Added files.

1 files changed, 711 insertions, 0 deletions

diff --git a/cryptodev.c b/cryptodev.c
new file mode 100644
index 0000000..6007648
--- /dev/null
+++ b/cryptodev.c
@@ -0,0 +1,711 @@
+/*
+ * Driver for /dev/crypto device (aka CryptoDev)
+ *
+ * Copyright (c) 2004 Michal Ludvig <mludvig@logix.net.nz>, SuSE Labs
+ * Copyright (c) 2009 Nikos Mavrogiannopoulos <nmav@gennetsa.com>, Gennet S.A.
+ *
+ * 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,
+ * although a bit extended.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/miscdevice.h>
+#include <linux/crypto.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/random.h>
+#include "cryptodev.h"
+#include <asm/uaccess.h>
+#include <asm/ioctl.h>
+#include <linux/scatterlist.h>
+
+MODULE_AUTHOR("Michal Ludvig <mludvig@logix.net.nz>");
+MODULE_DESCRIPTION("CryptoDev driver");
+MODULE_LICENSE("Dual BSD/GPL");
+
+/* ====== Compile-time config ====== */
+
+#define CRYPTODEV_STATS
+
+/* ====== Module parameters ====== */
+
+static int verbosity = 0;
+module_param(verbosity, int, 0644);
+MODULE_PARM_DESC(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
+
+/* ====== Debug helpers ====== */
+
+#define PFX "cryptodev: "
+#define dprintk(level,severity,format,a...)			\
+	do { 							\
+		if (level <= verbosity)				\
+			printk(severity PFX "%s[%u]: " format,	\
+			       current->comm, current->pid,	\
+			       ##a);				\
+	} while (0)
+
+/* ====== CryptoAPI ====== */
+
+#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 crypto_blkcipher *tfm;
+	struct crypto_hash *hash_tfm;
+	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
+};
+
+struct fcrypt {
+	struct list_head list;
+	struct semaphore sem;
+};
+
+/* Prepare session for future use. */
+static int
+crypto_create_session(struct fcrypt *fcr, struct session_op *sop)
+{
+	struct csession	*ses_new, *ses_ptr;
+	struct crypto_blkcipher *blk_tfm=NULL;
+	struct crypto_hash *hash_tfm=NULL;
+	int ret = 0;
+	const char *alg_name=NULL;
+	const char *hash_name=NULL;
+	struct blkcipher_alg* blkalg;
+	int hmac_mode = 1;
+
+	/* Does the request make sense? */
+	if (!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(3des_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;
+	}
+
+	/* Set-up crypto transform. */
+	if (alg_name) {
+		uint8_t keyp[CRYPTO_CIPHER_MAX_KEY_LEN];
+
+		blk_tfm = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC);
+		if (IS_ERR(blk_tfm)) {
+			dprintk(1,KERN_DEBUG,"%s: Failed to load transform for %s\n", __func__,
+				   alg_name);
+			return -EINVAL;
+		}
+
+		blkalg = crypto_blkcipher_alg(blk_tfm);
+		if (blkalg != NULL) {
+			/* Was correct key length supplied? */
+			if ((sop->keylen < blkalg->min_keysize) ||
+				(sop->keylen > blkalg->max_keysize)) {
+				dprintk(0,KERN_DEBUG,"Wrong keylen '%zu' for algorithm '%s'. Use %u to %u.\n",
+					   sop->keylen, alg_name, blkalg->min_keysize, 
+					   blkalg->max_keysize);
+				ret = -EINVAL;
+				goto error;
+			}
+		}
+
+		if (sop->keylen > CRYPTO_CIPHER_MAX_KEY_LEN) {
+			dprintk(0,KERN_DEBUG,"Setting key failed for %s-%zu.\n",
+				alg_name, sop->keylen*8);
+			ret = -EINVAL;
