/* Writes the value of the datum in the given ASN1_TYPE as a string.
*/
int
_gnutls_x509_write_string(ASN1_TYPE c, const char *root,
const gnutls_datum_t * data, unsigned int etype)
{
int ret;
gnutls_datum_t val = { NULL, 0 };
ret =
_gnutls_x509_encode_string(etype, data->data, data->size,
&val);
if (ret < 0)
return gnutls_assert_val(ret);
/* Write the data.
*/
ret = asn1_write_value(c, root, val.data, val.size);
if (ret != ASN1_SUCCESS) {
gnutls_assert();
ret = _gnutls_asn2err(ret);
goto cleanup;
}
ret = 0;
cleanup:
_gnutls_free_datum(&val);
return ret;
}
/**
* gnutls_tpm_privkey_generate:
* @pk: the public key algorithm
* @bits: the security bits
* @srk_password: a password to protect the exported key (optional)
* @key_password: the password for the TPM (optional)
* @format: the format of the private key
* @pub_format: the format of the public key
* @privkey: the generated key
* @pubkey: the corresponding public key (may be null)
* @flags: should be a list of GNUTLS_TPM_* flags
*
* This function will generate a private key in the TPM
* chip. The private key will be generated within the chip
* and will be exported in a wrapped with TPM's master key
* form. Furthermore the wrapped key can be protected with
* the provided @password.
*
* Note that bits in TPM is quantized value. If the input value
* is not one of the allowed values, then it will be quantized to
* one of 512, 1024, 2048, 4096, 8192 and 16384.
*
* Allowed flags are:
*
* %GNUTLS_TPM_KEY_SIGNING: Generate a signing key instead of a legacy,
* %GNUTLS_TPM_REGISTER_KEY: Register the generate key in TPM. In that
* case @privkey would contain a URL with the UUID.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
* negative error value.
*
* Since: 3.1.0
**/
int
gnutls_tpm_privkey_generate(gnutls_pk_algorithm_t pk, unsigned int bits,
const char *srk_password,
const char *key_password,
gnutls_tpmkey_fmt_t format,
gnutls_x509_crt_fmt_t pub_format,
gnutls_datum_t * privkey,
gnutls_datum_t * pubkey, unsigned int flags)
{
TSS_FLAG tpm_flags = TSS_KEY_VOLATILE;
TSS_HKEY key_ctx;
TSS_RESULT tssret;
int ret;
void *tdata;
UINT32 tint;
gnutls_datum_t tmpkey = { NULL, 0 };
TSS_HPOLICY key_policy;
gnutls_pubkey_t pub;
struct tpm_ctx_st s;
TSS_FLAG storage_type;
TSS_HTPM htpm;
uint8_t buf[32];
if (flags & GNUTLS_TPM_KEY_SIGNING)
tpm_flags |= TSS_KEY_TYPE_SIGNING;
else
tpm_flags |= TSS_KEY_TYPE_LEGACY;
if (flags & GNUTLS_TPM_KEY_USER)
storage_type = TSS_PS_TYPE_USER;
else
storage_type = TSS_PS_TYPE_SYSTEM;
if (bits <= 512)
tpm_flags |= TSS_KEY_SIZE_512;
else if (bits <= 1024)
tpm_flags |= TSS_KEY_SIZE_1024;
else if (bits <= 2048)
tpm_flags |= TSS_KEY_SIZE_2048;
else if (bits <= 4096)
tpm_flags |= TSS_KEY_SIZE_4096;
else if (bits <= 8192)
tpm_flags |= TSS_KEY_SIZE_8192;
else
tpm_flags |= TSS_KEY_SIZE_16384;
ret = tpm_open_session(&s, srk_password);
if (ret < 0)
return gnutls_assert_val(ret);
/* put some randomness into TPM.
* Let's not trust it completely.
*/
tssret = Tspi_Context_GetTpmObject(s.tpm_ctx, &htpm);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_cc;
}
ret = _gnutls_rnd(GNUTLS_RND_RANDOM, buf, sizeof(buf));
if (ret < 0) {
gnutls_assert();
goto err_cc;
}
tssret = Tspi_TPM_StirRandom(htpm, sizeof(buf), buf);
if (tssret) {
gnutls_assert();
}
tssret =
Tspi_Context_CreateObject(s.tpm_ctx, TSS_OBJECT_TYPE_RSAKEY,
tpm_flags, &key_ctx);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_cc;
}
tssret =
Tspi_SetAttribUint32(key_ctx, TSS_TSPATTRIB_KEY_INFO,
TSS_TSPATTRIB_KEYINFO_SIGSCHEME,
TSS_SS_RSASSAPKCS1V15_DER);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_sa;
}
/* set the password of the actual key */
if (key_password) {
tssret =
Tspi_GetPolicyObject(key_ctx, TSS_POLICY_USAGE,
&key_policy);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_sa;
}
tssret = myTspi_Policy_SetSecret(key_policy,
SAFE_LEN(key_password),
(void *) key_password);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_sa;
}
}
tssret = Tspi_Key_CreateKey(key_ctx, s.srk, 0);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_sa;
}
if (flags & GNUTLS_TPM_REGISTER_KEY) {
TSS_UUID key_uuid;
ret = randomize_uuid(&key_uuid);
if (ret < 0) {
gnutls_assert();
goto err_sa;
}
tssret =
Tspi_Context_RegisterKey(s.tpm_ctx, key_ctx,
