--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DIAG 0x320 support and certificate store handling
+ *
+ * Copyright IBM Corp. 2023
+ * Author(s): Anastasia Eskova <anastasia.eskova@ibm.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/key-type.h>
+#include <linux/key.h>
+#include <linux/keyctl.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <crypto/sha2.h>
+#include <keys/user-type.h>
+#include <asm/debug.h>
+#include <asm/diag.h>
+#include <asm/ebcdic.h>
+#include <asm/sclp.h>
+
+#define DIAG_MAX_RETRIES 10
+
+#define VCE_FLAGS_VALID_MASK 0x80
+
+#define ISM_LEN_DWORDS 4
+#define VCSSB_LEN_BYTES 128
+#define VCSSB_LEN_NO_CERTS 4
+#define VCB_LEN_NO_CERTS 64
+#define VC_NAME_LEN_BYTES 64
+
+#define CERT_STORE_KEY_TYPE_NAME "cert_store_key"
+#define CERT_STORE_KEYRING_NAME "cert_store"
+
+static debug_info_t *cert_store_dbf;
+static debug_info_t *cert_store_hexdump;
+
+#define pr_dbf_msg(fmt, ...) \
+ debug_sprintf_event(cert_store_dbf, 3, fmt "\n", ## __VA_ARGS__)
+
+enum diag320_subcode {
+ DIAG320_SUBCODES = 0,
+ DIAG320_STORAGE = 1,
+ DIAG320_CERT_BLOCK = 2,
+};
+
+enum diag320_rc {
+ DIAG320_RC_OK = 0x0001,
+ DIAG320_RC_CS_NOMATCH = 0x0306,
+};
+
+/* Verification Certificates Store Support Block (VCSSB). */
+struct vcssb {
+ u32 vcssb_length;
+ u8 pad_0x04[3];
+ u8 version;
+ u8 pad_0x08[8];
+ u32 cs_token;
+ u8 pad_0x14[12];
+ u16 total_vc_index_count;
+ u16 max_vc_index_count;
+ u8 pad_0x24[28];
+ u32 max_vce_length;
+ u32 max_vcxe_length;
+ u8 pad_0x48[8];
+ u32 max_single_vcb_length;
+ u32 total_vcb_length;
+ u32 max_single_vcxb_length;
+ u32 total_vcxb_length;
+ u8 pad_0x60[32];
+} __packed __aligned(8);
+
+/* Verification Certificate Entry (VCE) Header. */
+struct vce_header {
+ u32 vce_length;
+ u8 flags;
+ u8 key_type;
+ u16 vc_index;
+ u8 vc_name[VC_NAME_LEN_BYTES]; /* EBCDIC */
+ u8 vc_format;
+ u8 pad_0x49;
+ u16 key_id_length;
+ u8 pad_0x4c;
+ u8 vc_hash_type;
+ u16 vc_hash_length;
+ u8 pad_0x50[4];
+ u32 vc_length;
+ u8 pad_0x58[8];
+ u16 vc_hash_offset;
+ u16 vc_offset;
+ u8 pad_0x64[28];
+} __packed __aligned(4);
+
+/* Verification Certificate Block (VCB) Header. */
+struct vcb_header {
+ u32 vcb_input_length;
+ u8 pad_0x04[4];
+ u16 first_vc_index;
+ u16 last_vc_index;
+ u32 pad_0x0c;
+ u32 cs_token;
+ u8 pad_0x14[12];
+ u32 vcb_output_length;
+ u8 pad_0x24[3];
+ u8 version;
+ u16 stored_vc_count;
+ u16 remaining_vc_count;
+ u8 pad_0x2c[20];
+} __packed __aligned(4);
+
+/* Verification Certificate Block (VCB). */
+struct vcb {
+ struct vcb_header vcb_hdr;
+ u8 vcb_buf[];
+} __packed __aligned(4);
+
+/* Verification Certificate Entry (VCE). */
+struct vce {
+ struct vce_header vce_hdr;
+ u8 cert_data_buf[];
+} __packed __aligned(4);
+
+static void cert_store_key_describe(const struct key *key, struct seq_file *m)
+{
+ char ascii[VC_NAME_LEN_BYTES + 1];
+
+ /*
+ * First 64 bytes of the key description is key name in EBCDIC CP 500.
+ * Convert it to ASCII for displaying in /proc/keys.
