crypto: aead - Do not allow authsize=0 if auth. alg has digestsize>0

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 <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
Sonicadvance1 · Aug 15, 2019 · a62084d · a62084d
1 parent 440dc9a
commit a62084d
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/crypto/aead.c b/crypto/aead.c
@@ -70,7 +70,8 @@ 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) {