build: separate compiler and libs

compiler/internal/lib/crypto/hmac/hmac.go

@@ -0,0 +1,72 @@
+package hmac
+
+// llgo:skipall
+import (
+	"crypto/sha256"
+	"crypto/subtle"
+	"hash"
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/openssl"
+)
+
+type eface struct {
+	_type   unsafe.Pointer
+	funcPtr *unsafe.Pointer
+}
+
+func funcOf(a any) unsafe.Pointer {
+	e := (*eface)(unsafe.Pointer(&a))
+	return *e.funcPtr
+}
+
+type digest openssl.HMAC_CTX
+
+func (d *digest) Size() int { panic("todo: hmac.(*digest).Size") }
+
+func (d *digest) BlockSize() int { panic("todo: hmac.(*digest).BlockSize") }
+
+func (d *digest) Reset() {
+	(*openssl.HMAC_CTX)(d).Reset()
+}
+
+func (d *digest) Write(p []byte) (nn int, err error) {
+	(*openssl.HMAC_CTX)(d).UpdateBytes(p)
+	return len(p), nil
+}
+
+func (d *digest) Sum(in []byte) []byte {
+	const Size = openssl.EVP_MAX_MD_SIZE
+	var digestLen c.Uint
+	hash := (*[Size]byte)(c.Alloca(Size))
+	(*openssl.HMAC_CTX)(d).Final(&hash[0], &digestLen)
+	return append(in, hash[:digestLen]...)
+}
+
+// New returns a new HMAC hash using the given [hash.Hash] type and key.
+// New functions like sha256.New from [crypto/sha256] can be used as h.
+// h must return a new Hash every time it is called.
+// Note that unlike other hash implementations in the standard library,
+// the returned Hash does not implement [encoding.BinaryMarshaler]
+// or [encoding.BinaryUnmarshaler].
+func New(h func() hash.Hash, key []byte) hash.Hash {
+	var md *openssl.EVP_MD
+	switch funcOf(h) {
+	case c.Func(sha256.New):
+		md = openssl.EVP_sha256()
+	default:
+		panic("todo: hmac.New: unsupported hash function")
+	}
+	ctx := openssl.NewHMAC_CTX()
+	ctx.InitBytes(key, md)
+	return (*digest)(ctx)
+}
+
+// Equal compares two MACs for equality without leaking timing information.
+func Equal(mac1, mac2 []byte) bool {
+	// We don't have to be constant time if the lengths of the MACs are
+	// different as that suggests that a completely different hash function
+	// was used.
+	return subtle.ConstantTimeCompare(mac1, mac2) == 1
+}