/*
This file is part of TALER
Copyright (C) 2014-2020 Taler Systems SA
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, see
*/
/**
* @file util/taler-helper-crypto-rsa.c
* @brief Standalone process to perform private key RSA operations
* @author Christian Grothoff
*
* INTEGRATION NOTES:
* - Option 'DURATION_OVERLAP' renamed to 'OVERLAP_DURATION' for consistency;
* => need to update in deployment scripts and default configuration!
* - option 'KEY_DIR' moved from section 'exchange' to 'taler-helper-crypto-rsa'!
*
* Key design points:
* - EVERY thread of the exchange will have its own pair of connections to the
* crypto helpers. This way, every threat will also have its own /keys state
* and avoid the need to synchronize on those.
* - auditor signatures and master signatures are to be kept in the exchange DB,
* and merged with the public keys of the helper by the exchange HTTPD!
* - the main loop of the helper is SINGLE-THREADED, but there are
* threads for crypto-workers which (only) do the signing in parallel,
* working of a work-queue.
* - thread-safety: signing happens in parallel, thus when REMOVING private keys,
* we must ensure that all signers are done before we fully free() the
* private key. This is done by reference counting (as work is always
* assigned and collected by the main thread).
*/
#include "platform.h"
#include "taler_util.h"
#include "taler-helper-crypto-rsa.h"
#include
#include
#include
#include "taler_error_codes.h"
#include "taler_signatures.h"
/**
* Information we keep per denomination.
*/
struct Denomination;
/**
* One particular denomination key.
*/
struct DenominationKey
{
/**
* Kept in a DLL of the respective denomination. Sorted by anchor time.
*/
struct DenominationKey *next;
/**
* Kept in a DLL of the respective denomination. Sorted by anchor time.
*/
struct DenominationKey *prev;
/**
* Denomination this key belongs to.
*/
struct Denomination *denom;
/**
* Name of the file this key is stored under.
*/
char *filename;
/**
* The private key of the denomination.
*/
struct TALER_DenominationPrivateKey denom_priv;
/**
* The public key of the denomination.
*/
struct TALER_DenominationPublicKey denom_pub;
/**
* Hash of this denomination's public key.
*/
struct GNUNET_HashCode h_denom_pub;
/**
* Time at which this key is supposed to become valid.
*/
struct GNUNET_TIME_Absolute anchor;
/**
* Reference counter. Counts the number of threads that are
* using this key at this time.
*/
unsigned int rc;
/**
* Flag set to true if this key has been purged and the memory
* must be freed as soon as @e rc hits zero.
*/
bool purge;
};
struct Denomination
{
/**
* Kept in a DLL. Sorted by #denomination_action_time().
*/
struct Denomination *next;
/**
* Kept in a DLL. Sorted by #denomination_action_time().
*/
struct Denomination *prev;
/**
* Head of DLL of actual keys of this denomination.
*/
struct DenominationKey *keys_head;
/**
* Tail of DLL of actual keys of this denomination.
*/
struct DenominationKey *keys_tail;
/**
* How long can coins be withdrawn (generated)? Should be small
* enough to limit how many coins will be signed into existence with
* the same key, but large enough to still provide a reasonable
* anonymity set.
*/
struct GNUNET_TIME_Relative duration_withdraw;
/**
* What is the configuration section of this denomination type? Also used
* for the directory name where the denomination keys are stored.
*/
char *section;
/**
* Length of (new) RSA keys (in bits).
*/
uint32_t rsa_keysize;
};
/**
* Actively worked on client request.
*/
struct WorkItem;
/**
* Information we keep for a client connected to us.
*/
struct Client
{
/**
* Kept in a DLL.
*/
struct Client *next;
/**
* Kept in a DLL.
*/
struct Client *prev;
/**
* Client address.
*/
struct sockaddr_un addr;
/**
* Number of bytes used in @e addr.
*/
socklen_t addr_size;
};
struct WorkItem
{
/**
* Kept in a DLL.
*/
struct WorkItem *next;
/**
* Kept in a DLL.
*/
struct WorkItem *prev;
/**
* Key to be used for this operation.
*/
struct DenominationKey *dk;
/**
* RSA signature over @e blinded_msg using @e dk. Result of doing the
* work. Initially NULL.
*/
struct GNUNET_CRYPTO_RsaSignature *rsa_signature;
/**
* Coin_ev value to sign.
*/
void *blinded_msg;
/**
* Number of bytes in #blinded_msg.
*/
size_t blinded_msg_size;
/**
* Client address.
*/
struct sockaddr_un addr;
/**
* Number of bytes used in @e addr.
*/
socklen_t addr_size;
};
/**
* Return value from main().
*/
static int global_ret;
/**
* Private key of this security module. Used to sign denomination key
* announcements.
*/
static struct TALER_SecurityModulePrivateKeyP smpriv;
/**
* Public key of this security module.
*/
static struct TALER_SecurityModulePublicKeyP smpub;
/**
* Number of worker threads to use. Default (0) is to use one per CPU core
* available.
* Length of the #workers array.
*/
static unsigned int num_workers;
/**
* Time when the key update is executed.
* Either the actual current time, or a pretended time.
*/
static struct GNUNET_TIME_Absolute now;
/**
* The time for the key update, as passed by the user
* on the command line.
