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/* $OpenBSD: auth.c,v 1.20 2015/05/05 01:26:37 jsg Exp $ */ |
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/* |
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* Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <limits.h> |
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#include <md5.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include "ospfd.h" |
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#include "ospf.h" |
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#include "log.h" |
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#include "ospfe.h" |
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struct auth_md *md_list_find(struct auth_md_head *, u_int8_t); |
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int |
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auth_validate(void *buf, u_int16_t len, struct iface *iface, struct nbr *nbr) |
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{ |
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MD5_CTX hash; |
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u_int8_t digest[MD5_DIGEST_LENGTH]; |
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u_int8_t recv_digest[MD5_DIGEST_LENGTH]; |
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struct ospf_hdr *ospf_hdr = buf; |
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struct auth_md *md; |
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char *auth_data; |
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if (ntohs(ospf_hdr->auth_type) != (u_int16_t)iface->auth_type) { |
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log_debug("auth_validate: wrong auth type, interface %s", |
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iface->name); |
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return (-1); |
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} |
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switch (iface->auth_type) { |
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case AUTH_SIMPLE: |
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if (memcmp(ospf_hdr->auth_key.simple, iface->auth_key, |
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sizeof(ospf_hdr->auth_key.simple))) { |
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log_debug("auth_validate: wrong password, interface %s", |
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iface->name); |
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return (-1); |
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} |
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/* FALLTHROUGH */ |
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case AUTH_NONE: |
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/* clear the key before chksum */ |
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bzero(ospf_hdr->auth_key.simple, |
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sizeof(ospf_hdr->auth_key.simple)); |
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if (in_cksum(ospf_hdr, ntohs(ospf_hdr->len))) { |
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log_debug("auth_validate: invalid checksum, " |
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"interface %s", iface->name); |
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return (-1); |
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} |
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break; |
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case AUTH_CRYPT: |
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/* |
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* We must allow keys that are configured on the interface |
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* but not necessarily set as the transmit key |
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* (iface->auth_keyid). This allows for key rotation to new |
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* keys without taking down the network. |
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*/ |
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if ((md = md_list_find(&iface->auth_md_list, |
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ospf_hdr->auth_key.crypt.keyid)) == NULL) { |
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log_debug("auth_validate: keyid %d not configured, " |
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"interface %s", ospf_hdr->auth_key.crypt.keyid, |
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iface->name); |
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return (-1); |
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} |
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if (nbr != NULL && ntohl(ospf_hdr->auth_key.crypt.seq_num) < |
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nbr->crypt_seq_num) { |
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log_debug("auth_validate: decreasing seq num, " |
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"interface %s", iface->name); |
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return (-1); |
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} |
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if (ospf_hdr->auth_key.crypt.len != MD5_DIGEST_LENGTH) { |
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log_debug("auth_validate: invalid key length, " |
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"interface %s", iface->name); |
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return (-1); |
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} |
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if (len - ntohs(ospf_hdr->len) < MD5_DIGEST_LENGTH) { |
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log_debug("auth_validate: invalid key length, " |
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"interface %s", iface->name); |
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return (-1); |
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} |
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auth_data = buf; |
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auth_data += ntohs(ospf_hdr->len); |
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/* save the received digest and clear it in the packet */ |
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memcpy(recv_digest, auth_data, sizeof(recv_digest)); |
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bzero(auth_data, MD5_DIGEST_LENGTH); |
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/* insert plaintext key */ |
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bzero(digest, MD5_DIGEST_LENGTH); |
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strncpy(digest, md->key, MD5_DIGEST_LENGTH); |
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/* calculate MD5 digest */ |
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MD5Init(&hash); |
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MD5Update(&hash, buf, ntohs(ospf_hdr->len)); |
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MD5Update(&hash, digest, MD5_DIGEST_LENGTH); |
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MD5Final(digest, &hash); |
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if (memcmp(recv_digest, digest, sizeof(digest))) { |
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log_debug("auth_validate: invalid MD5 digest, " |
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"interface %s", iface->name); |
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return (-1); |
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} |
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if (nbr != NULL) |
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nbr->crypt_seq_num = |
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ntohl(ospf_hdr->auth_key.crypt.seq_num); |
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break; |
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default: |
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log_debug("auth_validate: unknown auth type, interface %s", |
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iface->name); |
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return (-1); |
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} |
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return (0); |
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} |
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int |
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auth_gen(struct ibuf *buf, struct iface *iface) |
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{ |
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MD5_CTX hash; |
