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Use the EAP-SIM/AKA crypto helper in EAP-SIM

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This commit is contained in:
Martin Willi
2009-11-12 10:33:59 +01:00
parent 55916dcc9e
commit e9c03f5243
4 changed files with 81 additions and 213 deletions
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src/charon/plugins/eap_sim/eap_sim_peer.c
+24 -95
View File
@@ -35,14 +35,6 @@
#define KC_LEN 8
/** length of SRES */
#define SRES_LEN 4
/** length of the k_encr key */
#define KENCR_LEN 16
/** length of the k_auth key */
#define KAUTH_LEN 16
/** length of the MSK */
#define MSK_LEN 64
/** length of the EMSK */
#define EMSK_LEN 64
typedef struct private_eap_sim_peer_t private_eap_sim_peer_t;
@@ -62,29 +54,9 @@ struct private_eap_sim_peer_t {
identification_t *peer;
/**
* RNG to create nonces, IVs
* EAP-SIM crypto helper
*/
rng_t *rng;
/**
* hashing function
*/
hasher_t *hasher;
/**
* prf
*/
prf_t *prf;
/**
* MAC function
*/
signer_t *signer;
/**
* encryption function
*/
crypter_t *crypter;
simaka_crypto_t *crypto;
/**
* how many times we try to authenticate
@@ -141,43 +113,6 @@ static bool get_card_triplet(private_eap_sim_peer_t *this,
return success;
}
/**
* Derive EAP keys from kc when using full authentication
*/
static void derive_keys_full(private_eap_sim_peer_t *this, chunk_t kcs)
{
char mk[HASH_SIZE_SHA1], k_encr[KENCR_LEN], k_auth[KAUTH_LEN];
chunk_t tmp;
int i;
/* MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */
tmp = chunk_cata("ccccc", this->peer->get_encoding(this->peer),
kcs, this->nonce, this->version_list, version);
this->hasher->get_hash(this->hasher, tmp, mk);
DBG3(DBG_IKE, "MK = SHA1(%B\n) = %b", &tmp, mk, HASH_SIZE_SHA1);
/* K_encr | K_auth | MSK | EMSK = prf() | prf() | prf() | prf()
* We currently don't need EMSK, so three prf() are sufficient */
this->prf->set_key(this->prf, chunk_create(mk, HASH_SIZE_SHA1));
tmp = chunk_alloca(this->prf->get_block_size(this->prf) * 3);
for (i = 0; i < 3; i++)
{
this->prf->get_bytes(this->prf, chunk_empty, tmp.ptr + tmp.len / 3 * i);
}
memcpy(k_encr, tmp.ptr, KENCR_LEN);
tmp = chunk_skip(tmp, KENCR_LEN);
memcpy(k_auth, tmp.ptr, KAUTH_LEN);
tmp = chunk_skip(tmp, KAUTH_LEN);
free(this->msk.ptr);
this->msk = chunk_alloc(MSK_LEN);
memcpy(this->msk.ptr, tmp.ptr, MSK_LEN);
DBG3(DBG_IKE, "K_encr %b\nK_auth %b\nMSK %B",
k_encr, KENCR_LEN, k_auth, KAUTH_LEN, &this->msk);
this->signer->set_key(this->signer, chunk_create(k_auth, KAUTH_LEN));
this->crypter->set_key(this->crypter, chunk_create(k_encr, KENCR_LEN));
}
/**
* Send a SIM_CLIENT_ERROR
*/
@@ -190,7 +125,7 @@ static eap_payload_t* create_client_error(private_eap_sim_peer_t *this,
message = simaka_message_create(FALSE, identifier,
EAP_SIM, SIM_CLIENT_ERROR);
message->add_attribute(message, AT_CLIENT_ERROR_CODE, code);
out = message->generate(message, NULL, NULL, NULL, chunk_empty);
out = message->generate(message, this->crypto, chunk_empty);
message->destroy(message);
return out;
}
@@ -205,6 +140,7 @@ static status_t process_start(private_eap_sim_peer_t *this,
enumerator_t *enumerator;
simaka_attribute_t type;
chunk_t data;
rng_t *rng;
bool supported = FALSE;
enumerator = in->create_attribute_enumerator(in);
@@ -243,14 +179,15 @@ static status_t process_start(private_eap_sim_peer_t *this,
}
