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From: Pascal van Leeuwen <pascalvanl@gmail.com>
To: linux-crypto@vger.kernel.org
Cc: herbert@gondor.apana.org.au, davem@davemloft.net,
	Pascal van Leeuwen <pvanleeuwen@verimatrix.com>
Subject: [PATCH] crypto: aead - Do not allow authsize=0 if auth. alg has digestsize>0
Date: Fri,  9 Aug 2019 17:51:07 +0200	[thread overview]
Message-ID: <1565365867-8251-1-git-send-email-pvanleeuwen@verimatrix.com> (raw)

Return -EINVAL on an attempt to set the authsize to 0 with an auth.
algorithm with a non-zero digestsize (i.e. anything but digest_null)
as authenticating the data and then throwing away the result does not
make any sense at all.

The digestsize zero exception is for use with digest_null for testing
purposes only.

Signed-off-by: Pascal van Leeuwen <pvanleeuwen@verimatrix.com>
---
 crypto/aead.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/crypto/aead.c b/crypto/aead.c
index 4908b5e..e423107 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c
@@ -75,7 +75,8 @@ int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 {
 	int err;
 
-	if (authsize > crypto_aead_maxauthsize(tfm))
+	if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
+	    authsize > crypto_aead_maxauthsize(tfm))
 		return -EINVAL;
 
 	if (crypto_aead_alg(tfm)->setauthsize) {
-- 
1.8.3.1


             reply	other threads:[~2019-08-09 16:53 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-09 15:51 Pascal van Leeuwen [this message]
2019-08-15 12:07 ` [PATCH] crypto: aead - Do not allow authsize=0 if auth. alg has digestsize>0 Herbert Xu

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