Re: [Qemu-devel] [PATCH v3 5/7] Add a VCARD_DIRECT implemention to the libcacard smartcard support.

[Marc-André Lureau]

ACK.

Reviewed-by: Marc-André Lureau <address@hidden>

(the extra symbols should be shaved in a future libcacard update)

On Fri, Mar 13, 2015 at 8:45 PM, Jeremy White <address@hidden> wrote:
> This uses libpcsclite to provide direct communication with a smartcard.
>
> Signed-off-by: Jeremy White <address@hidden>
> ---
>  Makefile.objs            |    5 +
>  libcacard/capcsc.c       |  498 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  libcacard/capcsc.h       |   18 ++
>  libcacard/card_7816.c    |    2 +-
>  libcacard/card_7816.h    |    3 +
>  libcacard/libcacard.syms |    2 +
>  6 files changed, 527 insertions(+), 1 deletion(-)
>  create mode 100644 libcacard/capcsc.c
>  create mode 100644 libcacard/capcsc.h
>
> diff --git a/Makefile.objs b/Makefile.objs
> index 28999d3..cc31b29 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -32,6 +32,11 @@ libcacard-y += libcacard/card_7816.o
>  libcacard-y += libcacard/vcardt.o
>  libcacard/vcard_emul_nss.o-cflags := $(NSS_CFLAGS)
>  libcacard/vcard_emul_nss.o-libs := $(NSS_LIBS)
> +ifeq ($(CONFIG_SMARTCARD_PCSC),y)
> +libcacard-y += libcacard/capcsc.o
> +libcacard/capcsc.o-cflags := $(PCSC_CFLAGS)
> +libcacard/capcsc.o-libs := $(PCSC_LIBS)
> +endif
>
>  ######################################################################
>  # Target independent part of system emulation. The long term path is to
> diff --git a/libcacard/capcsc.c b/libcacard/capcsc.c
> new file mode 100644
> index 0000000..a1030df
> --- /dev/null
> +++ b/libcacard/capcsc.c
> @@ -0,0 +1,498 @@
> +/*
> + * Supply a vreader using the PC/SC interface.
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.1 or 
> later.
> + * See the COPYING.LIB file in the top-level directory.
> + */
> +
> +#include <glib.h>
> +
> +#include "qemu-common.h"
> +
> +#include "vcard.h"
> +#include "card_7816.h"
> +#include "capcsc.h"
> +#include "vreader.h"
> +#include "vevent.h"
> +
> +#include <PCSC/wintypes.h>
> +#include <PCSC/winscard.h>
> +
> +
> +typedef struct _PCSCContext PCSCContext;
> +
> +typedef struct {
> +    PCSCContext *context;
> +    int index;
> +    char *name;
> +    DWORD protocol;
> +    DWORD state;
> +    SCARDHANDLE card;
> +    BYTE atr[MAX_ATR_SIZE];
> +    DWORD atrlen;
> +    int card_connected;
> +    unsigned long request_count;
> +} SCardReader;
> +
> +typedef struct _PCSCContext {
> +    SCARDCONTEXT context;
> +    SCardReader readers[CAPCSC_MAX_READERS];
> +    int reader_count;
> +    int readers_changed;
> +    GThread *thread;
> +    CompatGMutex lock;
> +} PCSCContext;
> +
> +
> +static void delete_reader(PCSCContext *pc, int i)
> +{
> +    SCardReader *r = &pc->readers[i];
> +    g_free(r->name);
> +    r->name = NULL;
> +
> +    if (i < (pc->reader_count - 1)) {
> +        int rem = pc->reader_count - i - 1;
> +        memmove(&pc->readers[i], &pc->readers[i + 1],
> +                sizeof(SCardReader) * rem);
> +    }
> +
> +    pc->reader_count--;
> +}
> +
> +static void delete_reader_cb(VReaderEmul *ve)
> +{
> +    SCardReader *r = (SCardReader *) ve;
> +
> +    g_mutex_lock(&r->context->lock);
