X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=internal%2Fbuiltin.go;fp=internal%2Fbuiltin.go;h=a65e889e14e2bc7d37181818222c49b67712f6be;hb=be69a4fc0c240c2772a0f0bf0955b39783e4c48a;hp=0000000000000000000000000000000000000000;hpb=ce902a58a32f42801603475c67dd75da86d4502a;p=meta4ra.git

diff --git a/internal/builtin.go b/internal/builtin.go
new file mode 100644
index 0000000..a65e889
--- /dev/null
+++ b/internal/builtin.go
@@ -0,0 +1,59 @@
+// meta4ra -- Metalink 4.0 utilities
+// Copyright (C) 2021-2024 Sergey Matveev <stargrave@stargrave.org>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 3 of the License.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package internal
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/hex"
+	"hash"
+	"io"
+)
+
+const BuiltinCmd = "builtin"
+
+var (
+	BuiltinHashes map[string]func() hash.Hash = map[string]func() hash.Hash{
+		"sha-256": sha256.New,
+		"sha-512": sha512.New,
+	}
+	HashesDefault = "sha-512:builtin,sha-256:builtin"
+)
+
+type BuiltinHasher struct {
+	h        hash.Hash
+	finished bool
+}
+
+func (h *BuiltinHasher) Write(p []byte) (int, error) {
+	return h.h.Write(p)
+}
+
+func (h *BuiltinHasher) Read(p []byte) (int, error) {
+	if h.finished {
+		return 0, io.EOF
+	}
+	if len(p) < 2*h.h.Size() {
+		panic("too small buffer for BuiltinHasher.h.Sum()")
+	}
+	hex.Encode(p, h.h.Sum(nil))
+	h.finished = true
+	return hex.EncodedLen(h.h.Size()), nil
+}
+
+func (h *BuiltinHasher) Close() error {
+	return nil
+}