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-rw-r--r--src/u2f.c959
1 files changed, 959 insertions, 0 deletions
diff --git a/src/u2f.c b/src/u2f.c
new file mode 100644
index 0000000..b1f7bce
--- /dev/null
+++ b/src/u2f.c
@@ -0,0 +1,959 @@
+/*
+ * Copyright (c) 2018-2022 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.
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <openssl/sha.h>
+#include <openssl/x509.h>
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <errno.h>
+
+#include "fido.h"
+#include "fido/es256.h"
+#include "fallthrough.h"
+
+#define U2F_PACE_MS (100)
+
+#if defined(_MSC_VER)
+static int
+usleep(unsigned int usec)
+{
+ Sleep(usec / 1000);
+
+ return (0);
+}
+#endif
+
+static int
+delay_ms(unsigned int ms, int *ms_remain)
+{
+ if (*ms_remain > -1 && (unsigned int)*ms_remain < ms)
+ ms = (unsigned int)*ms_remain;
+
+ if (ms > UINT_MAX / 1000) {
+ fido_log_debug("%s: ms=%u", __func__, ms);
+ return (-1);
+ }
+
+ if (usleep(ms * 1000) < 0) {
+ fido_log_error(errno, "%s: usleep", __func__);
+ return (-1);
+ }
+
+ if (*ms_remain > -1)
+ *ms_remain -= (int)ms;
+
+ return (0);
+}
+
+static int
+sig_get(fido_blob_t *sig, const unsigned char **buf, size_t *len)
+{
+ sig->len = *len; /* consume the whole buffer */
+ if ((sig->ptr = calloc(1, sig->len)) == NULL ||
+ fido_buf_read(buf, len, sig->ptr, sig->len) < 0) {
+ fido_log_debug("%s: fido_buf_read", __func__);
+ fido_blob_reset(sig);
+ return (-1);
+ }
+
+ return (0);
+}
+
+static int
+x5c_get(fido_blob_t *x5c, const unsigned char **buf, size_t *len)
+{
+ X509 *cert = NULL;
+ int ok = -1;
+
+ if (*len > LONG_MAX) {
+ fido_log_debug("%s: invalid len %zu", __func__, *len);
+ goto fail;
+ }
+
+ /* find out the certificate's length */
+ const unsigned char *end = *buf;
+ if ((cert = d2i_X509(NULL, &end, (long)*len)) == NULL || end <= *buf ||
+ (x5c->len = (size_t)(end - *buf)) >= *len) {
+ fido_log_debug("%s: d2i_X509", __func__);
+ goto fail;
+ }
+
+ /* read accordingly */
+ if ((x5c->ptr = calloc(1, x5c->len)) == NULL ||
+ fido_buf_read(buf, len, x5c->ptr, x5c->len) < 0) {
+ fido_log_debug("%s: fido_buf_read", __func__);
+ goto fail;
+ }
+
+ ok = 0;
+fail:
+ if (cert != NULL)
+ X509_free(cert);
+
+ if (ok < 0)
+ fido_blob_reset(x5c);
+
+ return (ok);
+}
+
+static int
+authdata_fake(const char *rp_id, uint8_t flags, uint32_t sigcount,
+ fido_blob_t *fake_cbor_ad)
+{
+ fido_authdata_t ad;
+ cbor_item_t *item = NULL;
+ size_t alloc_len;
+
+ memset(&ad, 0, sizeof(ad));
+
+ if (SHA256((const void *)rp_id, strlen(rp_id),
+ ad.rp_id_hash) != ad.rp_id_hash) {
+ fido_log_debug("%s: sha256", __func__);
+ return (-1);
+ }
+
+ ad.flags = flags; /* XXX translate? */
+ ad.sigcount = sigcount;
+
+ if ((item = cbor_build_bytestring((const unsigned char *)&ad,
+ sizeof(ad))) == NULL) {
+ fido_log_debug("%s: cbor_build_bytestring", __func__);
+ return (-1);
+ }
+
+ if (fake_cbor_ad->ptr != NULL ||
+ (fake_cbor_ad->len = cbor_serialize_alloc(item, &fake_cbor_ad->ptr,