> +    delete_reader(r->context, r->index);
> +    g_mutex_unlock(&r->context->lock);
> +}
> +
> +static int new_reader(PCSCContext *pc, const char *name, DWORD state)
> +{
> +    SCardReader *r;
> +    VReader *vreader;
> +
> +    if (pc->reader_count >= CAPCSC_MAX_READERS - 1) {
> +        return 1;
> +    }
> +
> +    r = &pc->readers[pc->reader_count];
> +    memset(r, 0, sizeof(*r));
> +    r->index = pc->reader_count++;
> +    r->context = pc;
> +    r->name = g_strdup(name);
> +
> +    vreader = vreader_new(name, (VReaderEmul *) r, delete_reader_cb);
> +    vreader_add_reader(vreader);
> +    vreader_free(vreader);
> +
> +    return 0;
> +}
> +
> +static int find_reader(PCSCContext *pc, const char *name)
> +{
> +    int i;
> +    for (i = 0; i < pc->reader_count; i++)
> +        if (strcmp(pc->readers[i].name, name) == 0) {
> +            return i;
> +        }
> +
> +    return -1;
> +}
> +
> +
> +static int scan_for_readers(PCSCContext *pc)
> +{
> +    LONG rc;
> +
> +    int i;
> +    char buf[8192];
> +    DWORD buflen = sizeof(buf);
> +
> +    char *p;
> +    int matches[CAPCSC_MAX_READERS];
> +
> +    g_mutex_lock(&pc->lock);
> +
> +    for (i = 0; i < CAPCSC_MAX_READERS; i++) {
> +        matches[i] = 0;
> +    }
> +
> +    pc->readers_changed = 1;
> +    memset(buf, 0, sizeof(buf));
> +    rc = SCardListReaders(pc->context, NULL, buf, &buflen);
> +    if (rc == SCARD_E_NO_READERS_AVAILABLE) {
> +        rc = 0;
> +        goto exit;
> +    }
> +
> +    if (rc != SCARD_S_SUCCESS) {
> +        fprintf(stderr, "SCardListReaders failed: %s (0x%lX)\n",
> +            pcsc_stringify_error(rc), rc);
> +        goto exit;
> +    }
> +
> +    for (p = buf; p && p < buf + sizeof(buf); p += (strlen(p) + 1)) {
> +        if (strlen(p) > 0) {
> +            i = find_reader(pc, p);
> +            if (i >= 0) {
> +                matches[i]++;
> +            } else {
> +                if (!new_reader(pc, p, SCARD_STATE_UNAWARE)) {
> +                    matches[pc->reader_count - 1]++;
> +                }
> +            }
> +        }
> +    }
> +
> +    rc = 0;
> +
> +exit:
> +    i = pc->reader_count - 1;
> +    g_mutex_unlock(&pc->lock);
> +
> +    for (; i >= 0; i--) {
> +        if (!matches[i]) {
> +            VReader *reader = 
> vreader_get_reader_by_name(pc->readers[i].name);
> +            if (reader) {
> +                vreader_free(reader);
> +                vreader_remove_reader(reader);
> +            }
> +        }
> +    }
> +
> +
> +    return rc;
> +}
> +
> +static int init_pcsc(PCSCContext *pc)
> +{
> +    LONG rc;
> +
> +    memset(pc, 0, sizeof(*pc));
> +
> +    rc = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL, &pc->context);
> +    if (rc != SCARD_S_SUCCESS) {
> +        fprintf(stderr, "SCardEstablishContext: "
> +                        "Cannot Connect to Resource Manager %lX\n", rc);
> +        return rc;
> +    }
> +
> +    return 0;
> +}
> +
> +
> +static void prepare_reader_states(PCSCContext *pc, SCARD_READERSTATE 
> **states,
> +                                  DWORD *reader_count)
> +{
> +    SCARD_READERSTATE *state;
> +    int i;
> +
> +    if (*states) {
> +        g_free(*states);
> +    }
> +
> +    *reader_count = pc->reader_count;
> +
