1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 #include "errno-util.h"
4 #include "format-table.h"
6 #include "homectl-pkcs11.h"
7 #include "libcrypt-util.h"
8 #include "memory-util.h"
9 #include "openssl-util.h"
10 #include "pkcs11-util.h"
11 #include "random-util.h"
14 struct pkcs11_callback_data
{
20 static void pkcs11_callback_data_release(struct pkcs11_callback_data
*data
) {
21 erase_and_free(data
->pin_used
);
22 X509_free(data
->cert
);
25 static int pkcs11_callback(
27 CK_SESSION_HANDLE session
,
29 const CK_SLOT_INFO
*slot_info
,
30 const CK_TOKEN_INFO
*token_info
,
34 _cleanup_(erase_and_freep
) char *pin_used
= NULL
;
35 struct pkcs11_callback_data
*data
= userdata
;
36 CK_OBJECT_HANDLE object
;
45 /* Called for every token matching our URI */
47 r
= pkcs11_token_login(m
, session
, slot_id
, token_info
, "home directory operation", "user-home", "pkcs11-pin", UINT64_MAX
, &pin_used
);
51 r
= pkcs11_token_find_x509_certificate(m
, session
, uri
, &object
);
55 r
= pkcs11_token_read_x509_certificate(m
, session
, object
, &data
->cert
);
59 /* Let's read some random data off the token and write it to the kernel pool before we generate our
60 * random key from it. This way we can claim the quality of the RNG is at least as good as the
61 * kernel's and the token's pool */
62 (void) pkcs11_token_acquire_rng(m
, session
);
64 data
->pin_used
= TAKE_PTR(pin_used
);
69 static int acquire_pkcs11_certificate(
72 char **ret_pin_used
) {
75 _cleanup_(pkcs11_callback_data_release
) struct pkcs11_callback_data data
= {};
78 r
= pkcs11_find_token(uri
, pkcs11_callback
, &data
);
79 if (r
== -EAGAIN
) /* pkcs11_find_token() doesn't log about this error, but all others */
80 return log_error_errno(ENXIO
, "Specified PKCS#11 token with URI '%s' not found.", uri
);
84 *ret_cert
= TAKE_PTR(data
.cert
);
85 *ret_pin_used
= TAKE_PTR(data
.pin_used
);
89 return log_error_errno(EOPNOTSUPP
, "PKCS#11 tokens not supported on this build.");
93 static int encrypt_bytes(
95 const void *decrypted_key
,
96 size_t decrypted_key_size
,
97 void **ret_encrypt_key
,
98 size_t *ret_encrypt_key_size
) {
100 _cleanup_(EVP_PKEY_CTX_freep
) EVP_PKEY_CTX
*ctx
= NULL
;
101 _cleanup_free_
void *b
= NULL
;
104 ctx
= EVP_PKEY_CTX_new(pkey
, NULL
);
106 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to allocate public key context");
108 if (EVP_PKEY_encrypt_init(ctx
) <= 0)
109 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to initialize public key context");
111 if (EVP_PKEY_CTX_set_rsa_padding(ctx
, RSA_PKCS1_PADDING
) <= 0)
112 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to configure PKCS#1 padding");
114 if (EVP_PKEY_encrypt(ctx
, NULL
, &l
, decrypted_key
, decrypted_key_size
) <= 0)
115 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to determine encrypted key size");
121 if (EVP_PKEY_encrypt(ctx
, b
, &l
, decrypted_key
, decrypted_key_size
) <= 0)
122 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to determine encrypted key size");
124 *ret_encrypt_key
= TAKE_PTR(b
);
125 *ret_encrypt_key_size
= l
;
130 static int add_pkcs11_encrypted_key(
133 const void *encrypted_key
, size_t encrypted_key_size
,
134 const void *decrypted_key
, size_t decrypted_key_size
) {
136 _cleanup_(json_variant_unrefp
) JsonVariant
*l
= NULL
, *w
= NULL
, *e
= NULL
;
137 _cleanup_(erase_and_freep
) char *base64_encoded
= NULL
, *hashed
= NULL
;
142 assert(encrypted_key
);
143 assert(encrypted_key_size
> 0);
144 assert(decrypted_key
);
145 assert(decrypted_key_size
> 0);
147 /* Before using UNIX hashing on the supplied key we base64 encode it, since crypt_r() and friends
148 * expect a NUL terminated string, and we use a binary key */
149 r
= base64mem(decrypted_key
, decrypted_key_size
, &base64_encoded
);
151 return log_error_errno(r
, "Failed to base64 encode secret key: %m");
153 r
= hash_password(base64_encoded
, &hashed
);
