Commit a4f3529b33 for strongswan.org

commit a4f3529b3392f89c5ac2ab959cb7105a70761bb9
Author: Tobias Brunner <tobias@strongswan.org>
Date:   Tue Oct 27 13:55:53 2026 +0100

    pkcs5: Reject zero length padding

    To comply with the RFC, we reject zero length padding right away.  The
    ASN.1 parser will reject invalid decrypted data right away anyway.

diff --git a/src/libstrongswan/crypto/pkcs5.c b/src/libstrongswan/crypto/pkcs5.c
index 19da811bdf..88cc965df7 100644
--- a/src/libstrongswan/crypto/pkcs5.c
+++ b/src/libstrongswan/crypto/pkcs5.c
@@ -131,7 +131,7 @@ static bool verify_padding(crypter_t *crypter, chunk_t *blob)

 	padding = count = blob->ptr[blob->len - 1];

-	if (padding > crypter->get_block_size(crypter))
+	if (!padding || padding > crypter->get_block_size(crypter))
 	{
 		return FALSE;
 	}