From: Ingo Franzki Date: Fri, 24 Aug 2018 09:29:15 +0000 (+0200) Subject: s390/pkey: Introduce new API for transforming key blobs X-Git-Tag: v4.20-rc1~173^2~10 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=fb1136d6580c93af3ec33bf7a5621d980a711f24;p=linux.git s390/pkey: Introduce new API for transforming key blobs Introduce a new ioctl API and in-kernel API to transform a variable length key blob of any supported type into a protected key. Transforming a secure key blob uses the already existing function pkey_sec2protk(). Transforming a protected key blob also verifies if the protected key is still valid. If not, -ENODEV is returned. Both APIs are described in detail in the header files arch/s390/include/asm/pkey.h and arch/s390/include/uapi/asm/pkey.h. Signed-off-by: Ingo Franzki Reviewed-by: Harald Freudenberger Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/include/asm/pkey.h b/arch/s390/include/asm/pkey.h index 2833d6324979..9b6e79077866 100644 --- a/arch/s390/include/asm/pkey.h +++ b/arch/s390/include/asm/pkey.h @@ -125,4 +125,14 @@ int pkey_genprotkey(__u32 keytype, struct pkey_protkey *protkey); */ int pkey_verifyprotkey(const struct pkey_protkey *protkey); +/* + * In-kernel API: Transform an key blob (of any type) into a protected key. + * @param key pointer to a buffer containing the key blob + * @param keylen size of the key blob in bytes + * @param protkey pointer to buffer receiving the protected key + * @return 0 on success, negative errno value on failure + */ +int pkey_keyblob2pkey(const __u8 *key, __u32 keylen, + struct pkey_protkey *protkey); + #endif /* _KAPI_PKEY_H */ diff --git a/arch/s390/include/uapi/asm/pkey.h b/arch/s390/include/uapi/asm/pkey.h index fef08dbd2e8d..c0e86ce4a00b 100644 --- a/arch/s390/include/uapi/asm/pkey.h +++ b/arch/s390/include/uapi/asm/pkey.h @@ -21,9 +21,13 @@ #define PKEY_IOCTL_MAGIC 'p' #define SECKEYBLOBSIZE 64 /* secure key blob size is always 64 bytes */ +#define PROTKEYBLOBSIZE 80 /* protected key blob size is always 80 bytes */ #define MAXPROTKEYSIZE 64 /* a protected key blob may be up to 64 bytes */ #define MAXCLRKEYSIZE 32 /* a clear key value may be up to 32 bytes */ +#define MINKEYBLOBSIZE SECKEYBLOBSIZE /* Minimum size of a key blob */ +#define MAXKEYBLOBSIZE PROTKEYBLOBSIZE /* Maximum size of a key blob */ + /* defines for the type field within the pkey_protkey struct */ #define PKEY_KEYTYPE_AES_128 1 #define PKEY_KEYTYPE_AES_192 2 @@ -148,4 +152,15 @@ struct pkey_verifyprotk { #define PKEY_VERIFYPROTK _IOW(PKEY_IOCTL_MAGIC, 0x09, struct pkey_verifyprotk) +/* + * Transform an key blob (of any type) into a protected key + */ +struct pkey_kblob2pkey { + __u8 __user *key; /* in: the key blob */ + __u32 keylen; /* in: the key blob length */ + struct pkey_protkey protkey; /* out: the protected key */ +}; + +#define PKEY_KBLOB2PROTK _IOWR(PKEY_IOCTL_MAGIC, 0x0A, struct pkey_kblob2pkey) + #endif /* _UAPI_PKEY_H */ diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c index c592270b906a..683ff72ae977 100644 --- a/drivers/s390/crypto/pkey_api.c +++ b/drivers/s390/crypto/pkey_api.c @@ -67,6 +67,14 @@ static void __exit pkey_debug_exit(void) /* For TOKTYPE_CCA_INTERNAL: */ #define TOKVER_CCA_AES 0x04 /* CCA AES key token */ +/* header part of a key token */ +struct keytoken_header { + u8 type; /* one of the TOKTYPE values */ + u8 res0[3]; + u8 version; /* one of the TOKVER values */ + u8 res1[3]; +} __packed; + /* inside view of a secure key token (only type 0x01 version 0x04) */ struct secaeskeytoken { u8 type; /* 0x01 for internal key token */ @@ -1160,6 +1168,80 @@ int pkey_verifyprotkey(const struct pkey_protkey *protkey) } 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 */ @@ -1300,6 +1382,34 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, 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;