crypto: rsa-pkcs1pad: Allow hash to be optional [ver #2]

The original pkcs1pad implementation allowed to pad/unpad raw RSA
output.  However, this has been taken out in commit:
commit c0d20d22e0 ("crypto: rsa-pkcs1pad - Require hash to be present")

This patch restored this ability as it is needed by the asymmetric key
implementation.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
This commit is contained in:
Denis Kenzior 2018-10-09 17:47:53 +01:00 committed by James Morris
parent 3c58b2362b
commit b3a8c8a5eb

View File

@ -392,6 +392,7 @@ static int pkcs1pad_sign(struct akcipher_request *req)
if (!ctx->key_size)
return -EINVAL;
if (digest_info)
digest_size = digest_info->size;
if (req->src_len + digest_size > ctx->key_size - 11)
@ -412,6 +413,7 @@ static int pkcs1pad_sign(struct akcipher_request *req)
memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
req_ctx->in_buf[ps_end] = 0x00;
if (digest_info)
memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
digest_info->size);
@ -475,10 +477,13 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
goto done;
pos++;
if (crypto_memneq(out_buf + pos, digest_info->data, digest_info->size))
if (digest_info) {
if (crypto_memneq(out_buf + pos, digest_info->data,
digest_info->size))
goto done;
pos += digest_info->size;
}
err = 0;
@ -608,11 +613,14 @@ static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
hash_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(hash_name))
return PTR_ERR(hash_name);
hash_name = NULL;
if (hash_name) {
digest_info = rsa_lookup_asn1(hash_name);
if (!digest_info)
return -EINVAL;
} else
digest_info = NULL;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
@ -632,14 +640,29 @@ static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >=
CRYPTO_MAX_ALG_NAME ||
snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"pkcs1pad(%s,%s)",
rsa_alg->base.cra_driver_name, hash_name) >=
if (!hash_name) {
if (snprintf(inst->alg.base.cra_name,
CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
if (snprintf(inst->alg.base.cra_driver_name,
CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
rsa_alg->base.cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
} else {
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
hash_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
if (snprintf(inst->alg.base.cra_driver_name,
CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
rsa_alg->base.cra_driver_name,
hash_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
}
inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.base.cra_priority = rsa_alg->base.cra_priority;