buffer hid messages then act on cmd

This commit is contained in:
Conor Patrick 2018-04-30 23:27:26 -04:00
parent f9d89dad4d
commit 2bea99d41e
4 changed files with 245 additions and 12 deletions

190
ctaphid.c
View File

@ -1,8 +1,10 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "ctaphid.h"
#include "time.h"
#include "util.h"
typedef enum
{
@ -10,16 +12,33 @@ typedef enum
HANDLING_REQUEST,
} CTAP_STATE;
typedef enum
{
EMPTY = 0,
BUFFERING,
BUFFERED,
} CTAP_BUFFER_STATE;
#define SUCESS 0
#define SEQUENCE_ERROR 1
static int state;
static int active_cid;
static uint64_t active_cid_timestamp;
static uint8_t ctap_buffer[CTAPHID_BUFFER_SIZE];
static int ctap_buffer_cmd;
static int ctap_buffer_bcnt;
static int ctap_buffer_offset;
static int ctap_packet_seq;
void ctaphid_init()
{
state = IDLE;
active_cid = 0;
active_cid_timestamp = millis();
ctap_buffer_bcnt = 0;
ctap_buffer_offset = 0;
ctap_packet_seq = 0;
}
uint32_t get_new_cid()
@ -38,6 +57,11 @@ static int is_init_pkt(CTAPHID_PACKET * pkt)
return (pkt->pkt.init.cmd == CTAPHID_INIT);
}
static int is_cont_pkt(CTAPHID_PACKET * pkt)
{
return (pkt->pkt.init.cmd == CTAPHID_INIT);
}
static int is_active_cid(CTAPHID_PACKET * pkt)
{
return (pkt->cid == active_cid);
@ -48,11 +72,65 @@ static int is_timed_out()
return (millis() - active_cid_timestamp > 500);
}
void ctaphid_handle_packet(uint8_t * pkt_raw)
static int buffer_packet(CTAPHID_PACKET * pkt)
{
if (pkt->pkt.init.cmd & TYPE_INIT)
{
ctap_buffer_bcnt = ctaphid_packet_len(pkt);
int pkt_len = (ctap_buffer_bcnt < CTAPHID_INIT_PAYLOAD_SIZE) ? ctap_buffer_bcnt : CTAPHID_INIT_PAYLOAD_SIZE;
ctap_buffer_cmd = pkt->pkt.init.cmd;
ctap_buffer_offset = pkt_len;
ctap_packet_seq = -1;
memmove(ctap_buffer, pkt->pkt.init.payload, pkt_len);
}
else
{
int leftover = ctap_buffer_bcnt - ctap_buffer_offset;
int diff = leftover - CTAPHID_CONT_PAYLOAD_SIZE;
ctap_packet_seq++;
if (ctap_packet_seq != pkt->pkt.cont.seq)
{
return SEQUENCE_ERROR;
}
if (diff <= 0)
{
// only move the leftover amount
memmove(ctap_buffer + ctap_buffer_offset, pkt->pkt.cont.payload, leftover);
ctap_buffer_offset += leftover;
}
else
{
memmove(ctap_buffer + ctap_buffer_offset, pkt->pkt.cont.payload, CTAPHID_CONT_PAYLOAD_SIZE);
ctap_buffer_offset += CTAPHID_CONT_PAYLOAD_SIZE;
}
}
return SUCESS;
}
static int buffer_status()
{
if (ctap_buffer_bcnt == 0)
{
return EMPTY;
}
else if (ctap_buffer_offset == ctap_buffer_bcnt)
{
return BUFFERED;
}
else
{
return BUFFERING;
}
}
static int buffer_cmd()
{
return ctap_buffer_cmd;
}
void ctaphid_handle_packet(uint8_t * pkt_raw, CTAPHID_STATUS * stat)
{
/*HID_MESSAGE_SIZE*/
CTAPHID_PACKET * pkt = (CTAPHID_PACKET *)(pkt_raw);
printf("Recv packet\n");
@ -60,6 +138,11 @@ void ctaphid_handle_packet(uint8_t * pkt_raw)
printf(" cmd: %02x\n", pkt->pkt.init.cmd);
printf(" length: %d\n", ctaphid_packet_len(pkt));
int ret;
static CTAPHID_INIT_RESPONSE init_resp;
memset(stat, 0, sizeof(CTAPHID_STATUS));
start_over:
switch (state)
@ -69,8 +152,7 @@ start_over:
{
printf("starting a new request\n");
state = HANDLING_REQUEST;
active_cid = get_new_cid();
active_cid_timestamp = millis();
buffer_packet(pkt);
}
else
{
@ -86,11 +168,22 @@ start_over:
ctaphid_init();
}
if (!is_cont_pkt(pkt) && buffer_status() == BUFFERING)
{
printf("Error, expecting cont packet\n");
}
active_cid_timestamp = millis();
ret = buffer_packet(pkt);
if (ret == SEQUENCE_ERROR)
{
printf("Sequence error\n");
}
}
else if (is_timed_out())
{
ctaphid_init();
printf("dropping last channel -- timeout");
goto start_over;
}
else
@ -99,11 +192,94 @@ start_over:
}
break;
default:
printf("invalid state\n");
printf("invalid state; abort\n");
exit(1);
}
switch(buffer_status())
{
case BUFFERING:
printf("BUFFERING\n");
stat->status = NO_RESPONSE;
stat->length = 0;
stat->data= NULL;
active_cid_timestamp = millis();
break;
case BUFFERED:
switch(buffer_cmd())
{
case CTAPHID_INIT:
printf("CTAPHID_INIT\n");
active_cid = get_new_cid();
active_cid_timestamp = millis();
init_resp.broadcast = CTAPHID_BROADCAST_CID;
init_resp.cmd = CTAPHID_INIT;
init_resp.bcnth = (17 & 0xff00) >> 8;
init_resp.bcntl = (17 & 0xff) >> 0;
memmove(init_resp.nonce, pkt->pkt.init.payload, 8);
init_resp.cid = active_cid;
init_resp.protocol_version = 0;//?
init_resp.version_major = 0;//?
init_resp.version_minor = 0;//?
init_resp.build_version = 0;//?
init_resp.capabilities = CAPABILITY_WINK | CAPABILITY_CBOR;
stat->status = CTAPHID_RESPONSE;
stat->length = sizeof(CTAPHID_INIT_RESPONSE);
stat->data = (uint8_t *)&init_resp;
break;
case CTAPHID_PING:
printf("CTAPHID_PING\n");
break;
case CTAPHID_WINK:
printf("CTAPHID_WINK\n");
break;
default:
printf("error, unimplemented HID cmd: %02x\r\n", buffer_cmd());
break;
}
break;
case EMPTY:
printf("empty buffer!\n");
default:
printf("invalid buffer state; abort\n");
exit(1);
break;
}
}
void ctaphid_dump_status(CTAPHID_STATUS * stat)
{
switch(stat->status)
{
case NO_RESPONSE:
printf("NO_RESPONSE");
break;
case CTAPHID_RESPONSE:
printf("CTAPHID_RESPONSE");
break;
case U2F_RESPONSE:
printf("U2F_RESPONSE");
break;
case CBOR_RESPONSE:
printf("CBOR_RESPONSE");
break;
default:
printf("\ninvalid status %d; abort\n", stat->status);
exit(1);
}
printf(" (%d)\n ", stat->length);
if (stat->length > 0)
{
dump_hex(stat->data, stat->length);
}
}

