Merge pull request #28658 from H5117/enroll_with_ec

cryptsetup: Add support for EC keys in PKCS#11 tokens

src/shared/openssl-util.c

@@ -4,11 +4,12 @@
 #include "fd-util.h"
 #include "hexdecoct.h"
 #include "openssl-util.h"
+#include "random-util.h"
 #include "string-util.h"
 
 #if HAVE_OPENSSL
-/* For each error in the the OpenSSL thread error queue, log the provided message and the OpenSSL error
- * string. If there are no errors in the OpenSSL thread queue, this logs the message with "No openssl
+/* For each error in the OpenSSL thread error queue, log the provided message and the OpenSSL error
+ * string. If there are no errors in the OpenSSL thread queue, this logs the message with "No OpenSSL
  * errors." This logs at level debug. Returns -EIO (or -ENOMEM). */
 #define log_openssl_errors(fmt, ...) _log_openssl_errors(UNIQ, fmt, ##__VA_ARGS__)
 #define _log_openssl_errors(u, fmt, ...)                                \
@@ -523,7 +524,6 @@ int rsa_encrypt_bytes(
 
         *ret_encrypt_key = TAKE_PTR(b);
         *ret_encrypt_key_size = l;
-
         return 0;
 }
 
@@ -989,7 +989,7 @@ int ecc_ecdh(const EVP_PKEY *private_pkey,
         if (EVP_PKEY_derive(ctx, NULL, &shared_secret_size) <= 0)
                 return log_openssl_errors("Failed to get ECC shared secret size");
 
-        _cleanup_free_ void *shared_secret = malloc(shared_secret_size);
+        _cleanup_(erase_and_freep) void *shared_secret = malloc(shared_secret_size);
         if (!shared_secret)
                 return log_oom_debug();
 
