From 3c90be7678566203d38624c4a6fe3affaffbe5e3 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Sat, 19 Dec 2009 18:57:54 +0100 Subject: [PATCH] Fix block cipher padding when using libgcrypt. --- src/gcrypt/cipher.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/src/gcrypt/cipher.c b/src/gcrypt/cipher.c index 2e8e057d..390959cb 100644 --- a/src/gcrypt/cipher.c +++ b/src/gcrypt/cipher.c @@ -196,7 +196,7 @@ bool cipher_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *ou if(!oneshot) return false; - size_t reqlen = ((inlen + 1) / cipher->blklen) * cipher->blklen; + size_t reqlen = ((inlen + 8) / cipher->blklen) * cipher->blklen; uint8_t padbyte = reqlen - inlen; inlen = reqlen - cipher->blklen; @@ -239,14 +239,18 @@ bool cipher_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *ou uint8_t padbyte = ((uint8_t *)outdata)[inlen - 1]; - if(padbyte == 0 || padbyte > cipher->blklen || padbyte > inlen) + if(padbyte == 0 || padbyte > cipher->blklen || padbyte > inlen) { + logger(LOG_ERR, "Error while decrypting: invalid padding"); return false; + } size_t origlen = inlen - padbyte; for(int i = inlen - 1; i >= origlen; i--) - if(((uint8_t *)indata)[i] != padbyte) + if(((uint8_t *)outdata)[i] != padbyte) { + logger(LOG_ERR, "Error while decrypting: invalid padding"); return false; + } *outlen = origlen; } -- 2.20.1