View File

@ -21,6 +21,11 @@
#define CTAPHID_BUFFER_SIZE 4096
#define CAPABILITY_WINK 0x01
#define CAPABILITY_LOCK 0x02
#define CAPABILITY_CBOR 0x04
#define CAPABILITY_NMSG 0x08
typedef struct
{
uint32_t cid;
@ -38,9 +43,46 @@ typedef struct
} pkt;
} CTAPHID_PACKET;
typedef struct
{
uint32_t broadcast;
uint8_t cmd;
uint8_t bcnth;
uint8_t bcntl;
uint8_t nonce[8];
uint32_t cid;
uint8_t protocol_version;
uint8_t version_major;
uint8_t version_minor;
uint8_t build_version;
uint8_t capabilities;
} __attribute__((packed)) CTAPHID_INIT_RESPONSE;
// API specific, not protocol specific //
typedef enum
{
NO_RESPONSE = 0,
CTAPHID_RESPONSE,
U2F_RESPONSE,
CBOR_RESPONSE,
} CTAPHID_CODE;
typedef struct
{
int status;
uint8_t * data;
int length;
} CTAPHID_STATUS;
////////
void ctaphid_init();
void ctaphid_handle_packet(uint8_t * pkt_raw);
void ctaphid_handle_packet(uint8_t * pkt_raw, CTAPHID_STATUS * stat);
void ctaphid_dump_status(CTAPHID_STATUS * stat);
#define ctaphid_packet_len(pkt) ((uint16_t)((pkt)->pkt.init.bcnth << 8) | ((pkt)->pkt.init.bcntl))

18
main.c
View File

@ -17,6 +17,7 @@ void check_ret(CborError ret)
}
}
int main(int argc, char * argv[])
{
/*CborError ret;*/
@ -34,7 +35,9 @@ int main(int argc, char * argv[])
printf("init ctaphid\n");
ctaphid_init();
int count = 0;
uint8_t hidmsg[64];
CTAPHID_STATUS res;
memset(hidmsg,0,sizeof(hidmsg));
printf("recv'ing hid msg \n");
@ -42,11 +45,20 @@ int main(int argc, char * argv[])
while(1)
{
usbhid_recv(hidmsg);
printf(">> "); dump_hex(hidmsg,sizeof(hidmsg));
printf("%d>> ",count++); dump_hex(hidmsg,sizeof(hidmsg));
ctaphid_handle_packet(hidmsg);
printf("<< "); dump_hex(hidmsg,sizeof(hidmsg));
ctaphid_handle_packet(hidmsg, &res);
memset(hidmsg, 0, sizeof(hidmsg));
ctaphid_dump_status(&res);
int i;
for(i = 0; i < res.length; i += 64)
{
memmove(hidmsg, res.data + i, MIN(res.length - i, 64));
usbhid_send(hidmsg);
printf("<< "); dump_hex(hidmsg,sizeof(hidmsg));
}
printf("\n");
}

3
util.h
View File

@ -4,4 +4,7 @@
void dump_hex(uint8_t * buf, int size);
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#define MAX(a,b) (((a) > (b)) ? (a) : (b))
#endif