Write admin key in PrintedInfo field by default, support UPN in certs

The admin key in PrintedInfo thing is used by ykman and the Windows
PIV minidriver, so it's nice to interop with those.

UPN support allows certs to be used with Windows AD more easily
(by default, only the 9A key, but you can use the option for others)

Author: arekinath

piv.c

@@ -3201,6 +3201,11 @@ piv_reset_pin(struct piv_token *pk, enum piv_pin type, const char *puk,
 		err = errf("PermissionError", swerrf("INS_RESET_PIN(%x)",
 		    apdu->a_sw, type), "Incorrect PUK supplied");
 
+	} else if (apdu->a_sw == SW_FILE_INVALID) {
+		err = errf("PermissionError", swerrf("INS_RESET_PIN(%x)",
+		    apdu->a_sw, type), "PUK is blocked due to too many "
+		    "incorrect attempts");
+
 	} else {
 		err = swerrf("INS_RESET_PIN(%x)", apdu->a_sw, type);
 		bunyan_log(BNY_DEBUG, "unexpected card error",

piv.h

@@ -138,6 +138,7 @@ enum piv_tags {
 	PIV_TAG_CHUID = 0x5FC102,
 	PIV_TAG_SECOBJ = 0x5FC106,
 	PIV_TAG_KEYHIST = 0x5FC10C,
+	PIV_TAG_PRINTINFO = 0x5FC109,
 	PIV_TAG_DISCOV = 0x7E,
 	PIV_TAG_CERT_9A = 0x5FC105,
 	PIV_TAG_CERT_9C = 0x5FC10A,

pivy-tool.c

@@ -69,6 +69,8 @@ int PEM_write_X509(FILE *fp, X509 *x);
 boolean_t debug = B_FALSE;
 static boolean_t parseable = B_FALSE;
 static const char *cn = NULL;
+static const char *upn = NULL;
+static boolean_t save_pinfo_admin = B_TRUE;
 static uint8_t *guid = NULL;
 static size_t guid_len = 0;
 static uint min_retries = 1;
@@ -542,6 +544,90 @@ cmd_list(void)
 	return (ERRF_OK);
 }
 
+static errf_t *
+save_pinfo_admin_key(struct piv_token *tk)
+{
+	struct tlv_state *tlv;
+	errf_t *err;
+
+	tlv = tlv_init_write();
+	tlv_push(tlv, 0x88);
+	tlv_push(tlv, 0x89);
+	tlv_write(tlv, admin_key, 24);
+	tlv_pop(tlv);
+	tlv_pop(tlv);
+
+	err = piv_write_file(tk, PIV_TAG_PRINTINFO,
+	    tlv_buf(tlv), tlv_len(tlv));
+	tlv_free(tlv);
+	return (err);
+}
+
+static errf_t *
+try_pinfo_admin_key(struct piv_token *tk)
+{
+	uint8_t *data = NULL;
+	size_t dlen = 0;
+	errf_t *err;
+	uint tag;
+	struct tlv_state *tlv = NULL;
+
+	assert_pin(tk, B_FALSE);
+again:
+	err = piv_read_file(tk, PIV_TAG_PRINTINFO, &data, &dlen);
+	if (err && errf_caused_by(err, "PermissionError")) {
+		assert_pin(tk, B_TRUE);
+		goto again;
+	}
+	if (err == ERRF_OK) {
+		tlv = tlv_init(data, 0, dlen);
+		while (!tlv_at_end(tlv)) {
+			if ((err = tlv_read_tag(tlv, &tag)))
+				goto out;
+			if (tag == 0x88) {
+				if ((err = tlv_read_tag(tlv, &tag)))
+					goto out;
+				if (tag == 0x89) {
+					uint8_t *key;
+					size_t keylen;
+					err = tlv_read_alloc(tlv, &key,
+					    &keylen);
+					if (err)
+						goto out;
+					if ((err = tlv_end(tlv)))
+						goto out;
+					if (keylen == 24) {
+						admin_key = key;
+						err = ERRF_OK;
+					} else {
+						err = errf("BadLength", NULL,
+						    "Data is wrong length for "
+						    "an admin key (%d bytes)",
+						    keylen);
+						goto out;
+					}
+				} else {
+					tlv_skip(tlv);
+				}
+				if ((err = tlv_end(tlv)))
+					goto out;
+			} else {
+				tlv_skip(tlv);
+			}
+		}
+		bunyan_log(BNY_DEBUG, "using admin key from printedinfo file",
+		    NULL);
+		tlv_free(tlv);
+		tlv = NULL;
+	}
+
+out:
+	if (tlv != NULL)
+		tlv_abort(tlv);
+	freezero(data, dlen);
+	return (err);
+}
+
 static errf_t *
 cmd_init(void)
 {
@@ -628,7 +714,14 @@ cmd_init(void)
 	if ((err = piv_txn_begin(selk)))
 		return (err);
 	assert_select(selk);
+admin_again:
 	err = piv_auth_admin(selk, admin_key, 24);
+	if (err && errf_caused_by(err, "PermissionError") &&
+	    admin_key == DEFAULT_ADMIN_KEY) {
+		err = try_pinfo_admin_key(selk);
+		if (err == ERRF_OK)
+			goto admin_again;
+	}
 	if (err == ERRF_OK) {
 		err = piv_write_file(selk, PIV_TAG_CARDCAP,
 		    tlv_buf(ccc), tlv_len(ccc));
@@ -679,6 +772,13 @@ cmd_set_admin(uint8_t *new_admin_key)
 		if (err) {
 			err = funcerrf(err, "Failed to set new admin key");
 		}
+		if (!err && save_pinfo_admin) {
+			admin_key = new_admin_key;
+			if ((err = save_pinfo_admin_key(selk))) {
+				err = funcerrf(err, "Failed to write new "
+				    "admin key to printed info object");
+			}
+		}
 	}
 	piv_txn_end(selk);
 