@@ -1128,6 +1128,170 @@ int string_hashsum(
         return 0;
 }
 #  endif
+
+static int ecc_pkey_generate_volume_keys(
+                EVP_PKEY *pkey,
+                void **ret_decrypted_key,
+                size_t *ret_decrypted_key_size,
+                void **ret_saved_key,
+                size_t *ret_saved_key_size) {
+
+        _cleanup_(EVP_PKEY_freep) EVP_PKEY *pkey_new = NULL;
+        _cleanup_(erase_and_freep) void *decrypted_key = NULL;
+        _cleanup_free_ unsigned char *saved_key = NULL;
+        size_t decrypted_key_size, saved_key_size;
+        int nid = NID_undef;
+        int r;
+
+#if OPENSSL_VERSION_MAJOR >= 3
+        _cleanup_free_ char *curve_name = NULL;
+        size_t len = 0;
+
+        if (EVP_PKEY_get_group_name(pkey, NULL, 0, &len) != 1 || len == 0)
+                return log_openssl_errors("Failed to determine PKEY group name length");
+
+        len++;
+        curve_name = new(char, len);
+        if (!curve_name)
+                return log_oom_debug();
+
+        if (EVP_PKEY_get_group_name(pkey, curve_name, len, &len) != 1)
+                return log_openssl_errors("Failed to get PKEY group name");
+
+        nid = OBJ_sn2nid(curve_name);
+#else
+        EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(pkey);
+        if (!ec_key)
+                return log_openssl_errors("PKEY doesn't have EC_KEY associated");
+
+        if (EC_KEY_check_key(ec_key) != 1)
+                return log_openssl_errors("EC_KEY associated with PKEY is not valid");
+
+        nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec_key));
+#endif
+
+        r = ecc_pkey_new(nid, &pkey_new);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to generate a new EC keypair: %m");
+
+        r = ecc_ecdh(pkey_new, pkey, &decrypted_key, &decrypted_key_size);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to derive shared secret: %m");
+
+#if OPENSSL_VERSION_MAJOR >= 3
+        /* EVP_PKEY_get1_encoded_public_key() always returns uncompressed format of EC points.
+           See https://github.com/openssl/openssl/discussions/22835 */
+        saved_key_size = EVP_PKEY_get1_encoded_public_key(pkey_new, &saved_key);
+        if (saved_key_size == 0)
+                return log_openssl_errors("Failed to convert the generated public key to SEC1 format");
+#else
+        EC_KEY *ec_key_new = EVP_PKEY_get0_EC_KEY(pkey_new);
+        if (!ec_key_new)
+                return log_openssl_errors("The generated key doesn't have associated EC_KEY");
+
+        if (EC_KEY_check_key(ec_key_new) != 1)
+                return log_openssl_errors("EC_KEY associated with the generated key is not valid");
+
+        saved_key_size = EC_POINT_point2oct(EC_KEY_get0_group(ec_key_new),
+                                            EC_KEY_get0_public_key(ec_key_new),
+                                            POINT_CONVERSION_UNCOMPRESSED,
+                                            NULL, 0, NULL);
+        if (saved_key_size == 0)
+                return log_openssl_errors("Failed to determine size of the generated public key");
+
+        saved_key = malloc(saved_key_size);
+        if (!saved_key)
+                return log_oom_debug();
+
+        saved_key_size = EC_POINT_point2oct(EC_KEY_get0_group(ec_key_new),
+                                            EC_KEY_get0_public_key(ec_key_new),
+                                            POINT_CONVERSION_UNCOMPRESSED,
+                                            saved_key, saved_key_size, NULL);
+        if (saved_key_size == 0)
+                return log_openssl_errors("Failed to convert the generated public key to SEC1 format");
+#endif
+
+        *ret_decrypted_key = TAKE_PTR(decrypted_key);
+        *ret_decrypted_key_size = decrypted_key_size;
+        *ret_saved_key = TAKE_PTR(saved_key);
+        *ret_saved_key_size = saved_key_size;
+        return 0;
+}
+
+static int rsa_pkey_generate_volume_keys(
+                EVP_PKEY *pkey,
+                void **ret_decrypted_key,
+                size_t *ret_decrypted_key_size,
+                void **ret_saved_key,
+                size_t *ret_saved_key_size) {
+
+        _cleanup_(erase_and_freep) void *decrypted_key = NULL;
+        _cleanup_free_ void *saved_key = NULL;
+        size_t decrypted_key_size, saved_key_size;
+        int r;
+
+        r = rsa_pkey_to_suitable_key_size(pkey, &decrypted_key_size);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to determine RSA public key size.");
+
+        log_debug("Generating %zu bytes random key.", decrypted_key_size);
+
+        decrypted_key = malloc(decrypted_key_size);
+        if (!decrypted_key)
+                return log_oom_debug();
+
+        r = crypto_random_bytes(decrypted_key, decrypted_key_size);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to generate random key: %m");
+
+        r = rsa_encrypt_bytes(pkey, decrypted_key, decrypted_key_size, &saved_key, &saved_key_size);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to encrypt random key: %m");
+
+        *ret_decrypted_key = TAKE_PTR(decrypted_key);
+        *ret_decrypted_key_size = decrypted_key_size;
+        *ret_saved_key = TAKE_PTR(saved_key);
+        *ret_saved_key_size = saved_key_size;
+        return 0;
+}
+
+int x509_generate_volume_keys(
+                X509 *cert,
+                void **ret_decrypted_key,
+                size_t *ret_decrypted_key_size,
+                void **ret_saved_key,
+                size_t *ret_saved_key_size) {
+
+        assert(cert);
+        assert(ret_decrypted_key);
+        assert(ret_decrypted_key_size);
+        assert(ret_saved_key);
+        assert(ret_saved_key_size);
+
+        EVP_PKEY *pkey = X509_get0_pubkey(cert);
+        if (!pkey)
+                return log_openssl_errors("Failed to extract public key from X.509 certificate.");
+
+#if OPENSSL_VERSION_MAJOR >= 3
+        int type = EVP_PKEY_get_base_id(pkey);
+#else
+        int type = EVP_PKEY_base_id(pkey);
+#endif
+        switch (type) {
+
+        case EVP_PKEY_RSA:
+                return rsa_pkey_generate_volume_keys(pkey, ret_decrypted_key, ret_decrypted_key_size, ret_saved_key, ret_saved_key_size);
+
+        case EVP_PKEY_EC:
+                return ecc_pkey_generate_volume_keys(pkey, ret_decrypted_key, ret_decrypted_key_size, ret_saved_key, ret_saved_key_size);
+
+        case NID_undef:
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine a type of public key");
+
+        default:
+                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Unsupported public key type: %s", OBJ_nid2sn(type));
+        }
+}
 #endif
 
 int x509_fingerprint(X509 *cert, uint8_t buffer[static SHA256_DIGEST_SIZE]) {

src/shared/openssl-util.h

@@ -108,6 +108,8 @@ int ecc_pkey_new(int curve_id, EVP_PKEY **ret);
 
 int ecc_ecdh(const EVP_PKEY *private_pkey, const EVP_PKEY *peer_pkey, void **ret_shared_secret, size_t *ret_shared_secret_size);
 