*/
static struct GNUNET_TIME_Absolute now_tmp;
/**
* Handle to the exchange's configuration
*/
static const struct GNUNET_CONFIGURATION_Handle *kcfg;
/**
* Where do we store the keys?
*/
static char *keydir;
/**
* How much should coin creation (@e duration_withdraw) duration overlap
* with the next denomination? Basically, the starting time of two
* denominations is always @e duration_withdraw - #duration_overlap apart.
*/
static struct GNUNET_TIME_Relative overlap_duration;
/**
* How long into the future do we pre-generate keys?
*/
static struct GNUNET_TIME_Relative lookahead_sign;
/**
* All of our denominations, in a DLL. Sorted?
*/
static struct Denomination *denom_head;
/**
* All of our denominations, in a DLL. Sorted?
*/
static struct Denomination *denom_tail;
/**
* Map of hashes of public (RSA) keys to `struct DenominationKey *`
* with the respective private keys.
*/
static struct GNUNET_CONTAINER_MultiHashMap *keys;
/**
* Our listen socket.
*/
static struct GNUNET_NETWORK_Handle *unix_sock;
/**
* Path where we are listening.
*/
static char *unixpath;
/**
* Task run to accept new inbound connections.
*/
static struct GNUNET_SCHEDULER_Task *read_task;
/**
* Task run to generate new keys.
*/
static struct GNUNET_SCHEDULER_Task *keygen_task;
/**
* Head of DLL of clients connected to us.
*/
static struct Client *clients_head;
/**
* Tail of DLL of clients connected to us.
*/
static struct Client *clients_tail;
/**
* Head of DLL with pending signing operations.
*/
static struct WorkItem *work_head;
/**
* Tail of DLL with pending signing operations.
*/
static struct WorkItem *work_tail;
/**
* Lock for the work queue.
*/
static pthread_mutex_t work_lock;
/**
* Condition variable for the semaphore of the work queue.
*/
static pthread_cond_t work_cond = PTHREAD_COND_INITIALIZER;
/**
* Number of items in the work queue. Also used as the semaphore counter.
*/
static unsigned long long work_counter;
/**
* Head of DLL with completed signing operations.
*/
static struct WorkItem *done_head;
/**
* Tail of DLL with completed signing operations.
*/
static struct WorkItem *done_tail;
/**
* Lock for the done queue.
*/
static pthread_mutex_t done_lock;
/**
* Task waiting for work to be done.
*/
static struct GNUNET_SCHEDULER_Task *done_task;
/**
* Signal used by threads to notify the #done_task that they
* completed work that is now in the done queue.
*/
static struct GNUNET_NETWORK_Handle *done_signal;
/**
* Set once we are in shutdown and workers should terminate.
*/
static volatile bool in_shutdown;
/**
* Array of #num_workers sign_worker() threads.
*/
static pthread_t *workers;
/**
* Main function of a worker thread that signs.
*
* @param cls NULL
* @return NULL
*/
static void *
sign_worker (void *cls)
{
(void) cls;
GNUNET_assert (0 == pthread_mutex_lock (&work_lock));
while (! in_shutdown)
{
struct WorkItem *wi;
while (NULL != (wi = work_head))
{
/* take work from queue */
GNUNET_CONTAINER_DLL_remove (work_head,
work_tail,
wi);
work_counter--;
GNUNET_assert (0 == pthread_mutex_unlock (&work_lock));
wi->rsa_signature
= GNUNET_CRYPTO_rsa_sign_blinded (wi->dk->denom_priv.rsa_private_key,
wi->blinded_msg,
wi->blinded_msg_size);
/* put completed work into done queue */
GNUNET_assert (0 == pthread_mutex_lock (&done_lock));
GNUNET_CONTAINER_DLL_insert (done_head,
done_tail,
wi);
GNUNET_assert (0 == pthread_mutex_unlock (&done_lock));
{
uint64_t val = GNUNET_htonll (1);
/* raise #done_signal */
if (sizeof(val) !=
write (GNUNET_NETWORK_get_fd (done_signal),
&val,
sizeof (val)))
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"write(eventfd)");
}
GNUNET_assert (0 == pthread_mutex_lock (&work_lock));
}
/* queue is empty, wait for work */
GNUNET_assert (0 ==
pthread_cond_wait (&work_cond,
&work_lock));
}
GNUNET_assert (0 ==
pthread_mutex_unlock (&work_lock));
return NULL;
}
/**
* Free @a client, releasing all (remaining) state.
*
* @param[in] client data to free
*/
static void
free_client (struct Client *client)
{
GNUNET_CONTAINER_DLL_remove (clients_head,
clients_tail,
client);
GNUNET_free (client);
}
/**
* Function run to read incoming requests from a client.
*
* @param cls the `struct Client`
*/
static void
read_job (void *cls);
/**
* Free @a dk. It must already have been removed from #keys and the
* denomination's DLL.
*
* @param[in] dk key to free
*/
static void
free_dk (struct DenominationKey *dk)
{
GNUNET_free (dk->filename);
GNUNET_CRYPTO_rsa_private_key_free (dk->denom_priv.rsa_private_key);
GNUNET_CRYPTO_rsa_public_key_free (dk->denom_pub.rsa_public_key);
GNUNET_free (dk);
}
/**
* Send a message starting with @a hdr to @a client.
