/*
* use the AUTH2_COMMAND form of unseal, to authorize both key and blob
*/
static int tpm_unseal(struct tpm_buf *tb,
uint32_t keyhandle, const unsigned char *keyauth,
const unsigned char *blob, int bloblen,
const unsigned char *blobauth,
unsigned char *data, unsigned int *datalen)
{
unsigned char nonceodd[TPM_NONCE_SIZE];
unsigned char enonce1[TPM_NONCE_SIZE];
unsigned char enonce2[TPM_NONCE_SIZE];
unsigned char authdata1[SHA1_DIGEST_SIZE];
unsigned char authdata2[SHA1_DIGEST_SIZE];
uint32_t authhandle1 = 0;
uint32_t authhandle2 = 0;
unsigned char cont = 0;
uint32_t ordinal;
uint32_t keyhndl;
int ret;
/* sessions for unsealing key and data */
ret = oiap(tb, &authhandle1, enonce1);
if (ret < 0) {
pr_info("trusted_key: oiap failed (%d)\n", ret);
return ret;
}
ret = oiap(tb, &authhandle2, enonce2);
if (ret < 0) {
pr_info("trusted_key: oiap failed (%d)\n", ret);
return ret;
}
ordinal = htonl(TPM_ORD_UNSEAL);
keyhndl = htonl(SRKHANDLE);
ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE);
if (ret != TPM_NONCE_SIZE) {
pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
return ret;
}
ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
enonce1, nonceodd, cont, sizeof(uint32_t),
&ordinal, bloblen, blob, 0, 0);
if (ret < 0)
return ret;
ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
enonce2, nonceodd, cont, sizeof(uint32_t),
&ordinal, bloblen, blob, 0, 0);
if (ret < 0)
return ret;
/* build and send TPM request packet */
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
store32(tb, TPM_UNSEAL_SIZE + bloblen);
store32(tb, TPM_ORD_UNSEAL);
store32(tb, keyhandle);
storebytes(tb, blob, bloblen);
store32(tb, authhandle1);
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
store32(tb, authhandle2);
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
if (ret < 0) {
pr_info("trusted_key: authhmac failed (%d)\n", ret);
return ret;
}
*datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
keyauth, SHA1_DIGEST_SIZE,
blobauth, SHA1_DIGEST_SIZE,
sizeof(uint32_t), TPM_DATA_OFFSET,
*datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
0);
if (ret < 0) {
pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
return ret;
}
memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
return 0;
}
/*
* Have the TPM seal(encrypt) the trusted key, possibly based on
* Platform Configuration Registers (PCRs). AUTH1 for sealing key.
*/
static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
uint32_t keyhandle, const unsigned char *keyauth,
const unsigned char *data, uint32_t datalen,
unsigned char *blob, uint32_t *bloblen,
const unsigned char *blobauth,
const unsigned char *pcrinfo, uint32_t pcrinfosize)
{
struct osapsess sess;
struct tpm_digests *td;
unsigned char cont;
uint32_t ordinal;
uint32_t pcrsize;
uint32_t datsize;
int sealinfosize;
int encdatasize;
int storedsize;
int ret;
int i;
/* alloc some work space for all the hashes */
td = kmalloc(sizeof *td, GFP_KERNEL);
if (!td)
return -ENOMEM;
/* get session for sealing key */
ret = osap(tb, &sess, keyauth, keytype, keyhandle);
if (ret < 0)
goto out;
dump_sess(&sess);
/* calculate encrypted authorization value */
memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
if (ret < 0)
goto out;
ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE);
if (ret != TPM_NONCE_SIZE)
goto out;
ordinal = htonl(TPM_ORD_SEAL);
datsize = htonl(datalen);
pcrsize = htonl(pcrinfosize);
cont = 0;
/* encrypt data authorization key */
for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
td->encauth[i] = td->xorhash[i] ^ blobauth[i];
/* calculate authorization HMAC value */
if (pcrinfosize == 0) {
/* no pcr info specified */
ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
sess.enonce, td->nonceodd, cont,
sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
td->encauth, sizeof(uint32_t), &pcrsize,
sizeof(uint32_t), &datsize, datalen, data, 0,
0);
} else {
/* pcr info specified */
ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
sess.enonce, td->nonceodd, cont,
sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
td->encauth, sizeof(uint32_t), &pcrsize,
pcrinfosize, pcrinfo, sizeof(uint32_t),
&datsize, datalen, data, 0, 0);
}
if (ret < 0)
goto out;
/* build and send the TPM request packet */
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
