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(SYNTHETIC_ERRNO(ENXIO
),
81 "Specified PKCS#11 token with URI '%s' not found.",
86 *ret_cert
= TAKE_PTR(data
.cert
);
87 *ret_pin_used
= TAKE_PTR(data
.pin_used
);
91 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP
),
92 "PKCS#11 tokens not supported on this build.");
96 static int encrypt_bytes(
98 const void *decrypted_key
,
99 size_t decrypted_key_size
,
100 void **ret_encrypt_key
,
101 size_t *ret_encrypt_key_size
) {
103 _cleanup_(EVP_PKEY_CTX_freep
) EVP_PKEY_CTX
*ctx
= NULL
;
104 _cleanup_free_
void *b
= NULL
;
107 ctx
= EVP_PKEY_CTX_new(pkey
, NULL
);
109 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to allocate public key context");
111 if (EVP_PKEY_encrypt_init(ctx
) <= 0)
112 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to initialize public key context");
114 if (EVP_PKEY_CTX_set_rsa_padding(ctx
, RSA_PKCS1_PADDING
) <= 0)
115 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to configure PKCS#1 padding");
117 if (EVP_PKEY_encrypt(ctx
, NULL
, &l
, decrypted_key
, decrypted_key_size
) <= 0)
118 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to determine encrypted key size");
124 if (EVP_PKEY_encrypt(ctx
, b
, &l
, decrypted_key
, decrypted_key_size
) <= 0)
125 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to determine encrypted key size");
127 *ret_encrypt_key
= TAKE_PTR(b
);
128 *ret_encrypt_key_size
= l
;
133 static int add_pkcs11_encrypted_key(
136 const void *encrypted_key
, size_t encrypted_key_size
,
137 const void *decrypted_key
, size_t decrypted_key_size
) {
139 _cleanup_(json_variant_unrefp
) JsonVariant
*l
= NULL
, *w
= NULL
, *e
= NULL
;
140 _cleanup_(erase_and_freep
) char *base64_encoded
= NULL
, *hashed
= NULL
;
145 assert(encrypted_key
);
146 assert(encrypted_key_size
> 0);
147 assert(decrypted_key
);
148 assert(decrypted_key_size
> 0);
150 /* Before using UNIX hashing on the supplied key we base64 encode it, since crypt_r() and friends
151 * expect a NUL terminated string, and we use a binary key */
152 r
= base64mem(decrypted_key
, decrypted_key_size
, &base64_encoded
);
154 return log_error_errno(r
, "Failed to base64 encode secret key: %m");
156 r
= hash_password(base64_encoded
, &hashed
);
158 return log_error_errno(errno_or_else(EINVAL
), "Failed to UNIX hash secret key: %m");
160 r
= json_build(&e
, JSON_BUILD_OBJECT(
161 JSON_BUILD_PAIR("uri", JSON_BUILD_STRING(uri
)),
162 JSON_BUILD_PAIR("data", JSON_BUILD_BASE64(encrypted_key
, encrypted_key_size
)),
163 JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRING(hashed
))));
165 return log_error_errno(r
, "Failed to build encrypted JSON key object: %m");
167 w
= json_variant_ref(json_variant_by_key(*v
, "privileged"));
168 l
= json_variant_ref(json_variant_by_key(w
, "pkcs11EncryptedKey"));
170 r
= json_variant_append_array(&l
, e
);
172 return log_error_errno(r
, "Failed append PKCS#11 encrypted key: %m");
174 r
= json_variant_set_field(&w
, "pkcs11EncryptedKey", l
);
176 return log_error_errno(r
, "Failed to set PKCS#11 encrypted key: %m");
178 r
= json_variant_set_field(v
, "privileged", w
);
180 return log_error_errno(r
, "Failed to update privileged field: %m");
185 static int add_pkcs11_token_uri(JsonVariant
**v
, const char *uri
) {
186 _cleanup_(json_variant_unrefp
) JsonVariant
*w
= NULL
;
187 _cleanup_strv_free_
char **l
= NULL
