crypto: ccree - convert to use crypto_authenc_extractkeys()

Convert the ccree crypto driver to use crypto_authenc_extractkeys() so
that it picks up the fix for broken validation of rtattr::rta_len.

Fixes: ff27e85a85bb ("crypto: ccree - add AEAD support")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 19 insertions, 21 deletions

diff --git a/drivers/crypto/ccree/cc_aead.c b/drivers/crypto/ccree/cc_aead.c
index f2643cda45db..a3527c00b29a 100644
--- a/drivers/crypto/ccree/cc_aead.c
+++ b/drivers/crypto/ccree/cc_aead.c
@@ -549,13 +549,12 @@ static int cc_aead_setkey(struct crypto_aead *tfm, const u8 *key,
                           unsigned int keylen)
 {
         struct cc_aead_ctx *ctx = crypto_aead_ctx(tfm);
-        struct rtattr *rta = (struct rtattr *)key;
         struct cc_crypto_req cc_req = {};
-        struct crypto_authenc_key_param *param;
         struct cc_hw_desc desc[MAX_AEAD_SETKEY_SEQ];
-        int rc = -EINVAL;
         unsigned int seq_len = 0;
         struct device *dev = drvdata_to_dev(ctx->drvdata);
+        const u8 *enckey, *authkey;
+        int rc;
 
         dev_dbg(dev, "Setting key in context @%p for %s. key=%p keylen=%u\n",
                 ctx, crypto_tfm_alg_name(crypto_aead_tfm(tfm)), key, keylen);
@@ -563,35 +562,33 @@ static int cc_aead_setkey(struct crypto_aead *tfm, const u8 *key,
         /* STAT_PHASE_0: Init and sanity checks */
 
         if (ctx->auth_mode != DRV_HASH_NULL) { /* authenc() alg. */
-                if (!RTA_OK(rta, keylen))
-                        goto badkey;
-                if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
-                        goto badkey;
-                if (RTA_PAYLOAD(rta) < sizeof(*param))
-                        goto badkey;
-                param = RTA_DATA(rta);
-                ctx->enc_keylen = be32_to_cpu(param->enckeylen);
-                key += RTA_ALIGN(rta->rta_len);
-                keylen -= RTA_ALIGN(rta->rta_len);
-                if (keylen < ctx->enc_keylen)
+                struct crypto_authenc_keys keys;
+
+                rc = crypto_authenc_extractkeys(&keys, key, keylen);
+                if (rc)
                         goto badkey;
-                ctx->auth_keylen = keylen - ctx->enc_keylen;
+                enckey = keys.enckey;
+                authkey = keys.authkey;
+                ctx->enc_keylen = keys.enckeylen;
+                ctx->auth_keylen = keys.authkeylen;
 
                 if (ctx->cipher_mode == DRV_CIPHER_CTR) {
                         /* the nonce is stored in bytes at end of key */
+                        rc = -EINVAL;
                         if (ctx->enc_keylen <
                             (AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE))
                                 goto badkey;
                         /* Copy nonce from last 4 bytes in CTR key to
                          *  first 4 bytes in CTR IV
                          */
-                        memcpy(ctx->ctr_nonce, key + ctx->auth_keylen +
-                               ctx->enc_keylen - CTR_RFC3686_NONCE_SIZE,
-                               CTR_RFC3686_NONCE_SIZE);
+                        memcpy(ctx->ctr_nonce, enckey + ctx->enc_keylen -
+                               CTR_RFC3686_NONCE_SIZE, CTR_RFC3686_NONCE_SIZE);
                         /* Set CTR key size */
                         ctx->enc_keylen -= CTR_RFC3686_NONCE_SIZE;
                 }
         } else { /* non-authenc - has just one key */
+                enckey = key;
+                authkey = NULL;
                 ctx->enc_keylen = keylen;
                 ctx->auth_keylen = 0;
         }
@@ -603,13 +600,14 @@ static int cc_aead_setkey(struct crypto_aead *tfm, const u8 *key,
         /* STAT_PHASE_1: Copy key to ctx */
 
         /* Get key material */
-        memcpy(ctx->enckey, key + ctx->auth_keylen, ctx->enc_keylen);
+        memcpy(ctx->enckey, enckey, ctx->enc_keylen);
         if (ctx->enc_keylen == 24)
                 memset(ctx->enckey + 24, 0, CC_AES_KEY_SIZE_MAX - 24);
         if (ctx->auth_mode == DRV_HASH_XCBC_MAC) {
-                memcpy(ctx->auth_state.xcbc.xcbc_keys, key, ctx->auth_keylen);
+                memcpy(ctx->auth_state.xcbc.xcbc_keys, authkey,
+                       ctx->auth_keylen);
         } else if (ctx->auth_mode != DRV_HASH_NULL) { /* HMAC */
-                rc = cc_get_plain_hmac_key(tfm, key, ctx->auth_keylen);
+                rc = cc_get_plain_hmac_key(tfm, authkey, ctx->auth_keylen);
                 if (rc)
                         goto badkey;
         }