// SPDX-License-Identifier: GPL-2.0 /* * pkey device driver * * Copyright IBM Corp. 2017 * Author(s): Harald Freudenberger */ #define KMSG_COMPONENT "pkey" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include "zcrypt_api.h" #include "zcrypt_ccamisc.h" MODULE_LICENSE("GPL"); MODULE_AUTHOR("IBM Corporation"); MODULE_DESCRIPTION("s390 protected key interface"); /* mask of available pckmo subfunctions, fetched once at module init */ static cpacf_mask_t pckmo_functions; /* * debug feature data and functions */ static debug_info_t *debug_info; #define DEBUG_DBG(...) debug_sprintf_event(debug_info, 6, ##__VA_ARGS__) #define DEBUG_INFO(...) debug_sprintf_event(debug_info, 5, ##__VA_ARGS__) #define DEBUG_WARN(...) debug_sprintf_event(debug_info, 4, ##__VA_ARGS__) #define DEBUG_ERR(...) debug_sprintf_event(debug_info, 3, ##__VA_ARGS__) static void __init pkey_debug_init(void) { /* 5 arguments per dbf entry (including the format string ptr) */ debug_info = debug_register("pkey", 1, 1, 5 * sizeof(long)); debug_register_view(debug_info, &debug_sprintf_view); debug_set_level(debug_info, 3); } static void __exit pkey_debug_exit(void) { debug_unregister(debug_info); } /* inside view of a protected key token (only type 0x00 version 0x01) */ struct protaeskeytoken { u8 type; /* 0x00 for PAES specific key tokens */ u8 res0[3]; u8 version; /* should be 0x01 for protected AES key token */ u8 res1[3]; u32 keytype; /* key type, one of the PKEY_KEYTYPE values */ u32 len; /* bytes actually stored in protkey[] */ u8 protkey[MAXPROTKEYSIZE]; /* the protected key blob */ } __packed; /* * Create a protected key from a clear key value. */ int pkey_clr2protkey(u32 keytype, const struct pkey_clrkey *clrkey, struct pkey_protkey *protkey) { long fc; int keysize; u8 paramblock[64]; switch (keytype) { case PKEY_KEYTYPE_AES_128: keysize = 16; fc = CPACF_PCKMO_ENC_AES_128_KEY; break; case PKEY_KEYTYPE_AES_192: keysize = 24; fc = CPACF_PCKMO_ENC_AES_192_KEY; break; case PKEY_KEYTYPE_AES_256: keysize = 32; fc = CPACF_PCKMO_ENC_AES_256_KEY; break; default: DEBUG_ERR("%s unknown/unsupported keytype %d\n", __func__, keytype); return -EINVAL; } /* * Check if the needed pckmo subfunction is available. * These subfunctions can be enabled/disabled by customers * in the LPAR profile or may even change on the fly. */ if (!cpacf_test_func(&pckmo_functions, fc)) { DEBUG_ERR("%s pckmo functions not available\n", __func__); return -ENODEV; } /* prepare param block */ memset(paramblock, 0, sizeof(paramblock)); memcpy(paramblock, clrkey->clrkey, keysize); /* call the pckmo instruction */ cpacf_pckmo(fc, paramblock); /* copy created protected key */ protkey->type = keytype; protkey->len = keysize + 32; memcpy(protkey->protkey, paramblock, keysize + 32); return 0; } EXPORT_SYMBOL(pkey_clr2protkey); /* * Find card and transform secure key into protected key. */ int pkey_skey2pkey(const struct pkey_seckey *seckey, struct pkey_protkey *pkey) { u16 cardnr, domain; int rc, verify; /* * The cca_sec2protkey call may fail when a card has been * addressed where the master key was changed after last fetch * of the mkvp into the cache. Try 3 times: First witout verify * then with verify and last round with verify and old master * key verification pattern match not ignored. */ for (verify = 0; verify < 3; verify++) { rc = cca_findcard(seckey->seckey, &cardnr, &domain, verify); if (rc < 0) continue; if (rc > 0 && verify < 2) continue; rc = cca_sec2protkey(cardnr, domain, seckey->seckey, pkey->protkey, &pkey->len, &pkey->type); if (rc == 0) break; } if (rc) DEBUG_DBG("%s failed rc=%d\n", __func__, rc); return rc; } EXPORT_SYMBOL(pkey_skey2pkey); /* * Verify key and give back some info about the key. */ int pkey_verifykey(const