diff options
Diffstat (limited to 'usr.bin')
| -rw-r--r-- | usr.bin/ssh/PROTOCOL.u2f | 98 | ||||
| -rw-r--r-- | usr.bin/ssh/sk-api.h | 6 | ||||
| -rw-r--r-- | usr.bin/ssh/sk-usbhid.c | 13 | ||||
| -rw-r--r-- | usr.bin/ssh/ssh-keygen.1 | 9 | ||||
| -rw-r--r-- | usr.bin/ssh/ssh-keygen.c | 44 | ||||
| -rw-r--r-- | usr.bin/ssh/ssh-sk.c | 44 |
6 files changed, 96 insertions, 118 deletions
diff --git a/usr.bin/ssh/PROTOCOL.u2f b/usr.bin/ssh/PROTOCOL.u2f index 5b8a06277c5..f8ca56b11c8 100644 --- a/usr.bin/ssh/PROTOCOL.u2f +++ b/usr.bin/ssh/PROTOCOL.u2f @@ -154,6 +154,16 @@ by trusted hardware before it will issue a certificate. To support this case, OpenSSH optionally allows retaining the attestation information at the time of key generation. It will take the following format: + string "ssh-sk-attest-v01" + string attestation certificate + string enrollment signature + string authenticator data (CBOR encoded) + uint32 reserved flags + string reserved string + +A previous version of this format, emitted prior to OpenSSH 8.4 omitted +the authenticator data. + string "ssh-sk-attest-v00" string attestation certificate string enrollment signature @@ -267,87 +277,15 @@ regress testing. For this reason, OpenSSH shall support a dynamically- loaded middleware libraries to communicate with security keys, but offer support for the common case of USB HID security keys internally. -The middleware library need only expose a handful of functions: - - #define SSH_SK_VERSION_MAJOR 0x00050000 /* API version */ - #define SSH_SK_VERSION_MAJOR_MASK 0xffff0000 - - /* Flags */ - #define SSH_SK_USER_PRESENCE_REQD 0x01 - #define SSH_SK_USER_VERIFICATION_REQD 0x04 - #define SSH_SK_RESIDENT_KEY 0x20 - - /* Algs */ - #define SSH_SK_ECDSA 0x00 - #define SSH_SK_ED25519 0x01 - - /* Error codes */ - #define SSH_SK_ERR_GENERAL -1 - #define SSH_SK_ERR_UNSUPPORTED -2 - #define SSH_SK_ERR_PIN_REQUIRED -3 - #define SSH_SK_ERR_DEVICE_NOT_FOUND -4 - - struct sk_enroll_response { - uint8_t *public_key; - size_t public_key_len; - uint8_t *key_handle; - size_t key_handle_len; - uint8_t *signature; - size_t signature_len; - uint8_t *attestation_cert; - size_t attestation_cert_len; - }; - - struct sk_sign_response { - uint8_t flags; - uint32_t counter; - uint8_t *sig_r; - size_t sig_r_len; - uint8_t *sig_s; - size_t sig_s_len; - }; - - struct sk_resident_key { - uint32_t alg; - size_t slot; - char *application; - struct sk_enroll_response key; - }; - - struct sk_option { - char *name; - char *value; - uint8_t important; - }; - - /* Return the version of the middleware API */ - uint32_t sk_api_version(void); - - /* Enroll a U2F key (private key generation) */ - int sk_enroll(uint32_t alg, - const uint8_t *challenge, size_t challenge_len, - const char *application, uint8_t flags, const char *pin, - struct sk_option **options, - struct sk_enroll_response **enroll_response); - - /* Sign a challenge */ - int sk_sign(uint32_t alg, const uint8_t *message, size_t message_len, - const char *application, - const uint8_t *key_handle, size_t key_handle_len, - uint8_t flags, const char *pin, struct sk_option **options, - struct sk_sign_response **sign_response); - - /* Enumerate all resident keys */ - int sk_load_resident_keys(const char *pin, struct sk_option **options, - struct sk_resident_key ***rks, size_t *nrks); - -The SSH_SK_VERSION_MAJOR should be incremented for each incompatible +The middleware library need only expose a handful of functions and +numbers listed in sk-api.h. Included in the defined numbers is a +SSH_SK_VERSION_MAJOR that should be incremented for each incompatible API change. -The options may be used to pass miscellaneous options to the middleware -as a NULL-terminated array of pointers to struct sk_option. The middleware -may ignore unsupported or unknown options unless the "important" flag is -set, in which case it should return failure if an unsupported option is +miscellaneous options may be passed to the middleware as a NULL- +terminated array of pointers to struct sk_option. The middleware may +ignore unsupported or unknown options unless the "required" flag is set, +in which