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u_int8_t digest[MD5_DIGEST_LENGTH]; |
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struct ospf_hdr *ospf_hdr; |
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struct auth_md *md; |
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if ((ospf_hdr = ibuf_seek(buf, 0, sizeof(*ospf_hdr))) == NULL) |
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fatalx("auth_gen: buf_seek failed"); |
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/* update length */ |
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if (ibuf_size(buf) > USHRT_MAX) |
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fatalx("auth_gen: resulting ospf packet too big"); |
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ospf_hdr->len = htons(ibuf_size(buf)); |
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/* clear auth_key field */ |
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bzero(ospf_hdr->auth_key.simple, sizeof(ospf_hdr->auth_key.simple)); |
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switch (iface->auth_type) { |
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case AUTH_NONE: |
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ospf_hdr->chksum = in_cksum(buf->buf, ibuf_size(buf)); |
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break; |
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case AUTH_SIMPLE: |
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ospf_hdr->chksum = in_cksum(buf->buf, ibuf_size(buf)); |
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strncpy(ospf_hdr->auth_key.simple, iface->auth_key, |
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sizeof(ospf_hdr->auth_key.simple)); |
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break; |
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case AUTH_CRYPT: |
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ospf_hdr->chksum = 0; |
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ospf_hdr->auth_key.crypt.keyid = iface->auth_keyid; |
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ospf_hdr->auth_key.crypt.seq_num = htonl(iface->crypt_seq_num); |
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ospf_hdr->auth_key.crypt.len = MD5_DIGEST_LENGTH; |
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iface->crypt_seq_num++; |
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/* insert plaintext key */ |
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if ((md = md_list_find(&iface->auth_md_list, |
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iface->auth_keyid)) == NULL) { |
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log_debug("auth_gen: keyid %d not configured, " |
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"interface %s", iface->auth_keyid, iface->name); |
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return (-1); |
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} |
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bzero(digest, MD5_DIGEST_LENGTH); |
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strncpy(digest, md->key, MD5_DIGEST_LENGTH); |
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/* calculate MD5 digest */ |
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MD5Init(&hash); |
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MD5Update(&hash, buf->buf, ibuf_size(buf)); |
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MD5Update(&hash, digest, MD5_DIGEST_LENGTH); |
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MD5Final(digest, &hash); |
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return (ibuf_add(buf, digest, MD5_DIGEST_LENGTH)); |
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default: |
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log_debug("auth_gen: unknown auth type, interface %s", |
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iface->name); |
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return (-1); |
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} |
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return (0); |
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} |
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/* md list */ |
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void |
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md_list_add(struct auth_md_head *head, u_int8_t keyid, char *key) |
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{ |
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struct auth_md *md; |
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if ((md = md_list_find(head, keyid)) != NULL) { |
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/* update key */ |
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strncpy(md->key, key, sizeof(md->key)); |
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return; |
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} |
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if ((md = calloc(1, sizeof(struct auth_md))) == NULL) |
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fatalx("md_list_add"); |
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md->keyid = keyid; |
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strncpy(md->key, key, sizeof(md->key)); |
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TAILQ_INSERT_TAIL(head, md, entry); |
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} |
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void |
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md_list_copy(struct auth_md_head *to, struct auth_md_head *from) |
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{ |
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struct auth_md *m, *md; |
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TAILQ_INIT(to); |
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✗✓ |
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TAILQ_FOREACH(m, from, entry) { |
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if ((md = calloc(1, sizeof(struct auth_md))) == NULL) |
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fatalx("md_list_copy"); |
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md->keyid = m->keyid; |
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strncpy(md->key, m->key, sizeof(md->key)); |
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TAILQ_INSERT_TAIL(to, md, entry); |
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} |
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} |
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void |
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md_list_clr(struct auth_md_head *head) |
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{ |
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struct auth_md *m; |
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✗✓ |
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while ((m = TAILQ_FIRST(head)) != NULL) { |
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TAILQ_REMOVE(head, m, entry); |
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free(m); |
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} |
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} |
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struct auth_md * |
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md_list_find(struct auth_md_head *head, u_int8_t keyid) |
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{ |
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struct auth_md *m; |
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TAILQ_FOREACH(m, head, entry) |
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if (m->keyid == keyid) |
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return (m); |
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return (NULL); |
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} |
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int |
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md_list_send(struct auth_md_head *head, struct imsgev *to) |
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{ |
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struct auth_md *m; |
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TAILQ_FOREACH(m, head, entry) |
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if (imsg_compose_event(to, IMSG_RECONF_AUTHMD, 0, 0, -1, m, |
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sizeof(*m)) == -1) |
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return (-1); |
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return (0); |
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} |