@@ -890,7 +990,7 @@ selfsign_slot(uint slotid, enum piv_alg alg, struct sshkey *pub)
 	X509 *cert;
 	EVP_PKEY *pkey;
 	X509_NAME *subj;
-	const char *ku, *basic;
+	const char *ku, *basic, *eku = NULL;
 	char *name;
 	enum sshdigest_types wantalg, hashalg;
 	int nid;
@@ -904,30 +1004,38 @@ selfsign_slot(uint slotid, enum piv_alg alg, struct sshkey *pub)
 	X509_EXTENSION *ext;
 	X509V3_CTX x509ctx;
 	const char *guidhex;
+	const char *myupn = upn;
+	const char *mycn = cn;
 
-	guidhex = piv_token_guid_hex(selk);
+	guidhex = piv_token_shortid(selk);
+
+	name = calloc(1, 64);
 
 	switch (slotid) {
 	case 0x9A:
-		name = "piv-auth";
+		snprintf(name, 64, "piv-auth@%s", guidhex);
 		basic = "critical,CA:FALSE";
 		ku = "critical,digitalSignature,nonRepudiation";
+		eku = "clientAuth,1.3.6.1.4.1.311.20.2.2";
+		if (myupn == NULL)
+			myupn = getenv("LOGNAME");
 		break;
 	case 0x9C:
-		name = "piv-sign";
+		snprintf(name, 64, "piv-sign@%s", guidhex);
 		basic = "critical,CA:TRUE";
 		ku = "critical,digitalSignature,nonRepudiation,"
 		    "keyCertSign,cRLSign";
 		break;
 	case 0x9D:
-		name = "piv-key-mgmt";
+		snprintf(name, 64, "piv-key-mgmt@%s", guidhex);
 		basic = "critical,CA:FALSE";
 		ku = "critical,keyAgreement,keyEncipherment,dataEncipherment";
 		break;
 	case 0x9E:
-		name = "piv-card-auth";
+		snprintf(name, 64, "piv-card-auth@%s", guidhex);
 		basic = "critical,CA:FALSE";
 		ku = "critical,digitalSignature,nonRepudiation";
+		eku = "clientAuth";
 		break;
 	case 0x82:
 	case 0x83:
@@ -949,8 +1057,7 @@ selfsign_slot(uint slotid, enum piv_alg alg, struct sshkey *pub)
 	case 0x93:
 	case 0x94:
 	case 0x95:
-		name = calloc(1, 64);
-		snprintf(name, 64, "piv-retired-%u", slotid - 0x81);
+		snprintf(name, 64, "piv-retired-%u@%s", slotid - 0x81, guidhex);
 		basic = "critical,CA:FALSE";
 		ku = "critical,digitalSignature,nonRepudiation";
 		if (slotid - 0x82 > piv_token_keyhistory_oncard(selk)) {
@@ -966,6 +1073,17 @@ selfsign_slot(uint slotid, enum piv_alg alg, struct sshkey *pub)
 		return (err);
 	}
 