+ */
+ strscpy(ascii, key->description, sizeof(ascii));
+ EBCASC_500(ascii, VC_NAME_LEN_BYTES);
+ seq_puts(m, ascii);
+
+ seq_puts(m, &key->description[VC_NAME_LEN_BYTES]);
+ if (key_is_positive(key))
+ seq_printf(m, ": %u", key->datalen);
+}
+
+/*
+ * Certificate store key type takes over properties of
+ * user key but cannot be updated.
+ */
+static struct key_type key_type_cert_store_key = {
+ .name = CERT_STORE_KEY_TYPE_NAME,
+ .preparse = user_preparse,
+ .free_preparse = user_free_preparse,
+ .instantiate = generic_key_instantiate,
+ .revoke = user_revoke,
+ .destroy = user_destroy,
+ .describe = cert_store_key_describe,
+ .read = user_read,
+};
+
+/* Logging functions. */
+static void pr_dbf_vcb(const struct vcb *b)
+{
+ pr_dbf_msg("VCB Header:");
+ pr_dbf_msg("vcb_input_length: %d", b->vcb_hdr.vcb_input_length);
+ pr_dbf_msg("first_vc_index: %d", b->vcb_hdr.first_vc_index);
+ pr_dbf_msg("last_vc_index: %d", b->vcb_hdr.last_vc_index);
+ pr_dbf_msg("cs_token: %d", b->vcb_hdr.cs_token);
+ pr_dbf_msg("vcb_output_length: %d", b->vcb_hdr.vcb_output_length);
+ pr_dbf_msg("version: %d", b->vcb_hdr.version);
+ pr_dbf_msg("stored_vc_count: %d", b->vcb_hdr.stored_vc_count);
+ pr_dbf_msg("remaining_vc_count: %d", b->vcb_hdr.remaining_vc_count);
+}
+
+static void pr_dbf_vce(const struct vce *e)
+{
+ unsigned char vc_name[VC_NAME_LEN_BYTES + 1];
+ char log_string[VC_NAME_LEN_BYTES + 40];
+
+ pr_dbf_msg("VCE Header:");
+ pr_dbf_msg("vce_hdr.vce_length: %d", e->vce_hdr.vce_length);
+ pr_dbf_msg("vce_hdr.flags: %d", e->vce_hdr.flags);
+ pr_dbf_msg("vce_hdr.key_type: %d", e->vce_hdr.key_type);
+ pr_dbf_msg("vce_hdr.vc_index: %d", e->vce_hdr.vc_index);
+ pr_dbf_msg("vce_hdr.vc_format: %d", e->vce_hdr.vc_format);
+ pr_dbf_msg("vce_hdr.key_id_length: %d", e->vce_hdr.key_id_length);
+ pr_dbf_msg("vce_hdr.vc_hash_type: %d", e->vce_hdr.vc_hash_type);
+ pr_dbf_msg("vce_hdr.vc_hash_length: %d", e->vce_hdr.vc_hash_length);
+ pr_dbf_msg("vce_hdr.vc_hash_offset: %d", e->vce_hdr.vc_hash_offset);
+ pr_dbf_msg("vce_hdr.vc_length: %d", e->vce_hdr.vc_length);
+ pr_dbf_msg("vce_hdr.vc_offset: %d", e->vce_hdr.vc_offset);
+
+ /* Certificate name in ASCII. */
+ memcpy(vc_name, e->vce_hdr.vc_name, VC_NAME_LEN_BYTES);
+ EBCASC_500(vc_name, VC_NAME_LEN_BYTES);
+ vc_name[VC_NAME_LEN_BYTES] = '\0';
+
+ snprintf(log_string, sizeof(log_string),
+ "index: %d vce_hdr.vc_name (ASCII): %s",
+ e->vce_hdr.vc_index, vc_name);
+ debug_text_event(cert_store_hexdump, 3, log_string);
+
+ /* Certificate data. */
+ debug_text_event(cert_store_hexdump, 3, "VCE: Certificate data start");
+ debug_event(cert_store_hexdump, 3, (u8 *)e->cert_data_buf, 128);
+ debug_text_event(cert_store_hexdump, 3, "VCE: Certificate data end");
+ debug_event(cert_store_hexdump, 3,
+ (u8 *)e->cert_data_buf + e->vce_hdr.vce_length - 128, 128);
+}
+
+static void pr_dbf_vcssb(const struct vcssb *s)
+{
+ debug_text_event(cert_store_hexdump, 3, "DIAG320 Subcode1");
+ debug_event(cert_store_hexdump, 3, (u8 *)s, VCSSB_LEN_BYTES);
+
