ccid: add ccid-card-emulated device

This devices uses libcacard (internal) to emulate a smartcard conforming
to the CAC standard. It attaches to the usb-ccid bus. Usage instructions
(example command lines) are in the following patch in docs/ccid.txt. It
uses libcacard which uses nss, so it can work with both hw cards and
certificates (files).
Signed-off-by: NAlon Levy <alevy@redhat.com>

---

changes from v20->v21: (Jes Sorenson review)
 * cosmetics
 * use qemu-thread and qemu_malloc/qemu_free

changes from v19->v20:
 * checkpatch.pl

changes from v18->v19:
 * add qdev.desc
 * backend: drop the enumeration property, back to using a string one.

changes from v16->v17:
 * use PROP_TYPE_ENUM for backend

changes from v15->v16:
 * fix error reporting in initfn
 * bump copyright year
 * update copyright license

changes from v1:
 * remove stale comments, use only c-style comments
 * bugfix, forgot to set recv_len
 * change reader name to 'Virtual Reader'

Makefile.objs

@@ -201,6 +201,7 @@ hw-obj-$(CONFIG_DMA) += dma.o
 hw-obj-$(CONFIG_HPET) += hpet.o
 hw-obj-$(CONFIG_APPLESMC) += applesmc.o
 hw-obj-$(CONFIG_SMARTCARD) += usb-ccid.o ccid-card-passthru.o
+hw-obj-$(CONFIG_SMARTCARD_NSS) += ccid-card-emulated.o
 
