Migrated EAP-TLS to the generic TLS helper
This commit is contained in:
Martin Willi
parent
877c910f04
commit
be751012c3
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@ -15,7 +15,7 @@
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#include "eap_tls.h"
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#include <tls.h>
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#include <tls_eap.h>
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#include <daemon.h>
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#include <library.h>
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@ -38,294 +38,46 @@ struct private_eap_tls_t {
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int processed;
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/**
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* Is this method instance acting as server?
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* TLS stack, wrapped by EAP helper
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*/
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bool is_server;
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/**
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* TLS layers
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*/
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tls_t *tls;
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/**
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* Allocated input buffer
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*/
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chunk_t input;
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/**
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* Number of bytes read in input buffer
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*/
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size_t inpos;
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/**
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* Allocated ouput buffer
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*/
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chunk_t output;
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/**
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* Number of bytes sent from output buffer
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*/
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size_t outpos;
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tls_eap_t *tls_eap;
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};
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/** Size limit for a single TLS message */
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#define MAX_TLS_MESSAGE_LEN 65536
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/** Size of a EAP-TLS fragment */
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#define EAP_TLS_FRAGMENT_LEN 1014
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/** Maximum number of EAP-TLS messages/fragments allowed */
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#define MAX_EAP_TLS_MESSAGE_COUNT 32
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/**
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* Flags of an EAP-TLS message
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*/
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typedef enum {
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EAP_TLS_LENGTH = (1<<7),
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EAP_TLS_MORE_FRAGS = (1<<6),
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EAP_TLS_START = (1<<5),
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} eap_tls_flags_t;
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/**
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* EAP-TLS packet format
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*/
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typedef struct __attribute__((packed)) {
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u_int8_t code;
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u_int8_t identifier;
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u_int16_t length;
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u_int8_t type;
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u_int8_t flags;
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} eap_tls_packet_t;
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#define MAX_EAP_TLS_MESSAGE_COUNT 24
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METHOD(eap_method_t, initiate, status_t,
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private_eap_tls_t *this, eap_payload_t **out)
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{
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if (this->is_server)
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{
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eap_tls_packet_t pkt = {
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.type = EAP_TLS,
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.code = EAP_REQUEST,
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.flags = EAP_TLS_START,
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};
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htoun16(&pkt.length, sizeof(eap_tls_packet_t));
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/* start with non-zero random identifier */
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do {
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pkt.identifier = random();
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} while (!pkt.identifier);
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DBG2(DBG_IKE, "sending EAP-TLS start packet");
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chunk_t data;
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*out = eap_payload_create_data(chunk_from_thing(pkt));
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if (this->tls_eap->initiate(this->tls_eap, &data) == NEED_MORE)
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{
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*out = eap_payload_create_data(data);
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free(data.ptr);
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return NEED_MORE;
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}
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return FAILED;
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}
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/**
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* Write received TLS data to the input buffer
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*/
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static bool write_buf(private_eap_tls_t *this, eap_tls_packet_t *pkt)
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{
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u_int32_t msg_len;
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u_int16_t pkt_len;
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chunk_t data;
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pkt_len = untoh16(&pkt->length);
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if (pkt->flags & EAP_TLS_LENGTH)
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{
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if (pkt_len < sizeof(eap_tls_packet_t) + sizeof(msg_len))
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{
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DBG1(DBG_IKE, "EAP-TLS packet too short");
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return FALSE;
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}
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msg_len = untoh32(pkt + 1);
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if (msg_len < pkt_len - sizeof(eap_tls_packet_t) - sizeof(msg_len) ||
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msg_len > MAX_TLS_MESSAGE_LEN)
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{
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DBG1(DBG_IKE, "invalid EAP-TLS packet length");
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return FALSE;
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}
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if (this->input.ptr)