;
193 w
= json_variant_ref(json_variant_by_key(*v
, "pkcs11TokenUri"));
195 r
= json_variant_strv(w
, &l
);
197 return log_error_errno(r
, "Failed to parse PKCS#11 token list: %m");
199 if (strv_contains(l
, uri
))
203 r
= strv_extend(&l
, uri
);
207 w
= json_variant_unref(w
);
208 r
= json_variant_new_array_strv(&w
, l
);
210 return log_error_errno(r
, "Failed to create PKCS#11 token URI JSON: %m");
212 r
= json_variant_set_field(v
, "pkcs11TokenUri", w
);
214 return log_error_errno(r
, "Failed to update PKCS#11 token URI list: %m");
219 int identity_add_token_pin(JsonVariant
**v
, const char *pin
) {
220 _cleanup_(json_variant_unrefp
) JsonVariant
*w
= NULL
, *l
= NULL
;
221 _cleanup_(strv_free_erasep
) char **pins
= NULL
;
229 w
= json_variant_ref(json_variant_by_key(*v
, "secret"));
230 l
= json_variant_ref(json_variant_by_key(w
, "tokenPin"));
232 r
= json_variant_strv(l
, &pins
);
234 return log_error_errno(r
, "Failed to convert PIN array: %m");
236 if (strv_find(pins
, pin
))
239 r
= strv_extend(&pins
, pin
);
245 l
= json_variant_unref(l
);
247 r
= json_variant_new_array_strv(&l
, pins
);
249 return log_error_errno(r
, "Failed to allocate new PIN array JSON: %m");
251 json_variant_sensitive(l
);
253 r
= json_variant_set_field(&w
, "tokenPin", l
);
255 return log_error_errno(r
, "Failed to update PIN field: %m");
257 r
= json_variant_set_field(v
, "secret", w
);
259 return log_error_errno(r
, "Failed to update secret object: %m");
264 int identity_add_pkcs11_key_data(JsonVariant
**v
, const char *uri
) {
265 _cleanup_(erase_and_freep
) void *decrypted_key
= NULL
, *encrypted_key
= NULL
;
266 _cleanup_(erase_and_freep
) char *pin
= NULL
;
267 size_t decrypted_key_size
, encrypted_key_size
;
268 _cleanup_(X509_freep
) X509
*cert
= NULL
;
276 r
= acquire_pkcs11_certificate(uri
, &cert
, &pin
);
280 pkey
= X509_get0_pubkey(cert
);
282 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to extract public key from X.509 certificate.");
284 if (EVP_PKEY_base_id(pkey
) != EVP_PKEY_RSA
)
285 return log_error_errno(SYNTHETIC_ERRNO(EBADMSG
), "X.509 certificate does not refer to RSA key.");
287 rsa
= EVP_PKEY_get0_RSA(pkey
);
289 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Failed to acquire RSA public key from X.509 certificate.");
291 bits
= RSA_bits(rsa
);
292 log_debug("Bits in RSA key: %i", bits
);
294 /* We use PKCS#1 padding for the RSA cleartext, hence let's leave some extra space for it, hence only
295 * generate a random key half the size of the RSA length */
296 decrypted_key_size
= bits
/ 8 / 2;
298 if (decrypted_key_size
< 1)
299 return log_error_errno(SYNTHETIC_ERRNO(EIO
), "Uh, RSA key size too short?");
301 log_debug("Generating %zu bytes random key.", decrypted_key_size
);
303 decrypted_key
= malloc(decrypted_key_size
);
307 r
= genuine_random_bytes(decrypted_key
, decrypted_key_size
, RANDOM_BLOCK
);
309 return log_error_errno(r
, "Failed to generate random key: %m");
311 r
= encrypt_bytes(pkey
, decrypted_key
, decrypted_key_size
, &encrypted_key
, &encrypted_key_size
);
313 return log_error_errno(r
, "Failed to encrypt key: %m");
315 /* Add the token URI to the public part of the record. */
316 r
= add_pkcs11_token_uri(v
, uri
);
320 /* Include the encrypted version of the random key we just generated in the privileged part of the record */
321 r
= add_pkcs11_encrypted_key(