 # PPC devices
 hw-obj-$(CONFIG_OPENPIC) += openpic.o

hw/ccid-card-emulated.c

+/*
+ * CCID Card Device. Emulated card.
+ *
+ * Copyright (c) 2011 Red Hat.
+ * Written by Alon Levy.
+ *
+ * This code is licenced under the GNU LGPL, version 2 or later.
+ */
+
+/*
+ * It can be used to provide access to the local hardware in a non exclusive
+ * way, or it can use certificates. It requires the usb-ccid bus.
+ *
+ * Usage 1: standard, mirror hardware reader+card:
+ * qemu .. -usb -device usb-ccid -device ccid-card-emulated
+ *
+ * Usage 2: use certificates, no hardware required
+ * one time: create the certificates:
+ *  for i in 1 2 3; do
+ *      certutil -d /etc/pki/nssdb -x -t "CT,CT,CT" -S -s "CN=user$i" -n user$i
+ *  done
+ * qemu .. -usb -device usb-ccid \
+ *  -device ccid-card-emulated,cert1=user1,cert2=user2,cert3=user3
+ *
+ * If you use a non default db for the certificates you can specify it using
+ * the db parameter.
+ */
+
+#include <eventt.h>
+#include <vevent.h>
+#include <vreader.h>
+#include <vcard_emul.h>
+
+#include "qemu-thread.h"
+#include "qemu-char.h"
+#include "monitor.h"
+#include "hw/ccid.h"
+
+#define DPRINTF(card, lvl, fmt, ...) \
+do {\
+    if (lvl <= card->debug) {\
+        printf("ccid-card-emul: %s: " fmt , __func__, ## __VA_ARGS__);\
+    } \
+} while (0)
+
+#define EMULATED_DEV_NAME "ccid-card-emulated"
+
+#define BACKEND_NSS_EMULATED_NAME "nss-emulated"
+#define BACKEND_CERTIFICATES_NAME "certificates"
+
+enum {
+    BACKEND_NSS_EMULATED = 1,
+    BACKEND_CERTIFICATES
+};
+
+#define DEFAULT_BACKEND BACKEND_NSS_EMULATED
+
+typedef struct EmulatedState EmulatedState;
+
+enum {
+    EMUL_READER_INSERT = 0,
+    EMUL_READER_REMOVE,
+    EMUL_CARD_INSERT,
+    EMUL_CARD_REMOVE,
+    EMUL_GUEST_APDU,
+    EMUL_RESPONSE_APDU,
+    EMUL_ERROR,
+};
+
+static const char *emul_event_to_string(uint32_t emul_event)
+{
+    switch (emul_event) {
+    case EMUL_READER_INSERT:
+        return "EMUL_READER_INSERT";
+    case EMUL_READER_REMOVE:
+        return "EMUL_READER_REMOVE";
+    case EMUL_CARD_INSERT:
+        return "EMUL_CARD_INSERT";
+    case EMUL_CARD_REMOVE:
+        return "EMUL_CARD_REMOVE";
+    case EMUL_GUEST_APDU:
+        return "EMUL_GUEST_APDU";
+    case EMUL_RESPONSE_APDU:
+        return "EMUL_RESPONSE_APDU";
+    case EMUL_ERROR:
+        return "EMUL_ERROR";
+    }
+    return "UNKNOWN";
+}
+
+typedef struct EmulEvent {
+    QSIMPLEQ_ENTRY(EmulEvent) entry;
+    union {
+        struct {
+            uint32_t type;
+        } gen;
+        struct {
+            uint32_t type;
+            uint64_t code;
+        } error;
+        struct {
+            uint32_t type;
+            uint32_t len;
+            uint8_t data[];
+        } data;
+    } p;
+} EmulEvent;
+
+#define MAX_ATR_SIZE 40
+struct EmulatedState {
+    CCIDCardState base;
+    uint8_t  debug;
+    char    *backend_str;
+    uint32_t backend;
+    char    *cert1;
+    char    *cert2;
+    char    *cert3;
+    char    *db;
+    uint8_t  atr[MAX_ATR_SIZE];
+    uint8_t  atr_length;
+    QSIMPLEQ_HEAD(event_list, EmulEvent) event_list;
+    QemuMutex event_list_mutex;
+    VReader *reader;
+    QSIMPLEQ_HEAD(guest_apdu_list, EmulEvent) guest_apdu_list;
+    QemuMutex vreader_mutex; /* and guest_apdu_list mutex */
+    QemuMutex handle_apdu_mutex;
+    QemuCond handle_apdu_cond;
+    int      pipe[2];
+    int      quit_apdu_thread;
+    QemuMutex apdu_thread_quit_mutex;
+    QemuCond apdu_thread_quit_cond;
+};
+
+static void emulated_apdu_from_guest(CCIDCardState *base,
+    const uint8_t *apdu, uint32_t len)
+{
+    EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
+    EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent) + len);
+
+    assert(event);
+    event->p.data.type = EMUL_GUEST_APDU;
+    event->p.data.len = len;
+    memcpy(event->p.data.data, apdu, len);
+    qemu_mutex_lock(&card->vreader_mutex);
+    QSIMPLEQ_INSERT_TAIL(&card->guest_apdu_list, event, entry);
