/* MUST BE THREAD-SAFE */
void calc_dh(struct pluto_crypto_req *r)
{
/* copy the request, since the reply will re-use the memory of the r->pcr_d.dhq */
struct pcr_skeyid_q dhq;
memcpy(&dhq, &r->pcr_d.dhq, sizeof(r->pcr_d.dhq));
/* clear out the reply */
struct pcr_skeyid_r *skr = &r->pcr_d.dhr;
zero(skr); /* ??? pointer fields might not be NULLed */
INIT_WIRE_ARENA(*skr);
const struct oakley_group_desc *group = lookup_group(dhq.oakley_group);
passert(group != NULL);
SECKEYPrivateKey *ltsecret = dhq.secret;
SECKEYPublicKey *pubk = dhq.pubk;
/* now calculate the (g^x)(g^y) */
chunk_t g;
setchunk_from_wire(g, &dhq, dhq.role == ORIGINAL_RESPONDER ? &dhq.gi : &dhq.gr);
DBG(DBG_CRYPT, DBG_dump_chunk("peer's g: ", g));
const char *story; /* we ignore the value */
skr->shared = calc_dh_shared(g, ltsecret, group, pubk, &story);
}
/* MUST BE THREAD-SAFE */
void calc_dh_v2(struct pluto_crypto_req *r, const char **story)
{
struct pcr_skeycalc_v2_r *const skr = &r->pcr_d.dhv2;
/* copy the request, since the reply will re-use the memory of the r->pcr_d.dhq */
struct pcr_skeyid_q dhq;
memcpy(&dhq, &r->pcr_d.dhq, sizeof(r->pcr_d.dhq));
/* clear out the reply (including pointers) */
static const struct pcr_skeycalc_v2_r zero_pcr_skeycalc_v2_r;
*skr = zero_pcr_skeycalc_v2_r;
INIT_WIRE_ARENA(*skr);
const struct oakley_group_desc *group = lookup_group(dhq.oakley_group);
passert(group != NULL);
SECKEYPrivateKey *ltsecret = dhq.secret;
SECKEYPublicKey *pubk = dhq.pubk;
/* now calculate the (g^x)(g^y) --- need gi on responder, gr on initiator */
chunk_t g;
setchunk_from_wire(g, &dhq, dhq.role == ORIGINAL_RESPONDER ? &dhq.gi : &dhq.gr);
DBG(DBG_CRYPT, DBG_dump_chunk("peer's g: ", g));
skr->shared = calc_dh_shared(g, ltsecret, group, pubk, story);
if (skr->shared != NULL) {
/* okay, so now all the shared key material */
calc_skeyseed_v2(&dhq, /* input */
skr->shared, /* input */
dhq.key_size, /* input */
dhq.salt_size, /* input */
&skr->skeyseed, /* output */
&skr->skeyid_d, /* output */
&skr->skeyid_ai, /* output */
&skr->skeyid_ar, /* output */
&skr->skeyid_ei, /* output */
&skr->skeyid_er, /* output */
&skr->skeyid_pi, /* output */
&skr->skeyid_pr, /* output */
&skr->skey_initiator_salt, /* output */
&skr->skey_responder_salt, /* output */
&skr->skey_chunk_SK_pi, /* output */
&skr->skey_chunk_SK_pr); /* output */
}
}
/* MUST BE THREAD-SAFE */
static void calc_skeyseed_v2(struct pcr_skeyid_q *skq,
PK11SymKey *shared,
const size_t key_size,
const size_t salt_size,
PK11SymKey **skeyseed_out,
PK11SymKey **SK_d_out,
PK11SymKey **SK_ai_out,
PK11SymKey **SK_ar_out,
PK11SymKey **SK_ei_out,
PK11SymKey **SK_er_out,
PK11SymKey **SK_pi_out,
PK11SymKey **SK_pr_out,
chunk_t *initiator_salt_out,
chunk_t *responder_salt_out,
chunk_t *chunk_SK_pi_out,
chunk_t *chunk_SK_pr_out)
{
DBG(DBG_CRYPT, DBG_log("NSS: Started key computation"));
PK11SymKey
*skeyseed_k,
*SK_d_k,
*SK_ai_k,
*SK_ar_k,
*SK_ei_k,
*SK_er_k,
*SK_pi_k,
*SK_pr_k;
chunk_t initiator_salt;
chunk_t responder_salt;
chunk_t chunk_SK_pi;
chunk_t chunk_SK_pr;
/* this doesn't take any memory, it's just moving pointers around */
chunk_t ni;
chunk_t nr;
chunk_t spii;
chunk_t spir;
setchunk_from_wire(ni, skq, &skq->ni);
setchunk_from_wire(nr, skq, &skq->nr);
setchunk_from_wire(spii, skq, &skq->icookie);
setchunk_from_wire(spir, skq, &skq->rcookie);
DBG(DBG_CONTROLMORE,
DBG_log("calculating skeyseed using prf=%s integ=%s cipherkey-size=%zu salt-size=%zu",
enum_name(&ikev2_trans_type_prf_names, skq->prf_hash),
enum_name(&ikev2_trans_type_integ_names, skq->integ_hash),
key_size, salt_size));