*
* @param addr address where to send the message
* @param addr_size number of bytes in @a addr
* @param hdr beginning of the message, length indicated in size field
* @return #GNUNET_OK on success
*/
static int
transmit (const struct sockaddr_un *addr,
socklen_t addr_size,
const struct GNUNET_MessageHeader *hdr)
{
ssize_t ret;
ret = GNUNET_NETWORK_socket_sendto (unix_sock,
hdr,
ntohs (hdr->size),
(const struct sockaddr *) addr,
addr_size);
if (ret != ntohs (hdr->size))
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO,
"sendto");
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Process completed tasks that are in the #done_head queue, sending
* the result back to the client (and resuming the client).
*
* @param cls NULL
*/
static void
handle_done (void *cls)
{
uint64_t data;
(void) cls;
/* consume #done_signal */
if (sizeof (data) !=
read (GNUNET_NETWORK_get_fd (done_signal),
&data,
sizeof (data)))
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"read(eventfd)");
done_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
done_signal,
&handle_done,
NULL);
GNUNET_assert (0 == pthread_mutex_lock (&done_lock));
while (NULL != done_head)
{
struct WorkItem *wi = done_head;
GNUNET_CONTAINER_DLL_remove (done_head,
done_tail,
wi);
GNUNET_assert (0 == pthread_mutex_unlock (&done_lock));
if (NULL == wi->rsa_signature)
{
struct TALER_CRYPTO_SignFailure sf = {
.header.size = htons (sizeof (sf)),
.header.type = htons (TALER_HELPER_RSA_MT_RES_SIGN_FAILURE),
.ec = htonl (TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE)
};
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Signing request failed, worker failed to produce signature\n");
(void) transmit (&wi->addr,
wi->addr_size,
&sf.header);
}
else
{
struct TALER_CRYPTO_SignResponse *sr;
void *buf;
size_t buf_size;
size_t tsize;
buf_size = GNUNET_CRYPTO_rsa_signature_encode (wi->rsa_signature,
&buf);
tsize = sizeof (*sr) + buf_size;
GNUNET_assert (tsize < UINT16_MAX);
sr = GNUNET_malloc (tsize);
sr->header.size = htons (tsize);
sr->header.type = htons (TALER_HELPER_RSA_MT_RES_SIGNATURE);
memcpy (&sr[1],
buf,
buf_size);
GNUNET_free (buf);
(void) transmit (&wi->addr,
wi->addr_size,
&sr->header);
GNUNET_free (sr);
}
{
struct DenominationKey *dk = wi->dk;
dk->rc--;
if ( (0 == dk->rc) &&
(dk->purge) )
free_dk (dk);
}
GNUNET_free (wi);
GNUNET_assert (0 == pthread_mutex_lock (&done_lock));
}
GNUNET_assert (0 == pthread_mutex_unlock (&done_lock));
}
/**
* Handle @a client request @a sr to create signature. Create the
* signature using the respective key and return the result to
* the client.
*
* @param addr address of the client making the request
* @param addr_size number of bytes in @a addr
* @param sr the request details
*/
static void
handle_sign_request (const struct sockaddr_un *addr,
socklen_t addr_size,
const struct TALER_CRYPTO_SignRequest *sr)
{
struct DenominationKey *dk;
struct WorkItem *wi;
const void *blinded_msg = &sr[1];
size_t blinded_msg_size = ntohs (sr->header.size) - sizeof (*sr);
dk = GNUNET_CONTAINER_multihashmap_get (keys,
&sr->h_denom_pub);
if (NULL == dk)
{
struct TALER_CRYPTO_SignFailure sf = {
.header.size = htons (sizeof (sr)),
.header.type = htons (TALER_HELPER_RSA_MT_RES_SIGN_FAILURE),
.ec = htonl (TALER_EC_EXCHANGE_GENERIC_DENOMINATION_KEY_UNKNOWN)
};
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Signing request failed, denomination key %s unknown\n",
GNUNET_h2s (&sr->h_denom_pub));
(void) transmit (addr,
addr_size,
&sf.header);
return;
}
if (0 !=
GNUNET_TIME_absolute_get_remaining (dk->anchor).rel_value_us)
{
/* it is too early */
struct TALER_CRYPTO_SignFailure sf = {
.header.size = htons (sizeof (sr)),
.header.type = htons (TALER_HELPER_RSA_MT_RES_SIGN_FAILURE),
.ec = htonl (TALER_EC_EXCHANGE_DENOMINATION_HELPER_TOO_EARLY)
};
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Signing request failed, denomination key %s is not yet valid\n",
GNUNET_h2s (&sr->h_denom_pub));
(void) transmit (addr,
addr_size,
&sf.header);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Received request to sign over %u bytes with key %s\n",
(unsigned int) blinded_msg_size,
GNUNET_h2s (&sr->h_denom_pub));
wi = GNUNET_new (struct WorkItem);
wi->addr = *addr;
wi->addr_size = addr_size;
wi->dk = dk;
dk->rc++;
wi->blinded_msg = GNUNET_memdup (blinded_msg,
blinded_msg_size);
wi->blinded_msg_size = blinded_msg_size;
GNUNET_assert (0 == pthread_mutex_lock (&work_lock));
work_counter++;
GNUNET_CONTAINER_DLL_insert (work_head,
work_tail,
wi);
GNUNET_assert (0 == pthread_mutex_unlock (&work_lock));
GNUNET_assert (0 == pthread_cond_signal (&work_cond));
}
/**
* Notify @a client about @a dk becoming available.