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{
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if (msg_len != this->input.len)
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{
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DBG1(DBG_IKE, "received unexpected TLS message length");
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return FALSE;
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}
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}
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else
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{
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this->input = chunk_alloc(msg_len);
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this->inpos = 0;
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}
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data = chunk_create((char*)(pkt + 1) + sizeof(msg_len),
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pkt_len - sizeof(eap_tls_packet_t) - sizeof(msg_len));
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}
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else
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{
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data = chunk_create((char*)(pkt + 1),
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pkt_len - sizeof(eap_tls_packet_t));
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}
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DBG2(DBG_IKE, "received EAP-TLS %s (%u bytes)",
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(pkt->flags & EAP_TLS_MORE_FRAGS) ? "fragment" : "packet", pkt_len);
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if (data.len > this->input.len - this->inpos)
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{
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DBG1(DBG_IKE, "EAP-TLS fragment exceeds TLS message length");
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return FALSE;
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}
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memcpy(this->input.ptr + this->inpos, data.ptr, data.len);
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this->inpos += data.len;
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return TRUE;
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}
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/**
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* Send an ack to request next fragment
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*/
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static eap_payload_t *create_ack(private_eap_tls_t *this, u_int8_t identifier)
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{
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eap_tls_packet_t pkt = {
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.code = this->is_server ? EAP_REQUEST : EAP_RESPONSE,
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.identifier = this->is_server ? identifier + 1 : identifier,
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.type = EAP_TLS,
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};
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htoun16(&pkt.length, sizeof(pkt));
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DBG2(DBG_IKE, "sending EAP-TLS acknowledgement packet");
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return eap_payload_create_data(chunk_from_thing(pkt));
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}
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/**
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* Create a eap response from data in the TLS output buffer
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*/
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static eap_payload_t *read_buf(private_eap_tls_t *this, u_int8_t identifier)
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{
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char buf[EAP_TLS_FRAGMENT_LEN + sizeof(eap_tls_packet_t) + 4], *start;
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eap_tls_packet_t *pkt = (eap_tls_packet_t*)buf;
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u_int16_t pkt_len = sizeof(eap_tls_packet_t);
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pkt->code = this->is_server ? EAP_REQUEST : EAP_RESPONSE;
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pkt->identifier = this->is_server ? identifier + 1 : identifier;
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pkt->type = EAP_TLS;
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pkt->flags = 0;
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if (this->output.len)
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{
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start = (char*)(pkt + 1);
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if (this->outpos == 0)
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{ /* first fragment */
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pkt->flags = EAP_TLS_LENGTH;
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pkt_len += 4;
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start += 4;
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htoun32(pkt + 1, this->output.len);
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}
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if (this->output.len - this->outpos > EAP_TLS_FRAGMENT_LEN)
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{
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pkt->flags |= EAP_TLS_MORE_FRAGS;
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pkt_len += EAP_TLS_FRAGMENT_LEN;
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memcpy(start, this->output.ptr + this->outpos, EAP_TLS_FRAGMENT_LEN);
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this->outpos += EAP_TLS_FRAGMENT_LEN;
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DBG2(DBG_IKE, "sending EAP-TLS fragment (%u bytes)", pkt_len);
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}
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else
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{
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pkt_len += this->output.len - this->outpos;
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memcpy(start, this->output.ptr + this->outpos,
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this->output.len - this->outpos);
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chunk_free(&this->output);
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this->outpos = 0;
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DBG2(DBG_IKE, "sending EAP-TLS packet (%u bytes)", pkt_len);
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}
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}
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else
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{
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DBG2(DBG_IKE, "sending EAP-TLS acknowledgement packet");
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}
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htoun16(&pkt->length, pkt_len);
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return eap_payload_create_data(chunk_create(buf, pkt_len));
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}
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/**
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* Pass data in input buffer to upper layers, write result to output buffer
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*/
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static status_t process_buf(private_eap_tls_t *this)
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{
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status_t status;
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status = this->tls->process(this->tls, this->input.ptr, this->input.len);
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if (status != NEED_MORE)
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{
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return status;
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}