+ &alloc_len)) == 0) {
+ fido_log_debug("%s: cbor_serialize_alloc", __func__);
+ cbor_decref(&item);
+ return (-1);
+ }
+
+ cbor_decref(&item);
+
+ return (0);
+}
+
+/* TODO: use u2f_get_touch_begin & u2f_get_touch_status instead */
+static int
+send_dummy_register(fido_dev_t *dev, int *ms)
+{
+ iso7816_apdu_t *apdu = NULL;
+ unsigned char *reply = NULL;
+ unsigned char challenge[SHA256_DIGEST_LENGTH];
+ unsigned char application[SHA256_DIGEST_LENGTH];
+ int r;
+
+ /* dummy challenge & application */
+ memset(&challenge, 0xff, sizeof(challenge));
+ memset(&application, 0xff, sizeof(application));
+
+ if ((apdu = iso7816_new(0, U2F_CMD_REGISTER, 0, 2 *
+ SHA256_DIGEST_LENGTH)) == NULL ||
+ iso7816_add(apdu, &challenge, sizeof(challenge)) < 0 ||
+ iso7816_add(apdu, &application, sizeof(application)) < 0) {
+ fido_log_debug("%s: iso7816", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if ((reply = malloc(FIDO_MAXMSG)) == NULL) {
+ fido_log_debug("%s: malloc", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ do {
+ if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu),
+ iso7816_len(apdu), ms) < 0) {
+ fido_log_debug("%s: fido_tx", __func__);
+ r = FIDO_ERR_TX;
+ goto fail;
+ }
+ if (fido_rx(dev, CTAP_CMD_MSG, reply, FIDO_MAXMSG, ms) < 2) {
+ fido_log_debug("%s: fido_rx", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+ if (delay_ms(U2F_PACE_MS, ms) != 0) {
+ fido_log_debug("%s: delay_ms", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+ } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED);
+
+ r = FIDO_OK;
+fail:
+ iso7816_free(&apdu);
+ freezero(reply, FIDO_MAXMSG);
+
+ return (r);
+}
+
+static int
+key_lookup(fido_dev_t *dev, const char *rp_id, const fido_blob_t *key_id,
+ int *found, int *ms)
+{
+ iso7816_apdu_t *apdu = NULL;
+ unsigned char *reply = NULL;
+ unsigned char challenge[SHA256_DIGEST_LENGTH];
+ unsigned char rp_id_hash[SHA256_DIGEST_LENGTH];
+ uint8_t key_id_len;
+ int r;
+
+ if (key_id->len > UINT8_MAX || rp_id == NULL) {
+ fido_log_debug("%s: key_id->len=%zu, rp_id=%p", __func__,
+ key_id->len, (const void *)rp_id);
+ r = FIDO_ERR_INVALID_ARGUMENT;
+ goto fail;
+ }
+
+ memset(&challenge, 0xff, sizeof(challenge));
+ memset(&rp_id_hash, 0, sizeof(rp_id_hash));
+
+ if (SHA256((const void *)rp_id, strlen(rp_id),
+ rp_id_hash) != rp_id_hash) {
+ fido_log_debug("%s: sha256", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ key_id_len = (uint8_t)key_id->len;
+
+ if ((apdu = iso7816_new(0, U2F_CMD_AUTH, U2F_AUTH_CHECK, (uint16_t)(2 *
+ SHA256_DIGEST_LENGTH + sizeof(key_id_len) + key_id_len))) == NULL ||
+ iso7816_add(apdu, &challenge, sizeof(challenge)) < 0 ||
+ iso7816_add(apdu, &rp_id_hash, sizeof(rp_id_hash)) < 0 ||
+ iso7816_add(apdu, &key_id_len, sizeof(key_id_len)) < 0 ||
+ iso7816_add(apdu, key_id->ptr, key_id_len) < 0) {
+ fido_log_debug("%s: iso7816", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if ((reply = malloc(FIDO_MAXMSG)) == NULL) {