+ pr_dbf_msg("VCSSB:");
+ pr_dbf_msg("vcssb_length: %u", s->vcssb_length);
+ pr_dbf_msg("version: %u", s->version);
+ pr_dbf_msg("cs_token: %u", s->cs_token);
+ pr_dbf_msg("total_vc_index_count: %u", s->total_vc_index_count);
+ pr_dbf_msg("max_vc_index_count: %u", s->max_vc_index_count);
+ pr_dbf_msg("max_vce_length: %u", s->max_vce_length);
+ pr_dbf_msg("max_vcxe_length: %u", s->max_vce_length);
+ pr_dbf_msg("max_single_vcb_length: %u", s->max_single_vcb_length);
+ pr_dbf_msg("total_vcb_length: %u", s->total_vcb_length);
+ pr_dbf_msg("max_single_vcxb_length: %u", s->max_single_vcxb_length);
+ pr_dbf_msg("total_vcxb_length: %u", s->total_vcxb_length);
+}
+
+static int __diag320(unsigned long subcode, void *addr)
+{
+ union register_pair rp = { .even = (unsigned long)addr, };
+
+ asm volatile(
+ " diag %[rp],%[subcode],0x320\n"
+ "0: nopr %%r7\n"
+ EX_TABLE(0b, 0b)
+ : [rp] "+d" (rp.pair)
+ : [subcode] "d" (subcode)
+ : "cc", "memory");
+
+ return rp.odd;
+}
+
+static int diag320(unsigned long subcode, void *addr)
+{
+ diag_stat_inc(DIAG_STAT_X320);
+
+ return __diag320(subcode, addr);
+}
+
+/*
+ * Calculate SHA256 hash of the VCE certificate and compare it to hash stored in
+ * VCE. Return -EINVAL if hashes don't match.
+ */
+static int check_certificate_hash(const struct vce *vce)
+{
+ u8 hash[SHA256_DIGEST_SIZE];
+ u16 vc_hash_length;
+ u8 *vce_hash;
+
+ vce_hash = (u8 *)vce + vce->vce_hdr.vc_hash_offset;
+ vc_hash_length = vce->vce_hdr.vc_hash_length;
+ sha256((u8 *)vce + vce->vce_hdr.vc_offset, vce->vce_hdr.vc_length, hash);
+ if (memcmp(vce_hash, hash, vc_hash_length) == 0)
+ return 0;
+
+ pr_dbf_msg("SHA256 hash of received certificate does not match");
+ debug_text_event(cert_store_hexdump, 3, "VCE hash:");
+ debug_event(cert_store_hexdump, 3, vce_hash, SHA256_DIGEST_SIZE);
+ debug_text_event(cert_store_hexdump, 3, "Calculated hash:");
+ debug_event(cert_store_hexdump, 3, hash, SHA256_DIGEST_SIZE);
+
+ return -EINVAL;
+}
+
+static int check_certificate_valid(const struct vce *vce)
+{
+ if (!(vce->vce_hdr.flags & VCE_FLAGS_VALID_MASK)) {
+ pr_dbf_msg("Certificate entry is invalid");
+ return -EINVAL;
+ }
+ if (vce->vce_hdr.vc_format != 1) {
+ pr_dbf_msg("Certificate format is not supported");
+ return -EINVAL;
+ }
+ if (vce->vce_hdr.vc_hash_type != 1) {
+ pr_dbf_msg("Hash type is not supported");
+ return -EINVAL;
+ }
+
+ return check_certificate_hash(vce);
+}
+
+static struct key *get_user_session_keyring(void)
+{
+ key_ref_t us_keyring_ref;
+
+ us_keyring_ref = lookup_user_key(KEY_SPEC_USER_SESSION_KEYRING,
+ KEY_LOOKUP_CREATE, KEY_NEED_LINK);
+ if (IS_ERR(us_keyring_ref)) {
+ pr_dbf_msg("Couldn't get user session keyring: %ld",
+ PTR_ERR(us_keyring_ref));
+ return ERR_PTR(-ENOKEY);
+ }
+ key_ref_put(us_keyring_ref);
+ return key_ref_to_ptr(us_keyring_ref);
+}
+
+/* Invalidate all keys from cert_store keyring. */
+static int invalidate_keyring_keys(struct key *keyring)
+{
+ unsigned long num_keys, key_index;
+ size_t keyring_payload_len;
+ key_serial_t *key_array;