*
* @param[in,out] client the client to notify; possible freed if transmission fails
* @param dk the key to notify @a client about
* @return #GNUNET_OK on success
*/
static int
notify_client_dk_add (struct Client *client,
const struct DenominationKey *dk)
{
struct Denomination *denom = dk->denom;
size_t nlen = strlen (denom->section) + 1;
struct TALER_CRYPTO_RsaKeyAvailableNotification *an;
size_t buf_len;
void *buf;
void *p;
size_t tlen;
buf_len = GNUNET_CRYPTO_rsa_public_key_encode (dk->denom_pub.rsa_public_key,
&buf);
GNUNET_assert (buf_len < UINT16_MAX);
GNUNET_assert (nlen < UINT16_MAX);
tlen = buf_len + nlen + sizeof (*an);
GNUNET_assert (tlen < UINT16_MAX);
an = GNUNET_malloc (tlen);
an->header.size = htons ((uint16_t) tlen);
an->header.type = htons (TALER_HELPER_RSA_MT_AVAIL);
an->pub_size = htons ((uint16_t) buf_len);
an->section_name_len = htons ((uint16_t) nlen);
an->anchor_time = GNUNET_TIME_absolute_hton (dk->anchor);
an->duration_withdraw = GNUNET_TIME_relative_hton (denom->duration_withdraw);
TALER_exchange_secmod_rsa_sign (&dk->h_denom_pub,
denom->section,
dk->anchor,
denom->duration_withdraw,
&smpriv,
&an->secm_sig);
an->secm_pub = smpub;
p = (void *) &an[1];
memcpy (p,
buf,
buf_len);
GNUNET_free (buf);
memcpy (p + buf_len,
denom->section,
nlen);
{
int ret = GNUNET_OK;
if (GNUNET_OK !=
transmit (&client->addr,
client->addr_size,
&an->header))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Client %s must have disconnected\n",
client->addr.sun_path);
free_client (client);
ret = GNUNET_SYSERR;
}
GNUNET_free (an);
return ret;
}
}
/**
* Notify @a client about @a dk being purged.
*
* @param[in,out] client the client to notify; possible freed if transmission fails
* @param dk the key to notify @a client about
* @return #GNUNET_OK on success
*/
static int
notify_client_dk_del (struct Client *client,
const struct DenominationKey *dk)
{
struct TALER_CRYPTO_RsaKeyPurgeNotification pn = {
.header.type = htons (TALER_HELPER_RSA_MT_PURGE),
.header.size = htons (sizeof (pn)),
.h_denom_pub = dk->h_denom_pub
};
if (GNUNET_OK !=
transmit (&client->addr,
client->addr_size,
&pn.header))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Client %s must have disconnected\n",
client->addr.sun_path);
free_client (client);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Initialize key material for denomination key @a dk (also on disk).
*
* @param[in,out] dk denomination key to compute key material for
* @param position where in the DLL will the @a dk go
* @return #GNUNET_OK on success
*/
static int
setup_key (struct DenominationKey *dk,
struct DenominationKey *position)
{
struct Denomination *denom = dk->denom;
struct GNUNET_CRYPTO_RsaPrivateKey *priv;
struct GNUNET_CRYPTO_RsaPublicKey *pub;
size_t buf_size;
void *buf;
priv = GNUNET_CRYPTO_rsa_private_key_create (denom->rsa_keysize);
if (NULL == priv)
{
GNUNET_break (0);
GNUNET_SCHEDULER_shutdown ();
global_ret = 40;
return GNUNET_SYSERR;
}
pub = GNUNET_CRYPTO_rsa_private_key_get_public (priv);
if (NULL == pub)
{
GNUNET_break (0);
GNUNET_CRYPTO_rsa_private_key_free (priv);
return GNUNET_SYSERR;
}
buf_size = GNUNET_CRYPTO_rsa_private_key_encode (priv,
&buf);
GNUNET_CRYPTO_rsa_public_key_hash (pub,
&dk->h_denom_pub);
GNUNET_asprintf (&dk->filename,
"%s/%s/%llu",
keydir,
denom->section,
(unsigned long long) (dk->anchor.abs_value_us
/ GNUNET_TIME_UNIT_SECONDS.rel_value_us));
if (GNUNET_OK !=
GNUNET_DISK_fn_write (dk->filename,
buf,
buf_size,
GNUNET_DISK_PERM_USER_READ))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
"write",
dk->filename);
GNUNET_free (buf);
GNUNET_CRYPTO_rsa_private_key_free (priv);
GNUNET_CRYPTO_rsa_public_key_free (pub);
return GNUNET_SYSERR;
}
GNUNET_free (buf);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Setup fresh private key %s in `%s'\n",
GNUNET_h2s (&dk->h_denom_pub),
dk->filename);
dk->denom_priv.rsa_private_key = priv;
dk->denom_pub.rsa_public_key = pub;
if (GNUNET_OK !=
GNUNET_CONTAINER_multihashmap_put (
keys,
&dk->h_denom_pub,
dk,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Duplicate private key created! Terminating.\n");
GNUNET_CRYPTO_rsa_private_key_free (dk->denom_priv.rsa_private_key);
GNUNET_CRYPTO_rsa_public_key_free (dk->denom_pub.rsa_public_key);
GNUNET_free (dk->filename);
GNUNET_free (dk);
return GNUNET_SYSERR;
}
GNUNET_CONTAINER_DLL_insert_after (denom->keys_head,
denom->keys_tail,
position,
dk);
/* tell clients about new key */
{
struct Client *nxt;
for (struct Client *client = clients_head;
NULL != client;
client = nxt)
{
nxt = client->next;
if (GNUNET_OK !=
notify_client_dk_add (client,
dk))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Failed to notify client about new key, client dropped\n");
}
}
}
return GNUNET_OK;
}
/**
* A client informs us that a key has been revoked.