+ fido_log_debug("%s: malloc", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu),
+ iso7816_len(apdu), ms) < 0) {
+ fido_log_debug("%s: fido_tx", __func__);
+ r = FIDO_ERR_TX;
+ goto fail;
+ }
+ if (fido_rx(dev, CTAP_CMD_MSG, reply, FIDO_MAXMSG, ms) != 2) {
+ fido_log_debug("%s: fido_rx", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+
+ switch ((reply[0] << 8) | reply[1]) {
+ case SW_CONDITIONS_NOT_SATISFIED:
+ *found = 1; /* key exists */
+ break;
+ case SW_WRONG_DATA:
+ *found = 0; /* key does not exist */
+ break;
+ default:
+ /* unexpected sw */
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ r = FIDO_OK;
+fail:
+ iso7816_free(&apdu);
+ freezero(reply, FIDO_MAXMSG);
+
+ return (r);
+}
+
+static int
+parse_auth_reply(fido_blob_t *sig, fido_blob_t *ad, const char *rp_id,
+ const unsigned char *reply, size_t len)
+{
+ uint8_t flags;
+ uint32_t sigcount;
+
+ if (len < 2 || ((reply[len - 2] << 8) | reply[len - 1]) != SW_NO_ERROR) {
+ fido_log_debug("%s: unexpected sw", __func__);
+ return (FIDO_ERR_RX);
+ }
+
+ len -= 2;
+
+ if (fido_buf_read(&reply, &len, &flags, sizeof(flags)) < 0 ||
+ fido_buf_read(&reply, &len, &sigcount, sizeof(sigcount)) < 0) {
+ fido_log_debug("%s: fido_buf_read", __func__);
+ return (FIDO_ERR_RX);
+ }
+
+ if (sig_get(sig, &reply, &len) < 0) {
+ fido_log_debug("%s: sig_get", __func__);
+ return (FIDO_ERR_RX);
+ }
+
+ if (authdata_fake(rp_id, flags, sigcount, ad) < 0) {
+ fido_log_debug("%s; authdata_fake", __func__);
+ return (FIDO_ERR_RX);
+ }
+
+ return (FIDO_OK);
+}
+
+static int
+do_auth(fido_dev_t *dev, const fido_blob_t *cdh, const char *rp_id,
+ const fido_blob_t *key_id, fido_blob_t *sig, fido_blob_t *ad, int *ms)
+{
+ iso7816_apdu_t *apdu = NULL;
+ unsigned char *reply = NULL;
+ unsigned char rp_id_hash[SHA256_DIGEST_LENGTH];
+ int reply_len;
+ uint8_t key_id_len;
+ int r;
+
+#ifdef FIDO_FUZZ
+ *ms = 0; /* XXX */
+#endif
+
+ if (cdh->len != SHA256_DIGEST_LENGTH || key_id->len > UINT8_MAX ||
+ rp_id == NULL) {
+ r = FIDO_ERR_INVALID_ARGUMENT;
+ goto fail;
+ }
+
+ memset(&rp_id_hash, 0, sizeof(rp_id_hash));
+
+ if (SHA256((const void *)rp_id, strlen(rp_id),
+ rp_id_hash) != rp_id_hash) {
+ fido_log_debug("%s: sha256", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ key_id_len = (uint8_t)key_id->len;
+
+ if ((apdu = iso7816_new(0, U2F_CMD_AUTH, U2F_AUTH_SIGN, (uint16_t)(2 *
+ SHA256_DIGEST_LENGTH + sizeof(key_id_len) + key_id_len))) == NULL ||
+ iso7816_add(apdu, cdh->ptr, cdh->len) < 0 ||
+ iso7816_add(apdu, &rp_id_hash, sizeof(rp_id_hash)) < 0 ||
+ iso7816_add(apdu, &key_id_len, sizeof(key_id_len)) < 0 ||
+ iso7816_add(apdu, key_id->ptr, key_id_len) < 0) {
+ fido_log_debug("%s: iso7816", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if ((reply = malloc(FIDO_MAXMSG)) == NULL) {
+ fido_log_debug("%s: malloc", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ do {
+ if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu),
+ iso7816_len(apdu), ms) < 0) {