+int x509_generate_volume_keys(X509 *cert, void **ret_decrypted_key, size_t *ret_decrypted_key_size, void **ret_saved_key, size_t *ret_saved_key_size);
+
 int pubkey_fingerprint(EVP_PKEY *pk, const EVP_MD *md, void **ret, size_t *ret_size);
 
 int digest_and_sign(const EVP_MD *md, EVP_PKEY *privkey, const void *data, size_t size, void **ret, size_t *ret_size);

src/shared/pkcs11-util.c

@@ -586,114 +586,61 @@ int pkcs11_token_find_private_key(
                 P11KitUri *search_uri,
                 CK_OBJECT_HANDLE *ret_object) {
 
-        bool found_decrypt = false, found_class = false, found_key_type = false;
+        uint_fast8_t n_objects = 0;
+        bool found_class = false;
         _cleanup_free_ CK_ATTRIBUTE *attributes_buffer = NULL;
-        CK_ULONG n_attributes, a, n_objects;
-        CK_ATTRIBUTE *attributes = NULL;
-        CK_OBJECT_HANDLE objects[2];
-        CK_RV rv, rv2;
-        int r;
+        CK_OBJECT_HANDLE object, candidate;
+        static const CK_OBJECT_CLASS class = CKO_PRIVATE_KEY;
+        CK_BBOOL decrypt_value, derive_value;
+        CK_ATTRIBUTE optional_attributes[] = {
+                { CKA_DECRYPT, &decrypt_value, sizeof(decrypt_value) },
+                { CKA_DERIVE,  &derive_value,  sizeof(derive_value)  }
+        };
+        CK_RV rv;
 
         assert(m);
         assert(search_uri);
         assert(ret_object);
 
-        r = dlopen_p11kit();
-        if (r < 0)
-                return r;
-
-        attributes = sym_p11_kit_uri_get_attributes(search_uri, &n_attributes);
-        for (a = 0; a < n_attributes; a++) {
+        CK_ULONG n_attributes;
+        CK_ATTRIBUTE *attributes = sym_p11_kit_uri_get_attributes(search_uri, &n_attributes);
+        for (CK_ULONG i = 0; i < n_attributes; i++) {
 
                 /* We use the URI's included match attributes, but make them more strict. This allows users
                  * to specify a token URL instead of an object URL and the right thing should happen if
                  * there's only one suitable key on the token. */
 
-                switch (attributes[a].type) {
-
+                switch (attributes[i].type) {
                 case CKA_CLASS: {
                         CK_OBJECT_CLASS c;
 
-                        if (attributes[a].ulValueLen != sizeof(c))
+                        if (attributes[i].ulValueLen != sizeof(c))
                                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid PKCS#11 CKA_CLASS attribute size.");
 
-                        memcpy(&c, attributes[a].pValue, sizeof(c));
+                        memcpy(&c, attributes[i].pValue, sizeof(c));
                         if (c != CKO_PRIVATE_KEY)
                                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                                        "Selected PKCS#11 object is not a private key, refusing.");
 
                         found_class = true;
                         break;
-                }
-
-                case CKA_DECRYPT: {
-                        CK_BBOOL b;
-
-                        if (attributes[a].ulValueLen != sizeof(b))
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid PKCS#11 CKA_DECRYPT attribute size.");
-
-                        memcpy(&b, attributes[a].pValue, sizeof(b));
-                        if (!b)
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                                       "Selected PKCS#11 object is not suitable for decryption, refusing.");
-
-                        found_decrypt = true;
-                        break;
-                }
-
-                case CKA_KEY_TYPE: {
-                        CK_KEY_TYPE t;
-
-                        if (attributes[a].ulValueLen != sizeof(t))
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid PKCS#11 CKA_KEY_TYPE attribute size.");
-
-                        memcpy(&t, attributes[a].pValue, sizeof(t));
-                        if (t != CKK_RSA)
-                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Selected PKCS#11 object is not an RSA key, refusing.");
-
-                        found_key_type = true;
-                        break;
                 }}
         }
 
-        if (!found_decrypt || !found_class || !found_key_type) {
+        if (!found_class) {
                 /* Hmm, let's slightly extend the attribute list we search for */
 
-                attributes_buffer = new(CK_ATTRIBUTE, n_attributes + !found_decrypt + !found_class + !found_key_type);
+                attributes_buffer = new(CK_ATTRIBUTE, n_attributes + 1);
                 if (!attributes_buffer)
                         return log_oom();
 
                 memcpy(attributes_buffer, attributes, sizeof(CK_ATTRIBUTE) * n_attributes);
 
