&packet->if_index, &packet->timestamp);
}
+
/** Sign a previously encoded packet
*
+ * @param packet the raw RADIUS packet (request or response)
+ * @param packet_len the length of the raw RADIUS packet
+ * @param original the raw original request (if this is a response)
+ * @param secret the shared secret
+ * @param secret_len the length of the secret
+ * @return
+ * - <0 on error
+ * - 0 on success
*/
-int fr_radius_packet_sign(RADIUS_PACKET *packet, RADIUS_PACKET const *original,
- char const *secret)
+static int fr_radius_sign(uint8_t *packet, size_t packet_len,
+ uint8_t const *original,
+ uint8_t const *secret, size_t secret_len)
{
- radius_packet_t *hdr = (radius_packet_t *)packet->data;
-
- /*
- * It wasn't assigned an Id, this is bad!
- */
- if (packet->id < 0) {
- fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id");
- return -1;
- }
+ int i;
+ bool done_authenticator = false;
+ uint32_t hash;
+ uint8_t *msg, *end;
+ FR_MD5_CTX context;
- if (!packet->data || (packet->data_len < RADIUS_HDR_LEN) ||
- (packet->offset < 0)) {
- fr_strerror_printf("ERROR: You must call fr_radius_encode() before fr_radius_packet_sign()");
+ if (packet_len < RADIUS_HDR_LEN) {
+ fr_strerror_printf("Packet must be encoded before calling fr_radius_sign()");
return -1;
}
/*
- * Set up the authentication vector with zero, or with
- * the original vector, prior to signing.
+ * Find Message-Authenticator. Its value has to be
+ * calculated before we calculate the Request
+ * Authenticator or the Response Authenticator.
*/
- switch (packet->code) {
- case PW_CODE_ACCOUNTING_REQUEST:
- case PW_CODE_DISCONNECT_REQUEST:
- case PW_CODE_COA_REQUEST:
- memset(packet->vector, 0, AUTH_VECTOR_LEN);
- break;
+ msg = packet + RADIUS_HDR_LEN;
+ end = packet + packet_len;
- case PW_CODE_ACCESS_ACCEPT:
- case PW_CODE_ACCESS_REJECT:
- case PW_CODE_ACCESS_CHALLENGE:
- case PW_CODE_ACCOUNTING_RESPONSE:
- case PW_CODE_DISCONNECT_ACK:
- case PW_CODE_DISCONNECT_NAK:
- case PW_CODE_COA_ACK:
- case PW_CODE_COA_NAK:
- if (!original) {
- fr_strerror_printf("ERROR: Cannot sign response packet without a request packet");
- return -1;
+ while (msg < end) {
+ if (msg[0] != PW_MESSAGE_AUTHENTICATOR) {
+ if ((msg + msg[1]) > end) {
+ fr_strerror_printf("Invalid attribute at offset %zd", msg - packet);
+ return -1;
+ }
+ msg += msg[1];
+ continue;
}
- memcpy(packet->vector, original->vector, AUTH_VECTOR_LEN);
- break;
-
- case PW_CODE_ACCESS_REQUEST:
- case PW_CODE_STATUS_SERVER:
- break; /* packet->vector is already random bytes */
- }
- /*
- * If there's a Message-Authenticator, update it
- * now.
- */
- if (packet->offset > 0) {
- uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
+ if (msg[1] < 18) {
+ fr_strerror_printf("Message-Authenticator is too small");
+ return -1;
+ }
- switch (packet->code) {
+ switch (packet[0]) {
case PW_CODE_ACCOUNTING_RESPONSE:
- if (original && original->code == PW_CODE_STATUS_SERVER) {
- goto do_ack;
- }
+ if (!original) goto need_original;
+ if (original[0] == PW_CODE_STATUS_SERVER) goto do_ack;
+ goto do_response;
case PW_CODE_ACCOUNTING_REQUEST:
case PW_CODE_DISCONNECT_REQUEST:
case PW_CODE_COA_REQUEST:
case PW_CODE_COA_ACK:
case PW_CODE_COA_NAK:
- memset(hdr->vector, 0, AUTH_VECTOR_LEN);
+ if (!original) goto need_original;
+
+ do_response:
+ memset(packet + 4, 0, AUTH_VECTOR_LEN);
break;
- do_ack:
case PW_CODE_ACCESS_ACCEPT:
case PW_CODE_ACCESS_REJECT:
case PW_CODE_ACCESS_CHALLENGE:
- memcpy(hdr->vector, original->vector, AUTH_VECTOR_LEN);
+ do_ack:
+ memcpy(packet + 4, original + 4, AUTH_VECTOR_LEN);
break;
case PW_CODE_ACCESS_REQUEST:
case PW_CODE_STATUS_SERVER:
+ for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(hash)) {
+ hash = fr_rand();
+ memcpy(packet + 4 + i, &hash, sizeof(hash));
+ }
+ done_authenticator = true;
break;
+
+ default:
+ goto bad_packet;
}
/*
- * Calculate the HMAC, and put it
- * into the Message-Authenticator
- * attribute.