+ struct key *current_key;
+ int rc;
+
+ keyring_payload_len = key_type_keyring.read(keyring, NULL, 0);
+ num_keys = keyring_payload_len / sizeof(key_serial_t);
+ key_array = kcalloc(num_keys, sizeof(key_serial_t), GFP_KERNEL);
+ if (!key_array)
+ return -ENOMEM;
+
+ rc = key_type_keyring.read(keyring, (char *)key_array, keyring_payload_len);
+ if (rc != keyring_payload_len) {
+ pr_dbf_msg("Couldn't read keyring payload");
+ goto out;
+ }
+
+ for (key_index = 0; key_index < num_keys; key_index++) {
+ current_key = key_lookup(key_array[key_index]);
+ pr_dbf_msg("Invalidating key %08x", current_key->serial);
+
+ key_invalidate(current_key);
+ key_put(current_key);
+ rc = key_unlink(keyring, current_key);
+ if (rc) {
+ pr_dbf_msg("Couldn't unlink key %08x: %d", current_key->serial, rc);
+ break;
+ }
+ }
+out:
+ kfree(key_array);
+ return rc;
+}
+
+static struct key *find_cs_keyring(void)
+{
+ key_ref_t cs_keyring_ref;
+ struct key *cs_keyring;
+
+ cs_keyring_ref = keyring_search(make_key_ref(get_user_session_keyring(), true),
+ &key_type_keyring, CERT_STORE_KEYRING_NAME,
+ false);
+ if (!IS_ERR(cs_keyring_ref)) {
+ cs_keyring = key_ref_to_ptr(cs_keyring_ref);
+ key_ref_put(cs_keyring_ref);
+ goto found;
+ }
+ /* Search default locations: thread, process, session keyrings */
+ cs_keyring = request_key(&key_type_keyring, CERT_STORE_KEYRING_NAME, NULL);
+ if (IS_ERR(cs_keyring))
+ return NULL;
+ key_put(cs_keyring);
+found:
+ return cs_keyring;
+}
+
+static void cleanup_cs_keys(void)
+{
+ struct key *cs_keyring;
+
+ cs_keyring = find_cs_keyring();
+ if (!cs_keyring)
+ return;
+
+ pr_dbf_msg("Found cert_store keyring. Purging...");
+ /*
+ * Remove cert_store_key_type in case invalidation
+ * of old cert_store keys failed (= severe error).
+ */
+ if (invalidate_keyring_keys(cs_keyring))
+ unregister_key_type(&key_type_cert_store_key);
+
+ keyring_clear(cs_keyring);
+ key_invalidate(cs_keyring);
+ key_put(cs_keyring);
+ key_unlink(get_user_session_keyring(), cs_keyring);
+}
+
+static struct key *create_cs_keyring(void)
+{
+ static struct key *cs_keyring;
+
+ /* Cleanup previous cs_keyring and all associated keys if any. */
+ cleanup_cs_keys();
+ cs_keyring = keyring_alloc(CERT_STORE_KEYRING_NAME, GLOBAL_ROOT_UID,
+ GLOBAL_ROOT_GID, current_cred(),
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ,
+ KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_SET_KEEP,
+ NULL, get_user_session_keyring());
+ if (IS_ERR(cs_keyring)) {
+ pr_dbf_msg("Can't allocate cert_store keyring");
+ return NULL;
+ }
+
+ pr_dbf_msg("Successfully allocated cert_store keyring: %08x", cs_keyring->serial);
+
+ /*
+ * In case a previous clean-up ran into an
+ * error and unregistered key type.
+ */
+ register_key_type(&key_type_cert_store_key);
+
+ return cs_keyring;
+}
+
+/*
+ * Allocate memory and create key description in format
+ * [key name in EBCDIC]:[VCE index]:[CS token].
+ * Return a pointer to key description or NULL if memory
+ * allocation failed. Memory should be freed by caller.