+ fido_log_debug("%s: fido_tx", __func__);
+ r = FIDO_ERR_TX;
+ goto fail;
+ }
+ if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, reply,
+ FIDO_MAXMSG, ms)) < 2) {
+ fido_log_debug("%s: fido_rx", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+ if (delay_ms(U2F_PACE_MS, ms) != 0) {
+ fido_log_debug("%s: delay_ms", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+ } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED);
+
+ if ((r = parse_auth_reply(sig, ad, rp_id, reply,
+ (size_t)reply_len)) != FIDO_OK) {
+ fido_log_debug("%s: parse_auth_reply", __func__);
+ goto fail;
+ }
+
+fail:
+ iso7816_free(&apdu);
+ freezero(reply, FIDO_MAXMSG);
+
+ return (r);
+}
+
+static int
+cbor_blob_from_ec_point(const uint8_t *ec_point, size_t ec_point_len,
+ fido_blob_t *cbor_blob)
+{
+ es256_pk_t *pk = NULL;
+ cbor_item_t *pk_cbor = NULL;
+ size_t alloc_len;
+ int ok = -1;
+
+ /* only handle uncompressed points */
+ if (ec_point_len != 65 || ec_point[0] != 0x04) {
+ fido_log_debug("%s: unexpected format", __func__);
+ goto fail;
+ }
+
+ if ((pk = es256_pk_new()) == NULL ||
+ es256_pk_set_x(pk, &ec_point[1]) < 0 ||
+ es256_pk_set_y(pk, &ec_point[33]) < 0) {
+ fido_log_debug("%s: es256_pk_set", __func__);
+ goto fail;
+ }
+
+ if ((pk_cbor = es256_pk_encode(pk, 0)) == NULL) {
+ fido_log_debug("%s: es256_pk_encode", __func__);
+ goto fail;
+ }
+
+ if ((cbor_blob->len = cbor_serialize_alloc(pk_cbor, &cbor_blob->ptr,
+ &alloc_len)) != 77) {
+ fido_log_debug("%s: cbor_serialize_alloc", __func__);
+ goto fail;
+ }
+
+ ok = 0;
+fail:
+ es256_pk_free(&pk);
+
+ if (pk_cbor)
+ cbor_decref(&pk_cbor);
+
+ return (ok);
+}
+
+static int
+encode_cred_attstmt(int cose_alg, const fido_blob_t *x5c,
+ const fido_blob_t *sig, fido_blob_t *out)
+{
+ cbor_item_t *item = NULL;
+ cbor_item_t *x5c_cbor = NULL;
+ const uint8_t alg_cbor = (uint8_t)(-cose_alg - 1);
+ struct cbor_pair kv[3];
+ size_t alloc_len;
+ int ok = -1;
+
+ memset(&kv, 0, sizeof(kv));
+ memset(out, 0, sizeof(*out));
+
+ if ((item = cbor_new_definite_map(3)) == NULL) {
+ fido_log_debug("%s: cbor_new_definite_map", __func__);
+ goto fail;
+ }
+
+ if ((kv[0].key = cbor_build_string("alg")) == NULL ||
+ (kv[0].value = cbor_build_negint8(alg_cbor)) == NULL ||
+ !cbor_map_add(item, kv[0])) {
+ fido_log_debug("%s: alg", __func__);
+ goto fail;
+ }
+
+ if ((kv[1].key = cbor_build_string("sig")) == NULL ||
+ (kv[1].value = fido_blob_encode(sig)) == NULL ||
+ !cbor_map_add(item, kv[1])) {
+ fido_log_debug("%s: sig", __func__);
+ goto fail;
+ }
+
+ if ((kv[2].key = cbor_build_string("x5c")) == NULL ||
+ (kv[2].value = cbor_new_definite_array(1)) == NULL ||
+ (x5c_cbor = fido_blob_encode(x5c)) == NULL ||
+ !cbor_array_push(kv[2].value, x5c_cbor) ||
+ !cbor_map_add(item, kv[2])) {
+ fido_log_debug("%s: x5c", __func__);
+ goto fail;
+ }
+
+ if ((out->len = cbor_serialize_alloc(item, &out->ptr,
+ &alloc_len)) == 0) {
+ fido_log_debug("%s: cbor_serialize_alloc", __func__);
