crypto: caam - simplify and harden key parsing

Use the common helper function crypto_authenc_extractkeys() for key
parsing.
Also fix the key buffer overflow condition: use split key pad length
instead of authentication key length.

Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 4cf5dec826e1e283aa8b5991cd1a4b80a0dbdba6..b71f2fd749df02de9a1f06a5c444ec33d4d72b11 100644 (file)
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -467,24 +467,10 @@ static int aead_setkey(struct crypto_aead *aead,
        static const u8 mdpadlen[] = { 16, 20, 32, 32, 64, 64 };
        struct caam_ctx *ctx = crypto_aead_ctx(aead);
        struct device *jrdev = ctx->jrdev;
-       struct rtattr *rta = (void *)key;
-       struct crypto_authenc_key_param *param;
-       unsigned int authkeylen;
-       unsigned int enckeylen;
+       struct crypto_authenc_keys keys;
        int ret = 0;
 
-       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 (keylen > CAAM_MAX_KEY_SIZE)
+       if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
                goto badkey;
 
        /* Pick class 2 key length from algorithm submask */
@@ -492,25 +478,29 @@ static int aead_setkey(struct crypto_aead *aead,
                                      OP_ALG_ALGSEL_SHIFT] * 2;
        ctx->split_key_pad_len = ALIGN(ctx->split_key_len, 16);
 
+       if (ctx->split_key_pad_len + keys.enckeylen > CAAM_MAX_KEY_SIZE)
+               goto badkey;
+
 #ifdef DEBUG
        printk(KERN_ERR "keylen %d enckeylen %d authkeylen %d\n",
-              keylen, enckeylen, authkeylen);
+              keys.authkeylen + keys.enckeylen, keys.enckeylen,
+              keys.authkeylen);
        printk(KERN_ERR "split_key_len %d split_key_pad_len %d\n",
               ctx->split_key_len, ctx->split_key_pad_len);
        print_hex_dump(KERN_ERR, "key in @"__stringify(__LINE__)": ",
                       DUMP_PREFIX_ADDRESS, 16, 4, key, keylen, 1);
 #endif
 
-       ret = gen_split_aead_key(ctx, key, authkeylen);
+       ret = gen_split_aead_key(ctx, keys.authkey, keys.authkeylen);
        if (ret) {
                goto badkey;
        }
 
        /* postpend encryption key to auth split key */
-       memcpy(ctx->key + ctx->split_key_pad_len, key + authkeylen, enckeylen);
+       memcpy(ctx->key + ctx->split_key_pad_len, keys.enckey, keys.enckeylen);
 
        ctx->key_dma = dma_map_single(jrdev, ctx->key, ctx->split_key_pad_len +
-                                      enckeylen, DMA_TO_DEVICE);
+                                     keys.enckeylen, DMA_TO_DEVICE);
        if (dma_mapping_error(jrdev, ctx->key_dma)) {
                dev_err(jrdev, "unable to map key i/o memory\n");
                return -ENOMEM;
@@ -518,15 +508,15 @@ static int aead_setkey(struct crypto_aead *aead,
 #ifdef DEBUG
        print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
                       DUMP_PREFIX_ADDRESS, 16, 4, ctx->key,
-                      ctx->split_key_pad_len + enckeylen, 1);
+                      ctx->split_key_pad_len + keys.enckeylen, 1);
 #endif
 
-       ctx->enckeylen = enckeylen;
+       ctx->enckeylen = keys.enckeylen;
 
        ret = aead_set_sh_desc(aead);
        if (ret) {
                dma_unmap_single(jrdev, ctx->key_dma, ctx->split_key_pad_len +
-                                enckeylen, DMA_TO_DEVICE);
+                                keys.enckeylen, DMA_TO_DEVICE);
        }
 
        return ret;