324 encrypted_key
, encrypted_key_size
,
325 decrypted_key
, decrypted_key_size
);
329 /* If we acquired the PIN also include it in the secret section of the record, so that systemd-homed
330 * can use it if it needs to, given that it likely needs to decrypt the key again to pass to LUKS or
332 r
= identity_add_token_pin(v
, pin
);
340 static int list_callback(
342 CK_SESSION_HANDLE session
,
344 const CK_SLOT_INFO
*slot_info
,
345 const CK_TOKEN_INFO
*token_info
,
349 _cleanup_free_
char *token_uri_string
= NULL
, *token_label
= NULL
, *token_manufacturer_id
= NULL
, *token_model
= NULL
;
350 _cleanup_(p11_kit_uri_freep
) P11KitUri
*token_uri
= NULL
;
357 /* We only care about hardware devices here with a token inserted. Let's filter everything else
358 * out. (Note that the user can explicitly specify non-hardware tokens if they like, but during
359 * enumeration we'll filter those, since software tokens are typically the system certificate store
360 * and such, and it's typically not what people want to bind their home directories to.) */
361 if (!FLAGS_SET(token_info
->flags
, CKF_HW_SLOT
|CKF_TOKEN_PRESENT
))
364 token_label
= pkcs11_token_label(token_info
);
368 token_manufacturer_id
= pkcs11_token_manufacturer_id(token_info
);
369 if (!token_manufacturer_id
)
372 token_model
= pkcs11_token_model(token_info
);
376 token_uri
= uri_from_token_info(token_info
);
380 uri_result
= p11_kit_uri_format(token_uri
, P11_KIT_URI_FOR_ANY
, &token_uri_string
);
381 if (uri_result
!= P11_KIT_URI_OK
)
382 return log_warning_errno(SYNTHETIC_ERRNO(EAGAIN
), "Failed to format slot URI: %s", p11_kit_uri_message(uri_result
));
386 TABLE_STRING
, token_uri_string
,
387 TABLE_STRING
, token_label
,
388 TABLE_STRING
, token_manufacturer_id
,
389 TABLE_STRING
, token_model
);
391 return table_log_add_error(r
);
393 return -EAGAIN
; /* keep scanning */
397 int list_pkcs11_tokens(void) {
399 _cleanup_(table_unrefp
) Table
*t
= NULL
;
402 t
= table_new("uri", "label", "manufacturer", "model");
406 r
= pkcs11_find_token(NULL
, list_callback
, t
);
407 if (r
< 0 && r
!= -EAGAIN
)
410 if (table_get_rows(t
) <= 1) {
411 log_info("No suitable PKCS#11 tokens found.");
415 r
= table_print(t
, stdout
);
417 return log_error_errno(r
, "Failed to show device table: %m");
421 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP
),
422 "PKCS#11 tokens not supported on this build.");
427 static int auto_callback(
429 CK_SESSION_HANDLE session
,
431 const CK_SLOT_INFO
*slot_info
,
432 const CK_TOKEN_INFO
*token_info
,
436 _cleanup_(p11_kit_uri_freep
) P11KitUri
*token_uri
= NULL
;
443 if (!FLAGS_SET(token_info
->flags
, CKF_HW_SLOT
|CKF_TOKEN_PRESENT
))
447 return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ
),
448 "More than one suitable PKCS#11 token found.");
450 token_uri
= uri_from_token_info(token_info
);
454 uri_result
= p11_kit_uri_format(token_uri
, P11_KIT_URI_FOR_ANY
, t
);
455 if (uri_result
!= P11_KIT_URI_OK
)
456 return log_warning_errno(SYNTHETIC_ERRNO(EAGAIN
), "Failed to format slot URI: %s", p11_kit_uri_message(uri_result
));
462 int find_pkcs11_token_auto(char **ret
) {
466 r
= pkcs11_find_token(NULL
, auto_callback
, ret
);
468 return log_error_errno(SYNTHETIC_ERRNO(ENODEV
), "No suitable PKCS#11 tokens found.");
474 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP
),
475 "PKCS#11 tokens not supported on this build.");