diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go')
-rw-r--r-- | vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go | 59 |
1 files changed, 53 insertions, 6 deletions
diff --git a/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go b/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go index 475503321..7cd7ad834 100644 --- a/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go +++ b/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) } |