/* * Driver for /dev/crypto device (aka CryptoDev) * * Copyright (c) 2004 Michal Ludvig , SuSE Labs * Copyright (c) 2009,2010 Nikos Mavrogiannopoulos * * This file is part of linux cryptodev. * * cryptodev is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * cryptodev is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ /* * Device /dev/crypto provides an interface for * accessing kernel CryptoAPI algorithms (ciphers, * hashes) from userspace programs. * * /dev/crypto interface was originally introduced in * OpenBSD and this module attempts to keep the API. * */ #include #include #include #include #include #include "cryptodev.h" #include #include #include #include "cryptodev_int.h" #include "ncr_int.h" #include #include "version.h" MODULE_AUTHOR("Nikos Mavrogiannopoulos "); MODULE_DESCRIPTION("CryptoDev driver"); MODULE_LICENSE("GPL"); /* ====== Compile-time config ====== */ #define CRYPTODEV_STATS /* ====== Module parameters ====== */ int cryptodev_verbosity = 0; module_param(cryptodev_verbosity, int, 0644); MODULE_PARM_DESC(cryptodev_verbosity, "0: normal, 1: verbose, 2: debug"); #ifdef CRYPTODEV_STATS static int enable_stats = 0; module_param(enable_stats, int, 0644); MODULE_PARM_DESC(enable_stats, "collect statictics about cryptodev usage"); #endif /* ====== CryptoAPI ====== */ struct fcrypt { struct list_head list; struct semaphore sem; }; struct crypt_priv { void * ncr; struct fcrypt fcrypt; }; #define FILL_SG(sg,ptr,len) \ do { \ (sg)->page = virt_to_page(ptr); \ (sg)->offset = offset_in_page(ptr); \ (sg)->length = len; \ (sg)->dma_address = 0; \ } while (0) struct csession { struct list_head entry; struct semaphore sem; struct cipher_data cdata; struct hash_data hdata; uint32_t sid; #ifdef CRYPTODEV_STATS #if ! ((COP_ENCRYPT < 2) && (COP_DECRYPT < 2)) #error Struct csession.stat uses COP_{ENCRYPT,DECRYPT} as indices. Do something! #endif unsigned long long stat[2]; size_t stat_max_size, stat_count; #endif }; /* Prepare session for future use. */ static int crypto_create_session(struct fcrypt *fcr, struct session_op *sop) { struct csession *ses_new = NULL, *ses_ptr; int ret = 0; const char *alg_name=NULL; const char *hash_name=NULL; int hmac_mode = 1; /* Does the request make sense? */ if (unlikely(!sop->cipher && !sop->mac)) { dprintk(1,KERN_DEBUG,"Both 'cipher' and 'mac' unset.\n"); return -EINVAL; } switch (sop->cipher) { case 0: break; case CRYPTO_DES_CBC: alg_name = "cbc(des)"; break; case CRYPTO_3DES_CBC: alg_name = "cbc(des3_ede)"; break; case CRYPTO_BLF_CBC: alg_name = "cbc(blowfish)"; break; case CRYPTO_AES_CBC: alg_name = "cbc(aes)"; break; case CRYPTO_CAMELLIA_CBC: alg_name = "cbc(camelia)"; break; default: dprintk(1,KERN_DEBUG,"%s: bad cipher: %d\n", __func__, sop->cipher); return -EINVAL; } switch (sop->mac) { case 0: break; case CRYPTO_MD5_HMAC: hash_name = "hmac(md5)"; break; case CRYPTO_RIPEMD160_HMAC: hash_name = "hmac(rmd160)"; break; case CRYPTO_SHA1_HMAC: hash_name = "hmac(sha1)"; break; case CRYPTO_SHA2_256_HMAC: hash_name = "hmac(sha256)"; break; case CRYPTO_SHA2_384_HMAC: hash_name = "hmac(sha384)"; break; case CRYPTO_SHA2_512_HMAC: hash_name = "hmac(sha512)"; break; /* non-hmac cases */ case CRYPTO_MD5: hash_name = "md5"; hmac_mode = 0; break; case CRYPTO_RIPEMD160: hash_name = "rmd160"; hmac_mode = 0; break; case CRYPTO_SHA1: hash_name = "sha1"; hmac_mode = 0; break; case CRYPTO_SHA2_256: hash_name = "sha256"; hmac_mode = 