[dev.boringcrypto] crypto/ecdsa, crypto/rsa: use boring.Cache

In the original BoringCrypto port, ecdsa and rsa's public and private
keys added a 'boring unsafe.Pointer' field to cache the BoringCrypto
form of the key. This led to problems with code that “knew” the layout
of those structs and in particular that they had no unexported fields.

In response, as an awful kludge, I changed the compiler to pretend
that field did not exist when laying out reflect data. Because we want
to merge BoringCrypto in the main tree, we need a different solution.
Using boring.Cache is that solution.

For #51940.

Change-Id: Ideb2b40b599a1dc223082eda35a5ea9abcc01e30
Reviewed-on: https://go-review.googlesource.com/c/go/+/395883
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/runtime/mgc.go b/src/runtime/mgc.go
index b2558c8bd3..f79bd54c5e 100644
--- a/src/runtime/mgc.go
+++ b/src/runtime/mgc.go
@@ -1536,13 +1536,18 @@ func gcResetMarkState() {
 // Hooks for other packages
 
 var poolcleanup func()
-var boringCaches []unsafe.Pointer
+var boringCaches []unsafe.Pointer // for crypto/internal/boring
 
 //go:linkname sync_runtime_registerPoolCleanup sync.runtime_registerPoolCleanup
 func sync_runtime_registerPoolCleanup(f func()) {
 	poolcleanup = f
 }
 
+//go:linkname boring_registerCache crypto/internal/boring.registerCache
+func boring_registerCache(p unsafe.Pointer) {
+	boringCaches = append(boringCaches, p)
+}
+
 func clearpools() {
 	// clear sync.Pools
 	if poolcleanup != nil {