+       }
+       haveAVX := isSet(28, ecx1) && osSupportsAVX
+
+       if maxId < 7 {
+               return
+       }
+
+       _, ebx7, _, _ := cpuid(7, 0)
+       haveAVX2 := isSet(5, ebx7) && haveAVX
+       haveBMI2 := isSet(8, ebx7)
+
+       useAVX2 = haveAVX2 && haveBMI2
+}
+
+// isSet checks if bit at bitpos is set in value.
+func isSet(bitpos uint, value uint32) bool {
+       return value&(1<<bitpos) != 0
 }
 
 // setupState writes a ChaCha20 input matrix to state. See
@@ -47,7 +94,7 @@ func setupState(state *[16]uint32, key *[32]byte, nonce []byte) {
 }
 
 func (c *chacha20poly1305) seal(dst, nonce, plaintext, additionalData []byte) []byte {
-       if !canUseASM {
+       if !useASM {
                return c.sealGeneric(dst, nonce, plaintext, additionalData)
        }
 
@@ -60,7 +107,7 @@ func (c *chacha20poly1305) seal(dst, nonce, plaintext, additionalData []byte) []
 }
 
 func (c *chacha20poly1305) open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
-       if !canUseASM {
+       if !useASM {
                return c.openGeneric(dst, nonce, ciphertext, additionalData)
        }
 

diff --git a/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s b/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s
index 39c58b44a373f76c550ff0e465509154f0fcf532..1c57e3894ca4e3f4160fceb8ffac9bb608609541 100644 (file)
--- a/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s
+++ b/src/vendor/golang_org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s
@@ -278,15 +278,8 @@ TEXT ·chacha20Poly1305Open(SB), 0, $288-97
        MOVQ ad+72(FP), adp
 
        // Check for AVX2 support
-       CMPB runtime·support_avx2(SB), $0
-       JE   noavx2bmi2Open
-
-       // Check BMI2 bit for MULXQ.
-       // runtime·cpuid_ebx7 is always available here
-       // because it passed avx2 check
-       TESTL $(1<<8), runtime·cpuid_ebx7(SB)
-       JNE   chacha20Poly1305Open_AVX2
-noavx2bmi2Open:
+       CMPB ·useAVX2(SB), $1
+       JE   chacha20Poly1305Open_AVX2
 
        // Special optimization, for very short buffers
        CMPQ inl, $128
@@ -1491,16 +1484,8 @@ TEXT ·chacha20Poly1305Seal(SB), 0, $288-96
        MOVQ src_len+56(FP), inl
        MOVQ ad+72(FP), adp
 
-       // Check for AVX2 support
-       CMPB runtime·support_avx2(SB), $0
-       JE   noavx2bmi2Seal
-
-       // Check BMI2 bit for MULXQ.
-       // runtime·cpuid_ebx7 is always available here
-       // because it passed avx2 check
-       TESTL $(1<<8), runtime·cpuid_ebx7(SB)
-       JNE   chacha20Poly1305Seal_AVX2
-noavx2bmi2Seal:
+       CMPB ·useAVX2(SB), $1
+       JE   chacha20Poly1305Seal_AVX2
 
        // Special optimization, for very short buffers
        CMPQ inl, $128
@@ -2709,13 +2694,21 @@ sealAVX2Tail512LoopB:
 
        JMP sealAVX2SealHash
 
-// func haveSSSE3() bool
-TEXT ·haveSSSE3(SB), NOSPLIT, $0
-       XORQ AX, AX
-       INCL AX
+// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
+TEXT ·cpuid(SB), NOSPLIT, $0-24
+       MOVL eaxArg+0(FP), AX
+       MOVL ecxArg+4(FP), CX
        CPUID
-       SHRQ $9, CX
-       ANDQ $1, CX
-       MOVB CX, ret+0(FP)
+       MOVL AX, eax+8(FP)
+       MOVL BX, ebx+12(FP)
+       MOVL CX, ecx+16(FP)
+       MOVL DX, edx+20(FP)
        RET
 
+// func xgetbv() (eax, edx uint32)
+TEXT ·xgetbv(SB),NOSPLIT,$0-8
+       MOVL $0, CX
+       XGETBV
+       MOVL AX, eax+0(FP)
+       MOVL DX, edx+4(FP)
+       RET