-                if (!found_decrypt) {
-                        static const CK_BBOOL yes = true;
-
-                        attributes_buffer[n_attributes++] = (CK_ATTRIBUTE) {
-                                .type = CKA_DECRYPT,
-                                .pValue = (CK_BBOOL*) &yes,
-                                .ulValueLen = sizeof(yes),
-                        };
-                }
-
-                if (!found_class) {
-                        static const CK_OBJECT_CLASS class = CKO_PRIVATE_KEY;
-
-                        attributes_buffer[n_attributes++] = (CK_ATTRIBUTE) {
-                                .type = CKA_CLASS,
-                                .pValue = (CK_OBJECT_CLASS*) &class,
-                                .ulValueLen = sizeof(class),
-                        };
-                }
-
-                if (!found_key_type) {
-                        static const CK_KEY_TYPE type = CKK_RSA;
-
-                        attributes_buffer[n_attributes++] = (CK_ATTRIBUTE) {
-                                .type = CKA_KEY_TYPE,
-                                .pValue = (CK_KEY_TYPE*) &type,
-                                .ulValueLen = sizeof(type),
-                        };
-                }
+                attributes_buffer[n_attributes++] = (CK_ATTRIBUTE) {
+                        .type = CKA_CLASS,
+                        .pValue = (CK_OBJECT_CLASS*) &class,
+                        .ulValueLen = sizeof(class),
+                };
 
                 attributes = attributes_buffer;
         }
@@ -703,26 +650,355 @@ int pkcs11_token_find_private_key(
                 return log_error_errno(SYNTHETIC_ERRNO(EIO),
                                        "Failed to initialize object find call: %s", sym_p11_kit_strerror(rv));
 
