diff options
| -rw-r--r-- | lib/blocks.go | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/blocks.go b/lib/blocks.go index 76f39d6..9b184d1 100644 --- a/lib/blocks.go +++ b/lib/blocks.go @@ -113,5 +113,14 @@ func Pkcs7Padding(in []byte, k int) []byte { // Removes PKCS#7 Padding from input `in` func Pkcs7PaddingUndo(in []byte) []byte { - return in[0:(len(in) - int(in[len(in)-1]))] + pd := in[len(in)-1] // padding character + pl := int(pd) // padding length + + // Validate + for i := len(in) - 1; i >= len(in)-pl; i-- { + if in[i] != pd { + panic("input is not pkcs#7 padded!") + } + } + return in[0:(len(in) - pl)] } |