/* generate AT_NONCE_MT value */
rng = this->crypto->get_rng(this->crypto);
free(this->nonce.ptr);
this->rng->allocate_bytes(this->rng, NONCE_LEN, &this->nonce);
rng->allocate_bytes(rng, NONCE_LEN, &this->nonce);
message = simaka_message_create(FALSE, in->get_identifier(in),
EAP_SIM, SIM_START);
message->add_attribute(message, AT_SELECTED_VERSION, version);
message->add_attribute(message, AT_NONCE_MT, this->nonce);
*out = message->generate(message, NULL, NULL, NULL, chunk_empty);
*out = message->generate(message, this->crypto, chunk_empty);
message->destroy(message);
return NEED_MORE;
@@ -321,10 +258,12 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
rands = chunk_skip(rands, RAND_LEN);
}
derive_keys_full(this, kcs);
data = chunk_cata("cccc", kcs, this->nonce, this->version_list, version);
free(this->msk.ptr);
this->msk = this->crypto->derive_keys_full(this->crypto, this->peer, data);
/* verify AT_MAC attribute, signature is over "EAP packet | NONCE_MT" */
if (!in->verify(in, this->signer, this->nonce))
if (!in->verify(in, this->crypto, this->nonce))
{
DBG1(DBG_IKE, "AT_MAC verification failed");
*out = create_client_error(this, in->get_identifier(in),
@@ -335,7 +274,7 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
/* build response with AT_MAC, built over "EAP packet | n*SRES" */
message = simaka_message_create(FALSE, in->get_identifier(in),
EAP_SIM, SIM_CHALLENGE);
*out = message->generate(message, NULL, NULL, this->signer, sreses);
*out = message->generate(message, this->crypto, sreses);
message->destroy(message);
return NEED_MORE;
}
@@ -375,7 +314,7 @@ static status_t process_notification(private_eap_sim_peer_t *this,
{ /* empty notification reply */
message = simaka_message_create(FALSE, in->get_identifier(in),
EAP_SIM, SIM_NOTIFICATION);
*out = message->generate(message, NULL, NULL, NULL, chunk_empty);
*out = message->generate(message, this->crypto, chunk_empty);
message->destroy(message);
}
else
@@ -402,7 +341,7 @@ static status_t process(private_eap_sim_peer_t *this,
client_error_general);
return NEED_MORE;
}
if (!message->parse(message, this->crypter))
if (!message->parse(message, this->crypto))
{
message->destroy(message);
*out = create_client_error(this, in->get_identifier(in),
@@ -475,11 +414,7 @@ static bool is_mutual(private_eap_sim_peer_t *this)
static void destroy(private_eap_sim_peer_t *this)
{
this->peer->destroy(this->peer);
DESTROY_IF(this->rng);
DESTROY_IF(this->hasher);
DESTROY_IF(this->prf);
DESTROY_IF(this->signer);
DESTROY_IF(this->crypter);
this->crypto->destroy(this->crypto);
free(this->version_list.ptr);
free(this->nonce.ptr);
free(this->msk.ptr);
@@ -494,12 +429,6 @@ eap_sim_peer_t *eap_sim_peer_create(identification_t *server,
{
private_eap_sim_peer_t *this = malloc_thing(private_eap_sim_peer_t);
this->peer = peer->clone(peer);
this->tries = MAX_TRIES;
this->version_list = chunk_empty;
this->nonce = chunk_empty;
this->msk = chunk_empty;
this->public.interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
this->public.interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
this->public.interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
@@ -507,18 +436,18 @@ eap_sim_peer_t *eap_sim_peer_create(identification_t *server,
this->public.interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
this->public.interface.destroy = (void(*)(eap_method_t*))destroy;
