12 files changed, 289 insertions, 40 deletions

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 1203592..7228860 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -3,6 +3,7 @@
 # license that can be found in the LICENSE file.
 
 list(APPEND COMPAT_SOURCES
+        ../openbsd-compat/clock_gettime.c
         ../openbsd-compat/getopt_long.c
         ../openbsd-compat/strlcat.c
         ../openbsd-compat/strlcpy.c
@@ -15,6 +16,13 @@ endif()
 # drop -rdynamic
 set(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
 
+# enable -Wconversion -Wsign-conversion
+if(NOT MSVC)
+        set_source_files_properties(assert.c cred.c info.c manifest.c reset.c
+            retries.c setpin.c util.c PROPERTIES COMPILE_FLAGS
+            "-Wconversion -Wsign-conversion")
+endif()
+
 # manifest
 add_executable(manifest manifest.c ${COMPAT_SOURCES})
 target_link_libraries(manifest fido2)
@@ -42,3 +50,11 @@ target_link_libraries(setpin fido2)
 # retries
 add_executable(retries retries.c ${COMPAT_SOURCES})
 target_link_libraries(retries fido2)
+
+# select
+add_executable(select select.c ${COMPAT_SOURCES})
+target_link_libraries(select fido2)
+if(MINGW)
+        # needed for nanosleep() in mingw
+        target_link_libraries(select winpthread)
+endif()
diff --git a/examples/README.adoc b/examples/README.adoc
index 091c6bc..b7b73d8 100644
--- a/examples/README.adoc
+++ b/examples/README.adoc
@@ -77,5 +77,14 @@ The following examples are provided:
 - retries <device>
         Get the number of PIN attempts left on <device> before lockout.
 
+- select
+
+        Enumerates available FIDO devices and, if more than one is present,
+        simultaneously requests touch on all of them, printing information
+        about the device touched.
+
 Debugging is possible through the use of the FIDO_DEBUG environment variable.
 If set, libfido2 will produce a log of its transactions with the authenticator.
+
+Additionally, an example of a WebAuthn client using libfido2 is available at
+https://github.com/martelletto/fido2-webauthn-client.
diff --git a/examples/assert.c b/examples/assert.c
index a421a51..a18d8af 100644
--- a/examples/assert.c
+++ b/examples/assert.c
@@ -14,17 +14,12 @@
 #include <unistd.h>
 #endif
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
 #include "fido/es256.h"
 #include "fido/rs256.h"
 #include "fido/eddsa.h"
 #include "extern.h"
-
-#ifdef SIGNAL_EXAMPLE
-extern volatile sig_atomic_t got_signal;
-#endif
+#include "../openbsd-compat/openbsd-compat.h"
 
 static const unsigned char cdh[32] = {
         0xec, 0x8d, 0x8f, 0x78, 0x42, 0x4a, 0x2b, 0xb7,
@@ -188,13 +183,15 @@ main(int argc, char **argv)
                         break;
                 case 'T':
 #ifndef SIGNAL_EXAMPLE
+                        (void)seconds;
                         errx(1, "-T not supported");
-#endif
+#else
                         if (base10(optarg, &seconds) < 0)
                                 errx(1, "base10: %s", optarg);
                         if (seconds <= 0 || seconds > 30)
                                 errx(1, "-T: %s must be in (0,30]", optarg);
                         break;
+#endif
                 case 'a':
                         if (read_blob(optarg, &body, &len) < 0)
                                 errx(1, "read_blob: %s", optarg);
@@ -312,6 +309,10 @@ main(int argc, char **argv)
                 errx(1, "fido_assert_count: %d signatures returned",
                     (int)fido_assert_count(assert));
 
+        /* when verifying, pin implies uv */
+        if (pin)
+                uv = true;
+
         verify_assert(type, fido_assert_authdata_ptr(assert, 0),
             fido_assert_authdata_len(assert, 0), fido_assert_sig_ptr(assert, 0),
             fido_assert_sig_len(assert, 0), up, uv, ext, argv[0]);
diff --git a/examples/cred.c b/examples/cred.c
index 3e0a30f..6bd0faf 100644
--- a/examples/cred.c
+++ b/examples/cred.c
@@ -16,14 +16,9 @@
 #include <unistd.h>
 #endif
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
 #include "extern.h"
-
-#ifdef SIGNAL_EXAMPLE
-extern volatile sig_atomic_t got_signal;
-#endif
+#include "../openbsd-compat/openbsd-compat.h"
 