+ */
+static char *get_key_description(struct vcssb *vcssb, const struct vce *vce)
+{
+ size_t len, name_len;
+ u32 cs_token;
+ char *desc;
+
+ cs_token = vcssb->cs_token;
+ /* Description string contains "%64s:%04u:%08u\0". */
+ name_len = sizeof(vce->vce_hdr.vc_name);
+ len = name_len + 1 + 4 + 1 + 8 + 1;
+ desc = kmalloc(len, GFP_KERNEL);
+ if (!desc)
+ return NULL;
+
+ memcpy(desc, vce->vce_hdr.vc_name, name_len);
+ sprintf(desc + name_len, ":%04u:%08u", vce->vce_hdr.vc_index, cs_token);
+
+ return desc;
+}
+
+/*
+ * Create a key of type "cert_store_key" using the data from VCE for key
+ * payload and key description. Link the key to "cert_store" keyring.
+ */
+static int create_key_from_vce(struct vcssb *vcssb, struct vce *vce,
+ struct key *keyring)
+{
+ key_ref_t newkey;
+ char *desc;
+ int rc;
+
+ desc = get_key_description(vcssb, vce);
+ if (!desc)
+ return -ENOMEM;
+
+ newkey = key_create_or_update(
+ make_key_ref(keyring, true), CERT_STORE_KEY_TYPE_NAME,
+ desc, (u8 *)vce + vce->vce_hdr.vc_offset,
+ vce->vce_hdr.vc_length,
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ,
+ KEY_ALLOC_NOT_IN_QUOTA);
+
+ rc = PTR_ERR_OR_ZERO(newkey);
+ if (rc) {
+ pr_dbf_msg("Couldn't create a key from Certificate Entry (%d)", rc);
+ rc = -ENOKEY;
+ goto out;
+ }
+
+ key_ref_put(newkey);
+out:
+ kfree(desc);
+ return rc;
+}
+
+/* Get Verification Certificate Storage Size block with DIAG320 subcode2. */
+static int get_vcssb(struct vcssb *vcssb)
+{
+ int diag320_rc;
+
+ memset(vcssb, 0, sizeof(*vcssb));
+ vcssb->vcssb_length = VCSSB_LEN_BYTES;
+ diag320_rc = diag320(DIAG320_STORAGE, vcssb);
+ pr_dbf_vcssb(vcssb);
+
+ if (diag320_rc != DIAG320_RC_OK) {
+ pr_dbf_msg("Diag 320 Subcode 1 returned bad RC: %04x", diag320_rc);
+ return -EIO;
+ }
+ if (vcssb->vcssb_length == VCSSB_LEN_NO_CERTS) {
+ pr_dbf_msg("No certificates available for current configuration");
+ return -ENOKEY;
+ }
+
+ return 0;
+}
+
+static u32 get_4k_mult_vcb_size(struct vcssb *vcssb)
+{
+ return round_up(vcssb->max_single_vcb_length, PAGE_SIZE);
+}
+
+/* Fill input fields of single-entry VCB that will be read by LPAR. */
+static void fill_vcb_input(struct vcssb *vcssb, struct vcb *vcb, u16 index)
+{
+ memset(vcb, 0, sizeof(*vcb));
+ vcb->vcb_hdr.vcb_input_length = get_4k_mult_vcb_size(vcssb);
+ vcb->vcb_hdr.cs_token = vcssb->cs_token;
+
+ /* Request single entry. */
+ vcb->vcb_hdr.first_vc_index = index;
+ vcb->vcb_hdr.last_vc_index = index;
+}
+
+static void extract_vce_from_sevcb(struct vcb *vcb, struct vce *vce)
+{
+ struct vce *extracted_vce;
+
+ extracted_vce = (struct vce *)vcb->vcb_buf;
+ memcpy(vce, vcb->vcb_buf, extracted_vce->vce_hdr.vce_length);
+ pr_dbf_vce(vce);
+}
+
+static int get_sevcb(struct vcssb *vcssb, u16 index, struct vcb *vcb)
+{
+ int rc, diag320_rc;
+
+ fill_vcb_input(vcssb, vcb, index);
+
+ diag320_rc = diag320(DIAG320_CERT_BLOCK, vcb);
+ pr_dbf_msg("Diag 320 Subcode2 RC %2x", diag320_rc);
+ pr_dbf_vcb(vcb);
+
+ switch (diag320_rc) {
+ case DIAG320_RC_OK:
+ rc = 0;
+ if (vcb->vcb_hdr.vcb_output_length == VCB_LEN_NO_CERTS) {
+ pr_dbf_msg("No certificate entry for index %u", index);
+ rc = -ENOKEY;
+ } else if (vcb->vcb_hdr.remaining_vc_count != 0) {
+ /* Retry on insufficient space. */
+ pr_dbf_msg("Couldn't get all requested certificates");
+ rc = -EAGAIN;
+ }
+ break;
+ case DIAG320_RC_CS_NOMATCH:
+ pr_dbf_msg("Certificate Store token mismatch");
+ rc = -EAGAIN;
+ break;
+ default:
+ pr_dbf_msg("Diag 320 Subcode2 returned bad rc (0x%4x)", diag320_rc);
+ rc = -EINVAL;
+ break;
+ }
+
+ return rc;
+}
+
+/*
+ * Allocate memory for single-entry VCB, get VCB via DIAG320 subcode 2 call,
+ * extract VCE and create a key from its' certificate.