-        rv = m->C_FindObjects(session, objects, ELEMENTSOF(objects), &n_objects);
-        rv2 = m->C_FindObjectsFinal(session);
+        for (;;) {
+                CK_ULONG b;
+                rv = m->C_FindObjects(session, &candidate, 1, &b);
+                if (rv != CKR_OK)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to find objects: %s", sym_p11_kit_strerror(rv));
+
+                if (b == 0)
+                        break;
+
+                bool can_decrypt = false, can_derive = false;
+                optional_attributes[0].ulValueLen = sizeof(decrypt_value);
+                optional_attributes[1].ulValueLen = sizeof(derive_value);
+
+                rv = m->C_GetAttributeValue(session, candidate, optional_attributes, ELEMENTSOF(optional_attributes));
+                if (rv != CKR_OK && rv != CKR_ATTRIBUTE_TYPE_INVALID)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to get attributes of a selected private key: %s", sym_p11_kit_strerror(rv));
+
+                if (optional_attributes[0].ulValueLen != CK_UNAVAILABLE_INFORMATION && decrypt_value == CK_TRUE)
+                        can_decrypt = true;
+
+                if (optional_attributes[1].ulValueLen != CK_UNAVAILABLE_INFORMATION && derive_value == CK_TRUE)
+                        can_derive = true;
+
+                if (can_decrypt || can_derive) {
+                        n_objects++;
+                        if (n_objects > 1)
+                                break;
+                        object = candidate;
+                }
+        }
+
+        rv = m->C_FindObjectsFinal(session);
         if (rv != CKR_OK)
                 return log_error_errno(SYNTHETIC_ERRNO(EIO),
-                                       "Failed to find objects: %s", sym_p11_kit_strerror(rv));
-        if (rv2 != CKR_OK)
-                return log_error_errno(SYNTHETIC_ERRNO(EIO),
-                                       "Failed to finalize object find call: %s", sym_p11_kit_strerror(rv));
+                        "Failed to finalize object find call: %s", sym_p11_kit_strerror(rv));
+
         if (n_objects == 0)
                 return log_error_errno(SYNTHETIC_ERRNO(ENOENT),
-                                       "Failed to find selected private key suitable for decryption on token.");
+                        "Failed to find selected private key suitable for decryption or derivation on token.");
+
         if (n_objects > 1)
                 return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ),
-                                       "Configured private key URI matches multiple keys, refusing.");
+                        "Configured private key URI matches multiple keys, refusing.");
+
+        *ret_object = object;
+        return 0;
+}
+
+static const char* object_class_to_string(CK_OBJECT_CLASS class) {
+        switch (class) {
+        case CKO_CERTIFICATE:
+                return "CKO_CERTIFICATE";
+        case CKO_PUBLIC_KEY:
+                return "CKO_PUBLIC_KEY";
+        case CKO_PRIVATE_KEY:
+                return "CKO_PRIVATE_KEY";
+        case CKO_SECRET_KEY:
+                return "CKO_SECRET_KEY";
+        default:
+                return NULL;
+        }
+}
+
+/* Returns an object with the given class and the same CKA_ID or CKA_LABEL as prototype */
+int pkcs11_token_find_related_object(
+                CK_FUNCTION_LIST *m,
+                CK_SESSION_HANDLE session,
+                CK_OBJECT_HANDLE prototype,
+                CK_OBJECT_CLASS class,
+                CK_OBJECT_HANDLE *ret_object ) {
+
+        _cleanup_free_ void *buffer = NULL;
+        CK_ATTRIBUTE attributes[] = {
+                { CKA_ID,    NULL_PTR, 0 },
+                { CKA_LABEL, NULL_PTR, 0 }
+        };
+        CK_OBJECT_CLASS search_class = class;
+        CK_ATTRIBUTE search_attributes[2] = {
+                { CKA_CLASS, &search_class, sizeof(search_class) }
+        };
+        CK_ULONG n_objects;
+        CK_OBJECT_HANDLE objects[2];
+        CK_RV rv;
+
+        rv = m->C_GetAttributeValue(session, prototype, attributes, ELEMENTSOF(attributes));
+        if (rv != CKR_OK && rv != CKR_ATTRIBUTE_TYPE_INVALID)
+                return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve length of attributes: %s", sym_p11_kit_strerror(rv));
+
+        if (attributes[0].ulValueLen != CK_UNAVAILABLE_INFORMATION) {
+                buffer = malloc(attributes[0].ulValueLen);
+                if (!buffer)
+                        return log_oom();
+
+                attributes[0].pValue = buffer;
+                rv = m->C_GetAttributeValue(session, prototype, &attributes[0], 1);
+                if (rv != CKR_OK)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to retrieve CKA_ID: %s", sym_p11_kit_strerror(rv));
+
+                search_attributes[1] = attributes[0];
+
+        } else if (attributes[1].ulValueLen != CK_UNAVAILABLE_INFORMATION) {
+                buffer = malloc(attributes[1].ulValueLen);
+                if (!buffer)
+                        return log_oom();
+
+                attributes[1].pValue = buffer;
+                rv = m->C_GetAttributeValue(session, prototype, &attributes[1], 1);
+                if (rv != CKR_OK)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to retrieve CKA_LABEL: %s", sym_p11_kit_strerror(rv));
+
+                search_attributes[1] = attributes[1];
+
+        } else
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "The prototype does not have CKA_ID or CKA_LABEL");
+
+        rv = m->C_FindObjectsInit(session, search_attributes, 2);
+        if (rv != CKR_OK)
+                return log_debug_errno(SYNTHETIC_ERRNO(EIO),
+                        "Failed to initialize object find call: %s", sym_p11_kit_strerror(rv));
+
+        rv = m->C_FindObjects(session, objects, 2, &n_objects);
+        if (rv != CKR_OK)
+                return log_debug_errno(SYNTHETIC_ERRNO(EIO),
+                        "Failed to find objects: %s", sym_p11_kit_strerror(rv));
+
+        rv = m->C_FindObjectsFinal(session);
+        if (rv != CKR_OK)
+                return log_debug_errno(SYNTHETIC_ERRNO(EIO),
+                        "Failed to finalize object find call: %s", sym_p11_kit_strerror(rv));
+
+         if (n_objects == 0)
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOENT),
+                        "Failed to find a related object with class %s", object_class_to_string(class));
+
+         if (n_objects > 1)
+                log_warning("Found multiple related objects with class %s, using the first object.",
+                        object_class_to_string(class));
 