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chunk_free(&this->input);
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this->inpos = 0;
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chunk_free(&this->output);
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this->output = chunk_alloc(EAP_TLS_FRAGMENT_LEN);
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return this->tls->build(this->tls, this->output.ptr, &this->output.len, NULL);
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}
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METHOD(eap_method_t, process, status_t,
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private_eap_tls_t *this, eap_payload_t *in, eap_payload_t **out)
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{
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eap_tls_packet_t *pkt;
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chunk_t data;
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status_t status;
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chunk_t data;
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if (++this->processed > MAX_EAP_TLS_MESSAGE_COUNT)
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{
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DBG1(DBG_IKE, "EAP-TLS packet count exceeded");
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DBG1(DBG_IKE, "EAP-TLS packet count exceeded (%d > %d)",
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this->processed, MAX_EAP_TLS_MESSAGE_COUNT);
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return FAILED;
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}
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data = in->get_data(in);
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pkt = (eap_tls_packet_t*)data.ptr;
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if (data.len < sizeof(eap_tls_packet_t) ||
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untoh16(&pkt->length) != data.len)
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{
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DBG1(DBG_IKE, "invalid EAP-TLS packet length");
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return FAILED;
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}
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if (!(pkt->flags & EAP_TLS_START))
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{
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if (data.len == sizeof(eap_tls_packet_t))
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{
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if (this->output.len)
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{ /* ACK to our fragment, send next */
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*out = read_buf(this, pkt->identifier);
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return NEED_MORE;
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}
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if (this->tls->is_complete(this->tls))
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{
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return SUCCESS;
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}
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return FAILED;
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}
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if (!write_buf(this, pkt))
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{
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return FAILED;
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}
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if (pkt->flags & EAP_TLS_MORE_FRAGS)
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{ /* more fragments follow */
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*out = create_ack(this, pkt->identifier);
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return NEED_MORE;
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}
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else if (this->input.len != this->inpos)
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{
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DBG1(DBG_IKE, "defragmented TLS message has invalid length");
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return FAILED;
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}
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}
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status = process_buf(this);
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status = this->tls_eap->process(this->tls_eap, data, &data);
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if (status == NEED_MORE)
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{
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*out = read_buf(this, pkt->identifier);
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}
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else if (status == FAILED && !this->is_server)
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{ /* client sends an empty TLS message, waits for a EAP-Failure */
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chunk_free(&this->output);
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*out = read_buf(this, pkt->identifier);
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return NEED_MORE;
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*out = eap_payload_create_data(data);
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free(data.ptr);
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}
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return status;
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}
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@ -340,7 +92,7 @@ METHOD(eap_method_t, get_type, eap_type_t,
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METHOD(eap_method_t, get_msk, status_t,
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private_eap_tls_t *this, chunk_t *msk)
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{
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*msk = this->tls->get_eap_msk(this->tls);
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*msk = this->tls_eap->get_msk(this->tls_eap);
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if (msk->len)
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{
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return SUCCESS;
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@ -357,11 +109,7 @@ METHOD(eap_method_t, is_mutual, bool,
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METHOD(eap_method_t, destroy, void,
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private_eap_tls_t *this)
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{
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free(this->input.ptr);
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free(this->output.ptr);
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this->tls->destroy(this->tls);
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this->tls_eap->destroy(this->tls_eap);
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free(this);
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}
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@ -384,11 +132,10 @@ static eap_tls_t *eap_tls_create(identification_t *server,
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.destroy = _destroy,
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},
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},
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.is_server = is_server,
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);
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this->tls = tls_create(is_server, server, peer, TLS_PURPOSE_EAP_TLS, NULL);
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if (!this->tls)
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this->tls_eap = tls_eap_create(EAP_TLS, is_server, server, peer, NULL);
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if (!this->tls_eap)
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{
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free(this);
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return NULL;
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