> +    (*reader_count)++;
> +    *states = g_malloc((*reader_count) * sizeof(**states));
> +    memset(*states, 0, sizeof((*reader_count) * sizeof(**states)));
> +
> +    for (i = 0, state = *states; i < pc->reader_count; i++, state++) {
> +        state->szReader = pc->readers[i].name;
> +        state->dwCurrentState = pc->readers[i].state;
> +    }
> +
> +    /* Leave a space to be notified of new readers */
> +    state->szReader = "\\\\?PnP?\\Notification";
> +    state->dwCurrentState = SCARD_STATE_UNAWARE;
> +}
> +
> +static int connect_card(SCardReader *r)
> +{
> +    LONG rc;
> +
> +    r->protocol = -1;
> +    rc = SCardConnect(r->context->context, r->name, SCARD_SHARE_SHARED,
> +                        SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1,
> +                        &r->card, &r->protocol);
> +    if (rc != SCARD_S_SUCCESS) {
> +        fprintf(stderr, "Failed to connect to a card reader: %s (0x%lX)\n",
> +            pcsc_stringify_error(rc), rc);
> +        return rc;
> +    }
> +
> +    r->card_connected = 1;
> +    r->request_count = 0;
> +
> +    return 0;
> +}
> +
> +static LONG send_receive(SCardReader *r, BYTE *transmit, DWORD transmit_len,
> +                 BYTE *receive, DWORD *receive_len)
> +{
> +    const SCARD_IO_REQUEST *send_header;
> +    SCARD_IO_REQUEST receive_header;
> +    LONG rc;
> +
> +    if (!r->card_connected) {
> +        rc = connect_card(r);
> +        if (rc) {
> +            return rc;
> +        }
> +    }
> +
> +    if (r->protocol == SCARD_PROTOCOL_T0) {
> +        send_header = SCARD_PCI_T0;
> +    } else if (r->protocol == SCARD_PROTOCOL_T1) {
> +        send_header = SCARD_PCI_T1;
> +    } else {
> +        fprintf(stderr, "Unknown protocol %lX\n", r->protocol);
> +        return 1;
> +    }
> +
> +    rc = SCardTransmit(r->card, send_header, transmit, transmit_len,
> +                        &receive_header, receive, receive_len);
> +    if (rc != SCARD_S_SUCCESS) {
> +        fprintf(stderr, "Failed to transmit %ld bytes: %s (0x%lX)\n",
> +            transmit_len, pcsc_stringify_error(rc), rc);
> +        return rc;
> +    }
> +
> +    return 0;
> +}
> +
> +
> +static VCardStatus apdu_cb(VCard *card, VCardAPDU *apdu,
> +                           VCardResponse **response)
> +{
> +    VCardStatus ret = VCARD_DONE;
> +    SCardReader *r = (SCardReader *) vcard_get_private(card);
> +    BYTE outbuf[4096];
> +    DWORD outlen = sizeof(outbuf);
> +    LONG rc;
> +
> +    rc = send_receive(r, apdu->a_data, apdu->a_len, outbuf, &outlen);
> +    if (rc || outlen < 2) {
> +        ret = VCARD_FAIL;
> +    } else {
> +        *response = vcard_response_new_data(outbuf, outlen - 2);
> +        if (*response == NULL) {
> +            return VCARD_FAIL;
> +        }
> +        vcard_response_set_status_bytes(*response, outbuf[outlen - 2],
> +                                                   outbuf[outlen - 1]);
> +    }
> +
> +    return ret;
> +}
> +
> +static VCardStatus reset_cb(VCard *card, int channel)
> +{
> +    SCardReader *r = (SCardReader *) vcard_get_private(card);
> +    LONG rc;
> +
> +    /* vreader_power_on is a bit too free with it's resets.
> +       And a reconnect is expensive; as much as 10-20 seconds.