0; break; case CRYPTO_SHA2_384: hash_name = "sha384"; hmac_mode = 0; break; case CRYPTO_SHA2_512: hash_name = "sha512"; hmac_mode = 0; break; default: dprintk(1,KERN_DEBUG,"%s: bad mac: %d\n", __func__, sop->mac); return -EINVAL; } /* Create a session and put it to the list. */ ses_new = kmalloc(sizeof(*ses_new), GFP_KERNEL); if(!ses_new) { return -ENOMEM; } memset(ses_new, 0, sizeof(*ses_new)); /* Set-up crypto transform. */ if (alg_name) { uint8_t keyp[CRYPTO_CIPHER_MAX_KEY_LEN]; if (unlikely(sop->keylen > CRYPTO_CIPHER_MAX_KEY_LEN)) { dprintk(1,KERN_DEBUG,"Setting key failed for %s-%zu.\n", alg_name, (size_t)sop->keylen*8); ret = -EINVAL; goto error_cipher; } if (unlikely(copy_from_user(keyp, sop->key, sop->keylen))) { ret = -EFAULT; goto error_cipher; } ret = cryptodev_cipher_init(&ses_new->cdata, alg_name, keyp, sop->keylen); if (ret < 0) { dprintk(1,KERN_DEBUG,"%s: Failed to load cipher for %s\n", __func__, alg_name); ret = -EINVAL; goto error_cipher; } } if (hash_name) { uint8_t keyp[CRYPTO_HMAC_MAX_KEY_LEN]; if (unlikely(sop->mackeylen > CRYPTO_HMAC_MAX_KEY_LEN)) { dprintk(1,KERN_DEBUG,"Setting key failed for %s-%zu.\n", alg_name, (size_t)sop->mackeylen*8); ret = -EINVAL; goto error_hash; } if (unlikely(copy_from_user(keyp, sop->mackey, sop->mackeylen))) { ret = -EFAULT; goto error_hash; } ret = cryptodev_hash_init(&ses_new->hdata, hash_name, hmac_mode, keyp, sop->mackeylen); if (ret != 0) { dprintk(1,KERN_DEBUG,"%s: Failed to load hash for %s\n", __func__, hash_name); ret = -EINVAL; goto error_hash; } } /* put the new session to the list */ get_random_bytes(&ses_new->sid, sizeof(ses_new->sid)); init_MUTEX(&ses_new->sem); down(&fcr->sem); restart: list_for_each_entry(ses_ptr, &fcr->list, entry) { /* Check for duplicate SID */ if (unlikely(ses_new->sid == ses_ptr->sid)) { get_random_bytes(&ses_new->sid, sizeof(ses_new->sid)); /* Unless we have a broken RNG this shouldn't loop forever... ;-) */ goto restart; } } list_add(&ses_new->entry, &fcr->list); up(&fcr->sem); /* Fill in some values for the user. */ sop->ses = ses_new->sid; return 0; error_hash: cryptodev_cipher_deinit( &ses_new->cdata); error_cipher: if (ses_new) kfree(ses_new); return ret; } /* Everything that needs to be done when remowing a session. */ static inline void crypto_destroy_session(struct csession *ses_ptr) { if(down_trylock(&ses_ptr->sem)) { dprintk(2, KERN_DEBUG, "Waiting for semaphore of sid=0x%08X\n", ses_ptr->sid); down(&ses_ptr->sem); } dprintk(2, KERN_DEBUG, "Removed session 0x%08X\n", ses_ptr->sid); #if defined(CRYPTODEV_STATS) if(enable_stats) dprintk(2, KERN_DEBUG, "Usage in Bytes: enc=%llu, dec=%llu, max=%zu, avg=%lu, cnt=%zu\n", ses_ptr->stat[COP_ENCRYPT], ses_ptr->stat[COP_DECRYPT], ses_ptr->stat_max_size, ses_ptr->stat_count > 0 ? ((unsigned long)(ses_ptr->stat[COP_ENCRYPT]+ ses_ptr->stat[COP_DECRYPT]) / ses_ptr->stat_count) : 0, ses_ptr->stat_count); #endif cryptodev_cipher_deinit(&ses_ptr->cdata); cryptodev_hash_deinit(&ses_ptr->hdata); up(&ses_ptr->sem); kfree(ses_ptr); } /* Look up a session by ID and remove. */ static int crypto_finish_session(struct fcrypt *fcr, uint32_t sid) { struct csession *tmp, *ses_ptr; struct list_head *head; int ret = 0; down(&fcr->sem); head = &fcr->list; list_for_each_entry_safe(ses_ptr, tmp, head, entry) { if(ses_ptr->sid == sid) { list_del(&ses_ptr->entry); crypto_destroy_session(ses_ptr); break; } } if (unlikely(!ses_ptr)) { dprintk(1, KERN_ERR, "Session with sid=0x%08X not found!