[CRYPTO] hmac: Avoid calling virt_to_page on key (67412f0e) · Commits · 戴 / test

When HMAC gets a key longer than the block size of the hash, it needs to feed it as input to the hash to reduce it to a fixed length. As it is HMAC converts the key to a scatter and gather list. However, this doesn't work on certain platforms if the key is not allocated via kmalloc. For example, the keys from tcrypt are stored in the rodata section and this causes it to fail with HMAC on x86-64. This patch fixes this by copying the key to memory obtained via kmalloc before hashing it. Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au>

crypto/hmac.c

+23 −2

Original line number	Diff line number	Diff line
		@@ -57,14 +57,35 @@ static int hmac_setkey(struct crypto_hash *parent,
		if (keylen > bs) {
		struct hash_desc desc;
		struct scatterlist tmp;
		int tmplen;
		int err;

		desc.tfm = tfm;
		desc.flags = crypto_hash_get_flags(parent);
		desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;
		sg_init_one(&tmp, inkey, keylen);

		err = crypto_hash_digest(&desc, &tmp, keylen, digest);
		err = crypto_hash_init(&desc);
		if (err)
		return err;

		tmplen = bs * 2 + ds;
		sg_init_one(&tmp, ipad, tmplen);

		for (; keylen > tmplen; inkey += tmplen, keylen -= tmplen) {
		memcpy(ipad, inkey, tmplen);
		err = crypto_hash_update(&desc, &tmp, tmplen);
		if (err)
		return err;
		}

		if (keylen) {
		memcpy(ipad, inkey, keylen);
		err = crypto_hash_update(&desc, &tmp, keylen);
		if (err)
		return err;
		}

		err = crypto_hash_final(&desc, digest);
		if (err)
		return err;

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