         *ret_object = objects[0];
         return 0;
 }
 
-int pkcs11_token_decrypt_data(
+#if HAVE_OPENSSL
+static int ecc_convert_to_compressed(
+                CK_FUNCTION_LIST *m,
+                CK_SESSION_HANDLE session,
+                CK_OBJECT_HANDLE object,
+                const void *uncompressed_point,
+                size_t uncompressed_point_size,
+                void **ret_compressed_point,
+                size_t *ret_compressed_point_size) {
+
+        _cleanup_free_ void *ec_params_buffer = NULL;
+        CK_ATTRIBUTE ec_params_attr = { CKA_EC_PARAMS, NULL_PTR, 0 };
+        CK_RV rv;
+        int r;
+
+        rv = m->C_GetAttributeValue(session, object, &ec_params_attr, 1);
+        if (rv != CKR_OK && rv != CKR_ATTRIBUTE_TYPE_INVALID)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                        "Failed to retrieve length of CKA_EC_PARAMS: %s", sym_p11_kit_strerror(rv));
+
+        if (ec_params_attr.ulValueLen != CK_UNAVAILABLE_INFORMATION) {
+                ec_params_buffer = malloc(ec_params_attr.ulValueLen);
+                if (!ec_params_buffer)
+                        return log_oom();
+
+                ec_params_attr.pValue = ec_params_buffer;
+                rv = m->C_GetAttributeValue(session, object, &ec_params_attr, 1);
+                if (rv != CKR_OK)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to retrieve CKA_EC_PARAMS from a private key: %s", sym_p11_kit_strerror(rv));
+        } else {
+                CK_OBJECT_HANDLE public_key;
+                r = pkcs11_token_find_related_object(m, session, object, CKO_PUBLIC_KEY, &public_key);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to find a public key for compressing a EC point");
+
+                ec_params_attr.ulValueLen = 0;
+                rv = m->C_GetAttributeValue(session, public_key, &ec_params_attr, 1);
+                if (rv != CKR_OK && rv != CKR_ATTRIBUTE_TYPE_INVALID)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to retrieve length of CKA_EC_PARAMS: %s", sym_p11_kit_strerror(rv));
+
+                if (ec_params_attr.ulValueLen == CK_UNAVAILABLE_INFORMATION)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                "The public key does not have CKA_EC_PARAMS");
+
+                ec_params_buffer = malloc(ec_params_attr.ulValueLen);
+                if (!ec_params_buffer)
+                        return log_oom();
+
+                ec_params_attr.pValue = ec_params_buffer;
+                rv = m->C_GetAttributeValue(session, public_key, &ec_params_attr, 1);
+                if (rv != CKR_OK)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                "Failed to retrieve CKA_EC_PARAMS from a public key: %s", sym_p11_kit_strerror(rv));
+        }
+
+        _cleanup_(EC_GROUP_freep) EC_GROUP *group = NULL;
+        _cleanup_(EC_POINT_freep) EC_POINT *point = NULL;
+        _cleanup_(BN_CTX_freep) BN_CTX *bnctx = NULL;
+        _cleanup_free_ void *compressed_point = NULL;
+        size_t compressed_point_size;
+
+        const unsigned char *ec_params_value = ec_params_attr.pValue;
+        group = d2i_ECPKParameters(NULL, &ec_params_value, ec_params_attr.ulValueLen);
+        if (!group)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unable to decode CKA_EC_PARAMS");
+
+        point = EC_POINT_new(group);
+        if (!point)
+                return log_oom();
+
+        bnctx = BN_CTX_new();
+        if (!bnctx)
+                return log_oom();
+
+        if (EC_POINT_oct2point(group, point, uncompressed_point, uncompressed_point_size, bnctx) != 1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unable to decode an uncompressed EC point");
+
+        compressed_point_size = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED, NULL, 0, bnctx);
+        if (compressed_point_size == 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to determine size of a compressed EC point");
+
+        compressed_point = malloc(compressed_point_size);
+        if (!compressed_point)
+                return log_oom();
+
+        compressed_point_size = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED, compressed_point, compressed_point_size, bnctx);
+        if (compressed_point_size == 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to convert a EC point to compressed format");
+
+        *ret_compressed_point = TAKE_PTR(compressed_point);
+        *ret_compressed_point_size = compressed_point_size;
+        return 0;
+}
+#endif
+
+/* Since EC keys doesn't support encryption directly, we use ECDH protocol to derive shared secret here.
+ * We use PKCS#11 C_DeriveKey function to derive a shared secret with a private key stored in the token and
+ * a public key saved on enrollment. */
+static int pkcs11_token_decrypt_data_ecc(
+                CK_FUNCTION_LIST *m,
+                CK_SESSION_HANDLE session,
+                CK_OBJECT_HANDLE object,
+                const void *encrypted_data,
+                size_t encrypted_data_size,
+                void **ret_decrypted_data,
+                size_t *ret_decrypted_data_size) {
+
+        static const CK_BBOOL yes = CK_TRUE, no = CK_FALSE;