\n", sid); ret = -ENOENT; } up(&fcr->sem); return ret; } /* Remove all sessions when closing the file */ static int crypto_finish_all_sessions(struct fcrypt *fcr) { struct csession *tmp, *ses_ptr; struct list_head *head; down(&fcr->sem); head = &fcr->list; list_for_each_entry_safe(ses_ptr, tmp, head, entry) { list_del(&ses_ptr->entry); crypto_destroy_session(ses_ptr); } up(&fcr->sem); return 0; } /* Look up session by session ID. The returned session is locked. */ static struct csession * crypto_get_session_by_sid(struct fcrypt *fcr, uint32_t sid) { struct csession *ses_ptr; down(&fcr->sem); list_for_each_entry(ses_ptr, &fcr->list, entry) { if(ses_ptr->sid == sid) { down(&ses_ptr->sem); break; } } up(&fcr->sem); return ses_ptr; } /* This is the main crypto function - feed it with plaintext and get a ciphertext (or vice versa :-) */ static int crypto_run(struct fcrypt *fcr, struct crypt_op *cop) { char *data; char __user *src, __user *dst; struct scatterlist sg; struct csession *ses_ptr; unsigned int ivsize=0; size_t nbytes, bufsize; int ret = 0; uint8_t hash_output[AALG_MAX_RESULT_LEN]; if (unlikely(cop->op != COP_ENCRYPT && cop->op != COP_DECRYPT)) { dprintk(1, KERN_DEBUG, "invalid operation op=%u\n", cop->op); return -EINVAL; } ses_ptr = crypto_get_session_by_sid(fcr, cop->ses); if (unlikely(!ses_ptr)) { dprintk(1, KERN_ERR, "invalid session ID=0x%08X\n", cop->ses); return -EINVAL; } nbytes = cop->len; data = (char*)__get_free_page(GFP_KERNEL); if (unlikely(!data)) { ret = -ENOMEM; goto out_unlock; } bufsize = PAGE_SIZE < nbytes ? PAGE_SIZE : nbytes; if (ses_ptr->hdata.init != 0) { ret = cryptodev_hash_reset(&ses_ptr->hdata); if (unlikely(ret)) { dprintk(1, KERN_ERR, "error in cryptodev_hash_reset()\n"); goto out; } } if (ses_ptr->cdata.init != 0) { int blocksize = ses_ptr->cdata.blocksize; if (unlikely(nbytes % blocksize)) { dprintk(1, KERN_ERR, "data size (%zu) isn't a multiple of block size (%u)\n", nbytes, blocksize); ret = -EINVAL; goto out; } if (cop->iv) { uint8_t iv[EALG_MAX_BLOCK_LEN]; ivsize = min((int)sizeof(iv), ses_ptr->cdata.ivsize); if (unlikely(copy_from_user(iv, cop->iv, ivsize))) { ret = -EFAULT; goto out; } cryptodev_cipher_set_iv(&ses_ptr->cdata, iv, ivsize); } } src = cop->src; dst = cop->dst; while(nbytes > 0) { size_t current_len = nbytes > bufsize ? bufsize : nbytes; if (unlikely(copy_from_user(data, src, current_len))) { ret = -EFAULT; goto out; } sg_init_one(&sg, data, current_len); /* Always hash before encryption and after decryption. Maybe * we should introduce a flag to switch... TBD later on. */ if (cop->op == COP_ENCRYPT) { if (ses_ptr->hdata.init != 0) { ret = cryptodev_hash_update(&ses_ptr->hdata, &sg, current_len); if (unlikely(ret)) { dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret); goto out; } } if (ses_ptr->cdata.init != 0) { ret = cryptodev_cipher_encrypt( &ses_ptr->cdata, &sg, &sg, current_len); if (unlikely(ret)) { dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret); goto out; } ret = copy_to_user(dst, data, current_len); if (unlikely(ret)) { ret = -EFAULT; goto out; } dst += current_len; } } else { if (ses_ptr->cdata.init != 0) { ret = cryptodev_cipher_decrypt( &ses_ptr->cdata, &sg, &sg, current_len); if (unlikely(ret)) { dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret); goto out; } ret = copy_to_user(dst, data, current_len); if (unlikely(ret)) { ret = -EFAULT; goto