static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
const struct rsa_asn1_template *digest_info;
unsigned int pos;
if (err == -EOVERFLOW)
/* Decrypted value had no leading 0 byte */
err = -EINVAL;
if (err)
goto done;
if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
err = -EINVAL;
goto done;
}
err = -EBADMSG;
if (req_ctx->out_buf[0] != 0x01)
goto done;
for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
if (req_ctx->out_buf[pos] != 0xff)
break;
if (pos < 9 || pos == req_ctx->child_req.dst_len ||
req_ctx->out_buf[pos] != 0x00)
goto done;
pos++;
if (ctx->hash_name) {
digest_info = rsa_lookup_asn1(ctx->hash_name);
if (!digest_info)
goto done;
if (memcmp(req_ctx->out_buf + pos, digest_info->data,
digest_info->size))
goto done;
pos += digest_info->size;
}
err = 0;
if (req->dst_len < req_ctx->child_req.dst_len - pos)
err = -EOVERFLOW;
req->dst_len = req_ctx->child_req.dst_len - pos;
if (!err)
sg_copy_from_buffer(req->dst,
sg_nents_for_len(req->dst, req->dst_len),
req_ctx->out_buf + pos, req->dst_len);
done:
kzfree(req_ctx->out_buf);
return err;
}
static int pkcs1pad_sign(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
const struct rsa_asn1_template *digest_info = NULL;
int err;
unsigned int ps_end, digest_size = 0;
if (!ctx->key_size)
return -EINVAL;
if (ctx->hash_name) {
digest_info = rsa_lookup_asn1(ctx->hash_name);
if (!digest_info)
return -EINVAL;
digest_size = digest_info->size;
}
if (req->src_len + digest_size > ctx->key_size - 11)
return -EOVERFLOW;
if (req->dst_len < ctx->key_size) {
req->dst_len = ctx->key_size;
return -EOVERFLOW;
}
if (ctx->key_size > PAGE_SIZE)
return -ENOTSUPP;
/*
* Replace both input and output to add the padding in the input and
* the potential missing leading zeros in the output.
*/
req_ctx->child_req.src = req_ctx->in_sg;
req_ctx->child_req.src_len = ctx->key_size - 1;
req_ctx->child_req.dst = req_ctx->out_sg;
req_ctx->child_req.dst_len = ctx->key_size;
req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC);
if (!req_ctx->in_buf)
return -ENOMEM;
ps_end = ctx->key_size - digest_size - req->src_len - 2;
req_ctx->in_buf[0] = 0x01;
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);
}
pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
ctx->key_size - 1 - req->src_len, req->src);
req_ctx->out_buf = kmalloc(ctx->key_size,
(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC);
if (!req_ctx->out_buf) {
kfree(req_ctx->in_buf);
return -ENOMEM;
}
pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
ctx->key_size, NULL);
akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
pkcs1pad_encrypt_sign_complete_cb, req);
err = crypto_akcipher_sign(&req_ctx->child_req);
if (err != -EINPROGRESS &&
(err != -EBUSY ||
!(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
return pkcs1pad_encrypt_sign_complete(req, err);
return err;
}
static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
{
const struct rsa_asn1_template *digest_info;
struct crypto_attr_type *algt;
struct akcipher_instance *inst;
struct pkcs1pad_inst_ctx *ctx;
struct crypto_akcipher_spawn *spawn;
struct akcipher_alg *rsa_alg;
const char *rsa_alg_name;
const char *hash_name;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
return -EINVAL;
rsa_alg_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(rsa_alg_name))
return PTR_ERR(rsa_alg_name);
hash_name = crypto_attr_alg_name(tb[2]);
if (IS_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)
return -ENOMEM;
ctx = akcipher_instance_ctx(inst);
spawn = &ctx->spawn;
ctx->digest_info = digest_info;
crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
crypto_requires_sync(algt->type, algt->mask));
if (err)
goto out_free_inst;
rsa_alg = crypto_spawn_akcipher_alg(spawn);
err = -ENAMETOOLONG;
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;
inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
inst->alg.init = pkcs1pad_init_tfm;
inst->alg.exit = pkcs1pad_exit_tfm;
inst->alg.encrypt = pkcs1pad_encrypt;
inst->alg.decrypt = pkcs1pad_decrypt;
inst->alg.sign = pkcs1pad_sign;
inst->alg.verify = pkcs1pad_verify;
inst->alg.set_pub_key = pkcs1pad_set_pub_key;
inst->alg.set_priv_key = pkcs1pad_set_priv_key;
inst->alg.max_size = pkcs1pad_get_max_size;
inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
inst->free = pkcs1pad_free;
err = akcipher_register_instance(tmpl, inst);
if (err)
goto out_drop_alg;
return 0;
out_drop_alg:
crypto_drop_akcipher(spawn);
out_free_inst:
kfree(inst);
return err;
}