this->rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
this->hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
this->prf = lib->crypto->create_prf(lib->crypto, PRF_FIPS_SHA1_160);
this->signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_SHA1_128);
this->crypter = lib->crypto->create_crypter(lib->crypto, ENCR_AES_CBC, 16);
if (!this->rng || !this->hasher || !this->prf ||
!this->signer || !this->crypter)
this->crypto = simaka_crypto_create();
if (!this->crypto)
{
DBG1(DBG_IKE, "unable to use EAP-SIM, missing algorithms");
destroy(this);
free(this);
return NULL;
}
this->peer = peer->clone(peer);
this->tries = MAX_TRIES;
this->version_list = chunk_empty;
this->nonce = chunk_empty;
this->msk = chunk_empty;
return &this->public;
}
src/charon/plugins/eap_sim/eap_sim_server.c
+27 -99
View File
@@ -18,12 +18,11 @@
#include <daemon.h>
#include <simaka_message.h>
#include <simaka_crypto.h>
/* number of triplets for one authentication */
#define TRIPLET_COUNT 3
/** length of the AT_NONCE_MT/AT_NONCE_S nonce value */
#define NONCE_LEN 16
/** length of the AT_MAC value */
#define MAC_LEN 16
/** length of the AT_RAND value */
@@ -32,14 +31,6 @@
#define KC_LEN 8
/** length of SRES */
#define SRES_LEN 4
/** length of the k_encr key */
#define KENCR_LEN 16
/** length of the k_auth key */
#define KAUTH_LEN 16
/** length of the MSK */
#define MSK_LEN 64
/** length of the EMSK */
#define EMSK_LEN 64
typedef struct private_eap_sim_server_t private_eap_sim_server_t;
@@ -59,29 +50,9 @@ struct private_eap_sim_server_t {
identification_t *peer;
/**
* Random number generator for nonce, IVs
* EAP-SIM/AKA crypto helper
*/
rng_t *rng;
/**
* hashing function
*/
hasher_t *hasher;
/**
* prf
*/
prf_t *prf;
/**
* MAC function
*/
signer_t *signer;
/**
* encryption function
*/
crypter_t *crypter;
simaka_crypto_t *crypto;
/**
* unique EAP identifier
@@ -99,6 +70,9 @@ struct private_eap_sim_server_t {
chunk_t msk;
};
/* version of SIM protocol we speak */
static chunk_t version = chunk_from_chars(0x00,0x01);
/**
* Fetch a triplet from a provider
*/
@@ -125,44 +99,6 @@ static bool get_provider_triplet(private_eap_sim_server_t *this,
return FALSE;
}
/**
* Derive EAP keys from kc when using full authentication
*/
static void derive_keys_full(private_eap_sim_server_t *this,
chunk_t kcs, chunk_t nonce)
{
char mk[HASH_SIZE_SHA1], k_encr[KENCR_LEN], k_auth[KAUTH_LEN];
chunk_t tmp;
int i;
/* MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */
tmp = chunk_cata("ccccc", this->peer->get_encoding(this->peer),
kcs, nonce, version, version);
this->hasher->get_hash(this->hasher, tmp, mk);
DBG3(DBG_IKE, "MK = SHA1(%B\n) = %b", &tmp, mk, HASH_SIZE_SHA1);
/* K_encr | K_auth | MSK | EMSK = prf() | prf() | prf() | prf()
* We currently don't need EMSK, so three prf() are sufficient */
this->prf->set_key(this->prf, chunk_create(mk, HASH_SIZE_SHA1));
tmp = chunk_alloca(this->prf->get_block_size(this->prf) * 3);
for (i = 0; i < 3; i++)
{
this->prf->get_bytes(this->prf, chunk_empty, tmp.ptr + tmp.len / 3 * i);
}
memcpy(k_encr, tmp.ptr, KENCR_LEN);
tmp = chunk_skip(tmp, KENCR_LEN);
memcpy(k_auth, tmp.ptr, KAUTH_LEN);
tmp = chunk_skip(tmp, KAUTH_LEN);
free(this->msk.ptr);
this->msk = chunk_alloc(MSK_LEN);
memcpy(this->msk.ptr, tmp.ptr, MSK_LEN);
DBG3(DBG_IKE, "K_encr %b\nK_auth %b\nMSK %B",