 static const unsigned char cdh[32] = {
         0xf9, 0x64, 0x57, 0xe7, 0x2d, 0x97, 0xf6, 0xbb,
@@ -192,13 +187,15 @@ main(int argc, char **argv)
                         break;
                 case 'T':
 #ifndef SIGNAL_EXAMPLE
+                        (void)seconds;
                         errx(1, "-T not supported");
-#endif
+#else
                         if (base10(optarg, &seconds) < 0)
                                 errx(1, "base10: %s", optarg);
                         if (seconds <= 0 || seconds > 30)
                                 errx(1, "-T: %s must be in (0,30]", optarg);
                         break;
+#endif
                 case 'e':
                         if (read_blob(optarg, &body, &len) < 0)
                                 errx(1, "read_blob: %s", optarg);
@@ -318,6 +315,10 @@ main(int argc, char **argv)
 
         fido_dev_free(&dev);
 
+        /* when verifying, pin implies uv */
+        if (pin)
+                uv = true;
+
         verify_cred(type, fido_cred_fmt(cred), fido_cred_authdata_ptr(cred),
             fido_cred_authdata_len(cred), fido_cred_x5c_ptr(cred),
             fido_cred_x5c_len(cred), fido_cred_sig_ptr(cred),
diff --git a/examples/extern.h b/examples/extern.h
index 578b8c4..0ea68c4 100644
--- a/examples/extern.h
+++ b/examples/extern.h
@@ -27,6 +27,7 @@ int write_rsa_pubkey(const char *, const void *, size_t);
 int write_eddsa_pubkey(const char *, const void *, size_t);
 #ifdef SIGNAL_EXAMPLE
 void prepare_signal_handler(int);
+extern volatile sig_atomic_t got_signal;
 #endif
 
 #endif /* _EXTERN_H_ */
diff --git a/examples/info.c b/examples/info.c
index ef0d97e..d81de85 100644
--- a/examples/info.c
+++ b/examples/info.c
@@ -4,17 +4,14 @@
  * license that can be found in the LICENSE file.
  */
 
-#include <openssl/ec.h>
-
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
+#include "../openbsd-compat/openbsd-compat.h"
 
 /*
  * Pretty-print a device's capabilities flags and return the result.
@@ -131,6 +128,26 @@ print_maxmsgsiz(uint64_t maxmsgsiz)
 }
 
 /*
+ * Auxiliary function to print an authenticator's maximum number of credentials
+ * in a credential list on stdout.
+ */
+static void
+print_maxcredcntlst(uint64_t maxcredcntlst)
+{
+        printf("maxcredcntlst: %d\n", (int)maxcredcntlst);
+}
+
+/*
+ * Auxiliary function to print an authenticator's maximum credential ID length
+ * on stdout.
+ */
+static void
+print_maxcredidlen(uint64_t maxcredidlen)
+{
+        printf("maxcredlen: %d\n", (int)maxcredidlen);
+}
+
+/*
  * Auxiliary function to print an authenticator's firmware version on stdout.
  */
 static void
@@ -199,6 +216,12 @@ getinfo(const char *path)
         /* print maximum message size */
         print_maxmsgsiz(fido_cbor_info_maxmsgsiz(ci));
 
+        /* print maximum number of credentials allowed in credential lists */
+        print_maxcredcntlst(fido_cbor_info_maxcredcntlst(ci));
+
+        /* print maximum length of a credential ID */
+        print_maxcredidlen(fido_cbor_info_maxcredidlen(ci));
+
         /* print firmware version */
         print_fwversion(fido_cbor_info_fwversion(ci));
 
diff --git a/examples/manifest.c b/examples/manifest.c
index 895447a..d5ebda2 100644
--- a/examples/manifest.c
+++ b/examples/manifest.c
@@ -4,15 +4,12 @@
  * license that can be found in the LICENSE file.
  */
 
-#include <openssl/ec.h>
-
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
+#include "../openbsd-compat/openbsd-compat.h"
 
 int
 main(void)
diff --git a/examples/reset.c b/examples/reset.c
index 36a7de2..3e715c4 100644
--- a/examples/reset.c
+++ b/examples/reset.c
@@ -8,21 +8,14 @@
  * Perform a factory reset on a given authenticator.
  */
 