+	if (myupn != NULL && eku == NULL) {
+		eku = "clientAuth,1.3.6.1.4.1.311.20.2.2";
+	}
+
+	if (myupn != NULL) {
+		char *newupn = calloc(1, 128);
+		snprintf(newupn, 128,
+		    "otherName:1.3.6.1.4.1.311.20.2.3;UTF8:%s", myupn);
+		myupn = newupn;
+	}
+
 	pkey = EVP_PKEY_new();
 	VERIFY(pkey != NULL);
 	if (pub->type == KEY_RSA) {
@@ -1021,15 +1139,11 @@ selfsign_slot(uint slotid, enum piv_alg alg, struct sshkey *pub)
 
 	subj = X509_NAME_new();
 	VERIFY(subj != NULL);
-	if (cn == NULL) {
-		VERIFY(X509_NAME_add_entry_by_NID(subj, NID_title, MBSTRING_ASC,
-		    (unsigned char *)name, -1, -1, 0) == 1);
-		VERIFY(X509_NAME_add_entry_by_NID(subj, NID_commonName,
-		    MBSTRING_ASC, (unsigned char *)guidhex, -1, -1, 0) == 1);
-	} else {
-		VERIFY(X509_NAME_add_entry_by_NID(subj, NID_commonName,
-		    MBSTRING_ASC, (unsigned char *)cn, -1, -1, 0) == 1);
+	if (mycn == NULL) {
+		mycn = name;
 	}
+	VERIFY(X509_NAME_add_entry_by_NID(subj, NID_commonName,
+	    MBSTRING_ASC, (unsigned char *)mycn, -1, -1, 0) == 1);
 	/*VERIFY(X509_NAME_add_entry_by_NID(subj, NID_organizationalUnitName,
 	    MBSTRING_ASC, (unsigned char *)"tokens", -1, -1, 0) == 1);
 	VERIFY(X509_NAME_add_entry_by_NID(subj, NID_organizationName,
@@ -1051,6 +1165,22 @@ selfsign_slot(uint slotid, enum piv_alg alg, struct sshkey *pub)
 	X509_add_ext(cert, ext, -1);
 	X509_EXTENSION_free(ext);
 
+	if (eku != NULL) {
+		ext = X509V3_EXT_conf_nid(NULL, &x509ctx, NID_ext_key_usage,
+		    (char *)eku);
+		VERIFY(ext != NULL);
+		X509_add_ext(cert, ext, -1);
+		X509_EXTENSION_free(ext);
+	}
+
+	if (myupn != NULL) {
+		ext = X509V3_EXT_conf_nid(NULL, &x509ctx, NID_subject_alt_name,
+		    (char *)myupn);
+		VERIFY(ext != NULL);
+		X509_add_ext(cert, ext, -1);
+		X509_EXTENSION_free(ext);
+	}
+
 	VERIFY(X509_set_pubkey(cert, pkey) == 1);
 