155 return log_error_errno(errno_or_else(EINVAL
), "Failed to UNIX hash secret key: %m");
157 r
= json_build(&e
, JSON_BUILD_OBJECT(
158 JSON_BUILD_PAIR("uri", JSON_BUILD_STRING(uri
)),
159 JSON_BUILD_PAIR("data", JSON_BUILD_BASE64(encrypted_key
, encrypted_key_size
)),
160 JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRING(hashed
))));
162 return log_error_errno(r
, "Failed to build encrypted JSON key object: %m");
164 w
= json_variant_ref(json_variant_by_key(*v
, "privileged"));
165 l
= json_variant_ref(json_variant_by_key(w
, "pkcs11EncryptedKey"));
167 r
= json_variant_append_array(&l
, e
);
169 return log_error_errno(r
, "Failed append PKCS#11 encrypted key: %m");
171 r
= json_variant_set_field(&w
, "pkcs11EncryptedKey", l
);
173 return log_error_errno(r
, "Failed to set PKCS#11 encrypted key: %m");
175 r
= json_variant_set_field(v
, "privileged", w
);
177 return log_error_errno(r
, "Failed to update privileged field: %m");
182 static int add_pkcs11_token_uri(JsonVariant
**v
, const char *uri
) {
183 _cleanup_(json_variant_unrefp
) JsonVariant
*w
= NULL
;
184 _cleanup_strv_free_
char **l
= NULL
;
190 w
= json_variant_ref(json_variant_by_key(*v
, "pkcs11TokenUri"));
192 r
= json_variant_strv(w
, &l
);
194 return log_error_errno(r
, "Failed to parse PKCS#11 token list: %m");
196 if (strv_contains(l
, uri
))
200 r
= strv_extend(&l
, uri
);
204 w
= json_variant_unref(w
);
205 r
= json_variant_new_array_strv(&w
, l
);
207 return log_error_errno(r
, "Failed to create PKCS#11 token URI JSON: %m");
209 r
= json_variant_set_field(v
, "pkcs11TokenUri", w
);
211 return log_error_errno(r
, "Failed to update PKCS#11 token URI list: %m");
216 int identity_add_token_pin(JsonVariant
**v
, const char *pin
) {
217 _cleanup_(json_variant_unrefp
) JsonVariant
*w
= NULL
, *l
= NULL
;
218 _cleanup_(strv_free_erasep
) char **pins
= NULL
;
226 w
= json_variant_ref(json_variant_by_key(*v
, "secret"));
227 l
= json_variant_ref(json_variant_by_key(w
, "tokenPin"));
229 r
= json_variant_strv(l
, &pins
);
231 return log_error_errno(r
, "Failed to convert PIN array: %m");
233 if (strv_find(pins
, pin
))
236 r
= strv_extend(&pins
, pin
);
242 l
= json_variant_unref(l
);
244 r
= json_variant_new_array_strv(&l
, pins
);
246 return log_error_errno(r
, "Failed to allocate new PIN array JSON: %m");
248 json_variant_sensitive(l
);
250 r
= json_variant_set_field(&w
, "tokenPin", l
);
252 return log_error_errno(r
, "Failed to update PIN field: %m");
254 r
= json_variant_set_field(v
, "secret", w
);
256 return log_error_errno(r
, "Failed to update secret object: %m");
261 int identity_add_pkcs11_key_data(JsonVariant
**v
, const char *uri
) {
262 _cleanup_(erase_and_freep
) void *decrypted_key
= NULL
, *encrypted_key
= NULL
;
263 _cleanup_(erase_and_freep
) char *pin
= NULL
;
264 size_t decrypted_key_size
, encrypted_key_size
;
265 _cleanup_(X509_freep
) X509
*cert
= NULL
;
273 r
= acquire_pkcs11_certificate(uri
, &cert
, &pin
);
277 pkey
= X509_get0_pubkey(cert
);
279 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to extract public key from X.509 certificate.");
281 if (EVP_PKEY_base_id(pkey
) != EVP_PKEY_RSA
)
282 return log_error_errno(SYNTHETIC_ERRNO(EBADMSG
), "X.509 certificate does not refer to RSA key.");
284 rsa
= EVP_PKEY_get0_RSA(pkey
);
286 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to acquire RSA public key from X.509 certificate.");
288 bits
= RSA_bits(rsa
);
289 log_debug("Bits in RSA key: %i", bits
);
291 /* We use PKCS#1 padding for the RSA cleartext, hence let's leave some extra space for it, hence only
292 * generate a random key half the size of the RSA length */
293 decrypted_key_size
= bits
/ 8 / 2;
295 if (decrypted_key_size
< 1)
296 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Uh, RSA key size too short?");
298 log_debug("Generating %zu bytes random key.", decrypted_key_size
);
300 decrypted_key
= malloc(decrypted_key_size
);
304 r
