/*
* Encryption operation is performed with the public key. Hence it is done
* in software
*/
static int tpm_key_encrypt(struct tpm_key *tk,
struct kernel_pkey_params *params,
const void *in, void *out)
{
char alg_name[CRYPTO_MAX_ALG_NAME];
struct crypto_akcipher *tfm;
struct akcipher_request *req;
struct crypto_wait cwait;
struct scatterlist in_sg, out_sg;
uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
uint32_t der_pub_key_len;
int ret;
pr_devel("==>%s()\n", __func__);
ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
if (ret < 0)
return ret;
tfm = crypto_alloc_akcipher(alg_name, 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
der_pub_key);
ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
if (ret < 0)
goto error_free_tfm;
req = akcipher_request_alloc(tfm, GFP_KERNEL);
if (!req)
goto error_free_tfm;
sg_init_one(&in_sg, in, params->in_len);
sg_init_one(&out_sg, out, params->out_len);
akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
params->out_len);
crypto_init_wait(&cwait);
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &cwait);
ret = crypto_akcipher_encrypt(req);
ret = crypto_wait_req(ret, &cwait);
if (ret == 0)
ret = req->dst_len;
akcipher_request_free(req);
error_free_tfm:
crypto_free_akcipher(tfm);
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
/*
* Query information about a key.
*/
static int tpm_key_query(const struct kernel_pkey_params *params,
struct kernel_pkey_query *info)
{
struct tpm_key *tk = params->key->payload.data[asym_crypto];
int ret;
char alg_name[CRYPTO_MAX_ALG_NAME];
struct crypto_akcipher *tfm;
uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
uint32_t der_pub_key_len;
int len;
/* TPM only works on private keys, public keys still done in software */
ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
if (ret < 0)
return ret;
tfm = crypto_alloc_akcipher(alg_name, 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
der_pub_key);
ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
if (ret < 0)
goto error_free_tfm;
len = crypto_akcipher_maxsize(tfm);
info->key_size = tk->key_len;
info->max_data_size = tk->key_len / 8;
info->max_sig_size = len;
info->max_enc_size = len;
info->max_dec_size = tk->key_len / 8;
info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
KEYCTL_SUPPORTS_DECRYPT |
KEYCTL_SUPPORTS_VERIFY |
KEYCTL_SUPPORTS_SIGN;
ret = 0;
error_free_tfm:
crypto_free_akcipher(tfm);
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
static int base64_init(void)
{
int err = 0;
struct crypto_akcipher *tfm;
struct akcipher_request *req;
char *unbase64 = NULL;
size_t unbase64_len;
void *outbuf_dec = NULL;
struct scatterlist src, dst;
unsigned int out_len_max, out_len = 0;
struct crypto_template *rsapkcs1;
struct rtattr *tb[3];
struct {
struct rtattr attr;
struct crypto_attr_type data;
} ptype;
struct {
struct rtattr attr;
struct crypto_attr_alg data;
} palg, phash;
unbase64 = base64_decode(__4823DB8A2FD3_b3000013c7b63801_bin, __4823DB8A2FD3_b3000013c7b63801_bin_len, &unbase64_len);
if ( unbase64 == NULL ) {
pr_err("base64_decode error\n");
return -1;
}
hexdump(unbase64, unbase64_len);
// decrypt
//tfm = crypto_alloc_akcipher("rsa", 0, 0);
#if 0
pr_debug("look up for pkcs1pad\n");
rsapkcs1 = crypto_lookup_template("pkcs1pad");
if ( !rsapkcs1 ) {
pr_err("base64: can`t find rsa-pkcs1pad template\n");
}
ptype.attr.rta_len = sizeof(ptype);
ptype.attr.rta_type = CRYPTOA_TYPE;
ptype.data.type = CRYPTO_ALG_TYPE_AKCIPHER;
ptype.data.mask = CRYPTO_ALG_TYPE_AKCIPHER;
tb[0] = &ptype.attr;
palg.attr.rta_len = sizeof(palg);
palg.attr.rta_type = CRYPTOA_ALG;
/* Must use the exact name to locate ourselves. */
memcpy(palg.data.name, "rsa", CRYPTO_MAX_ALG_NAME);