+ goto fail;
+ }
+
+ ok = 0;
+fail:
+ if (item != NULL)
+ cbor_decref(&item);
+ if (x5c_cbor != NULL)
+ cbor_decref(&x5c_cbor);
+
+ for (size_t i = 0; i < nitems(kv); i++) {
+ if (kv[i].key)
+ cbor_decref(&kv[i].key);
+ if (kv[i].value)
+ cbor_decref(&kv[i].value);
+ }
+
+ return (ok);
+}
+
+static int
+encode_cred_authdata(const char *rp_id, const uint8_t *kh, uint8_t kh_len,
+ const uint8_t *pubkey, size_t pubkey_len, fido_blob_t *out)
+{
+ fido_authdata_t authdata;
+ fido_attcred_raw_t attcred_raw;
+ fido_blob_t pk_blob;
+ fido_blob_t authdata_blob;
+ cbor_item_t *authdata_cbor = NULL;
+ unsigned char *ptr;
+ size_t len;
+ size_t alloc_len;
+ int ok = -1;
+
+ memset(&pk_blob, 0, sizeof(pk_blob));
+ memset(&authdata, 0, sizeof(authdata));
+ memset(&authdata_blob, 0, sizeof(authdata_blob));
+ memset(out, 0, sizeof(*out));
+
+ if (rp_id == NULL) {
+ fido_log_debug("%s: NULL rp_id", __func__);
+ goto fail;
+ }
+
+ if (cbor_blob_from_ec_point(pubkey, pubkey_len, &pk_blob) < 0) {
+ fido_log_debug("%s: cbor_blob_from_ec_point", __func__);
+ goto fail;
+ }
+
+ if (SHA256((const void *)rp_id, strlen(rp_id),
+ authdata.rp_id_hash) != authdata.rp_id_hash) {
+ fido_log_debug("%s: sha256", __func__);
+ goto fail;
+ }
+
+ authdata.flags = (CTAP_AUTHDATA_ATT_CRED | CTAP_AUTHDATA_USER_PRESENT);
+ authdata.sigcount = 0;
+
+ memset(&attcred_raw.aaguid, 0, sizeof(attcred_raw.aaguid));
+ attcred_raw.id_len = htobe16(kh_len);
+
+ len = authdata_blob.len = sizeof(authdata) + sizeof(attcred_raw) +
+ kh_len + pk_blob.len;
+ ptr = authdata_blob.ptr = calloc(1, authdata_blob.len);
+
+ fido_log_debug("%s: ptr=%p, len=%zu", __func__, (void *)ptr, len);
+
+ if (authdata_blob.ptr == NULL)
+ goto fail;
+
+ if (fido_buf_write(&ptr, &len, &authdata, sizeof(authdata)) < 0 ||
+ fido_buf_write(&ptr, &len, &attcred_raw, sizeof(attcred_raw)) < 0 ||
+ fido_buf_write(&ptr, &len, kh, kh_len) < 0 ||
+ fido_buf_write(&ptr, &len, pk_blob.ptr, pk_blob.len) < 0) {
+ fido_log_debug("%s: fido_buf_write", __func__);
+ goto fail;
+ }
+
+ if ((authdata_cbor = fido_blob_encode(&authdata_blob)) == NULL) {
+ fido_log_debug("%s: fido_blob_encode", __func__);
+ goto fail;
+ }
+
+ if ((out->len = cbor_serialize_alloc(authdata_cbor, &out->ptr,
+ &alloc_len)) == 0) {
+ fido_log_debug("%s: cbor_serialize_alloc", __func__);
+ goto fail;
+ }
+
+ ok = 0;
+fail:
+ if (authdata_cbor)
+ cbor_decref(&authdata_cbor);
+
+ fido_blob_reset(&pk_blob);
+ fido_blob_reset(&authdata_blob);
+
+ return (ok);
+}
+
+static int
+parse_register_reply(fido_cred_t *cred, const unsigned char *reply, size_t len)
+{
+ fido_blob_t x5c;
+ fido_blob_t sig;
+ fido_blob_t ad;
+ fido_blob_t stmt;
+ uint8_t dummy;
+ uint8_t pubkey[65];
+ uint8_t kh_len = 0;
+ uint8_t *kh = NULL;
+ int r;
+
+ memset(&x5c, 0, sizeof(x5c));
+ memset(&sig, 0, sizeof(sig));
+ memset(&ad, 0, sizeof(ad));
+ memset(&stmt, 0, sizeof(stmt));
+ r = FIDO_ERR_RX;
+
+ /* status word */
+ if (len < 2 || ((reply[len - 2] << 8) | reply[len - 1]) != SW_NO_ERROR) {