+    qemu_mutex_unlock(&card->vreader_mutex);
+    qemu_mutex_lock(&card->handle_apdu_mutex);
+    qemu_cond_signal(&card->handle_apdu_cond);
+    qemu_mutex_unlock(&card->handle_apdu_mutex);
+}
+
+static const uint8_t *emulated_get_atr(CCIDCardState *base, uint32_t *len)
+{
+    EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
+
+    *len = card->atr_length;
+    return card->atr;
+}
+
+static void emulated_push_event(EmulatedState *card, EmulEvent *event)
+{
+    qemu_mutex_lock(&card->event_list_mutex);
+    QSIMPLEQ_INSERT_TAIL(&(card->event_list), event, entry);
+    qemu_mutex_unlock(&card->event_list_mutex);
+    if (write(card->pipe[1], card, 1) != 1) {
+        DPRINTF(card, 1, "write to pipe failed\n");
+    }
+}
+
+static void emulated_push_type(EmulatedState *card, uint32_t type)
+{
+    EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent));
+
+    assert(event);
+    event->p.gen.type = type;
+    emulated_push_event(card, event);
+}
+
+static void emulated_push_error(EmulatedState *card, uint64_t code)
+{
+    EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent));
+
+    assert(event);
+    event->p.error.type = EMUL_ERROR;
+    event->p.error.code = code;
+    emulated_push_event(card, event);
+}
+
+static void emulated_push_data_type(EmulatedState *card, uint32_t type,
+    const uint8_t *data, uint32_t len)
+{
+    EmulEvent *event = (EmulEvent *)qemu_malloc(sizeof(EmulEvent) + len);
+
+    assert(event);
+    event->p.data.type = type;
+    event->p.data.len = len;
+    memcpy(event->p.data.data, data, len);
+    emulated_push_event(card, event);
+}
+
+static void emulated_push_reader_insert(EmulatedState *card)
+{
+    emulated_push_type(card, EMUL_READER_INSERT);
+}
+
+static void emulated_push_reader_remove(EmulatedState *card)
+{
+    emulated_push_type(card, EMUL_READER_REMOVE);
+}
+
+static void emulated_push_card_insert(EmulatedState *card,
+    const uint8_t *atr, uint32_t len)
+{
+    emulated_push_data_type(card, EMUL_CARD_INSERT, atr, len);
+}
+
+static void emulated_push_card_remove(EmulatedState *card)
+{
+    emulated_push_type(card, EMUL_CARD_REMOVE);
+}
+
+static void emulated_push_response_apdu(EmulatedState *card,
+    const uint8_t *apdu, uint32_t len)
+{
+    emulated_push_data_type(card, EMUL_RESPONSE_APDU, apdu, len);
+}
+
+#define APDU_BUF_SIZE 270
+static void *handle_apdu_thread(void* arg)
+{
+    EmulatedState *card = arg;
+    uint8_t recv_data[APDU_BUF_SIZE];
+    int recv_len;
+    VReaderStatus reader_status;
+    EmulEvent *event;
+
+    while (1) {
+        qemu_mutex_lock(&card->handle_apdu_mutex);
+        qemu_cond_wait(&card->handle_apdu_cond, &card->handle_apdu_mutex);
+        qemu_mutex_unlock(&card->handle_apdu_mutex);
+        if (card->quit_apdu_thread) {
+            card->quit_apdu_thread = 0; /* debugging */
+            break;
+        }
+        qemu_mutex_lock(&card->vreader_mutex);
+        while (!QSIMPLEQ_EMPTY(&card->guest_apdu_list)) {
+            event = QSIMPLEQ_FIRST(&card->guest_apdu_list);
+            assert((unsigned long)event > 1000);
+            QSIMPLEQ_REMOVE_HEAD(&card->guest_apdu_list, entry);
+            if (event->p.data.type != EMUL_GUEST_APDU) {
+                DPRINTF(card, 1, "unexpected message in handle_apdu_thread\n");
+                qemu_free(event);
+                continue;
+            }
+            if (card->reader == NULL) {
+                DPRINTF(card, 1, "reader is NULL\n");
+                qemu_free(event);
+                continue;
+            }
+            recv_len = sizeof(recv_data);
+            reader_status = vreader_xfr_bytes(card->reader,
+                    event->p.data.data, event->p.data.len,
+                    recv_data, &recv_len);
+            DPRINTF(card, 2, "got back apdu of length %d\n", recv_len);
+            if (reader_status == VREADER_OK) {
+                emulated_push_response_apdu(card, recv_data, recv_len);