store32(tb, TPM_ORD_SEAL);
store32(tb, keyhandle);
storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
store32(tb, pcrinfosize);
storebytes(tb, pcrinfo, pcrinfosize);
store32(tb, datalen);
storebytes(tb, data, datalen);
store32(tb, sess.handle);
storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
if (ret < 0)
goto out;
/* calculate the size of the returned Blob */
sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
sizeof(uint32_t) + sealinfosize);
storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
sizeof(uint32_t) + encdatasize;
/* check the HMAC in the response */
ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
0);
/* copy the returned blob to caller */
if (!ret) {
memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
*bloblen = storedsize;
}
out:
kfree(td);
return ret;
}
/*
* Load a TPM key from the blob provided by userspace
*/
static int tpm_loadkey2(struct tpm_buf *tb,
uint32_t keyhandle, unsigned char *keyauth,
const unsigned char *keyblob, int keybloblen,
uint32_t *newhandle)
{
unsigned char nonceodd[TPM_NONCE_SIZE];
unsigned char enonce[TPM_NONCE_SIZE];
unsigned char authdata[SHA1_DIGEST_SIZE];
uint32_t authhandle = 0;
unsigned char cont = 0;
uint32_t ordinal;
int ret;
ordinal = htonl(TPM_ORD_LOADKEY2);
/* session for loading the key */
ret = oiap(tb, &authhandle, enonce);
if (ret < 0) {
pr_info("oiap failed (%d)\n", ret);
return ret;
}
/* generate odd nonce */
ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
if (ret < 0) {
pr_info("tpm_get_random failed (%d)\n", ret);
return ret;
}
/* calculate authorization HMAC value */
ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
nonceodd, cont, sizeof(uint32_t), &ordinal,
keybloblen, keyblob, 0, 0);
if (ret < 0)
return ret;
/* build the request buffer */
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
store32(tb, TPM_LOADKEY2_SIZE + keybloblen);
store32(tb, TPM_ORD_LOADKEY2);
store32(tb, keyhandle);
storebytes(tb, keyblob, keybloblen);
store32(tb, authhandle);
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, authdata, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
pr_info("authhmac failed (%d)\n", ret);
return ret;
}
ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth,
SHA1_DIGEST_SIZE, 0, 0);
if (ret < 0) {
pr_info("TSS_checkhmac1 failed (%d)\n", ret);
return ret;
}
*newhandle = LOAD32(tb->data, TPM_DATA_OFFSET);
return 0;
}
/* Open and lock the cache file. If mode is FCC_OPEN_AND_ERASE, initialize it
* with a header. Call with the mutex locked. */
static krb5_error_code
open_cache_file(krb5_context context, krb5_ccache id, int mode)
{
krb5_os_context os_ctx = &context->os_context;
krb5_error_code ret;
fcc_data *data = id->data;
char fcc_fvno[2];
uint16_t fcc_flen, fcc_tag, fcc_taglen;
uint32_t time_offset, usec_offset;
int f, open_flag, lock_flag, cnt;
char buf[1024];
k5_cc_mutex_assert_locked(context, &data->lock);
invalidate_cache(data);
if (data->fd != NO_FILE) {
/* Don't know what state it's in; shut down and start anew. */
(void)krb5_unlock_file(context, data->fd);
(void)close(data->fd);
data->fd = NO_FILE;
}
switch (mode) {
case FCC_OPEN_AND_ERASE:
unlink(data->filename);
open_flag = O_CREAT | O_EXCL | O_TRUNC | O_RDWR;
break;
case FCC_OPEN_RDWR:
open_flag = O_RDWR;
break;
case FCC_OPEN_RDONLY:
default:
open_flag = O_RDONLY;
break;
}
f = THREEPARAMOPEN(data->filename, open_flag | O_BINARY, 0600);
if (f == NO_FILE) {
if (errno == ENOENT) {
ret = KRB5_FCC_NOFILE;
k5_setmsg(context, ret, _("Credentials cache file '%s' not found"),
data->filename);
return ret;
} else {
return interpret_errno(context, errno);
}
}
set_cloexec_fd(f);
data->mode = mode;
if (data->mode == FCC_OPEN_RDONLY)
lock_flag = KRB5_LOCKMODE_SHARED;
else
lock_flag = KRB5_LOCKMODE_EXCLUSIVE;
ret = krb5_lock_file(context, f, lock_flag);
if (ret) {
(void)close(f);
return ret;
}
if (mode == FCC_OPEN_AND_ERASE) {
/* write the version number */
store_16_be(context->fcc_default_format, fcc_fvno);
data->version = context->fcc_default_format;
cnt = write(f, fcc_fvno, 2);
if (cnt != 2) {
ret = (cnt == -1) ? interpret_errno(context, errno) : KRB5_CC_IO;
goto done;
}
data->fd = f;
if (data->version == FVNO_4) {
/* V4 of the credentials cache format allows for header tags */
fcc_flen = 0;