-#include <openssl/ec.h>
-
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
 #include "extern.h"
-
-#ifdef SIGNAL_EXAMPLE
-extern volatile sig_atomic_t got_signal;
-#endif
+#include "../openbsd-compat/openbsd-compat.h"
 
 int
 main(int argc, char **argv)
diff --git a/examples/retries.c b/examples/retries.c
index 3ed7558..5cc116c 100644
--- a/examples/retries.c
+++ b/examples/retries.c
@@ -8,15 +8,12 @@
  * Get an authenticator's number of PIN attempts left.
  */
 
-#include <openssl/ec.h>
-
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
+#include "../openbsd-compat/openbsd-compat.h"
 
 int
 main(int argc, char **argv)
diff --git a/examples/select.c b/examples/select.c
new file mode 100644
index 0000000..1fb2960
--- /dev/null
+++ b/examples/select.c
@@ -0,0 +1,215 @@
+/*
+ * Copyright (c) 2020 Yubico AB. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "fido.h"
+#include "../openbsd-compat/openbsd-compat.h"
+
+#define FIDO_POLL_MS    50
+
+#if defined(_MSC_VER)
+static int
+nanosleep(const struct timespec *rqtp, struct timespec *rmtp)
+{
+        if (rmtp != NULL) {
+                errno = EINVAL;
+                return (-1);
+        }
+
+        Sleep(rqtp->tv_nsec / 1000000);
+
+        return (0);
+}
+#endif
+
+static fido_dev_t *
+open_dev(const fido_dev_info_t *di)
+{
+        fido_dev_t      *dev;
+        int              r;
+
+        if ((dev = fido_dev_new()) == NULL) {
+                warnx("%s: fido_dev_new", __func__);
+                return (NULL);
+        }
+
+        if ((r = fido_dev_open(dev, fido_dev_info_path(di))) != FIDO_OK) {
+                warnx("%s: fido_dev_open %s: %s", __func__,
+                    fido_dev_info_path(di), fido_strerr(r));
+                fido_dev_free(&dev);
+                return (NULL);
+        }
+
+        printf("%s (0x%04x:0x%04x) is %s\n", fido_dev_info_path(di),
+            fido_dev_info_vendor(di), fido_dev_info_product(di),
+            fido_dev_is_fido2(dev) ? "fido2" : "u2f");
+
+        return (dev);
+}
+
+static int
+select_dev(const fido_dev_info_t *devlist, size_t ndevs, fido_dev_t **dev,
+    size_t *idx, int secs)
+{
+        const fido_dev_info_t    *di;
+        fido_dev_t              **devtab;
+        struct timespec           ts_start;
+        struct timespec           ts_now;
+        struct timespec           ts_delta;
+        struct timespec           ts_pause;
+        size_t                    nopen = 0;
+        int                       touched;
+        int                       r;
+        long                      ms_remain;
+
+        *dev = NULL;
+        *idx = 0;
+
+        printf("%u authenticator(s) detected\n", (unsigned)ndevs);
+
+        if (ndevs == 0)
+                return (0); /* nothing to do */
+
+        if ((devtab = calloc(ndevs, sizeof(*devtab))) == NULL) {
+                warn("%s: calloc", __func__);
+                return (-1);
+        }
+
+        for (size_t i = 0; i < ndevs; i++) {
+                di = fido_dev_info_ptr(devlist, i);
+                if ((devtab[i] = open_dev(di)) != NULL) {
+                        *idx = i;
+                        nopen++;
+                }
+        }
+
+        printf("%u authenticator(s) opened\n", (unsigned)nopen);
+
+        if (nopen < 2) {
+                if (nopen == 1)
+                        *dev = devtab[*idx]; /* single candidate */
+                r = 0;
+                goto out;
+        }
+
+        for (size_t i = 0; i < ndevs; i++) {
+                di = fido_dev_info_ptr(devlist, i);
+                if (devtab[i] == NULL)
+                        continue; /* failed to open */
+                if ((r = fido_dev_get_touch_begin(devtab[i])) != FIDO_OK) {
+                        warnx("%s: fido_dev_get_touch_begin %s: %s", __func__,
+                            fido_dev_info_path(di), fido_strerr(r));
+                        r = -1;
+                        goto out;
+                }
+        }
+
+        if (clock_gettime(CLOCK_MONOTONIC, &ts_start) != 0) {
+                warn("%s: clock_gettime", __func__);
+                r = -1;
+                goto out;
+        }
+
+        ts_pause.tv_sec = 0;