+            } else {
+                emulated_push_error(card, reader_status);
+            }
+            qemu_free(event);
+        }
+        qemu_mutex_unlock(&card->vreader_mutex);
+    }
+    qemu_mutex_lock(&card->apdu_thread_quit_mutex);
+    qemu_cond_signal(&card->apdu_thread_quit_cond);
+    qemu_mutex_unlock(&card->apdu_thread_quit_mutex);
+    return NULL;
+}
+
+static void *event_thread(void *arg)
+{
+    int atr_len = MAX_ATR_SIZE;
+    uint8_t atr[MAX_ATR_SIZE];
+    VEvent *event = NULL;
+    EmulatedState *card = arg;
+
+    while (1) {
+        const char *reader_name;
+
+        event = vevent_wait_next_vevent();
+        if (event == NULL || event->type == VEVENT_LAST) {
+            break;
+        }
+        if (event->type != VEVENT_READER_INSERT) {
+            if (card->reader == NULL && event->reader != NULL) {
+                /* Happens after device_add followed by card remove or insert.
+                 * XXX: create synthetic add_reader events if vcard_emul_init
+                 * already called, which happens if device_del and device_add
+                 * are called */
+                card->reader = vreader_reference(event->reader);
+            } else {
+                if (event->reader != card->reader) {
+                    fprintf(stderr,
+                        "ERROR: wrong reader: quiting event_thread\n");
+                    break;
+                }
+            }
+        }
+        switch (event->type) {
+        case VEVENT_READER_INSERT:
+            /* TODO: take a specific reader. i.e. track which reader
+             * we are seeing here, check it is the one we want (the first,
+             * or by a particular name), and ignore if we don't want it.
+             */
+            reader_name = vreader_get_name(event->reader);
+            if (card->reader != NULL) {
+                DPRINTF(card, 2, "READER INSERT - replacing %s with %s\n",
+                    vreader_get_name(card->reader), reader_name);
+                qemu_mutex_lock(&card->vreader_mutex);
+                vreader_free(card->reader);
+                qemu_mutex_unlock(&card->vreader_mutex);
+                emulated_push_reader_remove(card);
+            }
+            qemu_mutex_lock(&card->vreader_mutex);
+            DPRINTF(card, 2, "READER INSERT %s\n", reader_name);
+            card->reader = vreader_reference(event->reader);
+            qemu_mutex_unlock(&card->vreader_mutex);
+            emulated_push_reader_insert(card);
+            break;
+        case VEVENT_READER_REMOVE:
+            DPRINTF(card, 2, " READER REMOVE: %s\n",
+                    vreader_get_name(event->reader));
+            qemu_mutex_lock(&card->vreader_mutex);
+            vreader_free(card->reader);
+            card->reader = NULL;
+            qemu_mutex_unlock(&card->vreader_mutex);
+            emulated_push_reader_remove(card);
+            break;
+        case VEVENT_CARD_INSERT:
+            /* get the ATR (intended as a response to a power on from the
+             * reader */
+            atr_len = MAX_ATR_SIZE;
+            vreader_power_on(event->reader, atr, &atr_len);
+            card->atr_length = (uint8_t)atr_len;
+            DPRINTF(card, 2, " CARD INSERT\n");
+            emulated_push_card_insert(card, atr, atr_len);
+            break;
+        case VEVENT_CARD_REMOVE:
+            DPRINTF(card, 2, " CARD REMOVE\n");
+            emulated_push_card_remove(card);
+            break;
+        case VEVENT_LAST: /* quit */
+            vevent_delete(event);
+            return NULL;
+            break;
+        default:
+            break;
+        }
+        vevent_delete(event);
+    }
+    return NULL;
+}
+
+static void pipe_read(void *opaque)
+{
+    EmulatedState *card = opaque;
+    EmulEvent *event, *next;
+    char dummy;
+    int len;
+
+    do {
+        len = read(card->pipe[0], &dummy, sizeof(dummy));