if (os_ctx->os_flags & KRB5_OS_TOFFSET_VALID)
fcc_flen += 2 + 2 + 4 + 4;
/* Write header length. */
ret = store16(context, id, fcc_flen);
if (ret)
goto done;
if (os_ctx->os_flags & KRB5_OS_TOFFSET_VALID) {
/* Write time offset tag. */
fcc_tag = FCC_TAG_DELTATIME;
fcc_taglen = 2 * 4;
ret = store16(context, id, fcc_tag);
if (ret)
goto done;
ret = store16(context, id, fcc_taglen);
if (ret)
goto done;
ret = store32(context, id, os_ctx->time_offset);
if (ret)
goto done;
ret = store32(context, id, os_ctx->usec_offset);
if (ret)
goto done;
}
}
invalidate_cache(data);
goto done;
}
/* Verify a valid version number is there. */
invalidate_cache(data);
if (read(f, fcc_fvno, 2) != 2) {
ret = KRB5_CC_FORMAT;
goto done;
}
data->version = load_16_be(fcc_fvno);
if (data->version != FVNO_4 && data->version != FVNO_3 &&
data->version != FVNO_2 && data->version != FVNO_1) {
ret = KRB5_CCACHE_BADVNO;
goto done;
}
data->fd = f;
if (data->version == FVNO_4) {
if (read16(context, id, &fcc_flen) || fcc_flen > sizeof(buf)) {
ret = KRB5_CC_FORMAT;
goto done;
}
while (fcc_flen) {
if (fcc_flen < 2 * 2 || read16(context, id, &fcc_tag) ||
read16(context, id, &fcc_taglen) ||
fcc_taglen > fcc_flen - 2 * 2) {
ret = KRB5_CC_FORMAT;
goto done;
}
switch (fcc_tag) {
case FCC_TAG_DELTATIME:
if (fcc_taglen != 2 * 4) {
ret = KRB5_CC_FORMAT;
goto done;
}
if (!(context->library_options & KRB5_LIBOPT_SYNC_KDCTIME) ||
(os_ctx->os_flags & KRB5_OS_TOFFSET_VALID)) {
if (read_bytes(context, id, buf, fcc_taglen)) {
ret = KRB5_CC_FORMAT;
goto done;
}
break;
}
if (read32(context, id, NULL, &time_offset) ||
read32(context, id, NULL, &usec_offset)) {
ret = KRB5_CC_FORMAT;
goto done;
}
os_ctx->time_offset = time_offset;
os_ctx->usec_offset = usec_offset;
os_ctx->os_flags =
((os_ctx->os_flags & ~KRB5_OS_TOFFSET_TIME) |
KRB5_OS_TOFFSET_VALID);
break;
default:
if (fcc_taglen && read_bytes(context, id, buf, fcc_taglen)) {
ret = KRB5_CC_FORMAT;
goto done;
}
break;
}
fcc_flen -= (2 * 2 + fcc_taglen);
}
}
done:
if (ret) {
data->fd = -1;
(void)krb5_unlock_file(context, f);
(void)close(f);
}
return ret;
}
/*
* Sign a blob provided by userspace (that has had the hash function applied)
* using a specific key handle. The handle is assumed to have been previously
* loaded by e.g. LoadKey2.
*
* Note that the key signature scheme of the used key should be set to
* TPM_SS_RSASSAPKCS1v15_DER. This allows the hashed input to be of any size
* up to key_length_in_bytes - 11 and not be limited to size 20 like the
* TPM_SS_RSASSAPKCS1v15_SHA1 signature scheme.
*/
static int tpm_sign(struct tpm_buf *tb,
uint32_t keyhandle, unsigned char *keyauth,
const unsigned char *blob, uint32_t bloblen,
void *out, uint32_t outlen)
{
unsigned char nonceodd[TPM_NONCE_SIZE];
unsigned char enonce[TPM_NONCE_SIZE];
unsigned char authdata[SHA1_DIGEST_SIZE];
uint32_t authhandle = 0;
unsigned char cont = 0;
uint32_t ordinal;
uint32_t datalen;
int ret;
ordinal = htonl(TPM_ORD_SIGN);
datalen = htonl(bloblen);
/* session for loading the key */
ret = oiap(tb, &authhandle, enonce);
if (ret < 0) {
pr_info("oiap failed (%d)\n", ret);
return ret;
}
/* generate odd nonce */
ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
if (ret < 0) {
pr_info("tpm_get_random failed (%d)\n", ret);
return ret;
}
/* calculate authorization HMAC value */
ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
nonceodd, cont, sizeof(uint32_t), &ordinal,
sizeof(uint32_t), &datalen,
bloblen, blob, 0, 0);
if (ret < 0)
return ret;
/* build the request buffer */
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
store32(tb, TPM_SIGN_SIZE + bloblen);
store32(tb, TPM_ORD_SIGN);
store32(tb, keyhandle);
store32(tb, bloblen);
storebytes(tb, blob, bloblen);
store32(tb, authhandle);
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, authdata, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
if (ret < 0) {
pr_info("authhmac failed (%d)\n", ret);
return ret;
}
datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
keyauth, SHA1_DIGEST_SIZE,
sizeof(uint32_t), TPM_DATA_OFFSET,
datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
0, 0);
if (ret < 0) {
pr_info("TSS_checkhmac1 failed (%d)\n", ret);
return ret;
}
memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
min(datalen, outlen));
return datalen;
}