struct pkey_seckey *seckey, u16 *pcardnr, u16 *pdomain, u16 *pkeysize, u32 *pattributes) { struct secaeskeytoken *t = (struct secaeskeytoken *) seckey; u16 cardnr, domain; int rc; /* check the secure key for valid AES secure key */ rc = cca_check_secaeskeytoken(debug_info, 3, (u8 *) seckey, 0); if (rc) goto out; if (pattributes) *pattributes = PKEY_VERIFY_ATTR_AES; if (pkeysize) *pkeysize = t->bitsize; /* try to find a card which can handle this key */ rc = cca_findcard(seckey->seckey, &cardnr, &domain, 1); if (rc < 0) goto out; if (rc > 0) { /* key mkvp matches to old master key mkvp */ DEBUG_DBG("%s secure key has old mkvp\n", __func__); if (pattributes) *pattributes |= PKEY_VERIFY_ATTR_OLD_MKVP; rc = 0; } if (pcardnr) *pcardnr = cardnr; if (pdomain) *pdomain = domain; out: DEBUG_DBG("%s rc=%d\n", __func__, rc); return rc; } EXPORT_SYMBOL(pkey_verifykey); /* * Generate a random protected key */ int pkey_genprotkey(__u32 keytype, struct pkey_protkey *protkey) { struct pkey_clrkey clrkey; int keysize; int rc; switch (keytype) { case PKEY_KEYTYPE_AES_128: keysize = 16; break; case PKEY_KEYTYPE_AES_192: keysize = 24; break; case PKEY_KEYTYPE_AES_256: keysize = 32; break; default: DEBUG_ERR("%s unknown/unsupported keytype %d\n", __func__, keytype); return -EINVAL; } /* generate a dummy random clear key */ get_random_bytes(clrkey.clrkey, keysize); /* convert it to a dummy protected key */ rc = pkey_clr2protkey(keytype, &clrkey, protkey); if (rc) return rc; /* replace the key part of the protected key with random bytes */ get_random_bytes(protkey->protkey, keysize); return 0; } EXPORT_SYMBOL(pkey_genprotkey); /* * Verify if a protected key is still valid */ int pkey_verifyprotkey(const struct pkey_protkey *protkey) { unsigned long fc; struct { u8 iv[AES_BLOCK_SIZE]; u8 key[MAXPROTKEYSIZE]; } param; u8 null_msg[AES_BLOCK_SIZE]; u8 dest_buf[AES_BLOCK_SIZE]; unsigned int k; switch (protkey->type) { case PKEY_KEYTYPE_AES_128: fc = CPACF_KMC_PAES_128; break; case PKEY_KEYTYPE_AES_192: fc = CPACF_KMC_PAES_192; break; case PKEY_KEYTYPE_AES_256: fc = CPACF_KMC_PAES_256; break; default: DEBUG_ERR("%s unknown/unsupported keytype %d\n", __func__, protkey->type); return -EINVAL; } memset(null_msg, 0, sizeof(null_msg)); memset(param.iv, 0, sizeof(param.iv)); memcpy(param.key, protkey->protkey, sizeof(param.key)); k = cpacf_kmc(fc | CPACF_ENCRYPT, ¶m, null_msg, dest_buf, sizeof(null_msg)); if (k != sizeof(null_msg)) { DEBUG_ERR("%s protected key is not valid\n", __func__); return -EKEYREJECTED; } return 0; } EXPORT_SYMBOL(pkey_verifyprotkey); /* * Transform a non-CCA key token into a protected key */ static int pkey_nonccatok2pkey(const __u8 *key, __u32 keylen, struct pkey_protkey *protkey) { struct keytoken_header *hdr = (struct keytoken_header *)key; struct protaeskeytoken *t; switch (hdr->version) { case TOKVER_PROTECTED_KEY: if (keylen != sizeof(struct protaeskeytoken)) return -EINVAL; t = (struct protaeskeytoken *)key; protkey->len = t->len; protkey->type = t->keytype; memcpy(protkey->protkey, t->protkey, sizeof(protkey->protkey)); return pkey_verifyprotkey(protkey); default: DEBUG_ERR("%s unknown/unsupported non-CCA token version %d\n", __func__, hdr->version); return -EINVAL; } } /* * Transform a CCA internal key token into a protected key */ static int pkey_ccainttok2pkey(const __u8 *key, __u32 keylen, struct pkey_protkey *protkey) { struct keytoken_header *hdr = (struct keytoken_header *)key; switch (hdr->version) { case TOKVER_CCA_AES: if (keylen != sizeof(struct secaeskeytoken)) return -EINVAL; return pkey_skey2pkey((struct pkey_seckey *)key, protkey); default: DEBUG_ERR("%s unknown/unsupported CCA internal token version %d\n", __func__, hdr->version); return -EINVAL; } } /* * Transform a key blob (of any type) into a protected key */ int pkey_keyblob2pkey(const __u8 *key, __u32 keylen, struct pkey_protkey *protkey) { struct keytoken_header *hdr = (struct keytoken_header *)key; if (keylen < sizeof(struct keytoken_header)) return -EINVAL; switch (hdr->type) { case TOKTYPE_NON_CCA: return pkey_nonccatok2pkey(key, keylen, protkey); case TOKTYPE_CCA_INTERNAL: return pkey_ccainttok2pkey(key, keylen, protkey); default: DEBUG_ERR("%s unknown/unsupported blob type %d\n", __func__, hdr->type); return -EINVAL; } } EXPORT_SYMBOL(pkey_keyblob2pkey); /* * File io functions */ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int rc; switch (cmd) { case PKEY_GENSECK: { struct pkey_genseck __user *ugs = (void __user *) arg; struct pkey_genseck kgs; if (copy_from_user(&kgs, ugs, sizeof(kgs))) return -EFAULT; rc = cca_genseckey(kgs.cardnr, kgs.domain, kgs.keytype, kgs.seckey.seckey); DEBUG_DBG("%s cca_genseckey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(ugs, &kgs, sizeof(kgs))) return -EFAULT; break; } case PKEY_CLR2SECK: { struct pkey_clr2seck __user *ucs = (void __user *) arg; struct pkey_clr2seck kcs; if (copy_from_user(&kcs, ucs, sizeof(kcs))) return -EFAULT; rc = cca_clr2seckey(kcs.cardnr, kcs.domain, kcs.keytype, kcs.clrkey.clrkey, kcs.seckey.seckey); DEBUG_DBG("%s cca_clr2seckey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(ucs, &kcs, sizeof(kcs))) return -EFAULT; memzero_explicit(&kcs, sizeof(kcs)); break; } case PKEY_SEC2PROTK: { struct pkey_sec2protk __user *usp = (void __user *) arg; struct pkey_sec2protk ksp; if (copy_from_user(&ksp, usp, sizeof(ksp))) return -EFAULT; rc = cca_sec2protkey(ksp.cardnr, ksp.domain, ksp.seckey.seckey, ksp.protkey.protkey, NULL, &ksp.protkey.type); DEBUG_DBG("%s cca_sec2protkey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(usp, &ksp, sizeof(ksp))) return -EFAULT; break; } case PKEY_CLR2PROTK: { struct pkey_clr2protk __user *ucp = (void __user *) arg; struct pkey_clr2protk kcp; if (copy_from_user(&kcp, ucp, sizeof(kcp))) return -EFAULT; rc = pkey_clr2protkey(kcp.keytype, &kcp.clrkey, &kcp.protkey); DEBUG_DBG("%s pkey_clr2protkey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(ucp, &kcp, sizeof(kcp))) return -EFAULT; memzero_explicit(&kcp, sizeof(kcp)); break; } case PKEY_FINDCARD: { struct pkey_findcard __user *ufc = (void __user *) arg; struct pkey_findcard kfc; if (copy_from_user(&kfc, ufc, sizeof(kfc))) return -EFAULT; rc = cca_findcard(kfc.seckey.seckey, &kfc.cardnr, &kfc.domain, 1); DEBUG_DBG("%s cca_findcard()=%d\n", __func__, rc); if (rc < 0) break; if (copy_to_user(ufc, &kfc, sizeof(kfc))) return -EFAULT; break; } case PKEY_SKEY2PKEY: { struct pkey_skey2pkey __user *usp = (void __user *) arg; struct pkey_skey2pkey ksp; if (copy_from_user(&ksp, usp, sizeof(ksp))) return -EFAULT; rc = pkey_skey2pkey(&ksp.seckey, &ksp.protkey); DEBUG_DBG("%s pkey_skey2pkey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(usp, &ksp, sizeof(ksp))) return -EFAULT; break; } case PKEY_VERIFYKEY: { struct pkey_verifykey __user *uvk = (void __user *) arg; struct pkey_verifykey kvk; if (copy_from_user(&kvk, uvk, sizeof(kvk))) return -EFAULT; rc = pkey_verifykey(&kvk.seckey, &kvk.cardnr, &kvk.domain, &kvk.keysize, &kvk.attributes); DEBUG_DBG("%s pkey_verifykey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(uvk, &kvk, sizeof(kvk))) return -EFAULT; break; } case PKEY_GENPROTK: { struct pkey_genprotk __user *ugp = (void __user *) arg; struct pkey_genprotk kgp; if (copy_from_user(&kgp, ugp, sizeof(kgp))) return -EFAULT; rc = pkey_genprotkey(kgp.keytype, &kgp.protkey); DEBUG_DBG("%s pkey_genprotkey()=%d\n", __func__, rc); if (rc) break; if (copy_to_user(ugp, &kgp, sizeof(kgp))) return -EFAULT; break; } case PKEY_VERIFYPROTK: { struct pkey_verifyprotk __user *uvp = (void __user *) arg; struct pkey_verifyprotk kvp; if (copy_from_user(&kvp, uvp, sizeof(kvp))) return -EFAULT; rc = pkey_verifyprotkey(&kvp.protkey); DEBUG_DBG("%s pkey_verifyprotkey()=%d\n", __func__, rc); break; } case PKEY_KBLOB2PROTK: { struct pkey_kblob2pkey __user *utp = (void __user *) arg; struct pkey_kblob2pkey ktp; __u8 __user *ukey; __u8 *kkey; if (copy_from_user(&ktp, utp, sizeof(ktp))) return -EFAULT; if (ktp.keylen < MINKEYBLOBSIZE || ktp.keylen > MAXKEYBLOBSIZE) return -EINVAL; ukey = ktp.key; kkey = kmalloc(ktp.keylen, GFP_KERNEL); if (kkey == NULL) return -ENOMEM; if (copy_from_user(kkey, ukey, ktp.keylen)) { kfree(kkey); return -EFAULT; } rc = pkey_keyblob2pkey(kkey, ktp.keylen, &ktp.protkey); DEBUG_DBG("%s pkey_keyblob2pkey()=%d\n", __func__, rc); kfree(kkey); if (rc) break; if (copy_to_user(utp, &ktp, sizeof(ktp))) return -EFAULT; break; } default: /* unknown/unsupported ioctl cmd */ return -ENOTTY; } return rc; } /* * Sysfs and file io operations */ /* * Sysfs attribute read function for all protected key binary attributes. * The implementation can not deal with partial reads, because a new random * protected key blob is generated with each read. In case of partial reads * (i.e. off != 0 or count < key blob size) -EINVAL is returned. */ static ssize_t pkey_protkey_aes_attr_read(u32 keytype, bool is_xts, char *buf, loff_t off, size_t count) { struct protaeskeytoken protkeytoken; struct pkey_protkey protkey; int rc; if (off != 0 || count < sizeof(protkeytoken)) return -EINVAL; if (is_xts) if (count < 2 * sizeof(protkeytoken)) return -EINVAL; memset(&protkeytoken, 0, sizeof(protkeytoken)); protkeytoken.type = TOKTYPE_NON_CCA; protkeytoken.version = TOKVER_PROTECTED_KEY; protkeytoken.keytype = keytype; rc = pkey_genprotkey(protkeytoken.keytype, &protkey); if (rc) return rc; protkeytoken.len = protkey.len; memcpy(&protkeytoken.protkey, &protkey.protkey, protkey.len); memcpy(buf, &protkeytoken, sizeof(protkeytoken)); if (is_xts) { rc = pkey_genprotkey(protkeytoken.keytype, &protkey); if (rc) return rc; protkeytoken.len = protkey.len; memcpy(&protkeytoken.protkey, &protkey.protkey, protkey.len); memcpy(buf + sizeof(protkeytoken), &protkeytoken, sizeof(protkeytoken)); return 2 * sizeof(protkeytoken); } return sizeof(protkeytoken); } static ssize_t protkey_aes_128_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_protkey_aes_attr_read(PKEY_KEYTYPE_AES_128, false, buf, off, count); } static ssize_t protkey_aes_192_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_protkey_aes_attr_read(PKEY_KEYTYPE_AES_192, false, buf, off, count); } static ssize_t protkey_aes_256_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_protkey_aes_attr_read(PKEY_KEYTYPE_AES_256, false, buf, off, count); } static ssize_t protkey_aes_128_xts_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_protkey_aes_attr_read(PKEY_KEYTYPE_AES_128, true, buf, off, count); } static ssize_t protkey_aes_256_xts_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_protkey_aes_attr_read(PKEY_KEYTYPE_AES_256, true, buf, off, count); } static BIN_ATTR_RO(protkey_aes_128, sizeof(struct protaeskeytoken)); static BIN_ATTR_RO(protkey_aes_192, sizeof(struct protaeskeytoken)); static BIN_ATTR_RO(protkey_aes_256, sizeof(struct protaeskeytoken)); static BIN_ATTR_RO(protkey_aes_128_xts, 2 * sizeof(struct protaeskeytoken)); static BIN_ATTR_RO(protkey_aes_256_xts, 2 * sizeof(struct protaeskeytoken)); static struct bin_attribute *protkey_attrs[] = { &bin_attr_protkey_aes_128, &bin_attr_protkey_aes_192, &bin_attr_protkey_aes_256, &bin_attr_protkey_aes_128_xts, &bin_attr_protkey_aes_256_xts, NULL }; static struct attribute_group