vendor HEAD main

1 files changed, 30 insertions, 0 deletions

diff --git a/vendor/maunium.net/go/mautrix/crypto/pkcs7/pkcs7.go b/vendor/maunium.net/go/mautrix/crypto/pkcs7/pkcs7.go
new file mode 100644
index 0000000..dc28ed6
--- /dev/null
+++ b/vendor/maunium.net/go/mautrix/crypto/pkcs7/pkcs7.go
@@ -0,0 +1,30 @@
+// Copyright (c) 2024 Sumner Evans
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package pkcs7
+
+import "bytes"
+
+// Pad implements PKCS#7 padding as defined in [RFC2315]. It pads the data to
+// the given blockSize in the range [1, 255]. This is normally used in AES-CBC
+// encryption.
+//
+// [RFC2315]: https://www.ietf.org/rfc/rfc2315.txt
+func Pad(data []byte, blockSize int) []byte {
+	padding := blockSize - len(data)%blockSize
+	return append(data, bytes.Repeat([]byte{byte(padding)}, padding)...)
+}
+
+// Unpad implements PKCS#7 unpadding as defined in [RFC2315]. It unpads the
+// data by reading the padding amount from the last byte of the data. This is
+// normally used in AES-CBC decryption.
+//
+// [RFC2315]: https://www.ietf.org/rfc/rfc2315.txt
+func Unpad(data []byte) []byte {
+	length := len(data)
+	unpadding := int(data[length-1])
+	return data[:length-unpadding]
+}