+    } while (len == sizeof(dummy));
+    qemu_mutex_lock(&card->event_list_mutex);
+    QSIMPLEQ_FOREACH_SAFE(event, &card->event_list, entry, next) {
+        DPRINTF(card, 2, "event %s\n", emul_event_to_string(event->p.gen.type));
+        switch (event->p.gen.type) {
+        case EMUL_RESPONSE_APDU:
+            ccid_card_send_apdu_to_guest(&card->base, event->p.data.data,
+                event->p.data.len);
+            break;
+        case EMUL_READER_INSERT:
+            ccid_card_ccid_attach(&card->base);
+            break;
+        case EMUL_READER_REMOVE:
+            ccid_card_ccid_detach(&card->base);
+            break;
+        case EMUL_CARD_INSERT:
+            assert(event->p.data.len <= MAX_ATR_SIZE);
+            card->atr_length = event->p.data.len;
+            memcpy(card->atr, event->p.data.data, card->atr_length);
+            ccid_card_card_inserted(&card->base);
+            break;
+        case EMUL_CARD_REMOVE:
+            ccid_card_card_removed(&card->base);
+            break;
+        case EMUL_ERROR:
+            ccid_card_card_error(&card->base, event->p.error.code);
+            break;
+        default:
+            DPRINTF(card, 2, "unexpected event\n");
+            break;
+        }
+        qemu_free(event);
+    }
+    QSIMPLEQ_INIT(&card->event_list);
+    qemu_mutex_unlock(&card->event_list_mutex);
+}
+
+static int init_pipe_signaling(EmulatedState *card)
+{
+    if (pipe(card->pipe) < 0) {
+        DPRINTF(card, 2, "pipe creation failed\n");
+        return -1;
+    }
+    fcntl(card->pipe[0], F_SETFL, O_NONBLOCK);
+    fcntl(card->pipe[1], F_SETFL, O_NONBLOCK);
+    fcntl(card->pipe[0], F_SETOWN, getpid());
+    qemu_set_fd_handler(card->pipe[0], pipe_read, NULL, card);
+    return 0;
+}
+
+#define CERTIFICATES_DEFAULT_DB "/etc/pki/nssdb"
+#define CERTIFICATES_ARGS_TEMPLATE\
+    "db=\"%s\" use_hw=no soft=(,Virtual Reader,CAC,,%s,%s,%s)"
+
+static int wrap_vcard_emul_init(VCardEmulOptions *options)
+{
+    static int called;
+    static int options_was_null;
+
+    if (called) {
+        if ((options == NULL) != options_was_null) {
+            printf("%s: warning: running emulated with certificates"
+                   " and emulated side by side is not supported\n",
+                   __func__);
+            return VCARD_EMUL_FAIL;
+        }
+        vcard_emul_replay_insertion_events();
+        return VCARD_EMUL_OK;
+    }
+    options_was_null = (options == NULL);
+    called = 1;
+    return vcard_emul_init(options);
+}
+
+static int emulated_initialize_vcard_from_certificates(EmulatedState *card)
+{
+    char emul_args[200];
+    VCardEmulOptions *options = NULL;
+
+    snprintf(emul_args, sizeof(emul_args) - 1, CERTIFICATES_ARGS_TEMPLATE,
+        card->db ? card->db : CERTIFICATES_DEFAULT_DB,
+        card->cert1, card->cert2, card->cert3);
+    options = vcard_emul_options(emul_args);
+    if (options == NULL) {
+        printf("%s: warning: not using certificates due to"
+               " initialization error\n", __func__);
+    }
+    return wrap_vcard_emul_init(options);
+}
+
+typedef struct EnumTable {
+    const char *name;
+    uint32_t value;
+} EnumTable;
+
+EnumTable backend_enum_table[] = {
+    {BACKEND_NSS_EMULATED_NAME, BACKEND_NSS_EMULATED},
+    {BACKEND_CERTIFICATES_NAME, BACKEND_CERTIFICATES},
+    {NULL, 0},
+};
+
+static uint32_t parse_enumeration(char *str,
+    EnumTable *table, uint32_t not_found_value)
+{
+    uint32_t ret = not_found_value;
+
+    while (table->name != NULL) {
+        if (strcmp(table->name, str) == 0) {
+            ret = table->value;
+            break;
+        }
+        table++;
+    }
+    return ret;
+}
+
+static int emulated_initfn(CCIDCardState *base)
+{
+    EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
+    QemuThread thread_id;
+    VCardEmulError ret;
+    EnumTable *ptable;
+
+    QSIMPLEQ_INIT(&card->event_list);