k_encr, KENCR_LEN, k_auth, KAUTH_LEN, &this->msk);
this->signer->set_key(this->signer, chunk_create(k_auth, KAUTH_LEN));
this->crypter->set_key(this->crypter, chunk_create(k_encr, KENCR_LEN));
}
/**
* process an EAP-SIM/Response/Start message
*/
@@ -226,13 +162,15 @@ static status_t process_start(private_eap_sim_server_t *this,
free(this->sreses.ptr);
this->sreses = chunk_clone(sreses);
derive_keys_full(this, kcs, nonce);
data = chunk_cata("cccc", kcs, nonce, version, version);
free(this->msk.ptr);
this->msk = this->crypto->derive_keys_full(this->crypto, this->peer, data);
/* build response with AT_MAC, built over "EAP packet | NONCE_MT" */
message = simaka_message_create(TRUE, this->identifier++,
EAP_SIM, SIM_CHALLENGE);
message->add_attribute(message, AT_RAND, rands);
*out = message->generate(message, NULL, NULL, this->signer, nonce);
*out = message->generate(message, this->crypto, nonce);
message->destroy(message);
return NEED_MORE;
}
@@ -256,7 +194,7 @@ static status_t process_challenge(private_eap_sim_server_t *this,
enumerator->destroy(enumerator);
/* verify AT_MAC attribute, signature is over "EAP packet | n*SRES" */
if (!in->verify(in, this->signer, this->sreses))
if (!in->verify(in, this->crypto, this->sreses))
{
DBG1(DBG_IKE, "AT_MAC verification failed");
return FAILED;
@@ -305,7 +243,7 @@ static status_t process(private_eap_sim_server_t *this,
{
return FAILED;
}
if (!message->parse(message, this->crypter))
if (!message->parse(message, this->crypto))
{
message->destroy(message);
return FAILED;
@@ -341,7 +279,7 @@ static status_t initiate(private_eap_sim_server_t *this, eap_payload_t **out)
message = simaka_message_create(TRUE, this->identifier++,
EAP_SIM, SIM_START);
message->add_attribute(message, AT_VERSION_LIST, version);
*out = message->generate(message, NULL, NULL, NULL, chunk_empty);
*out = message->generate(message, this->crypto, chunk_empty);
message->destroy(message);
return NEED_MORE;
}
@@ -381,12 +319,8 @@ static bool is_mutual(private_eap_sim_server_t *this)
*/
static void destroy(private_eap_sim_server_t *this)
{
this->crypto->destroy(this->crypto);
this->peer->destroy(this->peer);
DESTROY_IF(this->rng);
DESTROY_IF(this->hasher);
DESTROY_IF(this->prf);
DESTROY_IF(this->signer);
DESTROY_IF(this->crypter);
free(this->sreses.ptr);
free(this->msk.ptr);
free(this);
@@ -400,6 +334,19 @@ eap_sim_server_t *eap_sim_server_create(identification_t *server,
{
private_eap_sim_server_t *this = malloc_thing(private_eap_sim_server_t);
this->public.interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
this->public.interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
this->public.interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
this->public.interface.is_mutual = (bool(*)(eap_method_t*))is_mutual;
this->public.interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
this->public.interface.destroy = (void(*)(eap_method_t*))destroy;
this->crypto = simaka_crypto_create();
if (!this->crypto)
{
free(this);
return NULL;
}
this->peer = peer->clone(peer);
this->sreses = chunk_empty;
this->msk = chunk_empty;
@@ -408,25 +355,6 @@ eap_sim_server_t *eap_sim_server_create(identification_t *server,
this->identifier = random();
} while (!this->identifier);
this->public.interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