case it should return failure if an unsupported option is requested. At present the following options names are supported: @@ -368,4 +306,4 @@ In OpenSSH, the middleware will be invoked by using a similar mechanism to ssh-pkcs11-helper to provide address-space containment of the middleware from ssh-agent. -$OpenBSD: PROTOCOL.u2f,v 1.25 2020/08/31 00:17:41 djm Exp $ +$OpenBSD: PROTOCOL.u2f,v 1.26 2020/09/09 03:08:01 djm Exp $ diff --git a/usr.bin/ssh/sk-api.h b/usr.bin/ssh/sk-api.h index 6bf7c092875..40cdc834a04 100644 --- a/usr.bin/ssh/sk-api.h +++ b/usr.bin/ssh/sk-api.h @@ -1,4 +1,4 @@ -/* $OpenBSD: sk-api.h,v 1.10 2020/08/27 01:08:19 djm Exp $ */ +/* $OpenBSD: sk-api.h,v 1.11 2020/09/09 03:08:01 djm Exp $ */ /* * Copyright (c) 2019 Google LLC * @@ -45,6 +45,8 @@ struct sk_enroll_response { size_t signature_len; uint8_t *attestation_cert; size_t attestation_cert_len; + uint8_t *authdata; + size_t authdata_len; }; struct sk_sign_response { @@ -70,7 +72,7 @@ struct sk_option { uint8_t required; }; -#define SSH_SK_VERSION_MAJOR 0x00060000 /* current API version */ +#define SSH_SK_VERSION_MAJOR 0x00070000 /* current API version */ #define SSH_SK_VERSION_MAJOR_MASK 0xffff0000 /* Return the version of the middleware API */ diff --git a/usr.bin/ssh/sk-usbhid.c b/usr.bin/ssh/sk-usbhid.c index 9dde5c10a26..878ce965111 100644 --- a/usr.bin/ssh/sk-usbhid.c +++ b/usr.bin/ssh/sk-usbhid.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sk-usbhid.c,v 1.25 2020/08/31 00:17:41 djm Exp $ */ +/* $OpenBSD: sk-usbhid.c,v 1.26 2020/09/09 03:08:01 djm Exp $ */ /* * Copyright (c) 2019 Markus Friedl * Copyright (c) 2020 Pedro Martelletto @@ -781,6 +781,16 @@ sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, memcpy(response->attestation_cert, ptr, len); response->attestation_cert_len = len; } + if ((ptr = fido_cred_authdata_ptr(cred)) != NULL) { + len = fido_cred_authdata_len(cred); + debug3("%s: authdata len=%zu", __func__, len); + if ((response->authdata = calloc(1, len)) == NULL) { + skdebug(__func__, "calloc authdata failed"); + goto out; + } + memcpy(response->authdata, ptr, len); + response->authdata_len = len; + } *enroll_response = response; response = NULL; ret = 0; @@ -791,6 +801,7 @@ sk_enroll(uint32_t alg, const uint8_t *challenge, size_t challenge_len, free(response->key_handle); free(response->signature); free(response->attestation_cert); + free(response->authdata); free(response); } sk_close(sk); diff --git a/usr.bin/ssh/ssh-keygen.1 b/usr.bin/ssh/ssh-keygen.1 index c51a0d9c8b5..3ae596caac8 100644 --- a/usr.bin/ssh/ssh-keygen.1 +++ b/usr.bin/ssh/ssh-keygen.1 @@ -1,4 +1,4 @@ -.\" $OpenBSD: ssh-keygen.1,v 1.208 2020/08/27 06:15:22 jmc Exp $ +.\" $OpenBSD: ssh-keygen.1,v 1.209 2020/09/09 03:08:01 djm Exp $ .\" .\" Author: Tatu Ylonen <ylo@cs.hut.fi> .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -35,7 +35,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.Dd $Mdocdate: August 27 2020 $ +.Dd $Mdocdate: September 9 2020 $ .Dt SSH-KEYGEN 1 .Os .Sh NAME @@ -520,9 +520,10 @@ Not all FIDO tokens support this option. Currently PIN authentication is the only supported verification method, but other methods may be supported in the future. .It Cm write-attestation Ns = Ns Ar path -May be used at key generation time to record the attestation certificate +May be used at key generation time to record the attestation data returned from FIDO tokens during key generation. -By default this information is discarded. +Please note that this information is potentially sensitive. +By default, this information is discarded. .El .Pp The diff --git a/usr.bin/ssh/ssh-keygen.c b/usr.bin/ssh/ssh-keygen.c index 0e169a2aaac..703a5fb2102 100644 --- a/usr.bin/ssh/ssh-keygen.c +++ b/usr.bin/ssh/ssh-keygen.