+ */
+static int create_key_from_sevcb(struct vcssb *vcssb, u16 index,
+ struct key *keyring)
+{
+ struct vcb *vcb;
+ struct vce *vce;
+ int rc;
+
+ rc = -ENOMEM;
+ vcb = vmalloc(get_4k_mult_vcb_size(vcssb));
+ vce = vmalloc(vcssb->max_single_vcb_length - sizeof(vcb->vcb_hdr));
+ if (!vcb || !vce)
+ goto out;
+
+ rc = get_sevcb(vcssb, index, vcb);
+ if (rc)
+ goto out;
+
+ extract_vce_from_sevcb(vcb, vce);
+ rc = check_certificate_valid(vce);
+ if (rc)
+ goto out;
+
+ rc = create_key_from_vce(vcssb, vce, keyring);
+ if (rc)
+ goto out;
+
+ pr_dbf_msg("Successfully created key from Certificate Entry %d", index);
+out:
+ vfree(vce);
+ vfree(vcb);
+ return rc;
+}
+
+/*
+ * Request a single-entry VCB for each VCE available for the partition.
+ * Create a key from it and link it to cert_store keyring. If no keys
+ * could be created (i.e. VCEs were invalid) return -ENOKEY.
+ */
+static int add_certificates_to_keyring(struct vcssb *vcssb, struct key *keyring)
+{
+ int rc, index, count, added;
+
+ count = 0;
+ added = 0;
+ /* Certificate Store entries indices start with 1 and have no gaps. */
+ for (index = 1; index < vcssb->total_vc_index_count + 1; index++) {
+ pr_dbf_msg("Creating key from VCE %u", index);
+ rc = create_key_from_sevcb(vcssb, index, keyring);
+ count++;
+
+ if (rc == -EAGAIN)
+ return rc;
+
+ if (rc)
+ pr_dbf_msg("Creating key from VCE %u failed (%d)", index, rc);
+ else
+ added++;
+ }
+
+ if (added == 0) {
+ pr_dbf_msg("Processed %d entries. No keys created", count);
+ return -ENOKEY;
+ }
+
+ pr_info("Added %d of %d keys to cert_store keyring", added, count);
+
+ /*
+ * Do not allow to link more keys to certificate store keyring after all
+ * the VCEs were processed.
+ */
+ rc = keyring_restrict(make_key_ref(keyring, true), NULL, NULL);
+ if (rc)
+ pr_dbf_msg("Failed to set restriction to cert_store keyring (%d)", rc);
+
+ return 0;
+}
+
+/*
+ * Check which DIAG320 subcodes are installed.
+ * Return -ENOENT if subcodes 1 or 2 are not available.
+ */
+static int query_diag320_subcodes(void)
+{
+ unsigned long ism[ISM_LEN_DWORDS];
+ int rc;
+
+ rc = diag320(0, ism);
+ if (rc != DIAG320_RC_OK) {
+ pr_dbf_msg("DIAG320 subcode query returned %04x", rc);
+ return -ENOENT;
+ }
+
+ debug_text_event(cert_store_hexdump, 3, "DIAG320 Subcode 0");
+ debug_event(cert_store_hexdump, 3, ism, sizeof(ism));
+
+ if (!test_bit_inv(1, ism) || !test_bit_inv(2, ism)) {
+ pr_dbf_msg("Not all required DIAG320 subcodes are installed");
+ return -ENOENT;
+ }
+
+ return 0;
+}
+
+/*
+ * Check if Certificate Store is supported by the firmware and DIAG320 subcodes
+ * 1 and 2 are installed. Create cert_store keyring and link all certificates
+ * available for the current partition to it as "cert_store_key" type
+ * keys. On refresh or error invalidate cert_store keyring and destroy
+ * all keys of "cert_store_key" type.