* Check if the key is still in use, and if so replace (!)
* it with a fresh key.
*
* @param addr address of the client making the request
* @param addr_size number of bytes in @a addr
* @param rr the revocation request
*/
static void
handle_revoke_request (const struct sockaddr_un *addr,
socklen_t addr_size,
const struct TALER_CRYPTO_RevokeRequest *rr)
{
struct DenominationKey *dk;
struct DenominationKey *ndk;
struct Denomination *denom;
dk = GNUNET_CONTAINER_multihashmap_get (keys,
&rr->h_denom_pub);
if (NULL == dk)
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Revocation request ignored, denomination key %s unknown\n",
GNUNET_h2s (&rr->h_denom_pub));
return;
}
/* kill existing key, done first to ensure this always happens */
if (0 != unlink (dk->filename))
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
"unlink",
dk->filename);
/* Setup replacement key */
denom = dk->denom;
ndk = GNUNET_new (struct DenominationKey);
ndk->denom = denom;
ndk->anchor = dk->anchor;
if (GNUNET_OK !=
setup_key (ndk,
dk))
{
GNUNET_break (0);
GNUNET_SCHEDULER_shutdown ();
global_ret = 44;
return;
}
/* get rid of the old key */
dk->purge = true;
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_multihashmap_remove (
keys,
&dk->h_denom_pub,
dk));
GNUNET_CONTAINER_DLL_remove (denom->keys_head,
denom->keys_tail,
dk);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Revocation complete\n");
/* Tell clients this key is gone */
{
struct Client *nxt;
for (struct Client *client = clients_head;
NULL != client;
client = nxt)
{
nxt = client->next;
if (GNUNET_OK !=
notify_client_dk_del (client,
dk))
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Failed to notify client about revoked key, client dropped\n");
}
}
if (0 == dk->rc)
free_dk (dk);
}
static void
read_job (void *cls)
{
struct Client *client = cls;
char buf[65536];
ssize_t buf_size;
const struct GNUNET_MessageHeader *hdr;
struct sockaddr_un addr;
socklen_t addr_size = sizeof (addr);
read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
unix_sock,
&read_job,
NULL);
buf_size = GNUNET_NETWORK_socket_recvfrom (unix_sock,
buf,
sizeof (buf),
(struct sockaddr *) &addr,
&addr_size);
if (-1 == buf_size)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"recv");
return;
}
if (0 == buf_size)
{
return;
}
if (buf_size < sizeof (struct GNUNET_MessageHeader))
{
GNUNET_break_op (0);
return;
}
hdr = (const struct GNUNET_MessageHeader *) buf;
if (ntohs (hdr->size) != buf_size)
{
GNUNET_break_op (0);
free_client (client);
return;
}
switch (ntohs (hdr->type))
{
case TALER_HELPER_RSA_MT_REQ_INIT:
if (ntohs (hdr->size) != sizeof (struct GNUNET_MessageHeader))
{
GNUNET_break_op (0);
return;
}
{
struct Client *client;
client = GNUNET_new (struct Client);
client->addr = addr;
client->addr_size = addr_size;
GNUNET_CONTAINER_DLL_insert (clients_head,
clients_tail,
client);
for (struct Denomination *denom = denom_head;
NULL != denom;
denom = denom->next)
{
for (struct DenominationKey *dk = denom->keys_head;
NULL != dk;
dk = dk->next)
{
if (GNUNET_OK !=
notify_client_dk_add (client,
dk))
{
/* client died, skip the rest */
client = NULL;
break;
}
}
if (NULL == client)
break;
}
if (NULL != client)
{
struct GNUNET_MessageHeader synced = {
.type = htons (TALER_HELPER_RSA_SYNCED),
.size = htons (sizeof (synced))
};
if (GNUNET_OK !=
transmit (&client->addr,
client->addr_size,
&synced))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Client %s must have disconnected\n",
client->addr.sun_path);
free_client (client);
}
}
}
break;
case TALER_HELPER_RSA_MT_REQ_SIGN:
if (ntohs (hdr->size) <= sizeof (struct TALER_CRYPTO_SignRequest))
{
GNUNET_break_op (0);
return;
}
handle_sign_request (&addr,
addr_size,
(const struct TALER_CRYPTO_SignRequest *) buf);
break;
case TALER_HELPER_RSA_MT_REQ_REVOKE:
if (ntohs (hdr->size) != sizeof (struct TALER_CRYPTO_RevokeRequest))
{
GNUNET_break_op (0);
return;
}
handle_revoke_request (&addr,
addr_size,
(const struct TALER_CRYPTO_RevokeRequest *) buf);
break;
default:
GNUNET_break_op (0);
return;
}
}
/**
* Create a new denomination key (we do not have enough).