out; } dst += current_len; } if (ses_ptr->hdata.init != 0) { ret = cryptodev_hash_update(&ses_ptr->hdata, &sg, current_len); if (unlikely(ret)) { dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret); goto out; } } } nbytes -= current_len; src += current_len; } if (ses_ptr->hdata.init != 0) { ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output); if (unlikely(ret)) { dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret); goto out; } ret = copy_to_user(cop->mac, hash_output, ses_ptr->hdata.digestsize); if (unlikely(ret)) { ret = -EFAULT; goto out; } } #if defined(CRYPTODEV_STATS) if (enable_stats) { /* this is safe - we check cop->op at the function entry */ ses_ptr->stat[cop->op] += cop->len; if (ses_ptr->stat_max_size < cop->len) ses_ptr->stat_max_size = cop->len; ses_ptr->stat_count++; } #endif out: free_page((unsigned long)data); out_unlock: up(&ses_ptr->sem); return ret; } /* ====== /dev/crypto ====== */ static int cryptodev_open(struct inode *inode, struct file *filp) { struct crypt_priv *pcr; pcr = kmalloc(sizeof(*pcr), GFP_KERNEL); if(!pcr) return -ENOMEM; memset(pcr, 0, sizeof(*pcr)); init_MUTEX(&pcr->fcrypt.sem); INIT_LIST_HEAD(&pcr->fcrypt.list); pcr->ncr = ncr_init_lists(); if (pcr->ncr == NULL) { kfree(pcr); return -ENOMEM; } filp->private_data = pcr; return 0; } static int cryptodev_release(struct inode *inode, struct file *filp) { struct crypt_priv *pcr = filp->private_data; if(pcr) { crypto_finish_all_sessions(&pcr->fcrypt); ncr_deinit_lists(pcr->ncr); kfree(pcr); filp->private_data = NULL; } return 0; } static int clonefd(struct file *filp) { int ret; ret = get_unused_fd(); if (ret >= 0) { get_file(filp); fd_install(ret, filp); } return ret; } static int cryptodev_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg_) { void __user *arg = (void __user *)arg_; int __user *p = arg; struct session_op sop; struct crypt_op cop; struct crypt_priv *pcr = filp->private_data; struct fcrypt * fcr; uint32_t ses; int ret, fd; if (unlikely(!pcr)) BUG(); fcr = &pcr->fcrypt; switch (cmd) { case CIOCASYMFEAT: return put_user(0, p); case CRIOGET: fd = clonefd(filp); ret = put_user(fd, p); if (unlikely(ret)) { sys_close(fd); return ret; } return ret; case CIOCGSESSION: if (unlikely(copy_from_user(&sop, arg, sizeof(sop)))) return -EFAULT; ret = crypto_create_session(fcr, &sop); if (unlikely(ret)) return ret; ret = copy_to_user(arg, &sop, sizeof(sop)); if (unlikely(ret)) { crypto_finish_session(fcr, sop.ses); return -EFAULT; } return ret; case CIOCFSESSION: ret = get_user(ses, (uint32_t __user *)arg); if (unlikely(ret)) return ret; ret = crypto_finish_session(fcr, ses); return ret; case CIOCCRYPT: if (unlikely(copy_from_user(&cop, arg, sizeof(cop)))) return -EFAULT; ret = crypto_run(fcr, &cop); if (unlikely(ret)) return ret; if (unlikely(copy_to_user(arg, &cop, sizeof(cop)))) return -EFAULT; return 0; default: return ncr_ioctl(pcr->ncr, filp, cmd, arg_); } } /* compatibility code for 32bit userlands */ #ifdef CONFIG_COMPAT static inline void compat_to_session_op(struct compat_session_op *compat, struct session_op *sop) { sop->cipher = compat->cipher; sop->mac = compat->mac; sop->keylen = compat->keylen; sop->key = compat_ptr(compat->key); sop->mackeylen = compat->mackeylen; sop->mackey = compat_ptr(compat->mackey); sop->ses = compat->ses; } static inline void session_op_to_compat(struct session_op *sop, struct compat_session_op *compat) { compat->cipher = sop->cipher; compat->mac = sop->mac; compat->keylen = sop->keylen; compat->key = ptr_to_compat(sop->key); compat->mackeylen = sop->mackeylen; compat->mackey = ptr_to_compat(sop->mackey); compat->ses = sop->ses; } static inline void compat_to_crypt_op(struct compat_crypt_op *compat, struct crypt_op *cop) { cop->ses = compat->ses; cop->op = compat->op; cop->flags = compat->flags; cop->len = compat->len; cop->src = compat_ptr(compat->src); cop->dst = compat_ptr(compat->dst); cop->mac = compat_ptr(compat->mac); cop->iv = compat_ptr(compat->iv); } static inline void crypt_op_to_compat(struct crypt_op *cop, struct compat_crypt_op *compat) { compat->ses = cop->ses; compat->op = cop->op; compat->flags = cop->flags; compat->len = cop->len; compat->src = ptr_to_compat(cop->src); compat->dst = ptr_to_compat(cop->dst); compat->mac = ptr_to_compat(cop->mac); compat->iv = ptr_to_compat(cop->iv); } static long cryptodev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg_) { void __user *arg = (void __user *)arg_; struct fcrypt *fcr = file->private_data; struct session_op sop; struct compat_session_op compat_sop; struct crypt_op cop; struct compat_crypt_op compat_cop; int ret; if (unlikely(!fcr)) BUG(); switch (cmd) { case CIOCASYMFEAT: case CRIOGET: case CIOCFSESSION: return cryptodev_ioctl(NULL, file, cmd, arg_); case COMPAT_CIOCGSESSION: if (unlikely(copy_from_user(&compat_sop, arg, sizeof(compat_sop)))) return -EFAULT; compat_to_session_op(&compat_sop, &sop); ret = crypto_create_session(fcr, &sop); if (unlikely(ret)) return ret; session_op_to_compat(&sop, &compat_sop); ret = copy_to_user(arg, &compat_sop, sizeof(compat_sop)); if (unlikely(ret)) { crypto_finish_session(fcr, sop.ses); return -EFAULT; } return ret; case COMPAT_CIOCCRYPT: if (unlikely(copy_from_user(&compat_cop, arg, sizeof(compat_cop)))) return -EFAULT; compat_to_crypt_op(&compat_cop, &cop); ret = crypto_run(fcr, &cop); if (unlikely(ret)) return ret; crypt_op_to_compat(&cop, &compat_cop); if (unlikely(copy_to_user(arg, &compat_cop, sizeof(compat_cop)))) return -EFAULT; return 0; default: return -EINVAL; } } #endif /* CONFIG_COMPAT */ static struct file_operations cryptodev_fops = { .owner = THIS_MODULE, .open = cryptodev_open, .release = cryptodev_release, .ioctl = cryptodev_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = cryptodev_compat_ioctl, #endif /* CONFIG_COMPAT */ }; static struct miscdevice cryptodev = { .minor = MISC_DYNAMIC_MINOR, .name = "crypto", .fops = &cryptodev_fops, }; static int __init cryptodev_register(void) { int rc; ncr_limits_init(); ncr_master_key_reset(); rc = ncr_pk_queue_init(); if (unlikely(rc)) { ncr_limits_deinit(); printk(KERN_ERR PFX "initialization of PK workqueue failed\n"); return rc; } rc = misc_register (&cryptodev); if (unlikely(rc)) { ncr_limits_deinit(); ncr_pk_queue_deinit(); printk(KERN_ERR PFX "registration of /dev/crypto failed\n"); return rc; } return 0; } static void __exit cryptodev_deregister(void) { misc_deregister(&cryptodev); ncr_limits_deinit(); ncr_pk_queue_deinit(); } /* ====== Module init/exit ====== */ static int __init init_cryptodev(void) { int rc; rc = cryptodev_register(); if (unlikely(rc)) return rc; printk(KERN_INFO PFX "driver %s loaded.\n", VERSION); return 0; } static void __exit exit_cryptodev(void) { cryptodev_deregister(); printk(KERN_INFO PFX "driver unloaded.\n"); } module_init(init_cryptodev); module_exit(exit_cryptodev);