matterbridge/vendor/github.com/Philipp15b/go-steam/cryptoutil/pkcs7.go

26 lines
627 B
Go

package cryptoutil
import (
"crypto/aes"
)
// Returns a new byte array padded with PKCS7 and prepended
// with empty space of the AES block size (16 bytes) for the IV.
func padPKCS7WithIV(src []byte) []byte {
missing := aes.BlockSize - (len(src) % aes.BlockSize)
newSize := len(src) + aes.BlockSize + missing
dest := make([]byte, newSize, newSize)
copy(dest[aes.BlockSize:], src)
padding := byte(missing)
for i := newSize - missing; i < newSize; i++ {
dest[i] = padding
}
return dest
}
func unpadPKCS7(src []byte) []byte {
padLen := src[len(src)-1]
return src[:len(src)-int(padLen)]
}