diff options
Diffstat (limited to 'drivers/s390/crypto/pkey_pckmo.c')
| -rw-r--r-- | drivers/s390/crypto/pkey_pckmo.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/s390/crypto/pkey_pckmo.c b/drivers/s390/crypto/pkey_pckmo.c new file mode 100644 index 000000000000..7eca9f1340bd --- /dev/null +++ b/drivers/s390/crypto/pkey_pckmo.c @@ -0,0 +1,474 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * pkey pckmo specific code + * + * Copyright IBM Corp. 2024 + */ + +#define KMSG_COMPONENT "pkey" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/cpufeature.h> +#include <asm/cpacf.h> +#include <crypto/aes.h> +#include <linux/random.h> + +#include "zcrypt_ccamisc.h" +#include "pkey_base.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("IBM Corporation"); +MODULE_DESCRIPTION("s390 protected key PCKMO handler"); + +/* + * Check key blob for known and supported here. + */ +static bool is_pckmo_key(const u8 *key, u32 keylen) +{ + struct keytoken_header *hdr = (struct keytoken_header *)key; + struct clearkeytoken *t = (struct clearkeytoken *)key; + + if (keylen < sizeof(*hdr)) + return false; + + switch (hdr->type) { + case TOKTYPE_NON_CCA: + switch (hdr->version) { + case TOKVER_CLEAR_KEY: + if (pkey_keytype_to_size(t->keytype)) + return true; + return false; + case TOKVER_PROTECTED_KEY: + return true; + default: + return false; + } + default: + return false; + } +} + +static bool is_pckmo_keytype(enum pkey_key_type keytype) +{ + switch (keytype) { + case PKEY_TYPE_PROTKEY: + return true; + default: + return false; + } +} + +/* + * Create a protected key from a clear key value via PCKMO instruction. + */ +static int pckmo_clr2protkey(u32 keytype, const u8 *clrkey, u32 clrkeylen, + u8 *protkey, u32 *protkeylen, u32 *protkeytype) +{ + /* mask of available pckmo subfunctions */ + static cpacf_mask_t pckmo_functions; + + int keysize, rc = -EINVAL; + u8 paramblock[160]; + u32 pkeytype = 0; + unsigned int fc; + + switch (keytype) { + case PKEY_KEYTYPE_AES_128: + fc = CPACF_PCKMO_ENC_AES_128_KEY; + break; + case PKEY_KEYTYPE_AES_192: + fc = CPACF_PCKMO_ENC_AES_192_KEY; + break; + case PKEY_KEYTYPE_AES_256: + fc = CPACF_PCKMO_ENC_AES_256_KEY; + break; + case PKEY_KEYTYPE_ECC_P256: + pkeytype = PKEY_KEYTYPE_ECC; + fc = CPACF_PCKMO_ENC_ECC_P256_KEY; + break; + case PKEY_KEYTYPE_ECC_P384: + pkeytype = PKEY_KEYTYPE_ECC; + fc = CPACF_PCKMO_ENC_ECC_P384_KEY; + break; + case PKEY_KEYTYPE_ECC_P521: + pkeytype = PKEY_KEYTYPE_ECC; + fc = CPACF_PCKMO_ENC_ECC_P521_KEY; + break; + case PKEY_KEYTYPE_ECC_ED25519: + pkeytype = PKEY_KEYTYPE_ECC; + fc = CPACF_PCKMO_ENC_ECC_ED25519_KEY; + break; + case PKEY_KEYTYPE_ECC_ED448: + pkeytype = PKEY_KEYTYPE_ECC; + fc = CPACF_PCKMO_ENC_ECC_ED448_KEY; + break; + case PKEY_KEYTYPE_AES_XTS_128: + fc = CPACF_PCKMO_ENC_AES_XTS_128_DOUBLE_KEY; + break; + case PKEY_KEYTYPE_AES_XTS_256: + fc = CPACF_PCKMO_ENC_AES_XTS_256_DOUBLE_KEY; + break; + case PKEY_KEYTYPE_HMAC_512: + fc = CPACF_PCKMO_ENC_HMAC_512_KEY; + break; + case PKEY_KEYTYPE_HMAC_1024: + fc = CPACF_PCKMO_ENC_HMAC_1024_KEY; + break; + default: + PKEY_DBF_ERR("%s unknown/unsupported keytype %u\n", + __func__, keytype); + goto out; + } + + keysize = pkey_keytype_to_size(keytype); + pkeytype = pkeytype ?: keytype; + + if (clrkeylen && clrkeylen < keysize) { + PKEY_DBF_ERR("%s clear key size too small: %u < %d\n", + __func__, clrkeylen, keysize); + goto out; + } + if (*protkeylen < keysize + AES_WK_VP_SIZE) { + PKEY_DBF_ERR("%s prot key buffer size too small: %u < %d\n", + __func__, *protkeylen, keysize + AES_WK_VP_SIZE); + goto out; + } + + /* Did we already check for PCKMO ? */ + if (!pckmo_functions.bytes[0]) { + /* no, so check now */ + if (!cpacf_query(CPACF_PCKMO, &pckmo_functions)) { + PKEY_DBF_ERR("%s cpacf_query() failed\n", __func__); + rc = -ENODEV; + goto out; + } + } + /* check for the