+        ts_pause.tv_nsec = 200000000; /* 200ms */
+
+        do {
+                nanosleep(&ts_pause, NULL);
+
+                for (size_t i = 0; i < ndevs; i++) {
+                        di = fido_dev_info_ptr(devlist, i);
+                        if (devtab[i] == NULL) {
+                                /* failed to open or discarded */
+                                continue;
+                        }
+                        if ((r = fido_dev_get_touch_status(devtab[i], &touched,
+                            FIDO_POLL_MS)) != FIDO_OK) {
+                                warnx("%s: fido_dev_get_touch_status %s: %s",
+                                    __func__, fido_dev_info_path(di),
+                                    fido_strerr(r));
+                                fido_dev_close(devtab[i]);
+                                fido_dev_free(&devtab[i]);
+                                continue; /* discard */
+                        }
+                        if (touched) {
+                                *dev = devtab[i];
+                                *idx = i;
+                                r = 0;
+                                goto out;
+                        }
+                }
+
+                if (clock_gettime(CLOCK_MONOTONIC, &ts_now) != 0) {
+                        warn("%s: clock_gettime", __func__);
+                        r = -1;
+                        goto out;
+                }
+
+                timespecsub(&ts_now, &ts_start, &ts_delta);
+                ms_remain = (secs * 1000) - ((long)ts_delta.tv_sec * 1000) +
+                    ((long)ts_delta.tv_nsec / 1000000);
+        } while (ms_remain > FIDO_POLL_MS);
+
+        printf("timeout after %d seconds\n", secs);
+        r = -1;
+out:
+        if (r != 0) {
+                *dev = NULL;
+                *idx = 0;
+        }
+
+        for (size_t i = 0; i < ndevs; i++) {
+                if (devtab[i] && devtab[i] != *dev) {
+                        fido_dev_cancel(devtab[i]);
+                        fido_dev_close(devtab[i]);
+                        fido_dev_free(&devtab[i]);
+                }
+        }
+
+        free(devtab);
+
+        return (r);
+}
+
+int
+main(void)
+{
+        const fido_dev_info_t   *di;
+        fido_dev_info_t         *devlist;
+        fido_dev_t              *dev;
+        size_t                   idx;
+        size_t                   ndevs;
+        int                      r;
+
+        fido_init(0);
+
+        if ((devlist = fido_dev_info_new(64)) == NULL)
+                errx(1, "fido_dev_info_new");
+
+        if ((r = fido_dev_info_manifest(devlist, 64, &ndevs)) != FIDO_OK)
+                errx(1, "fido_dev_info_manifest: %s (0x%x)", fido_strerr(r), r);
+        if (select_dev(devlist, ndevs, &dev, &idx, 15) != 0)
+                errx(1, "select_dev");
+        if (dev == NULL)
+                errx(1, "no authenticator found");
+
+        di = fido_dev_info_ptr(devlist, idx);
+        printf("%s: %s by %s (PIN %sset)\n", fido_dev_info_path(di),
+            fido_dev_info_product_string(di),
+            fido_dev_info_manufacturer_string(di),
+            fido_dev_has_pin(dev) ? "" : "un");
+
+        fido_dev_close(dev);
+        fido_dev_free(&dev);
+        fido_dev_info_free(&devlist, ndevs);
+
+        exit(0);
+}
diff --git a/examples/setpin.c b/examples/setpin.c
index 75d3d4a..5413bf9 100644
--- a/examples/setpin.c
+++ b/examples/setpin.c
@@ -8,16 +8,13 @@
  * Configure a PIN on a given authenticator.
  */
 
-#include <openssl/ec.h>
-
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
+#include "../openbsd-compat/openbsd-compat.h"
 
 static void
 setpin(const char *path, const char *pin, const char *oldpin)
diff --git a/examples/util.c b/examples/util.c
index 2f6a845..5291cd8 100644
--- a/examples/util.c
+++ b/examples/util.c
@@ -27,13 +27,12 @@
 #include "../openbsd-compat/posix_win.h"
 #endif
 
-#include "../openbsd-compat/openbsd-compat.h"
-
 #include "fido.h"
 #include "fido/es256.h"
 #include "fido/rs256.h"
 #include "fido/eddsa.h"
 #include "extern.h"
+#include "../openbsd-compat/openbsd-compat.h"
 
 #ifdef SIGNAL_EXAMPLE
 volatile sig_atomic_t got_signal = 0;