this->public.interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
this->public.interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
this->public.interface.is_mutual = (bool(*)(eap_method_t*))is_mutual;
this->public.interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
this->public.interface.destroy = (void(*)(eap_method_t*))destroy;
this->rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
this->hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
this->prf = lib->crypto->create_prf(lib->crypto, PRF_FIPS_SHA1_160);
this->signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_SHA1_128);
this->crypter = lib->crypto->create_crypter(lib->crypto, ENCR_AES_CBC, 16);
if (!this->rng || !this->hasher || !this->prf ||
!this->signer || !this->crypter)
{
DBG1(DBG_IKE, "unable to use EAP-SIM, missing algorithms");
destroy(this);
return NULL;
}
return &this->public;
}
src/libsimaka/simaka_message.c
+19 -9
View File
@@ -217,8 +217,8 @@ static void add_attribute(private_simaka_message_t *this,
/**
* Implementation of simaka_message_t.parse
*/
static bool parse(private_simaka_message_t *this, crypter_t *crypter,
signer_t *signer, chunk_t sigdata)
static bool parse(private_simaka_message_t *this, simaka_crypto_t *crypto,
chunk_t sigdata)
{
chunk_t in, iv = chunk_empty, encr = chunk_empty;
@@ -397,6 +397,7 @@ static bool parse(private_simaka_message_t *this, crypter_t *crypter,
if (iv.len && encr.len)
{
bool success;
crypter_t *crypter;
if (this->encrypted)
{
@@ -404,6 +405,7 @@ static bool parse(private_simaka_message_t *this, crypter_t *crypter,
eap_type_names, this->hdr->type);
return FALSE;
}
crypter = crypto->get_crypter(crypto);
if (!crypter)
{
DBG1(DBG_IKE, "%N message contains unexpected encrypted data",
@@ -421,7 +423,7 @@ static bool parse(private_simaka_message_t *this, crypter_t *crypter,
crypter->decrypt(crypter, encr, iv, NULL);
this->encrypted = TRUE;
success = parse(this, NULL, NULL, chunk_empty);
success = parse(this, crypto, chunk_empty);
this->encrypted = FALSE;
return success;
}
@@ -432,9 +434,12 @@ static bool parse(private_simaka_message_t *this, crypter_t *crypter,
* Implementation of simaka_message_t.verify
*/
static bool verify(private_simaka_message_t *this,
signer_t *signer, chunk_t sigdata)
simaka_crypto_t *crypto, chunk_t sigdata)
{
chunk_t data, backup;
signer_t *signer;
signer = crypto->get_signer(crypto);
switch (this->hdr->subtype)
{
@@ -502,8 +507,7 @@ static bool verify(private_simaka_message_t *this,
* Implementation of simaka_message_t.generate
*/
static eap_payload_t* generate(private_simaka_message_t *this,
crypter_t *crypter, rng_t *rng,
signer_t *signer, chunk_t sigdata)
simaka_crypto_t *crypto, chunk_t sigdata)
{
/* buffers large enough for messages we generate */
char out_buf[1024], encr_buf[512];
@@ -512,6 +516,7 @@ static eap_payload_t* generate(private_simaka_message_t *this,
simaka_attribute_t type;
attr_hdr_t *hdr;
u_int16_t len;
signer_t *signer;
out = chunk_create(out_buf, sizeof(out_buf));
encr = chunk_create(encr_buf, sizeof(encr_buf));
@@ -640,7 +645,10 @@ static eap_payload_t* generate(private_simaka_message_t *this,
{
chunk_t iv;
size_t bs;
crypter_t *crypter;
rng_t *rng;
crypter = crypto->get_crypter(crypto);
encr = chunk_create(encr_buf, sizeof(encr_buf) - encr.len);
bs = crypter->get_block_size(crypter);