= genuine_random_bytes(decrypted_key
, decrypted_key_size
, RANDOM_BLOCK
);
306 return log_error_errno(r
, "Failed to generate random key: %m");
308 r
= encrypt_bytes(pkey
, decrypted_key
, decrypted_key_size
, &encrypted_key
, &encrypted_key_size
);
310 return log_error_errno(r
, "Failed to encrypt key: %m");
312 /* Add the token URI to the public part of the record. */
313 r
= add_pkcs11_token_uri(v
, uri
);
317 /* Include the encrypted version of the random key we just generated in the privileged part of the record */
318 r
= add_pkcs11_encrypted_key(
321 encrypted_key
, encrypted_key_size
,
322 decrypted_key
, decrypted_key_size
);
326 /* If we acquired the PIN also include it in the secret section of the record, so that systemd-homed
327 * can use it if it needs to, given that it likely needs to decrypt the key again to pass to LUKS or
329 r
= identity_add_token_pin(v
, pin
);
337 static int list_callback(
339 CK_SESSION_HANDLE session
,
341 const CK_SLOT_INFO
*slot_info
,
342 const CK_TOKEN_INFO
*token_info
,
346 _cleanup_free_
char *token_uri_string
= NULL
, *token_label
= NULL
, *token_manufacturer_id
= NULL
, *token_model
= NULL
;
347 _cleanup_(p11_kit_uri_freep
) P11KitUri
*token_uri
= NULL
;
354 /* We only care about hardware devices here with a token inserted. Let's filter everything else
355 * out. (Note that the user can explicitly specify non-hardware tokens if they like, but during
356 * enumeration we'll filter those, since software tokens are typically the system certificate store
357 * and such, and it's typically not what people want to bind their home directories to.) */
358 if (!FLAGS_SET(token_info
->flags
, CKF_HW_SLOT
|CKF_TOKEN_PRESENT
))
361 token_label
= pkcs11_token_label(token_info
);
365 token_manufacturer_id
= pkcs11_token_manufacturer_id(token_info
);
366 if (!token_manufacturer_id
)
369 token_model
= pkcs11_token_model(token_info
);
373 token_uri
= uri_from_token_info(token_info
);
377 uri_result
= p11_kit_uri_format(token_uri
, P11_KIT_URI_FOR_ANY
, &token_uri_string
);
378 if (uri_result
!= P11_KIT_URI_OK
)
379 return log_warning_errno(SYNTHETIC_ERRNO(EAGAIN
), "Failed to format slot URI: %s", p11_kit_uri_message(uri_result
));
383 TABLE_STRING
, token_uri_string
,
384 TABLE_STRING
, token_label
,
385 TABLE_STRING
, token_manufacturer_id
,
386 TABLE_STRING
, token_model
);
388 return table_log_add_error(r
);
390 return -EAGAIN
; /* keep scanning */
394 int list_pkcs11_tokens(void) {
396 _cleanup_(table_unrefp
) Table
*t
= NULL
;
399 t
= table_new("uri", "label", "manufacturer", "model");
403 r
= pkcs11_find_token(NULL
, list_callback
, t
);
404 if (r
< 0 && r
!= -EAGAIN
)
407 if (table_get_rows(t
) <= 1) {
408 log_info("No suitable PKCS#11 tokens found.");
412 r
= table_print(t
, stdout
);
414 return log_error_errno(r
, "Failed to show device table: %m");
418 return log_error_errno(EOPNOTSUPP
, "PKCS#11 tokens not supported on this build.");
423 static int auto_callback(
425 CK_SESSION_HANDLE session
,
427 const CK_SLOT_INFO
*slot_info
,
428 const CK_TOKEN_INFO
*token_info
,
432 _cleanup_(p11_kit_uri_freep
) P11KitUri
*token_uri
= NULL
;
439 if (!FLAGS_SET(token_info
->flags
, CKF_HW_SLOT
|CKF_TOKEN_PRESENT
))
443 return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ
),
444 "More than one suitable PKCS#11 token found.");
446 token_uri
= uri_from_token_info(token_info
);
450 uri_result
= p11_kit_uri_format(token_uri
, P11_KIT_URI_FOR_ANY
, t
);
451 if (uri_result
!= P11_KIT_URI_OK
)
452 return log_warning_errno(SYNTHETIC_ERRNO(EAGAIN
), "Failed to format slot URI: %s", p11_kit_uri_message(uri_result
));
458 int find_pkcs11_token_auto(char **ret
) {
462 r
= pkcs11_find_token(NULL
, auto_callback
, ret
);
464 return log_error_errno(SYNTHETIC_ERRNO(ENODEV
), "No suitable PKCS#11 tokens found.");
470 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP
),
471 "PKCS#11 tokens not supported on this build.");