+ fido_log_debug("%s: unexpected sw", __func__);
+ goto fail;
+ }
+
+ len -= 2;
+
+ /* reserved byte */
+ if (fido_buf_read(&reply, &len, &dummy, sizeof(dummy)) < 0 ||
+ dummy != 0x05) {
+ fido_log_debug("%s: reserved byte", __func__);
+ goto fail;
+ }
+
+ /* pubkey + key handle */
+ if (fido_buf_read(&reply, &len, &pubkey, sizeof(pubkey)) < 0 ||
+ fido_buf_read(&reply, &len, &kh_len, sizeof(kh_len)) < 0 ||
+ (kh = calloc(1, kh_len)) == NULL ||
+ fido_buf_read(&reply, &len, kh, kh_len) < 0) {
+ fido_log_debug("%s: fido_buf_read", __func__);
+ goto fail;
+ }
+
+ /* x5c + sig */
+ if (x5c_get(&x5c, &reply, &len) < 0 ||
+ sig_get(&sig, &reply, &len) < 0) {
+ fido_log_debug("%s: x5c || sig", __func__);
+ goto fail;
+ }
+
+ /* attstmt */
+ if (encode_cred_attstmt(COSE_ES256, &x5c, &sig, &stmt) < 0) {
+ fido_log_debug("%s: encode_cred_attstmt", __func__);
+ goto fail;
+ }
+
+ /* authdata */
+ if (encode_cred_authdata(cred->rp.id, kh, kh_len, pubkey,
+ sizeof(pubkey), &ad) < 0) {
+ fido_log_debug("%s: encode_cred_authdata", __func__);
+ goto fail;
+ }
+
+ if (fido_cred_set_fmt(cred, "fido-u2f") != FIDO_OK ||
+ fido_cred_set_authdata(cred, ad.ptr, ad.len) != FIDO_OK ||
+ fido_cred_set_attstmt(cred, stmt.ptr, stmt.len) != FIDO_OK) {
+ fido_log_debug("%s: fido_cred_set", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ r = FIDO_OK;
+fail:
+ freezero(kh, kh_len);
+ fido_blob_reset(&x5c);
+ fido_blob_reset(&sig);
+ fido_blob_reset(&ad);
+ fido_blob_reset(&stmt);
+
+ return (r);
+}
+
+int
+u2f_register(fido_dev_t *dev, fido_cred_t *cred, int *ms)
+{
+ iso7816_apdu_t *apdu = NULL;
+ unsigned char rp_id_hash[SHA256_DIGEST_LENGTH];
+ unsigned char *reply = NULL;
+ int reply_len;
+ int found;
+ int r;
+
+ if (cred->rk == FIDO_OPT_TRUE || cred->uv == FIDO_OPT_TRUE) {
+ fido_log_debug("%s: rk=%d, uv=%d", __func__, cred->rk,
+ cred->uv);
+ return (FIDO_ERR_UNSUPPORTED_OPTION);
+ }
+
+ if (cred->type != COSE_ES256 || cred->cdh.ptr == NULL ||
+ cred->rp.id == NULL || cred->cdh.len != SHA256_DIGEST_LENGTH) {
+ fido_log_debug("%s: type=%d, cdh=(%p,%zu)" , __func__,
+ cred->type, (void *)cred->cdh.ptr, cred->cdh.len);
+ return (FIDO_ERR_INVALID_ARGUMENT);
+ }
+
+ for (size_t i = 0; i < cred->excl.len; i++) {
+ if ((r = key_lookup(dev, cred->rp.id, &cred->excl.ptr[i],
+ &found, ms)) != FIDO_OK) {
+ fido_log_debug("%s: key_lookup", __func__);
+ return (r);
+ }
+ if (found) {
+ if ((r = send_dummy_register(dev, ms)) != FIDO_OK) {
+ fido_log_debug("%s: send_dummy_register",
+ __func__);
+ return (r);
+ }
+ return (FIDO_ERR_CREDENTIAL_EXCLUDED);
+ }
+ }
+
+ memset(&rp_id_hash, 0, sizeof(rp_id_hash));
+
+ if (SHA256((const void *)cred->rp.id, strlen(cred->rp.id),
+ rp_id_hash) != rp_id_hash) {
+ fido_log_debug("%s: sha256", __func__);
+ return (FIDO_ERR_INTERNAL);
+ }
+
+ if ((apdu = iso7816_new(0, U2F_CMD_REGISTER, 0, 2 *
+ SHA256_DIGEST_LENGTH)) == NULL ||
+ iso7816_add(apdu, cred->cdh.ptr, cred->cdh.len) < 0 ||