*
* @param denom denomination key to create
* @param now current time to use (to get many keys to use the exact same time)
* @return #GNUNET_OK on success
*/
static int
create_key (struct Denomination *denom,
struct GNUNET_TIME_Absolute now)
{
struct DenominationKey *dk;
struct GNUNET_TIME_Absolute anchor;
if (NULL == denom->keys_tail)
{
anchor = now;
}
else
{
anchor = GNUNET_TIME_absolute_add (denom->keys_tail->anchor,
GNUNET_TIME_relative_subtract (
denom->duration_withdraw,
overlap_duration));
if (now.abs_value_us > anchor.abs_value_us)
anchor = now;
}
dk = GNUNET_new (struct DenominationKey);
dk->denom = denom;
dk->anchor = anchor;
if (GNUNET_OK !=
setup_key (dk,
denom->keys_tail))
{
GNUNET_free (dk);
GNUNET_SCHEDULER_shutdown ();
global_ret = 42;
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* At what time does this denomination require its next action?
* Basically, the minimum of the withdraw expiration time of the
* oldest denomination key, and the withdraw expiration time of
* the newest denomination key minus the #lookahead_sign time.
*
* @param denom denomination to compute action time for
*/
static struct GNUNET_TIME_Absolute
denomination_action_time (const struct Denomination *denom)
{
return GNUNET_TIME_absolute_min (
GNUNET_TIME_absolute_add (denom->keys_head->anchor,
denom->duration_withdraw),
GNUNET_TIME_absolute_subtract (
GNUNET_TIME_absolute_subtract (
GNUNET_TIME_absolute_add (denom->keys_tail->anchor,
denom->duration_withdraw),
lookahead_sign),
overlap_duration));
}
/**
* The withdraw period of a key @a dk has expired. Purge it.
*
* @param[in] dk expired denomination key to purge and free
*/
static void
purge_key (struct DenominationKey *dk)
{
struct Denomination *denom = dk->denom;
struct Client *nxt;
for (struct Client *client = clients_head;
NULL != client;
client = nxt)
{
nxt = client->next;
if (GNUNET_OK !=
notify_client_dk_del (client,
dk))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Failed to notify client about purged key, client dropped\n");
}
}
GNUNET_CONTAINER_DLL_remove (denom->keys_head,
denom->keys_tail,
dk);
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_multihashmap_remove (keys,
&dk->h_denom_pub,
dk));
if (0 != unlink (dk->filename))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
"unlink",
dk->filename);
}
else
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Purged expired private key `%s'\n",
dk->filename);
}
GNUNET_free (dk->filename);
if (0 != dk->rc)
{
/* delay until all signing threads are done with this key */
dk->purge = true;
return;
}
GNUNET_CRYPTO_rsa_private_key_free (dk->denom_priv.rsa_private_key);
GNUNET_free (dk);
}
/**
* Create new keys and expire ancient keys of the given denomination @a denom.
* Removes the @a denom from the #denom_head DLL and re-insert its at the
* correct location sorted by next maintenance activity.
*
* @param[in,out] denom denomination to update material for
* @param now current time to use (to get many keys to use the exact same time)
*/
static void
update_keys (struct Denomination *denom,
struct GNUNET_TIME_Absolute now)
{
/* create new denomination keys */
while ( (NULL == denom->keys_tail) ||
(0 ==
GNUNET_TIME_absolute_get_remaining (
GNUNET_TIME_absolute_subtract (
GNUNET_TIME_absolute_subtract (
GNUNET_TIME_absolute_add (denom->keys_tail->anchor,
denom->duration_withdraw),
lookahead_sign),
overlap_duration)).rel_value_us) )
if (GNUNET_OK !=
create_key (denom,
now))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to create keys for `%s'\n",
denom->section);
return;
}
/* remove expired denomination keys */
while ( (NULL != denom->keys_head) &&
(0 ==
GNUNET_TIME_absolute_get_remaining
(GNUNET_TIME_absolute_add (denom->keys_head->anchor,
denom->duration_withdraw)).rel_value_us) )
purge_key (denom->keys_head);
/* Update position of 'denom' in #denom_head DLL: sort by action time */
{
struct Denomination *before;
struct GNUNET_TIME_Absolute at;
at = denomination_action_time (denom);
GNUNET_CONTAINER_DLL_remove (denom_head,
denom_tail,
denom);
before = NULL;
for (struct Denomination *pos = denom_head;
NULL != pos;
pos = pos->next)
{
if (denomination_action_time (pos).abs_value_us >= at.abs_value_us)
break;
before = pos;
}
GNUNET_CONTAINER_DLL_insert_after (denom_head,
denom_tail,
before,
denom);
}
}
/**
* Task run periodically to expire keys and/or generate fresh ones.
*
* @param cls NULL
*/
static void
update_denominations (void *cls)
{
struct Denomination *denom;
struct GNUNET_TIME_Absolute now;
(void) cls;
now = GNUNET_TIME_absolute_get ();
(void) GNUNET_TIME_round_abs (&now);
keygen_task = NULL;
do {
denom = denom_head;
update_keys (denom,
now);
} while (denom != denom_head);
keygen_task = GNUNET_SCHEDULER_add_at (denomination_action_time (denom),
&update_denominations,
NULL);
}
/**
* Parse private key of denomination @a denom in @a buf.
