osxkeychain: switch to github.com/keybase/go-keychain

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/keybase/go-keychain/datetime.go

@@ -0,0 +1,69 @@
+//go:build darwin || ios
+// +build darwin ios
+
+package keychain
+
+/*
+#cgo LDFLAGS: -framework CoreFoundation
+
+#include <CoreFoundation/CoreFoundation.h>
+*/
+import "C"
+import (
+	"math"
+	"time"
+)
+
+const nsPerSec = 1000 * 1000 * 1000
+
+// absoluteTimeIntervalSince1970() returns the number of seconds from
+// the Unix epoch (1970-01-01T00:00:00+00:00) to the Core Foundation
+// absolute reference date (2001-01-01T00:00:00+00:00). It should be
+// exactly 978307200.
+func absoluteTimeIntervalSince1970() int64 {
+	return int64(C.kCFAbsoluteTimeIntervalSince1970)
+}
+
+func unixToAbsoluteTime(s int64, ns int64) C.CFAbsoluteTime {
+	// Subtract as int64s first before converting to floating
+	// point to minimize precision loss (assuming the given time
+	// isn't much earlier than the Core Foundation absolute
+	// reference date).
+	abs := s - absoluteTimeIntervalSince1970()
+	return C.CFAbsoluteTime(abs) + C.CFTimeInterval(ns)/nsPerSec
+}
+
+func absoluteTimeToUnix(abs C.CFAbsoluteTime) (int64, int64) {
+	i, frac := math.Modf(float64(abs))
+	return int64(i) + absoluteTimeIntervalSince1970(), int64(frac * nsPerSec)
+}
+
+// TimeToCFDate will convert the given time.Time to a CFDateRef, which
+// must be released with Release(ref).
+func TimeToCFDate(t time.Time) C.CFDateRef {
+	s := t.Unix()
+	ns := int64(t.Nanosecond())
+	abs := unixToAbsoluteTime(s, ns)
+	return C.CFDateCreate(C.kCFAllocatorDefault, abs)
+}
+
+// CFDateToTime will convert the given CFDateRef to a time.Time.
+func CFDateToTime(d C.CFDateRef) time.Time {
+	abs := C.CFDateGetAbsoluteTime(d)
+	s, ns := absoluteTimeToUnix(abs)
+	return time.Unix(s, ns)
+}
+
+// Wrappers around C functions for testing.
+
+func cfDateToAbsoluteTime(d C.CFDateRef) C.CFAbsoluteTime {
+	return C.CFDateGetAbsoluteTime(d)
+}
+
+func absoluteTimeToCFDate(abs C.CFAbsoluteTime) C.CFDateRef {
+	return C.CFDateCreate(C.kCFAllocatorDefault, abs)
+}
+
+func releaseCFDate(d C.CFDateRef) {
+	Release(C.CFTypeRef(d))
+}