+        static const CK_OBJECT_CLASS shared_secret_class = CKO_SECRET_KEY;
+        static const CK_KEY_TYPE shared_secret_type = CKK_GENERIC_SECRET;
+        static const CK_ATTRIBUTE shared_secret_template[] = {
+                { CKA_TOKEN,       (void*) &no,                  sizeof(no)                  },
+                { CKA_CLASS,       (void*) &shared_secret_class, sizeof(shared_secret_class) },
+                { CKA_KEY_TYPE,    (void*) &shared_secret_type,  sizeof(shared_secret_type)  },
+                { CKA_SENSITIVE,   (void*) &no,                  sizeof(no)                  },
+                { CKA_EXTRACTABLE, (void*) &yes,                 sizeof(yes)                 }
+        };
+        CK_ECDH1_DERIVE_PARAMS params = {
+                .kdf = CKD_NULL,
+                .pPublicData = (void*) encrypted_data,
+                .ulPublicDataLen = encrypted_data_size
+        };
+        CK_MECHANISM mechanism = {
+                .mechanism = CKM_ECDH1_DERIVE,
+                .pParameter = &params,
+                .ulParameterLen = sizeof(params)
+        };
+        CK_OBJECT_HANDLE shared_secret_handle;
+        CK_SESSION_INFO session_info;
+        CK_MECHANISM_INFO mechanism_info;
+        CK_RV rv, rv2;
+#if HAVE_OPENSSL
+        _cleanup_free_ void *compressed_point = NULL;
+        int r;
+#endif
+
+        rv = m->C_GetSessionInfo(session, &session_info);
+        if (rv != CKR_OK)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                        "Failed to get information about the PKCS#11 session: %s", sym_p11_kit_strerror(rv));
+
+        rv = m->C_GetMechanismInfo(session_info.slotID, CKM_ECDH1_DERIVE, &mechanism_info);
+        if (rv != CKR_OK)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                        "Failed to get information about CKM_ECDH1_DERIVE: %s", sym_p11_kit_strerror(rv));
+
+        if (!(mechanism_info.flags & CKF_EC_UNCOMPRESS)) {
+                if (mechanism_info.flags & CKF_EC_COMPRESS) {
+#if HAVE_OPENSSL
+                        log_debug("CKM_ECDH1_DERIVE accepts compressed EC points only, trying to convert.");
+                        size_t compressed_point_size;
+                        r = ecc_convert_to_compressed(m, session, object, encrypted_data, encrypted_data_size, &compressed_point, &compressed_point_size);
+                        if (r < 0)
+                                return r;
+
+                        params.pPublicData = compressed_point;
+                        params.ulPublicDataLen = compressed_point_size;
+#else
+                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                "CKM_ECDH1_DERIVE does not support uncompressed format of EC points");
+#endif
+                } else
+                        log_debug("Both CKF_EC_UNCOMPRESS and CKF_EC_COMPRESS are false for CKM_ECDH1_DERIVE, ignoring.");
+        }
+
+        rv = m->C_DeriveKey(session, &mechanism, object, (CK_ATTRIBUTE*) shared_secret_template, ELEMENTSOF(shared_secret_template), &shared_secret_handle);
+        if (rv != CKR_OK)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to derive a shared secret: %s", sym_p11_kit_strerror(rv));
+
+        CK_ATTRIBUTE shared_secret_attr = { CKA_VALUE, NULL_PTR, 0};
+
+        rv = m->C_GetAttributeValue(session, shared_secret_handle, &shared_secret_attr, 1);
+        if (rv != CKR_OK) {
+                rv2 = m->C_DestroyObject(session, shared_secret_handle);
+                if (rv2 != CKR_OK)
+                        log_warning("Failed to destroy a shared secret, ignoring: %s", sym_p11_kit_strerror(rv2));
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve shared secret length: %s", sym_p11_kit_strerror(rv));
+        }
+
+        shared_secret_attr.pValue = malloc(shared_secret_attr.ulValueLen);
+        if (!shared_secret_attr.pValue)
+                return log_oom();
+
+        rv = m->C_GetAttributeValue(session, shared_secret_handle, &shared_secret_attr, 1);
+        rv2 = m->C_DestroyObject(session, shared_secret_handle);
+        if (rv2 != CKR_OK)
+                log_warning("Failed to destroy a shared secret, ignoring: %s", sym_p11_kit_strerror(rv2));
+
+        if (rv != CKR_OK) {
+                erase_and_free(shared_secret_attr.pValue);
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve a shared secret: %s", sym_p11_kit_strerror(rv));
+        }
+
+        log_info("Successfully derived key with security token.");
+
+        *ret_decrypted_data = shared_secret_attr.pValue;
+        *ret_decrypted_data_size = shared_secret_attr.ulValueLen;
+        return 0;
+}
+
+static int pkcs11_token_decrypt_data_rsa(
                 CK_FUNCTION_LIST *m,
                 CK_SESSION_HANDLE session,
                 CK_OBJECT_HANDLE object,
@@ -737,17 +1013,6 @@ int pkcs11_token_decrypt_data(
         _cleanup_(erase_and_freep) CK_BYTE *dbuffer = NULL;
         CK_ULONG dbuffer_size = 0;
         CK_RV rv;
-        int r;
-
-        assert(m);
-        assert(encrypted_data);
-        assert(encrypted_data_size > 0);
-        assert(ret_decrypted_data);
-        assert(ret_decrypted_data_size);
-
-        r = dlopen_p11kit();
-        if (r < 0)
-                return r;
 