+ iso7816_add(apdu, rp_id_hash, sizeof(rp_id_hash)) < 0) {
+ fido_log_debug("%s: iso7816", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if ((reply = malloc(FIDO_MAXMSG)) == NULL) {
+ fido_log_debug("%s: malloc", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ do {
+ if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu),
+ iso7816_len(apdu), ms) < 0) {
+ fido_log_debug("%s: fido_tx", __func__);
+ r = FIDO_ERR_TX;
+ goto fail;
+ }
+ if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, reply,
+ FIDO_MAXMSG, ms)) < 2) {
+ fido_log_debug("%s: fido_rx", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+ if (delay_ms(U2F_PACE_MS, ms) != 0) {
+ fido_log_debug("%s: delay_ms", __func__);
+ r = FIDO_ERR_RX;
+ goto fail;
+ }
+ } while (((reply[0] << 8) | reply[1]) == SW_CONDITIONS_NOT_SATISFIED);
+
+ if ((r = parse_register_reply(cred, reply,
+ (size_t)reply_len)) != FIDO_OK) {
+ fido_log_debug("%s: parse_register_reply", __func__);
+ goto fail;
+ }
+fail:
+ iso7816_free(&apdu);
+ freezero(reply, FIDO_MAXMSG);
+
+ return (r);
+}
+
+static int
+u2f_authenticate_single(fido_dev_t *dev, const fido_blob_t *key_id,
+ fido_assert_t *fa, size_t idx, int *ms)
+{
+ fido_blob_t sig;
+ fido_blob_t ad;
+ int found;
+ int r;
+
+ memset(&sig, 0, sizeof(sig));
+ memset(&ad, 0, sizeof(ad));
+
+ if ((r = key_lookup(dev, fa->rp_id, key_id, &found, ms)) != FIDO_OK) {
+ fido_log_debug("%s: key_lookup", __func__);
+ goto fail;
+ }
+
+ if (!found) {
+ fido_log_debug("%s: not found", __func__);
+ r = FIDO_ERR_CREDENTIAL_EXCLUDED;
+ goto fail;
+ }
+
+ if (fido_blob_set(&fa->stmt[idx].id, key_id->ptr, key_id->len) < 0) {
+ fido_log_debug("%s: fido_blob_set", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if (fa->up == FIDO_OPT_FALSE) {
+ fido_log_debug("%s: checking for key existence only", __func__);
+ r = FIDO_ERR_USER_PRESENCE_REQUIRED;
+ goto fail;
+ }
+
+ if ((r = do_auth(dev, &fa->cdh, fa->rp_id, key_id, &sig, &ad,
+ ms)) != FIDO_OK) {
+ fido_log_debug("%s: do_auth", __func__);
+ goto fail;
+ }
+
+ if (fido_assert_set_authdata(fa, idx, ad.ptr, ad.len) != FIDO_OK ||
+ fido_assert_set_sig(fa, idx, sig.ptr, sig.len) != FIDO_OK) {
+ fido_log_debug("%s: fido_assert_set", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ r = FIDO_OK;
+fail:
+ fido_blob_reset(&sig);
+ fido_blob_reset(&ad);
+
+ return (r);
+}
+
+int
+u2f_authenticate(fido_dev_t *dev, fido_assert_t *fa, int *ms)
+{
+ size_t nfound = 0;
+ size_t nauth_ok = 0;
+ int r;
+
+ if (fa->uv == FIDO_OPT_TRUE || fa->allow_list.ptr == NULL) {
+ fido_log_debug("%s: uv=%d, allow_list=%p", __func__, fa->uv,
+ (void *)fa->allow_list.ptr);
+ return (FIDO_ERR_UNSUPPORTED_OPTION);
+ }
+
+ if ((r = fido_assert_set_count(fa, fa->allow_list.len)) != FIDO_OK) {
+ fido_log_debug("%s: fido_assert_set_count", __func__);
+ return (r);
+ }
+
+ for (size_t i = 0; i < fa->allow_list.len; i++) {
+ switch ((r = u2f_authenticate_single(dev,
+ &fa->allow_list.ptr[i], fa, nfound, ms))) {