protkey_attr_group = { .name = "protkey", .bin_attrs = protkey_attrs, }; /* * Sysfs attribute read function for all secure key ccadata binary attributes. * The implementation can not deal with partial reads, because a new random * protected key blob is generated with each read. In case of partial reads * (i.e. off != 0 or count < key blob size) -EINVAL is returned. */ static ssize_t pkey_ccadata_aes_attr_read(u32 keytype, bool is_xts, char *buf, loff_t off, size_t count) { int rc; struct pkey_seckey *seckey = (struct pkey_seckey *) buf; if (off != 0 || count < sizeof(struct secaeskeytoken)) return -EINVAL; if (is_xts) if (count < 2 * sizeof(struct secaeskeytoken)) return -EINVAL; rc = cca_genseckey(-1, -1, keytype, seckey->seckey); if (rc) return rc; if (is_xts) { seckey++; rc = cca_genseckey(-1, -1, keytype, seckey->seckey); if (rc) return rc; return 2 * sizeof(struct secaeskeytoken); } return sizeof(struct secaeskeytoken); } static ssize_t ccadata_aes_128_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_ccadata_aes_attr_read(PKEY_KEYTYPE_AES_128, false, buf, off, count); } static ssize_t ccadata_aes_192_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_ccadata_aes_attr_read(PKEY_KEYTYPE_AES_192, false, buf, off, count); } static ssize_t ccadata_aes_256_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_ccadata_aes_attr_read(PKEY_KEYTYPE_AES_256, false, buf, off, count); } static ssize_t ccadata_aes_128_xts_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_ccadata_aes_attr_read(PKEY_KEYTYPE_AES_128, true, buf, off, count); } static ssize_t ccadata_aes_256_xts_read(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { return pkey_ccadata_aes_attr_read(PKEY_KEYTYPE_AES_256, true, buf, off, count); } static BIN_ATTR_RO(ccadata_aes_128, sizeof(struct secaeskeytoken)); static BIN_ATTR_RO(ccadata_aes_192, sizeof(struct secaeskeytoken)); static BIN_ATTR_RO(ccadata_aes_256, sizeof(struct secaeskeytoken)); static BIN_ATTR_RO(ccadata_aes_128_xts, 2 * sizeof(struct secaeskeytoken)); static BIN_ATTR_RO(ccadata_aes_256_xts, 2 * sizeof(struct secaeskeytoken)); static struct bin_attribute *ccadata_attrs[] = { &bin_attr_ccadata_aes_128, &bin_attr_ccadata_aes_192, &bin_attr_ccadata_aes_256, &bin_attr_ccadata_aes_128_xts, &bin_attr_ccadata_aes_256_xts, NULL }; static struct attribute_group ccadata_attr_group = { .name = "ccadata", .bin_attrs = ccadata_attrs, }; static const struct attribute_group *pkey_attr_groups[] = { &protkey_attr_group, &ccadata_attr_group, NULL, }; static const struct file_operations pkey_fops = { .owner = THIS_MODULE, .open = nonseekable_open, .llseek = no_llseek, .unlocked_ioctl = pkey_unlocked_ioctl, }; static struct miscdevice pkey_dev = { .name = "pkey", .minor = MISC_DYNAMIC_MINOR, .mode = 0666, .fops = &pkey_fops, .groups = pkey_attr_groups, }; /* * Module init */ static int __init pkey_init(void) { cpacf_mask_t kmc_functions; /* * The pckmo instruction should be available - even if we don't * actually invoke it. This instruction comes with MSA 3 which * is also the minimum level for the kmc instructions which * are able to work with protected keys. */ if (!cpacf_query(CPACF_PCKMO, &pckmo_functions)) return -ENODEV; /* check for kmc instructions available */ if (!cpacf_query(CPACF_KMC, &kmc_functions)) return -ENODEV; if (!cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) || !cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) || !cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) return -ENODEV; pkey_debug_init(); return misc_register(&pkey_dev); } /* * Module exit */ static void __exit pkey_exit(void) { misc_deregister(&pkey_dev); pkey_debug_exit(); } module_cpu_feature_match(MSA, pkey_init); module_exit(pkey_exit);