         rv = m->C_DecryptInit(session, (CK_MECHANISM*) &mechanism, object);
         if (rv != CKR_OK)
@@ -780,6 +1045,42 @@ int pkcs11_token_decrypt_data(
         return 0;
 }
 
+int pkcs11_token_decrypt_data(
+                CK_FUNCTION_LIST *m,
+                CK_SESSION_HANDLE session,
+                CK_OBJECT_HANDLE object,
+                const void *encrypted_data,
+                size_t encrypted_data_size,
+                void **ret_decrypted_data,
+                size_t *ret_decrypted_data_size) {
+
+        CK_KEY_TYPE key_type;
+        CK_ATTRIBUTE key_type_template = { CKA_KEY_TYPE, &key_type, sizeof(key_type) };
+        CK_RV rv;
+
+        assert(m);
+        assert(encrypted_data);
+        assert(encrypted_data_size > 0);
+        assert(ret_decrypted_data);
+        assert(ret_decrypted_data_size);
+
+        rv = m->C_GetAttributeValue(session, object, &key_type_template, 1);
+        if (rv != CKR_OK)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve private key type");
+
+        switch (key_type) {
+
+        case CKK_RSA:
+                return pkcs11_token_decrypt_data_rsa(m, session, object, encrypted_data, encrypted_data_size, ret_decrypted_data, ret_decrypted_data_size);
+
+        case CKK_EC:
+                return pkcs11_token_decrypt_data_ecc(m, session, object, encrypted_data, encrypted_data_size, ret_decrypted_data, ret_decrypted_data_size);
+
+        default:
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Unsupported private key type: %lu", key_type);
+        }
+}
+
 int pkcs11_token_acquire_rng(
                 CK_FUNCTION_LIST *m,
                 CK_SESSION_HANDLE session) {

src/shared/pkcs11-util.h

@@ -1,6 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#if HAVE_OPENSSL
+#  include <openssl/x509.h>
+#endif
 #include <stdbool.h>
 
 #if HAVE_P11KIT
@@ -10,7 +13,6 @@
 
 #include "ask-password-api.h"
 #include "macro.h"
-#include "openssl-util.h"
 #include "time-util.h"
 
 bool pkcs11_uri_valid(const char *uri);
@@ -50,6 +52,7 @@ char *pkcs11_token_model(const CK_TOKEN_INFO *token_info);
 int pkcs11_token_login_by_pin(CK_FUNCTION_LIST *m, CK_SESSION_HANDLE session, const CK_TOKEN_INFO *token_info, const char *token_label, const void *pin, size_t pin_size);
 int pkcs11_token_login(CK_FUNCTION_LIST *m, CK_SESSION_HANDLE session, CK_SLOT_ID slotid, const CK_TOKEN_INFO *token_info, const char *friendly_name, const char *icon_name, const char *key_name, const char *credential_name, usec_t until, AskPasswordFlags ask_password_flags, bool headless, char **ret_used_pin);
 
+int pkcs11_token_find_related_object(CK_FUNCTION_LIST *m, CK_SESSION_HANDLE session, CK_OBJECT_HANDLE prototype, CK_OBJECT_CLASS class, CK_OBJECT_HANDLE *ret_object);
 int pkcs11_token_find_x509_certificate(CK_FUNCTION_LIST *m, CK_SESSION_HANDLE session, P11KitUri *search_uri, CK_OBJECT_HANDLE *ret_object);
 #if HAVE_OPENSSL
 int pkcs11_token_read_x509_certificate(CK_FUNCTION_LIST *m, CK_SESSION_HANDLE session, CK_OBJECT_HANDLE object, X509 **ret_cert);