*
* @param[out] denom denomination of the key
* @param filename name of the file we are parsing, for logging
* @param buf key material
* @param buf_size number of bytes in @a buf
*/
static void
parse_key (struct Denomination *denom,
const char *filename,
const void *buf,
size_t buf_size)
{
struct GNUNET_CRYPTO_RsaPrivateKey *priv;
char *anchor_s;
char dummy;
unsigned long long anchor_ll;
struct GNUNET_TIME_Absolute anchor;
anchor_s = strrchr (filename,
'/');
if (NULL == anchor_s)
{
/* File in a directory without '/' in the name, this makes no sense. */
GNUNET_break (0);
return;
}
anchor_s++;
if (1 != sscanf (anchor_s,
"%llu%c",
&anchor_ll,
&dummy))
{
/* Filenames in KEYDIR must ONLY be the anchor time in seconds! */
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Filename `%s' invalid for key file, skipping\n",
filename);
return;
}
anchor.abs_value_us = anchor_ll * GNUNET_TIME_UNIT_SECONDS.rel_value_us;
if (anchor_ll != anchor.abs_value_us / GNUNET_TIME_UNIT_SECONDS.rel_value_us)
{
/* Integer overflow. Bad, invalid filename. */
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Filename `%s' invalid for key file, skipping\n",
filename);
return;
}
priv = GNUNET_CRYPTO_rsa_private_key_decode (buf,
buf_size);
if (NULL == priv)
{
/* Parser failure. */
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"File `%s' is malformed, skipping\n",
filename);
return;
}
{
struct GNUNET_CRYPTO_RsaPublicKey *pub;
struct DenominationKey *dk;
struct DenominationKey *before;
pub = GNUNET_CRYPTO_rsa_private_key_get_public (priv);
if (NULL == pub)
{
GNUNET_break (0);
GNUNET_CRYPTO_rsa_private_key_free (priv);
return;
}
dk = GNUNET_new (struct DenominationKey);
dk->denom_priv.rsa_private_key = priv;
dk->denom = denom;
dk->anchor = anchor;
dk->filename = GNUNET_strdup (filename);
GNUNET_CRYPTO_rsa_public_key_hash (pub,
&dk->h_denom_pub);
dk->denom_pub.rsa_public_key = pub;
if (GNUNET_OK !=
GNUNET_CONTAINER_multihashmap_put (
keys,
&dk->h_denom_pub,
dk,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Duplicate private key %s detected in file `%s'. Skipping.\n",
GNUNET_h2s (&dk->h_denom_pub),
filename);
GNUNET_CRYPTO_rsa_private_key_free (priv);
GNUNET_CRYPTO_rsa_public_key_free (pub);
GNUNET_free (dk);
return;
}
before = NULL;
for (struct DenominationKey *pos = denom->keys_head;
NULL != pos;
pos = pos->next)
{
if (pos->anchor.abs_value_us > anchor.abs_value_us)
break;
before = pos;
}
GNUNET_CONTAINER_DLL_insert_after (denom->keys_head,
denom->keys_tail,
before,
dk);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Imported key %s from `%s'\n",
GNUNET_h2s (&dk->h_denom_pub),
filename);
}
}
/**
* Import a private key from @a filename for the denomination
* given in @a cls.
*
* @param[in,out] cls a `struct Denomiantion`
* @param filename name of a file in the directory
*/
static int
import_key (void *cls,
const char *filename)
{
struct Denomination *denom = cls;
struct GNUNET_DISK_FileHandle *fh;
struct GNUNET_DISK_MapHandle *map;
void *ptr;
int fd;
struct stat sbuf;
{
struct stat lsbuf;
if (0 != lstat (filename,
&lsbuf))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"lstat",
filename);
return GNUNET_OK;
}
if (! S_ISREG (lsbuf.st_mode))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"File `%s' is not a regular file, which is not allowed for private keys!\n",
filename);
return GNUNET_OK;
}
}
fd = open (filename,
O_CLOEXEC);
if (-1 == fd)
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"open",
filename);
return GNUNET_OK;
}
if (0 != fstat (fd,
&sbuf))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"stat",
filename);
return GNUNET_OK;
}
if (! S_ISREG (sbuf.st_mode))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"File `%s' is not a regular file, which is not allowed for private keys!\n",
filename);
return GNUNET_OK;
}
if (0 != (sbuf.st_mode & (S_IWUSR | S_IRWXG | S_IRWXO)))
{
/* permission are NOT tight, try to patch them up! */
if (0 !=
fchmod (fd,
S_IRUSR))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"fchmod",
filename);
/* refuse to use key if file has wrong permissions */
GNUNET_break (0 == close (fd));
return GNUNET_OK;
}
}
fh = GNUNET_DISK_get_handle_from_int_fd (fd);
if (NULL == fh)
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"open",
filename);
GNUNET_break (0 == close (fd));
return GNUNET_OK;
}
if (sbuf.st_size > 2048)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"File `%s' to big to be a private key\n",
filename);
GNUNET_DISK_file_close (fh);
return GNUNET_OK;
}
ptr = GNUNET_DISK_file_map (fh,
&map,
GNUNET_DISK_MAP_TYPE_READ,
(size_t) sbuf.st_size);
if (NULL == ptr)
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"mmap",
filename);
GNUNET_DISK_file_close (fh);
return GNUNET_OK;
}
parse_key (denom,
filename,
ptr,
(size_t) sbuf.st_size);
GNUNET_DISK_file_unmap (map);
GNUNET_DISK_file_close (fh);
return GNUNET_OK;
}
/**
* Parse configuration for denomination type parameters. Also determines
* our anchor by looking at the existing denominations of the same type.
