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Code Releases Activity

OSPF: Use message authentication interface

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Based on former commit from Pavel Tvrdik
This commit is contained in:
Ondrej Zajicek (work)
2016-10-27 20:58:21 +02:00
parent 390601f038
commit 29239ba2bb
4 changed files with 94 additions and 73 deletions
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108
proto/ospf/packet.c
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@@ -32,25 +32,12 @@ ospf_pkt_fill_hdr(struct ospf_iface *ifa, void *buf, u8 h_type)
pkt->autype = ifa->autype;
}
uint
ospf_pkt_maxsize(struct ospf_iface *ifa)
{
uint headers = SIZE_OF_IP_HEADER;
/* Relevant just for OSPFv2 */
if (ifa->autype == OSPF_AUTH_CRYPT)
headers += OSPF_AUTH_CRYPT_SIZE;
return ifa->tx_length - headers;
}
/* We assume OSPFv2 in ospf_pkt_finalize() */
static void
ospf_pkt_finalize(struct ospf_iface *ifa, struct ospf_packet *pkt)
ospf_pkt_finalize(struct ospf_iface *ifa, struct ospf_packet *pkt, uint *plen)
{
struct password_item *passwd = NULL;
struct password_item *pass = NULL;
union ospf_auth *auth = (void *) (pkt + 1);
uint plen = ntohs(pkt->length);
pkt->checksum = 0;
pkt->autype = ifa->autype;
@@ -62,25 +49,25 @@ ospf_pkt_finalize(struct ospf_iface *ifa, struct ospf_packet *pkt)
switch (ifa->autype)
{
case OSPF_AUTH_SIMPLE:
passwd = password_find(ifa->passwords, 1);
if (!passwd)
pass = password_find(ifa->passwords, 1);
if (!pass)
{
log(L_ERR "No suitable password found for authentication");
return;
}
strncpy(auth->password, passwd->password, sizeof(auth->password));
strncpy(auth->password, pass->password, sizeof(auth->password));
case OSPF_AUTH_NONE:
{
void *body = (void *) (auth + 1);
uint blen = plen - sizeof(struct ospf_packet) - sizeof(union ospf_auth);
uint blen = *plen - sizeof(struct ospf_packet) - sizeof(union ospf_auth);
pkt->checksum = ipsum_calculate(pkt, sizeof(struct ospf_packet), body, blen, NULL);
}
break;
case OSPF_AUTH_CRYPT:
passwd = password_find(ifa->passwords, 0);
if (!passwd)
pass = password_find(ifa->passwords, 0);
if (!pass)
{
log(L_ERR "No suitable password found for authentication");
return;
@@ -101,20 +88,25 @@ ospf_pkt_finalize(struct ospf_iface *ifa, struct ospf_packet *pkt)
ifa->csn_use = now;
auth->md5.zero = 0;
auth->md5.keyid = passwd->id;
auth->md5.len = OSPF_AUTH_CRYPT_SIZE;
auth->md5.csn = htonl(ifa->csn);
uint auth_len = mac_type_length(pass->alg);
byte *auth_tail = ((byte *) pkt + *plen);
*plen += auth_len;
void *tail = ((void *) pkt) + plen;
char password[OSPF_AUTH_CRYPT_SIZE];
strncpy(password, passwd->password, sizeof(password));
ASSERT(*plen < ifa->sk->tbsize);
struct hash_context ctx;
md5_init(&ctx);
md5_update(&ctx, (char *) pkt, plen);
md5_update(&ctx, password, OSPF_AUTH_CRYPT_SIZE);
memcpy((byte *) tail, md5_final(&ctx), MD5_SIZE);
auth->c32.zero = 0;
auth->c32.keyid = pass->id;
auth->c32.len = auth_len;
auth->c32.csn = htonl(ifa->csn);
/* Append key for keyed hash, append padding for HMAC (RFC 5709 3.3) */
if (pass->alg < ALG_HMAC)
strncpy(auth_tail, pass->password, auth_len);
else
memset32(auth_tail, HMAC_MAGIC, auth_len / 4);
mac_fill(pass->alg, pass->password, pass->length,
(byte *) pkt, *plen, auth_tail);
break;
default:
@@ -155,13 +147,19 @@ ospf_pkt_checkauth(struct ospf_neighbor *n, struct ospf_iface *ifa, struct ospf_
return 1;
case OSPF_AUTH_CRYPT:
if (auth->md5.len != OSPF_AUTH_CRYPT_SIZE)
DROP("invalid MD5 digest length", auth->md5.len);
pass = password_find_by_id(ifa->passwords, auth->c32.keyid);
if (!pass)
DROP("no suitable password found", auth->c32.keyid);
if (plen + OSPF_AUTH_CRYPT_SIZE > len)
DROP("length mismatch", len);
uint auth_len = mac_type_length(pass->alg);
u32 rcv_csn = ntohl(auth->md5.csn);
if (plen + auth->c32.len > len)
DROP("packet length mismatch", len);
if (auth->c32.len != auth_len)
DROP("wrong authentication length", auth->c32.len);
u32 rcv_csn = ntohl(auth->c32.csn);
if (n && (rcv_csn < n->csn))
// DROP("lower sequence number", rcv_csn);
{
@@ -172,22 +170,19 @@ ospf_pkt_checkauth(struct ospf_neighbor *n, struct ospf_iface *ifa, struct ospf_
return 0;
}
pass = password_find_by_id(ifa->passwords, auth->md5.keyid);
if (!pass)
DROP("no suitable password found", auth->md5.keyid);
byte *auth_tail = ((byte *) pkt) + plen;
byte *auth_data = alloca(auth_len);
memcpy(auth_data, auth_tail, auth_len);
byte *tail = ((byte *) pkt) + plen;
char received[OSPF_AUTH_CRYPT_SIZE];
memcpy(received, tail, OSPF_AUTH_CRYPT_SIZE);
strncpy(tail, pass->password, OSPF_AUTH_CRYPT_SIZE);
/* Append key for keyed hash, append padding for HMAC (RFC 5709 3.3) */
if (pass->alg < ALG_HMAC)
strncpy(auth_tail, pass->password, auth_len);
else
memset32(auth_tail, HMAC_MAGIC, auth_len / 4);
struct hash_context ctx;
md5_init(&ctx);
md5_update(&ctx, (byte *) pkt, plen + OSPF_AUTH_CRYPT_SIZE);
char *computed = md5_final(&ctx);
if (memcmp(received, computed, OSPF_AUTH_CRYPT_SIZE))
DROP("wrong MD5 digest", pass->id);
if (!mac_verify(pass->alg, pass->password, pass->length,
(byte *) pkt, plen + auth_len, auth_data))
DROP("wrong authentication code", pass->id);
if (n)
n->csn = rcv_csn;
@@ -473,15 +468,10 @@ ospf_send_to(struct ospf_iface *ifa, ip_addr dst)
{
sock *sk = ifa->sk;
struct ospf_packet *pkt = (struct ospf_packet *) sk->tbuf;
int plen = ntohs(pkt->length);
uint plen = ntohs(pkt->length);
if (ospf_is_v2(ifa->oa->po))
{
if (ifa->autype == OSPF_AUTH_CRYPT)
plen += OSPF_AUTH_CRYPT_SIZE;
ospf_pkt_finalize(ifa, pkt);
}
ospf_pkt_finalize(ifa, pkt, &plen);
int done = sk_send_to(sk, plen, dst, 0);
if (!done)