diff options
Diffstat (limited to 'sysdep/bsd/setkey.h')
| -rw-r--r-- | sysdep/bsd/setkey.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/sysdep/bsd/setkey.h b/sysdep/bsd/setkey.h new file mode 100644 index 00000000..b417faca --- /dev/null +++ b/sysdep/bsd/setkey.h @@ -0,0 +1,170 @@ +/* + * BIRD -- Manipulation the IPsec SA/SP database using setkey(8) utility + * + * (c) 2016 CZ.NIC z.s.p.o. + */ + +#include <unistd.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <net/pfkeyv2.h> +#include <netipsec/ipsec.h> + +#include "nest/bird.h" +#include "lib/unix.h" + + +/* + * Open a socket for manage the IPsec SA/SP database entries + */ +static int +setkey_open_socket(void) +{ + int s = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); + if (s < 0) + { + log(L_ERR "SETKEY: socket: %m"); + return -1; + } + + return s; +} + +static int +setkey_send(struct sadb_msg *msg, uint len) +{ + int s = setkey_open_socket(); + if (s < 0) + return -1; + + if (msg->sadb_msg_type == SADB_ADD) + { + /* Delete possible current key in the IPsec SA/SP database */ + msg->sadb_msg_type = SADB_DELETE; + send(s, msg, len, 0); + msg->sadb_msg_type = SADB_ADD; + } + + if (send(s, msg, len, 0) < 0) + { + log(L_ERR "SETKEY: send: %m"); + close(s); + return -1; + } + + close(s); + return 0; +} + +/* + * Perform setkey(8)-like operation for set the password for TCP MD5 Signature. + * Could be called with SABD_ADD or SADB_DELETE argument. Note that SADB_ADD + * argument is internally processed as a pair of SADB_ADD and SADB_DELETE + * operations to implement replace. + */ +static int +setkey_md5(sockaddr *src, sockaddr *dst, char *passwd, uint type) +{ + uint passwd_len = passwd ? strlen(passwd) : 0; + + uint total = + sizeof(struct sadb_msg) + + sizeof(struct sadb_key) + PFKEY_ALIGN8(passwd_len) + + sizeof(struct sadb_sa) + + sizeof(struct sadb_x_sa2) + + sizeof(struct sadb_address) + PFKEY_ALIGN8(src->sa.sa_len) + + sizeof(struct sadb_address) + PFKEY_ALIGN8(dst->sa.sa_len); + + char *buf = alloca(total); + char *pos = buf; + uint len; + + memset(buf, 0, total); + + struct sadb_msg *msg = (void *) pos; + len = sizeof(struct sadb_msg); + msg->sadb_msg_version = PF_KEY_V2; + msg->sadb_msg_type = type; + msg->sadb_msg_satype = SADB_X_SATYPE_TCPSIGNATURE; + msg->sadb_msg_len = 0; /* Fix it later */ + msg->sadb_msg_pid = getpid(); + pos += len; + + /* Set authentication algorithm and password */ + struct sadb_key *key = (void *) pos; + len = sizeof(struct sadb_key) + PFKEY_ALIGN8(passwd_len); + key->sadb_key_len = PFKEY_UNIT64(len); + key->sadb_key_exttype = SADB_EXT_KEY_AUTH; + key->sadb_key_bits = passwd_len * 8; + memcpy(pos + sizeof(struct sadb_key), passwd, passwd_len); + pos += len; + + struct sadb_sa *sa = (void *) pos; + len = sizeof(struct sadb_sa); + sa->sadb_sa_len = PFKEY_UNIT64(len); + sa->sadb_sa_exttype = SADB_EXT_SA; + sa->sadb_sa_spi = htonl((u32) TCP_SIG_SPI); + sa->sadb_sa_auth = SADB_X_AALG_TCP_MD5; + sa->sadb_sa_encrypt = SADB_EALG_NONE; + sa->sadb_sa_flags = SADB_X_EXT_CYCSEQ; + pos += len; + + struct sadb_x_sa2 *sa2 = (void *) pos; + len = sizeof(struct sadb_x_sa2); + sa2->sadb_x_sa2_len = PFKEY_UNIT64(len); + sa2->sadb_x_sa2_exttype = SADB_X_EXT_SA2; + sa2->sadb_x_sa2_mode = IPSEC_MODE_ANY; + pos += len; + + /* Set source address */ + struct sadb_address *saddr = (void *) pos; + len = sizeof(struct sadb_address) + PFKEY_ALIGN8(src->sa.sa_len); + saddr->sadb_address_len = PFKEY_UNIT64(len); + saddr->sadb_address_exttype = SADB_EXT_ADDRESS_SRC; + saddr->sadb_address_proto = IPSEC_ULPROTO_ANY; + saddr->sadb_address_prefixlen = MAX_PREFIX_LENGTH; + memcpy(pos + sizeof(struct sadb_address), &src->sa, src->sa.sa_len); + pos += len; + + /* Set destination address */ + struct sadb_address *daddr = (void *) pos; + len = sizeof(struct sadb_address) + PFKEY_ALIGN8(dst->sa.sa_len); + daddr->sadb_address_len = PFKEY_UNIT64(len); + daddr->sadb_address_exttype = SADB_EXT_ADDRESS_DST; + daddr->sadb_address_proto = IPSEC_ULPROTO_ANY; + daddr->sadb_address_prefixlen = MAX_PREFIX_LENGTH; + memcpy(pos + sizeof(struct sadb_address), &dst->sa, dst->sa.sa_len); + pos += len; + + len = pos - buf; + msg->sadb_msg_len = PFKEY_UNIT64(len); + + return setkey_send(msg, len); +} + +/* + * Manipulation with the IPsec SA/SP database + */ +static int +sk_set_md5_in_sasp_db(sock *s, ip_addr local, ip_addr remote, struct iface *ifa, char *passwd) +{ + sockaddr src, dst; + sockaddr_fill(&src, s->af, local, ifa, 0); + sockaddr_fill(&dst, s->af, remote, ifa, 0); + + if (passwd && *passwd) + { + int len = strlen(passwd); + if (len > TCP_KEYLEN_MAX) + ERR_MSG("The password for TCP MD5 Signature is too long"); + + if (setkey_md5(&src, &dst, passwd, SADB_ADD) < 0) + ERR_MSG("Cannot add TCP-MD5 password into the IPsec SA/SP database"); + } + else + { + if (setkey_md5(&src, &dst, NULL, SADB_DELETE) < 0) + ERR_MSG("Cannot delete TCP-MD5 password from the IPsec SA/SP database"); + } + return 0; +} |