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-keygen.c,v 1.419 2020/08/27 09:46:04 djm Exp $ */ +/* $OpenBSD: ssh-keygen.c,v 1.420 2020/09/09 03:08:01 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -3050,6 +3050,27 @@ do_download_sk(const char *skprovider, const char *device) } static void +save_attestation(struct sshbuf *attest, const char *path) +{ + mode_t omask; + int r; + + if (path == NULL) + return; /* nothing to do */ + if (attest == NULL || sshbuf_len(attest) == 0) + fatal("Enrollment did not return attestation data"); + omask = umask(077); + r = sshbuf_write_file(path, attest); + umask(omask); + if (r != 0) + fatal("Unable to write attestation data \"%s\": %s", path, + ssh_err(r)); + if (!quiet) + printf("Your FIDO attestation certificate has been saved in " + "%s\n", path); +} + +static void usage(void) { fprintf(stderr, @@ -3115,7 +3136,7 @@ main(int argc, char **argv) unsigned long long cert_serial = 0; char *identity_comment = NULL, *ca_key_path = NULL, **opts = NULL; char *sk_application = NULL, *sk_device = NULL, *sk_user = NULL; - char *sk_attestaion_path = NULL; + char *sk_attestation_path = NULL; struct sshbuf *challenge = NULL, *attest = NULL; size_t i, nopts = 0; u_int32_t bits = 0; @@ -3568,7 +3589,7 @@ main(int argc, char **argv) } } else if (strncasecmp(opts[i], "write-attestation=", 18) == 0) { - sk_attestaion_path = opts[i] + 18; + sk_attestation_path = opts[i] + 18; } else if (strncasecmp(opts[i], "application=", 12) == 0) { sk_application = xstrdup(opts[i] + 12); @@ -3690,20 +3711,9 @@ main(int argc, char **argv) free(fp); } - if (sk_attestaion_path != NULL) { - if (attest == NULL || sshbuf_len(attest) == 0) { - fatal("Enrollment did not return attestation " - "certificate"); - } - if ((r = sshbuf_write_file(sk_attestaion_path, attest)) != 0) { - fatal("Unable to write attestation certificate " - "\"%s\": %s", sk_attestaion_path, ssh_err(r)); - } - if (!quiet) { - printf("Your FIDO attestation certificate has been " - "saved in %s\n", sk_attestaion_path); - } - } + if (sk_attestation_path != NULL) + save_attestation(attest, sk_attestation_path); + sshbuf_free(attest); sshkey_free(public); diff --git a/usr.bin/ssh/ssh-sk.c b/usr.bin/ssh/ssh-sk.c index 6a2422f2bba..1262bce4b97 100644 --- a/usr.bin/ssh/ssh-sk.c +++ b/usr.bin/ssh/ssh-sk.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-sk.c,v 1.31 2020/08/27 01:08:19 djm Exp $ */ +/* $OpenBSD: ssh-sk.c,v 1.32 2020/09/09 03:08:02 djm Exp $ */ /* * Copyright (c) 2019 Google LLC * @@ -164,6 +164,7 @@ sshsk_free_enroll_response(struct sk_enroll_response *r) freezero(r->public_key, r->public_key_len); freezero(r->signature, r->signature_len); freezero(r->attestation_cert, r->attestation_cert_len); + freezero(r->authdata, r->authdata_len); freezero(r, sizeof(*r)); } @@ -409,6 +410,31 @@ make_options(const char *device, const char *user_id, return ret; } + +static int +fill_attestation_blob(const struct sk_enroll_response *resp, + struct sshbuf *attest) +{ + int r; + + if (attest == NULL) + return 0; /* nothing to do */ + if ((r = sshbuf_put_cstring(attest, "ssh-sk-attest-v01")) != 0 || + (r = sshbuf_put_string(attest, + resp->attestation_cert, resp->attestation_cert_len)) != 0 || + (r = sshbuf_put_string(attest, + resp->signature, resp->signature_len)) != 0 || + (r = sshbuf_put_string(attest, + resp->authdata, resp->authdata_len)) != 0 || + (r = sshbuf_put_u32(attest, 0)) != 0 || /* resvd flags */ + (r = sshbuf_put_string(attest, NULL, 0)) != 0 /* resvd */) { + error("%s: buffer error: %s", __func__, ssh_err(r)); + return r; + } + /* success */ + return 0; +} + int sshsk_enroll(int type, const char *provider_path, const char *device, const char *application, const char *userid, uint8_t flags, @@ -496,19 +522,9 @@ sshsk_enroll(int type, const char *provider_path, const char *device, goto out; /* Optionally fill in the attestation information */ - if (attest != NULL) { - if ((r = sshbuf_put_cstring(attest, - "ssh-sk-attest-v00")) != 0 || - (r = sshbuf_put_string(attest, - resp->attestation_cert, resp->attestation_cert_len)) != 0 || - (r = sshbuf_put_string(attest, - resp->signature, resp->signature_len)) != 0 || - (r = sshbuf_put_u32(attest, 0)) != 0 || /* resvd flags */ - (r = sshbuf_put_string(attest, NULL, 0)) != 0 /* resvd */) { - error("%s: buffer error: %s", __func__, ssh_err(r)); - goto out; - } - } + if ((r = fill_attestation_blob(resp, attest)) != 0) + goto out; + /* success */ *keyp = key; key = NULL; /* transferred */ |