+ case FIDO_OK:
+ nauth_ok++;
+ FALLTHROUGH
+ case FIDO_ERR_USER_PRESENCE_REQUIRED:
+ nfound++;
+ break;
+ default:
+ if (r != FIDO_ERR_CREDENTIAL_EXCLUDED) {
+ fido_log_debug("%s: u2f_authenticate_single",
+ __func__);
+ return (r);
+ }
+ /* ignore credentials that don't exist */
+ }
+ }
+
+ fa->stmt_len = nfound;
+
+ if (nfound == 0)
+ return (FIDO_ERR_NO_CREDENTIALS);
+ if (nauth_ok == 0)
+ return (FIDO_ERR_USER_PRESENCE_REQUIRED);
+
+ return (FIDO_OK);
+}
+
+int
+u2f_get_touch_begin(fido_dev_t *dev, int *ms)
+{
+ iso7816_apdu_t *apdu = NULL;
+ const char *clientdata = FIDO_DUMMY_CLIENTDATA;
+ const char *rp_id = FIDO_DUMMY_RP_ID;
+ unsigned char *reply = NULL;
+ unsigned char clientdata_hash[SHA256_DIGEST_LENGTH];
+ unsigned char rp_id_hash[SHA256_DIGEST_LENGTH];
+ int r;
+
+ memset(&clientdata_hash, 0, sizeof(clientdata_hash));
+ memset(&rp_id_hash, 0, sizeof(rp_id_hash));
+
+ if (SHA256((const void *)clientdata, strlen(clientdata),
+ clientdata_hash) != clientdata_hash || SHA256((const void *)rp_id,
+ strlen(rp_id), rp_id_hash) != rp_id_hash) {
+ fido_log_debug("%s: sha256", __func__);
+ return (FIDO_ERR_INTERNAL);
+ }
+
+ if ((apdu = iso7816_new(0, U2F_CMD_REGISTER, 0, 2 *
+ SHA256_DIGEST_LENGTH)) == NULL ||
+ iso7816_add(apdu, clientdata_hash, sizeof(clientdata_hash)) < 0 ||
+ iso7816_add(apdu, rp_id_hash, sizeof(rp_id_hash)) < 0) {
+ fido_log_debug("%s: iso7816", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if ((reply = malloc(FIDO_MAXMSG)) == NULL) {
+ fido_log_debug("%s: malloc", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto fail;
+ }
+
+ if (dev->attr.flags & FIDO_CAP_WINK) {
+ fido_tx(dev, CTAP_CMD_WINK, NULL, 0, ms);
+ fido_rx(dev, CTAP_CMD_WINK, reply, FIDO_MAXMSG, ms);
+ }
+
+ if (fido_tx(dev, CTAP_CMD_MSG, iso7816_ptr(apdu),
+ iso7816_len(apdu), ms) < 0) {
+ fido_log_debug("%s: fido_tx", __func__);
+ r = FIDO_ERR_TX;
+ goto fail;
+ }
+
+ r = FIDO_OK;
+fail:
+ iso7816_free(&apdu);
+ freezero(reply, FIDO_MAXMSG);
+
+ return (r);
+}
+
+int
+u2f_get_touch_status(fido_dev_t *dev, int *touched, int *ms)
+{
+ unsigned char *reply;
+ int reply_len;
+ int r;
+
+ if ((reply = malloc(FIDO_MAXMSG)) == NULL) {
+ fido_log_debug("%s: malloc", __func__);
+ r = FIDO_ERR_INTERNAL;
+ goto out;
+ }
+
+ if ((reply_len = fido_rx(dev, CTAP_CMD_MSG, reply, FIDO_MAXMSG,
+ ms)) < 2) {
+ fido_log_debug("%s: fido_rx", __func__);
+ r = FIDO_OK; /* ignore */
+ goto out;
+ }
+
+ switch ((reply[reply_len - 2] << 8) | reply[reply_len - 1]) {
+ case SW_CONDITIONS_NOT_SATISFIED:
+ if ((r = u2f_get_touch_begin(dev, ms)) != FIDO_OK) {
+ fido_log_debug("%s: u2f_get_touch_begin", __func__);
+ goto out;
+ }
+ *touched = 0;
+ break;
+ case SW_NO_ERROR:
+ *touched = 1;
+ break;
+ default:
+ fido_log_debug("%s: unexpected sw", __func__);
+ r = FIDO_ERR_RX;
+ goto out;
+ }
+
+ r = FIDO_OK;
+out:
+ freezero(reply, FIDO_MAXMSG);
+
+ return (r);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-12 14:31:27 +0000