 	cert->sig_alg->algorithm = OBJ_nid2obj(nid);
@@ -1185,7 +1315,14 @@ cmd_import(uint slotid)
 	if ((err = piv_txn_begin(selk)))
 		return (err);
 	assert_select(selk);
+admin_again:
 	err = piv_auth_admin(selk, admin_key, 24);
+	if (err && errf_caused_by(err, "PermissionError") &&
+	    admin_key == DEFAULT_ADMIN_KEY) {
+		err = try_pinfo_admin_key(selk);
+		if (err == ERRF_OK)
+			goto admin_again;
+	}
 	if (err == ERRF_OK) {
 		err = ykpiv_import(selk, slotid, priv, pinpolicy, touchpolicy);
 	}
@@ -1241,7 +1378,14 @@ cmd_generate(uint slotid, enum piv_alg alg)
 	if ((err = piv_txn_begin(selk)))
 		return (err);
 	assert_select(selk);
+admin_again:
 	err = piv_auth_admin(selk, admin_key, 24);
+	if (err && errf_caused_by(err, "PermissionError") &&
+	    admin_key == DEFAULT_ADMIN_KEY) {
+		err = try_pinfo_admin_key(selk);
+		if (err == ERRF_OK)
+			goto admin_again;
+	}
 	if (err == ERRF_OK) {
 		if (pinpolicy == YKPIV_PIN_DEFAULT &&
 		    touchpolicy == YKPIV_TOUCH_DEFAULT) {
@@ -2033,15 +2177,15 @@ cmd_setup(SCARDCONTEXT ctx)
 	arc4random_buf(admin_key, 24);
 	if (usetouch)
 		touchpolicy = YKPIV_TOUCH_ALWAYS;
-	hex = buf_to_hex(admin_key, 24, B_FALSE);
-	printf("Admin 3DES key: %s\n", hex);
-	fprintf(stderr, "This key is only needed to generate new slot keys or "
-	    "change certificates in future. If you don't intend to do either "
-	    "you can simply forget about this key and the Yubikey will be "
-	    "sealed.\n");
+
 	if ((err = cmd_set_admin(admin_key)))
 		return (err);
 
+	if (!save_pinfo_admin) {
+		hex = buf_to_hex(admin_key, 24, B_FALSE);
+		printf("Admin 3DES key: %s\n", hex);
+	}
+
 	fprintf(stderr, "Done!\n");
 
 	return (ERRF_OK);
@@ -2119,6 +2263,8 @@ usage(void)
 	    "                         RSA algos: rsa1024, rsa2048, rsa4096\n"
 	    "  -n <cn>                Set a CN= attribute to be used on\n"
 	    "                         the new slot's certificate\n"
+	    "  -u <upn>               Set a UPN= attribute to be used on\n"
+	    "                         the new slot's certificate\n"
 	    "  -t <never|always|cached>\n"
 	    "                         Set the touch policy. Only supported\n"
 	    "                         with YubiKeys\n"
@@ -2127,7 +2273,12 @@ usage(void)
 	    "\n"
 	    "Options for 'box'/'unbox':\n"
 	    "  -k <pubkey>            Use a public key for box operation\n"
-	    "                         instead of a slot\n");
+	    "                         instead of a slot\n"
+	    "\n"
+	    "Options for 'set-admin'/'setup':\n"
+	    "  -R                     Don't save admin key in the PIV\n"
+	    "                         'printed info' object (compat with\n"
+	    "                         Yubico PIV manager)\n");
 	exit(EXIT_BAD_ARGS);
 }
 
@@ -2140,7 +2291,7 @@ usage(void)
     "f(force)"
     "K:(admin-key)"
     "k:(key)";*/
-const char *optstring = "dpg:P:a:fK:k:n:t:i:";
+const char *optstring = "dpg:P:a:fK:k:n:t:i:u:R";
 
 int
 main(int argc, char *argv[])
@@ -2167,6 +2318,9 @@ main(int argc, char *argv[])
 			if (++d_level > 1)
 				piv_full_apdu_debug = B_TRUE;
 			break;
+		case 'R':
+			save_pinfo_admin = B_FALSE;
+			break;
 		case 'K':
 			if (strcmp(optarg, "default") == 0) {
 				admin_key = DEFAULT_ADMIN_KEY;
@@ -2186,6 +2340,9 @@ main(int argc, char *argv[])
 				    "24 bytes in length (%d given)", len);
 			}
 			break;
+		case 'u':
+			upn = optarg;
+			break;
 		case 'n':
 			cn = optarg;
 			break;