+ */
+static int fill_cs_keyring(void)
+{
+ struct key *cs_keyring;
+ struct vcssb *vcssb;
+ int rc;
+
+ rc = -ENOMEM;
+ vcssb = kmalloc(VCSSB_LEN_BYTES, GFP_KERNEL);
+ if (!vcssb)
+ goto cleanup_keys;
+
+ rc = -ENOENT;
+ if (!sclp.has_diag320) {
+ pr_dbf_msg("Certificate Store is not supported");
+ goto cleanup_keys;
+ }
+
+ rc = query_diag320_subcodes();
+ if (rc)
+ goto cleanup_keys;
+
+ rc = get_vcssb(vcssb);
+ if (rc)
+ goto cleanup_keys;
+
+ cs_keyring = create_cs_keyring();
+ if (!cs_keyring)
+ goto cleanup_keys;
+
+ rc = add_certificates_to_keyring(vcssb, cs_keyring);
+ if (rc)
+ goto cleanup_cs_keyring;
+
+ goto out;
+
+cleanup_cs_keyring:
+ key_put(cs_keyring);
+cleanup_keys:
+ cleanup_cs_keys();
+out:
+ kfree(vcssb);
+ return rc;
+}
+
+static DEFINE_MUTEX(cs_refresh_lock);
+static int cs_status_val = -1;
+
+static ssize_t cs_status_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ if (cs_status_val == -1)
+ return sysfs_emit(buf, "uninitialized\n");
+ else if (cs_status_val == 0)
+ return sysfs_emit(buf, "ok\n");
+
+ return sysfs_emit(buf, "failed (%d)\n", cs_status_val);
+}
+
+static struct kobj_attribute cs_status_attr = __ATTR_RO(cs_status);
+
+static ssize_t refresh_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc, retries;
+
+ pr_dbf_msg("Refresh certificate store information requested");
+ rc = mutex_lock_interruptible(&cs_refresh_lock);
+ if (rc)
+ return rc;
+
+ for (retries = 0; retries < DIAG_MAX_RETRIES; retries++) {
+ /* Request certificates from certificate store. */
+ rc = fill_cs_keyring();
+ if (rc)
+ pr_dbf_msg("Failed to refresh certificate store information (%d)", rc);
+ if (rc != -EAGAIN)
+ break;
+ }
+ cs_status_val = rc;
+ mutex_unlock(&cs_refresh_lock);
+
+ return rc ?: count;
+}
+
+static struct kobj_attribute refresh_attr = __ATTR_WO(refresh);
+
+static const struct attribute *cert_store_attrs[] __initconst = {
+ &cs_status_attr.attr,
+ &refresh_attr.attr,
+ NULL,
+};
+
+static struct kobject *cert_store_kobj;
+
+static int __init cert_store_init(void)
+{
+ int rc = -ENOMEM;
+
+ cert_store_dbf = debug_register("cert_store_msg", 10, 1, 64);
+ if (!cert_store_dbf)
+ goto cleanup_dbf;
+
+ cert_store_hexdump = debug_register("cert_store_hexdump", 3, 1, 128);
+ if (!cert_store_hexdump)
+ goto cleanup_dbf;
+
+ debug_register_view(cert_store_hexdump, &debug_hex_ascii_view);
+ debug_register_view(cert_store_dbf, &debug_sprintf_view);
+
+ /* Create directory /sys/firmware/cert_store. */
+ cert_store_kobj = kobject_create_and_add("cert_store", firmware_kobj);
+ if (!cert_store_kobj)
+ goto cleanup_dbf;
+
+ rc = sysfs_create_files(cert_store_kobj, cert_store_attrs);
+ if (rc)
+ goto cleanup_kobj;
+
+ register_key_type(&key_type_cert_store_key);
+
+ return rc;
+
+cleanup_kobj:
+ kobject_put(cert_store_kobj);
+cleanup_dbf:
+ debug_unregister(cert_store_dbf);
+ debug_unregister(cert_store_hexdump);
+
+ return rc;
+}
+device_initcall(cert_store_init);
projects / linux-2.6-block.git / commitdiff