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authorJordan <me@jordan.im>2022-03-17 09:43:29 -0700
committerJordan <me@jordan.im>2022-03-17 09:43:29 -0700
commit66bfe530b4fd5cb9755337ce718df26ee81f1b77 (patch)
tree9dfc8a79183b8bffc12db5a92f957e3bfd37d4f2 /vendor/golang.org/x/crypto/internal/poly1305/bits_compat.go
parent2f0b35e3c25bc4394f3288e1baa77d250cb510ed (diff)
downloadkeep-66bfe530b4fd5cb9755337ce718df26ee81f1b77.tar.gz
keep-66bfe530b4fd5cb9755337ce718df26ee81f1b77.zip
misc: go get -u ./... ; go mod vendor
Diffstat (limited to 'vendor/golang.org/x/crypto/internal/poly1305/bits_compat.go')
-rw-r--r--vendor/golang.org/x/crypto/internal/poly1305/bits_compat.go40
1 files changed, 40 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/internal/poly1305/bits_compat.go b/vendor/golang.org/x/crypto/internal/poly1305/bits_compat.go
new file mode 100644
index 0000000..45b5c96
--- /dev/null
+++ b/vendor/golang.org/x/crypto/internal/poly1305/bits_compat.go
@@ -0,0 +1,40 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !go1.13
+// +build !go1.13
+
+package poly1305
+
+// Generic fallbacks for the math/bits intrinsics, copied from
+// src/math/bits/bits.go. They were added in Go 1.12, but Add64 and Sum64 had
+// variable time fallbacks until Go 1.13.
+
+func bitsAdd64(x, y, carry uint64) (sum, carryOut uint64) {
+ sum = x + y + carry
+ carryOut = ((x & y) | ((x | y) &^ sum)) >> 63
+ return
+}
+
+func bitsSub64(x, y, borrow uint64) (diff, borrowOut uint64) {
+ diff = x - y - borrow
+ borrowOut = ((^x & y) | (^(x ^ y) & diff)) >> 63
+ return
+}
+
+func bitsMul64(x, y uint64) (hi, lo uint64) {
+ const mask32 = 1<<32 - 1
+ x0 := x & mask32
+ x1 := x >> 32
+ y0 := y & mask32
+ y1 := y >> 32
+ w0 := x0 * y0
+ t := x1*y0 + w0>>32
+ w1 := t & mask32
+ w2 := t >> 32
+ w1 += x0 * y1
+ hi = x1*y1 + w2 + w1>>32
+ lo = x * y
+ return
+}