+ * Calculate the HMAC, and put it into the
+ * Message-Authenticator attribute.
*/
- fr_hmac_md5(calc_auth_vector, packet->data, packet->data_len,
- (uint8_t const *) secret, talloc_array_length(secret) - 1);
- memcpy(packet->data + packet->offset + 2,
- calc_auth_vector, AUTH_VECTOR_LEN);
+ fr_hmac_md5(msg + 2, packet, packet_len, secret, secret_len);
+ break;
}
/*
- * Copy the request authenticator over to the packet.
+ * Initialize the request authenticator.
*/
- memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
+ switch (packet[0]) {
+ case PW_CODE_ACCOUNTING_REQUEST:
+ case PW_CODE_DISCONNECT_REQUEST:
+ case PW_CODE_COA_REQUEST:
+ memset(packet + 4, 0, AUTH_VECTOR_LEN);
+ break;
+
+ case PW_CODE_ACCESS_ACCEPT:
+ case PW_CODE_ACCESS_REJECT:
+ case PW_CODE_ACCESS_CHALLENGE:
+ case PW_CODE_ACCOUNTING_RESPONSE:
+ case PW_CODE_DISCONNECT_ACK:
+ case PW_CODE_DISCONNECT_NAK:
+ case PW_CODE_COA_ACK:
+ case PW_CODE_COA_NAK:
+ if (!original) {
+ need_original:
+ fr_strerror_printf("Cannot sign response packet without a request packet");
+ return -1;
+ }
+ memcpy(packet + 4, original + 4, AUTH_VECTOR_LEN);
+ break;
- /*
- * Switch over the packet code, deciding how to
- * sign the packet.
- */
- switch (packet->code) {
/*
- * Request packets are not signed, but
- * have a random authentication vector.
+ * The Request Authenticator is random numbers.
+ * We don't need to sign anything else, so
+ * return.
*/
case PW_CODE_ACCESS_REQUEST:
case PW_CODE_STATUS_SERVER:
- break;
+ if (!done_authenticator) {
+ for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(hash)) {
+ hash = fr_rand();
+ memcpy(packet + 4 + i, &hash, sizeof(hash));
+ }
+ }
+ return 0;
- /*
- * Reply packets are signed with the
- * authentication vector of the request.
- */
default:
- {
- uint8_t digest[16];
-
- FR_MD5_CTX context;
- fr_md5_init(&context);
- fr_md5_update(&context, packet->data, packet->data_len);
- fr_md5_update(&context, (uint8_t const *) secret,
- talloc_array_length(secret) - 1);
- fr_md5_final(digest, &context);
-
- memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
- memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
- break;
- }
- }/* switch over packet codes */
+ bad_packet:
+ fr_strerror_printf("Cannot sign unknown packet code %u", packet[0]);
+ return -1;
+ }
+
+ /*
+ * Request / Response Authenticator = MD5(packet + secret)
+ */
+ fr_md5_init(&context);
+ fr_md5_update(&context, packet, packet_len);
+ fr_md5_update(&context, secret, secret_len);
+ fr_md5_final(packet + 4, &context);
+
+ return 0;
+}
+
+/** Sign a previously encoded packet
+ *
+ */
+int fr_radius_packet_sign(RADIUS_PACKET *packet, RADIUS_PACKET const *original,
+ char const *secret)
+{
+ int rcode;
+ uint8_t const *original_data;
+
+ if (original) {
+ original_data = original->data;
+ } else {
+ original_data = NULL;
+ }
+
+ rcode = fr_radius_sign(packet->data, packet->data_len, original_data,
+ (uint8_t const *) secret, talloc_array_length(secret) - 1);
+ if (rcode < 0) return rcode;
+ memcpy(packet->vector, packet->data + 4, AUTH_VECTOR_LEN);
return 0;
}
projects / thirdparty / freeradius-server.git / commitdiff