> +       Hence, we discard any initial reconnect request. */
> +    if (r->request_count++ == 0) {
> +        return VCARD_DONE;
> +    }
> +
> +    rc = SCardReconnect(r->card, SCARD_SHARE_SHARED,
> +                        SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1,
> +                        SCARD_RESET_CARD, &r->protocol);
> +    if (rc != SCARD_S_SUCCESS) {
> +        fprintf(stderr, "Failed to reconnect to a card reader: %s (0x%lX)\n",
> +            pcsc_stringify_error(rc), rc);
> +        return VCARD_FAIL;
> +    }
> +    return VCARD_DONE;
> +}
> +
> +static void get_atr_cb(VCard *card, unsigned char *atr, int *atr_len)
> +{
> +    SCardReader *r = (SCardReader *) vcard_get_private(card);
> +    *atr_len = r->atrlen;
> +    if (atr) {
> +        memcpy(atr, r->atr, r->atrlen);
> +    }
> +}
> +
> +static void delete_card_cb(VCardEmul *ve)
> +{
> +    fprintf(stderr, "TODO, got a delete_card_cb\n");
> +}
> +
> +static void insert_card(SCardReader *r, SCARD_READERSTATE *s)
> +{
> +    memcpy(r->atr, s->rgbAtr, MIN(sizeof(r->atr), sizeof(s->rgbAtr)));
> +    r->atrlen = s->cbAtr;
> +
> +    VReader *reader = vreader_get_reader_by_name(r->name);
> +    if (!reader) {
> +        return;
> +    }
> +
> +    if (connect_card(r)) {
> +        return;
> +    }
> +
> +    VCardApplet *applet =
> +        vcard_new_applet(apdu_cb,
> +                         reset_cb,
> +                         (const unsigned char *) CAPCSC_APPLET,
> +                         strlen(CAPCSC_APPLET));
> +    if (!applet) {
> +        return;
> +    }
> +
> +    VCard * card =  vcard_new((VCardEmul *) r, delete_card_cb);
> +    if (!card) {
> +        vcard_delete_applet(applet);
> +        vreader_free(reader);
> +        return;
> +    }
> +
> +    vcard_set_type(card, VCARD_DIRECT);
> +    vcard_set_atr_func(card, get_atr_cb);
> +    vcard_add_applet(card, applet);
> +
> +    vreader_insert_card(reader, card);
> +    vreader_free(reader);
> +}
> +
> +static void remove_card(SCardReader *r)
> +{
> +    LONG rc;
> +    memset(r->atr, 0, sizeof(r->atr));
> +    r->atrlen = 0;
> +
> +    rc = SCardDisconnect(r->card, SCARD_LEAVE_CARD);
> +    if (rc != SCARD_S_SUCCESS) {
> +        fprintf(stderr, "Non fatal info:"
> +                        "failed to disconnect card reader: %s (0x%lX)\n",
> +            pcsc_stringify_error(rc), rc);
> +    }
> +    r->card_connected = 0;
> +
> +    VReader *reader = vreader_get_reader_by_name(r->name);
> +    if (!reader) {
> +        return;
> +    }
> +
> +    vreader_insert_card(reader, NULL);
> +    vreader_free(reader);
> +}
> +
> +static void process_reader_change(SCardReader *r, SCARD_READERSTATE *s)
> +{
> +    if (s->dwEventState & SCARD_STATE_PRESENT) {
> +        insert_card(r, s);
> +    } else if (s->dwEventState & SCARD_STATE_EMPTY) {
> +        remove_card(r);
> +    } else {
> +        fprintf(stderr, "Unexpected card state change from %lx to %lx:\n",
> +                        r->state, s->dwEventState);
> +    }
> +
> +    r->state = s->dwEventState & ~SCARD_STATE_CHANGED;
> +}
> +
> +/*
> + * This thread looks for card and reader insertions and puts events on the
> + * event queue.
> + */
> +static gpointer event_thread(gpointer arg)
> +{
> +    PCSCContext *pc = (PCSCContext *) arg;
> +    DWORD reader_count = 0;
> +    SCARD_READERSTATE *reader_states = NULL;
> +    LONG rc;
> +
> +    scan_for_readers(pc);
> +
> +    do {
> +        int i;
> +        DWORD timeout = INFINITE;
> +
> +        g_mutex_lock(&pc->lock);
> +        if (pc->readers_changed) {
> +            prepare_reader_states(pc, &reader_states, &reader_count);
> +            timeout = 0;
> +        } else if (reader_count > 1) {
> +            timeout = 0;
> +        }
> +
> +        pc->readers_changed = 0;
> +        g_mutex_unlock(&pc->lock);
> +
> +        rc = SCardGetStatusChange(pc->context, timeout, reader_states,
> +                                  reader_count);
> +
> +        /* If we have a new reader, or an unknown reader,
> +           rescan and go back and do it again */
> +        if ((rc == SCARD_S_SUCCESS && (reader_states[reader_count - 
