crypto: picoxcell - Simplify and harden key parsing

Use the common helper function crypto_authenc_extractkeys() for key
parsing. Also ensure the auth key won't overflow the hash_ctx buffer.

Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mathias Krause <mathias.krause@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 8 insertions, 24 deletions

diff --git a/drivers/crypto/picoxcell_crypto.c b/drivers/crypto/picoxcell_crypto.c
index 888f7f4a6d3f..a6175ba6d238 100644
--- a/drivers/crypto/picoxcell_crypto.c
+++ b/drivers/crypto/picoxcell_crypto.c
@@ -495,45 +495,29 @@ static int spacc_aead_setkey(struct crypto_aead *tfm, const u8 *key,
 {
         struct spacc_aead_ctx *ctx = crypto_aead_ctx(tfm);
         struct spacc_alg *alg = to_spacc_alg(tfm->base.__crt_alg);
-        struct rtattr *rta = (void *)key;
-        struct crypto_authenc_key_param *param;
-        unsigned int authkeylen, enckeylen;
+        struct crypto_authenc_keys keys;
         int err = -EINVAL;
 
-        if (!RTA_OK(rta, keylen))
+        if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
                 goto badkey;
 
-        if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
+        if (keys.enckeylen > AES_MAX_KEY_SIZE)
                 goto badkey;
 
-        if (RTA_PAYLOAD(rta) < sizeof(*param))
-                goto badkey;
-
-        param = RTA_DATA(rta);
-        enckeylen = be32_to_cpu(param->enckeylen);
-
-        key += RTA_ALIGN(rta->rta_len);
-        keylen -= RTA_ALIGN(rta->rta_len);
-
-        if (keylen < enckeylen)
-                goto badkey;
-
-        authkeylen = keylen - enckeylen;
-
-        if (enckeylen > AES_MAX_KEY_SIZE)
+        if (keys.authkeylen > sizeof(ctx->hash_ctx))
                 goto badkey;
 
         if ((alg->ctrl_default & SPACC_CRYPTO_ALG_MASK) ==
             SPA_CTRL_CIPH_ALG_AES)
-                err = spacc_aead_aes_setkey(tfm, key + authkeylen, enckeylen);
+                err = spacc_aead_aes_setkey(tfm, keys.enckey, keys.enckeylen);
         else
-                err = spacc_aead_des_setkey(tfm, key + authkeylen, enckeylen);
+                err = spacc_aead_des_setkey(tfm, keys.enckey, keys.enckeylen);
 
         if (err)
                 goto badkey;
 
-        memcpy(ctx->hash_ctx, key, authkeylen);
-        ctx->hash_key_len = authkeylen;
+        memcpy(ctx->hash_ctx, keys.authkey, keys.authkeylen);
+        ctx->hash_key_len = keys.authkeylen;
 
         return 0;