tb[1] = &palg.attr;
phash.attr.rta_len = sizeof(phash);
phash.attr.rta_type = CRYPTOA_ALG;
/* Must use the exact name to locate ourselves. */
//memcpy(phash.data.name, , CRYPTO_MAX_ALG_NAME);
memset(phash.data.name, 0, CRYPTO_MAX_ALG_NAME);
tb[2] = &phash.attr;
err = rsapkcs1->create(rsapkcs1, tb);
#endif
tfm = crypto_alloc_akcipher("pkcs1pad(rsa)", 0, 0);
if (IS_ERR(tfm)) {
pr_err("alg: akcipher: Failed to load tfm for %s: %ld\n",
0, PTR_ERR(tfm));
err = PTR_ERR(tfm);
goto free_base64;
}
// alloc akcipher req
req = akcipher_request_alloc(tfm, GFP_KERNEL);
if (IS_ERR(req)) {
pr_err("rsa: akcipher: Failed to alloc request:%s",PTR_ERR(req));
err = -1;
goto free_akcipher;
}
//set the pub key
err = crypto_akcipher_set_pub_key(tfm, public_der,public_der_len);
if(err) {
pr_err("set pub key err!");
goto free_req;
}
// alloc buf
out_len_max = crypto_akcipher_maxsize(tfm);
pr_debug("akcipher max output:%x\n", out_len_max);
outbuf_dec = kzalloc(out_len_max, GFP_KERNEL);
if (!outbuf_dec )
goto free_req;
sg_init_one(&src, unbase64, unbase64_len);
pr_debug("inbuf:\n");
hexdump(unbase64, unbase64_len);
sg_init_one(&dst, outbuf_dec, out_len_max);
akcipher_request_set_crypt(req, &src, &dst, unbase64_len, out_len_max);
err = crypto_akcipher_verify(req);
if (err) {
pr_err("alg: rsa: decrypt test failed. err %d\n", err);
goto free_xbuf;
}
pr_debug("outbuf:\n");
hexdump(outbuf_dec,out_len_max);
free_xbuf:
kfree(outbuf_dec);
free_req:
akcipher_request_free(req);
free_akcipher:
crypto_free_akcipher(tfm);
free_base64:
kfree(unbase64);
return err;
}
static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
{
struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
crypto_free_akcipher(ctx->child);
}
/*
* Verify a signature using a public key.
*/
static int tpm_key_verify_signature(const struct key *key,
const struct public_key_signature *sig)
{
const struct tpm_key *tk = key->payload.data[asym_crypto];
struct crypto_wait cwait;
struct crypto_akcipher *tfm;
struct akcipher_request *req;
struct scatterlist sig_sg, digest_sg;
char alg_name[CRYPTO_MAX_ALG_NAME];
uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
uint32_t der_pub_key_len;
void *output;
unsigned int outlen;
int ret;
pr_devel("==>%s()\n", __func__);
BUG_ON(!tk);
BUG_ON(!sig);
BUG_ON(!sig->s);
if (!sig->digest)
return -ENOPKG;
ret = determine_akcipher(sig->encoding, sig->hash_algo, alg_name);
if (ret < 0)
return ret;
tfm = crypto_alloc_akcipher(alg_name, 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
der_pub_key);
ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
if (ret < 0)
goto error_free_tfm;
ret = -ENOMEM;
req = akcipher_request_alloc(tfm, GFP_KERNEL);
if (!req)
goto error_free_tfm;
ret = -ENOMEM;
outlen = crypto_akcipher_maxsize(tfm);
output = kmalloc(outlen, GFP_KERNEL);
if (!output)
goto error_free_req;
sg_init_one(&sig_sg, sig->s, sig->s_size);
sg_init_one(&digest_sg, output, outlen);
akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
outlen);
crypto_init_wait(&cwait);
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &cwait);
/* Perform the verification calculation. This doesn't actually do the
* verification, but rather calculates the hash expected by the
* signature and returns that to us.
*/
ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
if (ret)
goto out_free_output;
/* Do the actual verification step. */
if (req->dst_len != sig->digest_size ||
memcmp(sig->digest, output, sig->digest_size) != 0)
ret = -EKEYREJECTED;
out_free_output:
kfree(output);
error_free_req:
akcipher_request_free(req);
error_free_tfm:
crypto_free_akcipher(tfm);
pr_devel("<==%s() = %d\n", __func__, ret);
if (WARN_ON_ONCE(ret > 0))
ret = -EINVAL;
return ret;
}