const struct hash_desc *prf_hasher = (struct hash_desc *)
ikev2_alg_find(IKE_ALG_HASH, skq->prf_hash);
passert(prf_hasher != NULL);
const struct encrypt_desc *encrypter = skq->encrypter;
passert(encrypter != NULL);
/* generate SKEYSEED from key=(Ni|Nr), hash of shared */
skeyseed_k = ikev2_ike_sa_skeyseed(prf_hasher, ni, nr, shared);
passert(skeyseed_k != NULL);
/* now we have to generate the keys for everything */
/* need to know how many bits to generate */
/* SK_d needs PRF hasher key bytes */
/* SK_p needs PRF hasher*2 key bytes */
/* SK_e needs key_size*2 key bytes */
/* ..._salt needs salt_size*2 bytes */
/* SK_a needs integ's key size*2 bytes */
int skd_bytes = prf_hasher->hash_key_size;
int skp_bytes = prf_hasher->hash_key_size;
const struct hash_desc *integ_hasher =
(struct hash_desc *)ikev2_alg_find(IKE_ALG_INTEG, skq->integ_hash);
int integ_size = integ_hasher != NULL ? integ_hasher->hash_key_size : 0;
size_t total_keysize = skd_bytes + 2*skp_bytes + 2*key_size + 2*salt_size + 2*integ_size;
PK11SymKey *finalkey = ikev2_ike_sa_keymat(prf_hasher, skeyseed_k,
ni, nr, spii, spir,
total_keysize);
size_t next_byte = 0;
SK_d_k = key_from_symkey_bytes(finalkey, next_byte, skd_bytes);
next_byte += skd_bytes;
SK_ai_k = key_from_symkey_bytes(finalkey, next_byte, integ_size);
next_byte += integ_size;
SK_ar_k = key_from_symkey_bytes(finalkey, next_byte, integ_size);
next_byte += integ_size;
/* The encryption key and salt are extracted together. */
SK_ei_k = encrypt_key_from_symkey_bytes(finalkey, encrypter,
next_byte, key_size);
next_byte += key_size;
PK11SymKey *initiator_salt_key = key_from_symkey_bytes(finalkey, next_byte,
salt_size);
initiator_salt = chunk_from_symkey("initiator salt", initiator_salt_key);
free_any_symkey("initiator salt key:", &initiator_salt_key);
next_byte += salt_size;
/* The encryption key and salt are extracted together. */
SK_er_k = encrypt_key_from_symkey_bytes(finalkey, encrypter,
next_byte, key_size);
next_byte += key_size;
PK11SymKey *responder_salt_key = key_from_symkey_bytes(finalkey, next_byte,
salt_size);
responder_salt = chunk_from_symkey("responder salt", responder_salt_key);
free_any_symkey("responder salt key:", &responder_salt_key);
next_byte += salt_size;
SK_pi_k = key_from_symkey_bytes(finalkey, next_byte, skp_bytes);
/* store copy of SK_pi_k for later use in authnull */
chunk_SK_pi = chunk_from_symkey("chunk_SK_pi", SK_pi_k);
next_byte += skp_bytes;
SK_pr_k = key_from_symkey_bytes(finalkey, next_byte, skp_bytes);
/* store copy of SK_pr_k for later use in authnull */
chunk_SK_pr = chunk_from_symkey("chunk_SK_pr", SK_pr_k);
next_byte += skp_bytes; /* next_byte not subsequently used */
DBG(DBG_CRYPT,
DBG_log("NSS ikev2: finished computing individual keys for IKEv2 SA"));
free_any_symkey("finalkey", &finalkey);
*skeyseed_out = skeyseed_k;
*SK_d_out = SK_d_k;
*SK_ai_out = SK_ai_k;
*SK_ar_out = SK_ar_k;
*SK_ei_out = SK_ei_k;
*SK_er_out = SK_er_k;
*SK_pi_out = SK_pi_k;
*SK_pr_out = SK_pr_k;
*initiator_salt_out = initiator_salt;
*responder_salt_out = responder_salt;
*chunk_SK_pi_out = chunk_SK_pi;
*chunk_SK_pr_out = chunk_SK_pr;
DBG(DBG_CRYPT,
DBG_log("calc_skeyseed_v2 pointers: shared %p, skeyseed %p, SK_d %p, SK_ai %p, SK_ar %p, SK_ei %p, SK_er %p, SK_pi %p, SK_pr %p",
shared, skeyseed_k, SK_d_k, SK_ai_k, SK_ar_k, SK_ei_k, SK_er_k, SK_pi_k, SK_pr_k);
DBG_dump_chunk("calc_skeyseed_v2 initiator salt", initiator_salt);
DBG_dump_chunk("calc_skeyseed_v2 responder salt", responder_salt);
DBG_dump_chunk("calc_skeyseed_v2 SK_pi", chunk_SK_pi);
DBG_dump_chunk("calc_skeyseed_v2 SK_pr", chunk_SK_pr));
}