storage_type, key_uuid,
TSS_PS_TYPE_SYSTEM, srk_uuid);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_sa;
}
ret =
encode_tpmkey_url((char **) &privkey->data, &key_uuid,
storage_type);
if (ret < 0) {
TSS_HKEY tkey;
Tspi_Context_UnregisterKey(s.tpm_ctx, storage_type,
key_uuid, &tkey);
gnutls_assert();
goto err_sa;
}
privkey->size = strlen((char *) privkey->data);
} else { /* get the key as blob */
tssret =
Tspi_GetAttribData(key_ctx, TSS_TSPATTRIB_KEY_BLOB,
TSS_TSPATTRIB_KEYBLOB_BLOB, &tint,
(void *) &tdata);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto err_sa;
}
if (format == GNUTLS_TPMKEY_FMT_CTK_PEM) {
ret =
_gnutls_x509_encode_string
(ASN1_ETYPE_OCTET_STRING, tdata, tint,
&tmpkey);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
ret =
_gnutls_fbase64_encode("TSS KEY BLOB",
tmpkey.data,
tmpkey.size, privkey);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
} else {
UINT32 tint2;
tmpkey.size = tint + 32; /* spec says no more than 20 */
tmpkey.data = gnutls_malloc(tmpkey.size);
if (tmpkey.data == NULL) {
gnutls_assert();
ret = GNUTLS_E_MEMORY_ERROR;
goto cleanup;
}
tint2 = tmpkey.size;
tssret =
Tspi_EncodeDER_TssBlob(tint, tdata,
TSS_BLOB_TYPE_PRIVATEKEY,
&tint2, tmpkey.data);
if (tssret != 0) {
gnutls_assert();
ret = tss_err(tssret);
goto cleanup;
}
tmpkey.size = tint2;
privkey->data = tmpkey.data;
privkey->size = tmpkey.size;
tmpkey.data = NULL;
}
}
/* read the public key */
if (pubkey != NULL) {
size_t psize;
ret = gnutls_pubkey_init(&pub);
if (ret < 0) {
gnutls_assert();
goto privkey_cleanup;
}
ret = read_pubkey(pub, key_ctx, &psize);
if (ret < 0) {
gnutls_assert();
goto privkey_cleanup;
}
psize += 512;
pubkey->data = gnutls_malloc(psize);
if (pubkey->data == NULL) {
gnutls_assert();
ret = GNUTLS_E_MEMORY_ERROR;
goto pubkey_cleanup;
}
ret =
gnutls_pubkey_export(pub, pub_format, pubkey->data,
&psize);
if (ret < 0) {
gnutls_assert();
goto pubkey_cleanup;
}
pubkey->size = psize;
gnutls_pubkey_deinit(pub);
}
ret = 0;
goto cleanup;
pubkey_cleanup:
gnutls_pubkey_deinit(pub);
privkey_cleanup:
gnutls_free(privkey->data);
privkey->data = NULL;
cleanup:
gnutls_free(tmpkey.data);
tmpkey.data = NULL;
err_sa:
Tspi_Context_CloseObject(s.tpm_ctx, key_ctx);
err_cc:
tpm_close_session(&s);
return ret;
}
/* Encodes a private key to the raw format PKCS #8 needs.
* For RSA it is a PKCS #1 DER private key and for DSA it is
* an ASN.1 INTEGER of the x value.
*/
inline static int
_encode_privkey(gnutls_x509_privkey_t pkey, gnutls_datum_t * raw)
{
int ret;
ASN1_TYPE spk = ASN1_TYPE_EMPTY;
switch (pkey->params.algo) {
case GNUTLS_PK_EDDSA_ED25519:
/* we encode as octet string (which is going to be stored inside
* another octet string). No comments. */
ret = _gnutls_x509_encode_string(ASN1_ETYPE_OCTET_STRING,
pkey->params.raw_priv.data, pkey->params.raw_priv.size,
raw);
if (ret < 0)
gnutls_assert();
return ret;
case GNUTLS_PK_GOST_01:
case GNUTLS_PK_GOST_12_256:
case GNUTLS_PK_GOST_12_512:
if ((ret = asn1_create_element
(_gnutls_get_gnutls_asn(), "GNUTLS.GOSTPrivateKey", &spk))
!= ASN1_SUCCESS) {
gnutls_assert();
ret = _gnutls_asn2err(ret);
goto error;
}
ret = _gnutls_x509_write_key_int_le(spk, "", pkey->params.params[GOST_K]);
if (ret < 0) {
gnutls_assert();
goto error;
}
ret = _gnutls_x509_der_encode(spk, "", raw, 0);
if (ret < 0) {
gnutls_assert();
goto error;
}
asn1_delete_structure2(&spk, ASN1_DELETE_FLAG_ZEROIZE);
break;
case GNUTLS_PK_RSA:
case GNUTLS_PK_RSA_PSS:
case GNUTLS_PK_ECDSA:
ret =
_gnutls_x509_export_int2(pkey->key, GNUTLS_X509_FMT_DER,
"", raw);
if (ret < 0) {
gnutls_assert();
goto error;
}
break;
case GNUTLS_PK_DSA:
/* DSAPublicKey == INTEGER */
if ((ret = asn1_create_element
(_gnutls_get_gnutls_asn(), "GNUTLS.DSAPublicKey",
&spk))
!= ASN1_SUCCESS) {
gnutls_assert();
return _gnutls_asn2err(ret);
}
ret =
_gnutls_x509_write_int(spk, "", pkey->params.params[4],
1);
if (ret < 0) {
gnutls_assert();
goto error;
}
ret = _gnutls_x509_der_encode(spk, "", raw, 0);
if (ret < 0) {
gnutls_assert();
goto error;
}
asn1_delete_structure2(&spk, ASN1_DELETE_FLAG_ZEROIZE);
break;
default:
gnutls_assert();
return GNUTLS_E_INVALID_REQUEST;
}
return 0;
error:
asn1_delete_structure2(&spk, ASN1_DELETE_FLAG_ZEROIZE);
asn1_delete_structure(&spk);
return ret;
}