> 1].dwEventState & SCARD_STATE_CHANGED))
> +                      ||
> +             rc == SCARD_E_UNKNOWN_READER) {
> +            scan_for_readers(pc);
> +            continue;
> +        }
> +
> +        if (rc != SCARD_S_SUCCESS && rc != SCARD_E_TIMEOUT) {
> +            fprintf(stderr, "Unexpected SCardGetStatusChange ret %lx(%s)\n",
> +                            rc, pcsc_stringify_error(rc));
> +            continue;
> +        }
> +
> +        g_mutex_lock(&pc->lock);
> +        for (i = 0; i < reader_count; i++) {
> +            if (reader_states[i].dwEventState & SCARD_STATE_CHANGED) {
> +                process_reader_change(&pc->readers[i], &reader_states[i]);
> +                pc->readers_changed++;
> +            }
> +
> +        }
> +        g_mutex_unlock(&pc->lock);
> +
> +        /* libpcsclite is only thread safe at a high level.  If we constantly
> +           hold long calls into SCardGetStatusChange, we'll starve any 
> running
> +           clients.  So, if we have an active session, and nothing has 
> changed
> +           on our front, we just idle.  */
> +        if (!pc->readers_changed && reader_count > 1) {
> +            usleep(CAPCSC_POLL_TIME * 1000);
> +        }
> +
> +
> +    } while (1);
> +
> +    return NULL;
> +}
> +
> +/*
> + * We poll the PC/SC interface, looking for device changes
> + */
> +static int new_event_thread(PCSCContext *pc)
> +{
> +    pc->thread = g_thread_new("capcsc_event_thread", event_thread, pc);
> +    return pc->thread == NULL;
> +}
> +
> +
> +static PCSCContext context;
> +
> +int capcsc_init(void)
> +{
> +    g_mutex_init(&context.lock);
> +
> +    if (init_pcsc(&context)) {
> +        return -1;
> +    }
> +
> +    if (new_event_thread(&context)) {
> +        return -1;
> +    }
> +
> +    return 0;
> +}
> diff --git a/libcacard/capcsc.h b/libcacard/capcsc.h
> new file mode 100644
> index 0000000..bb59a4e
> --- /dev/null
> +++ b/libcacard/capcsc.h
> @@ -0,0 +1,18 @@
> +/*
> + * This work is licensed under the terms of the GNU LGPL, version 2.1 or 
> later.
> + * See the COPYING.LIB file in the top-level directory.
> + */
> +#ifndef CAPCSC_H
> +#define CAPCSC_H 1
> +
> +#define CAPCSC_POLL_TIME            50      /* ms  - Time we will poll for */
> +                                            /*       card change when a    */
> +                                            /*       reader is connected */
> +#define CAPCSC_MAX_READERS          16
> +
> +#define CAPCSC_APPLET               "CAPCSC APPLET"
> +
> +int capcsc_init(void);
> +
> +
> +#endif
> diff --git a/libcacard/card_7816.c b/libcacard/card_7816.c
> index 814fa16..d84d26b 100644
> --- a/libcacard/card_7816.c
> +++ b/libcacard/card_7816.c
> @@ -31,7 +31,7 @@ vcard_response_set_status(VCardResponse *response, 
> vcard_7816_status_t status)
>  /*
>   * set the status bytes in a response buffer
>   */
> -static void
> +void
>  vcard_response_set_status_bytes(VCardResponse *response,
>                                 unsigned char sw1, unsigned char sw2)
>  {
> diff --git a/libcacard/card_7816.h b/libcacard/card_7816.h
> index 4a01993..c6b3a6b 100644
> --- a/libcacard/card_7816.h
> +++ b/libcacard/card_7816.h
> @@ -31,6 +31,9 @@ VCardResponse *vcard_make_response(vcard_7816_status_t 
> status);
>  /* create a raw response (status has already been encoded */
>  VCardResponse *vcard_response_new_data(unsigned char *buf, int len);
>
> +void
> +vcard_response_set_status_bytes(VCardResponse *response,
> +                               unsigned char sw1, unsigned char sw2);
>
>
>
> diff --git a/libcacard/libcacard.syms b/libcacard/libcacard.syms
> index 1697515..e17158f 100644
> --- a/libcacard/libcacard.syms
> +++ b/libcacard/libcacard.syms
> @@ -1,5 +1,6 @@
>  cac_card_init
>  cac_is_cac_card
> +capcsc_init
>  vcard_add_applet
>  vcard_apdu_delete
>  vcard_apdu_new
> @@ -41,6 +42,7 @@ vcard_response_new
>  vcard_response_new_bytes
>  vcard_response_new_data
>  vcard_response_new_status_bytes
> +vcard_response_set_status_bytes
>  vcard_select_applet
>  vcard_set_applet_private
>  vcard_set_atr_func
> --
> 1.7.10.4
>
>



-- 
Marc-André Lureau