pckmo subfunction we need now */ + if (!cpacf_test_func(&pckmo_functions, fc)) { + PKEY_DBF_ERR("%s pckmo fc 0x%02x not available\n", + __func__, fc); + rc = -ENODEV; + goto out; + } + + /* prepare param block */ + memset(paramblock, 0, sizeof(paramblock)); + memcpy(paramblock, clrkey, keysize); + + /* call the pckmo instruction */ + cpacf_pckmo(fc, paramblock); + + /* copy created protected key to key buffer including the wkvp block */ + *protkeylen = keysize + AES_WK_VP_SIZE; + memcpy(protkey, paramblock, *protkeylen); + *protkeytype = pkeytype; + + rc = 0; + +out: + pr_debug("rc=%d\n", rc); + return rc; +} + +/* + * Verify a raw protected key blob. + */ +static int pckmo_verify_protkey(const u8 *protkey, u32 protkeylen, + u32 protkeytype) +{ + u8 clrkey[16] = { 0 }, tmpkeybuf[16 + AES_WK_VP_SIZE]; + u32 tmpkeybuflen, tmpkeytype; + int keysize, rc = -EINVAL; + u8 *wkvp; + + /* check protkey type and size */ + keysize = pkey_keytype_to_size(protkeytype); + if (!keysize) { + PKEY_DBF_ERR("%s unknown/unsupported keytype %u\n", __func__, + protkeytype); + goto out; + } + if (protkeylen < keysize + AES_WK_VP_SIZE) + goto out; + + /* generate a dummy AES 128 protected key */ + tmpkeybuflen = sizeof(tmpkeybuf); + rc = pckmo_clr2protkey(PKEY_KEYTYPE_AES_128, + clrkey, sizeof(clrkey), + tmpkeybuf, &tmpkeybuflen, &tmpkeytype); + if (rc) + goto out; + memzero_explicit(tmpkeybuf, 16); + wkvp = tmpkeybuf + 16; + + /* compare WK VP from the temp key with that of the given prot key */ + if (memcmp(wkvp, protkey + keysize, AES_WK_VP_SIZE)) { + PKEY_DBF_ERR("%s protected key WK VP mismatch\n", __func__); + rc = -EKEYREJECTED; + goto out; + } + +out: + pr_debug("rc=%d\n", rc); + return rc; +} + +static int pckmo_key2protkey(const u8 *key, u32 keylen, + u8 *protkey, u32 *protkeylen, u32 *protkeytype) +{ + struct keytoken_header *hdr = (struct keytoken_header *)key; + int rc = -EINVAL; + + if (keylen < sizeof(*hdr)) + return -EINVAL; + if (hdr->type != TOKTYPE_NON_CCA) + return -EINVAL; + + switch (hdr->version) { + case TOKVER_PROTECTED_KEY: { + struct protkeytoken *t = (struct protkeytoken *)key; + u32 keysize; + + if (keylen < sizeof(*t)) + goto out; + keysize = pkey_keytype_to_size(t->keytype); + if (!keysize) { + PKEY_DBF_ERR("%s protected key token: unknown keytype %u\n", + __func__, t->keytype); + goto out; + } + switch (t->keytype) { + case PKEY_KEYTYPE_AES_128: + case PKEY_KEYTYPE_AES_192: + case PKEY_KEYTYPE_AES_256: + if (t->len != keysize + AES_WK_VP_SIZE || + keylen < sizeof(struct protaeskeytoken)) + goto out; + rc = pckmo_verify_protkey(t->protkey, t->len, + t->keytype); + if (rc) + goto out; + break; + default: + if (t->len != keysize + AES_WK_VP_SIZE || + keylen < sizeof(*t) + keysize + AES_WK_VP_SIZE) + goto out; + break; + } + memcpy(protkey, t->protkey, t->len); + *protkeylen = t->len; + *protkeytype = t->keytype; + rc = 0; + break; + } + case TOKVER_CLEAR_KEY: { + struct clearkeytoken *t = (struct clearkeytoken *)key; + u32 keysize; + + if (keylen < sizeof(*t) || + keylen < sizeof(*t) + t->len) + goto out; + keysize = pkey_keytype_to_size(t->keytype); + if (!keysize) { + PKEY_DBF_ERR("%s clear key token: unknown keytype %u\n", + __func__, t->keytype); + goto out; + } + if (t->len != keysize) { + PKEY_DBF_ERR("%s clear key token: invalid key len %u\n", + __func__, t->len); + goto out; + } + rc = pckmo_clr2protkey(t->keytype, t->clearkey, t->len, + protkey, protkeylen, protkeytype); + break; + } + default: + PKEY_DBF_ERR("%s unknown non-CCA token version %d\n", + __func__, hdr->version); + break; + } + +out: + pr_debug("rc=%d\n", rc); + return rc; +} + +/* + * Generate a random protected key. + */ +static int pckmo_gen_protkey(u32 keytype, u32 subtype, + u8 *protkey, u32 *protkeylen, u32 *protkeytype) +{ + u8 clrkey[128]; + int keysize; + int rc; + + keysize = pkey_keytype_to_size(keytype); + if (!keysize) { + PKEY_DBF_ERR("%s unknown/unsupported keytype %d\n", + __func__, keytype); + return -EINVAL; + } + if (subtype != PKEY_TYPE_PROTKEY) { + PKEY_DBF_ERR("%s unknown/unsupported subtype %d\n", + __func__, subtype); + return -EINVAL; + } + + switch (keytype) { + case PKEY_KEYTYPE_AES_128: + case PKEY_KEYTYPE_AES_192: + case PKEY_KEYTYPE_AES_256: + case PKEY_KEYTYPE_AES_XTS_128: + case PKEY_KEYTYPE_AES_XTS_256: + case PKEY_KEYTYPE_HMAC_512: + case PKEY_KEYTYPE_HMAC_1024: + break; + default: + PKEY_DBF_ERR("%s unsupported keytype %d\n", + __func__, keytype); + return -EINVAL; + } + + /* generate a dummy random clear key */ + get_random_bytes(clrkey, keysize); + + /* convert it to a dummy protected key */ + rc = pckmo_clr2protkey(keytype, clrkey, keysize, + protkey, protkeylen, protkeytype); + if (rc) + goto out; + + /* replace the key part of the protected key with random bytes */ + get_random_bytes(protkey, keysize); + +out: + pr_debug("rc=%d\n", rc); + return rc; +} + +/* + * Verify a protected key token blob. + */ +static int pckmo_verify_key(const u8 *key, u32 keylen) +{ + struct keytoken_header *hdr = (struct keytoken_header *)key; + int rc = -EINVAL; + + if (keylen < sizeof(*hdr)) + return -EINVAL; + if (hdr->type != TOKTYPE_NON_CCA) + return -EINVAL; + + switch (hdr->version) { + case TOKVER_PROTECTED_KEY: { + struct protkeytoken *t = (struct protkeytoken *)key; + u32 keysize; + + if (keylen < sizeof(*t)) + goto out; + keysize = pkey_keytype_to_size(t->keytype); + if (!keysize || t->len != keysize + AES_WK_VP_SIZE) + goto out; + switch (t->keytype) { + case PKEY_KEYTYPE_AES_128: + case PKEY_KEYTYPE_AES_192: + case PKEY_KEYTYPE_AES_256: + if (keylen < sizeof(struct protaeskeytoken)) + goto out; + break; + default: + if (keylen < sizeof(*t) + keysize + AES_WK_VP_SIZE) + goto out; + break; + } + rc = pckmo_verify_protkey(t->protkey, t->len, t->keytype); + break; + } + default: + PKEY_DBF_ERR("%s unknown non-CCA token version %d\n", + __func__, hdr->version); + break; + } + +out: + pr_debug("rc=%d\n", rc); + return rc; +} + +/* + * Wrapper functions used for the pkey handler struct + */ + +static int pkey_pckmo_key2protkey(const struct pkey_apqn *_apqns, + size_t _nr_apqns, + const u8 *key, u32 keylen, + u8 *protkey, u32 *protkeylen, u32 *keyinfo, + u32 _xflags __always_unused) +{ + return pckmo_key2protkey(key, keylen, + protkey, protkeylen, keyinfo); +} + +static int pkey_pckmo_gen_key(const struct pkey_apqn *_apqns, size_t _nr_apqns, + u32 keytype, u32 keysubtype, + u32 _keybitsize, u32 _flags, + u8 *keybuf, u32 *keybuflen, u32 *keyinfo, + u32 _xflags __always_unused) +{ + return pckmo_gen_protkey(keytype, keysubtype, + keybuf, keybuflen, keyinfo); +} + +static int pkey_pckmo_verifykey(const u8 *key, u32 keylen, + u16 *_card, u16 *_dom, + u32 *_keytype, u32 *_keybitsize, + u32 *_flags, u32 _xflags __always_unused) +{ + return pckmo_verify_key(key, keylen); +} + +static struct pkey_handler pckmo_handler = { + .module = THIS_MODULE, + .name = "PKEY PCKMO handler", + .is_supported_key = is_pckmo_key, + .is_supported_keytype = is_pckmo_keytype, + .key_to_protkey = pkey_pckmo_key2protkey, + .gen_key = pkey_pckmo_gen_key, + .verify_key = pkey_pckmo_verifykey, +}; + +/* + * Module init + */ +static int __init pkey_pckmo_init(void) +{ + cpacf_mask_t func_mask; + + /* + * 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, &func_mask)) + return -ENODEV; + + /* register this module as pkey handler for all the pckmo stuff */ + return pkey_handler_register(&pckmo_handler); +} + +/* + * Module exit + */ +static void __exit pkey_pckmo_exit(void) +{ + /* unregister this module as pkey handler */ + pkey_handler_unregister(&pckmo_handler); +} + +module_cpu_feature_match(S390_CPU_FEATURE_MSA, pkey_pckmo_init); +module_exit(pkey_pckmo_exit); |