@@ -651,6 +659,7 @@ static eap_payload_t* generate(private_simaka_message_t *this,
memset(out.ptr + 2, 0, 2);
out = chunk_skip(out, 4);
rng = crypto->get_rng(crypto);
rng->get_bytes(rng, bs, out.ptr);
iv = chunk_clonea(chunk_create(out.ptr, bs));
@@ -669,6 +678,7 @@ static eap_payload_t* generate(private_simaka_message_t *this,
}
/* include MAC ? */
signer = crypto->get_signer(crypto);
switch (this->hdr->subtype)
{
case SIM_CHALLENGE:
@@ -750,9 +760,9 @@ static simaka_message_t *simaka_message_create_data(chunk_t data)
this->public.get_subtype = (simaka_subtype_t(*)(simaka_message_t*))get_subtype;
this->public.create_attribute_enumerator = (enumerator_t*(*)(simaka_message_t*))create_attribute_enumerator;
this->public.add_attribute = (void(*)(simaka_message_t*, simaka_attribute_t type, chunk_t data))add_attribute;
this->public.parse = (bool(*)(simaka_message_t*, crypter_t *crypter))parse;
this->public.verify = (bool(*)(simaka_message_t*, signer_t *signer, chunk_t sigdata))verify;
this->public.generate = (eap_payload_t*(*)(simaka_message_t*, crypter_t *crypter, rng_t *rng, signer_t *signer, chunk_t sigdata))generate;
this->public.parse = (bool(*)(simaka_message_t*, simaka_crypto_t* crypto))parse;
this->public.verify = (bool(*)(simaka_message_t*, simaka_crypto_t* crypto, chunk_t sigdata))verify;
this->public.generate = (eap_payload_t*(*)(simaka_message_t*, simaka_crypto_t* crypto, chunk_t sigdata))generate;
this->public.destroy = (void(*)(simaka_message_t*))destroy;
this->attributes = linked_list_create();
src/libsimaka/simaka_message.h
+11 -10
View File
@@ -21,8 +21,10 @@
#ifndef SIMAKA_MESSAGE_H_
#define SIMAKA_MESSAGE_H_
#include <daemon.h>
#include <enum.h>
#include <daemon.h>
#include "simaka_crypto.h"
typedef struct simaka_message_t simaka_message_t;
typedef enum simaka_attribute_t simaka_attribute_t;
@@ -147,31 +149,30 @@ struct simaka_message_t {
* This method does not verify message integrity, as the key is available
* only after the payload has been parsed.
*
* @param crypter crypter to decrypt AT_ENCR_DATA attribute
* @param crypto EAP-SIM/AKA crypto helper
* @return TRUE if message parsed successfully
*/
bool (*parse)(simaka_message_t *this, crypter_t *crypter);
bool (*parse)(simaka_message_t *this, simaka_crypto_t *crypto);
/**
* Verify the message integrity of a parsed message.
*
* @param signer signer to verify AT_MAC attribute
* @param crypto EAP-SIM/AKA crypto helper
* @param sigdata additional data to include in signature, if any
* @return TRUE if message integrity check successful
*/
bool (*verify)(simaka_message_t *this, signer_t *signer, chunk_t sigdata);
bool (*verify)(simaka_message_t *this, simaka_crypto_t *crypto,
chunk_t sigdata);
/**
* Generate a message, optionally encrypt attributes and create a MAC.
*
* @param crypter crypter to encrypt attributes requiring encryption
* @param rng random number generator for IV
* @param signer signer to create AT_MAC attribute
* @param crypto EAP-SIM/AKA crypto helper
* @param sigdata additional data to include in signature, if any
* @return generated eap payload, NULL if failed
*/
eap_payload_t* (*generate)(simaka_message_t *this, crypter_t *crypter,
rng_t *rng, signer_t *signer, chunk_t sigdata);
eap_payload_t* (*generate)(simaka_message_t *this, simaka_crypto_t *crypto,
chunk_t sigdata);
/**
* Destroy a simaka_message_t.