+    QSIMPLEQ_INIT(&card->guest_apdu_list);
+    qemu_mutex_init(&card->event_list_mutex);
+    qemu_mutex_init(&card->vreader_mutex);
+    qemu_mutex_init(&card->handle_apdu_mutex);
+    qemu_cond_init(&card->handle_apdu_cond);
+    card->reader = NULL;
+    card->quit_apdu_thread = 0;
+    if (init_pipe_signaling(card) < 0) {
+        return -1;
+    }
+    card->backend = parse_enumeration(card->backend_str, backend_enum_table, 0);
+    if (card->backend == 0) {
+        printf("unknown backend, must be one of:\n");
+        for (ptable = backend_enum_table; ptable->name != NULL; ++ptable) {
+            printf("%s\n", ptable->name);
+        }
+        return -1;
+    }
+
+    /* TODO: a passthru backened that works on local machine. third card type?*/
+    if (card->backend == BACKEND_CERTIFICATES) {
+        if (card->cert1 != NULL && card->cert2 != NULL && card->cert3 != NULL) {
+            ret = emulated_initialize_vcard_from_certificates(card);
+        } else {
+            printf("%s: you must provide all three certs for"
+                   " certificates backend\n", EMULATED_DEV_NAME);
+            return -1;
+        }
+    } else {
+        if (card->backend != BACKEND_NSS_EMULATED) {
+            printf("%s: bad backend specified. The options are:\n%s (default),"
+                " %s.\n", EMULATED_DEV_NAME, BACKEND_NSS_EMULATED_NAME,
+                BACKEND_CERTIFICATES_NAME);
+            return -1;
+        }
+        if (card->cert1 != NULL || card->cert2 != NULL || card->cert3 != NULL) {
+            printf("%s: unexpected cert parameters to nss emulated backend\n",
+                   EMULATED_DEV_NAME);
+            return -1;
+        }
+        /* default to mirroring the local hardware readers */
+        ret = wrap_vcard_emul_init(NULL);
+    }
+    if (ret != VCARD_EMUL_OK) {
+        printf("%s: failed to initialize vcard\n", EMULATED_DEV_NAME);
+        return -1;
+    }
+    qemu_thread_create(&thread_id, event_thread, card);
+    qemu_thread_create(&thread_id, handle_apdu_thread, card);
+    return 0;
+}
+
+static int emulated_exitfn(CCIDCardState *base)
+{
+    EmulatedState *card = DO_UPCAST(EmulatedState, base, base);
+    VEvent *vevent = vevent_new(VEVENT_LAST, NULL, NULL);
+
+    vevent_queue_vevent(vevent); /* stop vevent thread */
+    qemu_mutex_lock(&card->apdu_thread_quit_mutex);
+    card->quit_apdu_thread = 1; /* stop handle_apdu thread */
+    qemu_cond_signal(&card->handle_apdu_cond);
+    qemu_cond_wait(&card->apdu_thread_quit_cond,
+                      &card->apdu_thread_quit_mutex);
+    /* handle_apdu thread stopped, can destroy all of it's mutexes */
+    qemu_cond_destroy(&card->handle_apdu_cond);
+    qemu_cond_destroy(&card->apdu_thread_quit_cond);
+    qemu_mutex_destroy(&card->apdu_thread_quit_mutex);
+    qemu_mutex_destroy(&card->handle_apdu_mutex);
+    qemu_mutex_destroy(&card->vreader_mutex);
+    qemu_mutex_destroy(&card->event_list_mutex);
+    return 0;
+}
+
+static CCIDCardInfo emulated_card_info = {
+    .qdev.name = EMULATED_DEV_NAME,
+    .qdev.desc = "emulated smartcard",
+    .qdev.size = sizeof(EmulatedState),
+    .initfn = emulated_initfn,
+    .exitfn = emulated_exitfn,
+    .get_atr = emulated_get_atr,
+    .apdu_from_guest = emulated_apdu_from_guest,
+    .qdev.unplug    = qdev_simple_unplug_cb,
+    .qdev.props     = (Property[]) {
+        DEFINE_PROP_STRING("backend", EmulatedState, backend_str),
+        DEFINE_PROP_STRING("cert1", EmulatedState, cert1),
+        DEFINE_PROP_STRING("cert2", EmulatedState, cert2),
+        DEFINE_PROP_STRING("cert3", EmulatedState, cert3),
+        DEFINE_PROP_STRING("db", EmulatedState, db),
+        DEFINE_PROP_UINT8("debug", EmulatedState, debug, 0),
+        DEFINE_PROP_END_OF_LIST(),
+    },
+};
+
+static void ccid_card_emulated_register_devices(void)
+{
+    ccid_card_qdev_register(&emulated_card_info);
+}
+
+device_init(ccid_card_emulated_register_devices)