*
* @param ct section in the configuration file giving the denomination type parameters
* @param[out] denom set to the denomination parameters from the configuration
* @return #GNUNET_OK on success, #GNUNET_SYSERR if the configuration is invalid
*/
static int
parse_denomination_cfg (const char *ct,
struct Denomination *denom)
{
unsigned long long rsa_keysize;
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_time (kcfg,
ct,
"DURATION_WITHDRAW",
&denom->duration_withdraw))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
ct,
"DURATION_WITHDRAW");
return GNUNET_SYSERR;
}
GNUNET_TIME_round_rel (&denom->duration_withdraw);
if (overlap_duration.rel_value_us >=
denom->duration_withdraw.rel_value_us)
{
GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
"taler-helper-crypto-rsa",
"OVERLAP_DURATION",
"Value given must be smaller than value for DURATION_WITHDRAW!");
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_number (kcfg,
ct,
"RSA_KEYSIZE",
&rsa_keysize))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
ct,
"RSA_KEYSIZE");
return GNUNET_SYSERR;
}
if ( (rsa_keysize > 4 * 2048) ||
(rsa_keysize < 1024) )
{
GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
ct,
"RSA_KEYSIZE",
"Given RSA keysize outside of permitted range [1024,8192]\n");
return GNUNET_SYSERR;
}
denom->rsa_keysize = (unsigned int) rsa_keysize;
denom->section = GNUNET_strdup (ct);
return GNUNET_OK;
}
/**
* Closure for #load_denominations.
*/
struct LoadContext
{
/**
* Current time to use.
*/
struct GNUNET_TIME_Absolute now;
/**
* Status, to be set to #GNUNET_SYSERR on failure
*/
int ret;
};
/**
* Generate new denomination signing keys for the denomination type of the given @a
* denomination_alias.
*
* @param cls a `struct LoadContext`, with 'ret' to be set to #GNUNET_SYSERR on failure
* @param denomination_alias name of the denomination's section in the configuration
*/
static void
load_denominations (void *cls,
const char *denomination_alias)
{
struct LoadContext *ctx = cls;
struct Denomination *denom;
if (0 != strncasecmp (denomination_alias,
"coin_",
strlen ("coin_")))
return; /* not a denomination type definition */
denom = GNUNET_new (struct Denomination);
if (GNUNET_OK !=
parse_denomination_cfg (denomination_alias,
denom))
{
ctx->ret = GNUNET_SYSERR;
GNUNET_free (denom);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Loading keys for denomination %s\n",
denom->section);
{
char *dname;
GNUNET_asprintf (&dname,
"%s/%s",
keydir,
denom->section);
GNUNET_break (GNUNET_OK ==
GNUNET_DISK_directory_create (dname));
GNUNET_DISK_directory_scan (dname,
&import_key,
denom);
GNUNET_free (dname);
}
GNUNET_CONTAINER_DLL_insert (denom_head,
denom_tail,
denom);
update_keys (denom,
ctx->now);
}
/**
* Load the various duration values from #kcfg.
*
* @return #GNUNET_OK on success
*/
static int
load_durations (void)
{
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_time (kcfg,
"taler-helper-crypto-rsa",
"OVERLAP_DURATION",
&overlap_duration))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
"taler-helper-crypto-rsa",
"OVERLAP_DURATION");
return GNUNET_SYSERR;
}
GNUNET_TIME_round_rel (&overlap_duration);
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_time (kcfg,
"taler-helper-crypto-rsa",
"LOOKAHEAD_SIGN",
&lookahead_sign))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
"taler-helper-crypto-rsa",
"LOOKAHEAD_SIGN");
return GNUNET_SYSERR;
}
GNUNET_TIME_round_rel (&lookahead_sign);
return GNUNET_OK;
}
/**
* Function run on shutdown. Stops the various jobs (nicely).
*
* @param cls NULL
*/
static void
do_shutdown (void *cls)
{
(void) cls;
if (NULL != read_task)
{
GNUNET_SCHEDULER_cancel (read_task);
read_task = NULL;
}
if (NULL != unix_sock)
{
GNUNET_break (GNUNET_OK ==
GNUNET_NETWORK_socket_close (unix_sock));
unix_sock = NULL;
}
if (0 != unlink (unixpath))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"unlink",
unixpath);
}
GNUNET_free (unixpath);
if (NULL != keygen_task)
{
GNUNET_SCHEDULER_cancel (keygen_task);
keygen_task = NULL;
}
if (NULL != done_task)
{
GNUNET_SCHEDULER_cancel (done_task);
done_task = NULL;
}
/* shut down worker threads */
GNUNET_assert (0 == pthread_mutex_lock (&work_lock));
in_shutdown = true;
GNUNET_assert (0 == pthread_cond_broadcast (&work_cond));
GNUNET_assert (0 == pthread_mutex_unlock (&work_lock));
for (unsigned int i = 0; i