+			goto error;
+		}
+
+		/* Copy the key from user and set to TFM. */
+		copy_from_user(keyp, sop->key, sop->keylen);
+		ret = crypto_blkcipher_setkey(blk_tfm, keyp, sop->keylen);
+		if (ret) {
+			dprintk(0,KERN_DEBUG,"Setting key failed for %s-%zu.\n",
+				alg_name, sop->keylen*8);
+			ret = -EINVAL;
+			goto error;
+		}
+
+	}
+	
+	if (hash_name) {
+		hash_tfm = crypto_alloc_hash(hash_name, 0, CRYPTO_ALG_ASYNC);
+		if (IS_ERR(hash_tfm)) {
+			dprintk(1,KERN_DEBUG,"%s: Failed to load transform for %s\n", __func__,
+				   hash_name);
+			return -EINVAL;
+		}
+
+		/* Copy the key from user and set to TFM. */
+		if (hmac_mode != 0) {
+			uint8_t hkeyp[CRYPTO_HMAC_MAX_KEY_LEN];
+
+			if (sop->mackeylen > CRYPTO_HMAC_MAX_KEY_LEN) {
+				dprintk(0,KERN_DEBUG,"Setting hmac key failed for %s-%zu.\n",
+					hash_name, sop->mackeylen*8);
+				ret = -EINVAL;
+				goto error;
+			}
+
+			copy_from_user(hkeyp, sop->mackey, sop->mackeylen);
+			ret = crypto_hash_setkey(hash_tfm, hkeyp, sop->mackeylen);
+			if (ret) {
+				dprintk(0,KERN_DEBUG,"Setting hmac key failed for %s-%zu.\n",
+					hash_name, sop->mackeylen*8);
+				ret = -EINVAL;
+				goto error;
+			}
+		}
+
+	}
+
+	/* Create a session and put it to the list. */
+	ses_new = kmalloc(sizeof(*ses_new), GFP_KERNEL);
+	if(!ses_new) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	memset(ses_new, 0, sizeof(*ses_new));
+	get_random_bytes(&ses_new->sid, sizeof(ses_new->sid));
+	ses_new->tfm = blk_tfm;
+	ses_new->hash_tfm = hash_tfm;
+	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:
+	if (blk_tfm)
+		crypto_free_blkcipher(blk_tfm);
+	if (hash_tfm)
+		crypto_free_hash(hash_tfm);
+	
+	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
+	if (ses_ptr->tfm) {
+		crypto_free_blkcipher(ses_ptr->tfm);
+		ses_ptr->tfm = NULL;
+	}
+	if (ses_ptr->hash_tfm) {
+		crypto_free_hash(ses_ptr->hash_tfm);
+		ses_ptr->hash_tfm = NULL;
+	}
+	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 (!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, ivp[EALG_MAX_BLOCK_LEN];
+	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[HASH_MAX_LEN];
+	struct blkcipher_desc bdesc = {
+        .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
+	};
+	struct hash_desc hdesc = {
+		.flags = CRYPTO_TFM_REQ_MAY_SLEEP,
+	};
+
+
+	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 (!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;
+
+	nbytes = cop->len;
+	bdesc.tfm = ses_ptr->tfm;
+	hdesc.tfm = ses_ptr->hash_tfm;
+	if (hdesc.tfm) {
+		ret = crypto_hash_init(&hdesc);
+		if (unlikely(ret)) {
+			dprintk(1, KERN_ERR,
+				"error in crypto_hash_init()\n");
+			goto out_unlock;
+		}
+	}
+
+	if (ses_ptr->tfm) {
+		if (nbytes % crypto_blkcipher_blocksize(ses_ptr->tfm)) {
+			dprintk(1, KERN_ERR,
+				"data size (%zu) isn't a multiple of block size (%u)\n",
+				nbytes, crypto_blkcipher_blocksize(ses_ptr->tfm));
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
+		ivsize = crypto_blkcipher_ivsize(ses_ptr->tfm);
+
+		if (cop->iv) {
+			copy_from_user(ivp, cop->iv, ivsize);
+			crypto_blkcipher_set_iv(ses_ptr->tfm, ivp, ivsize);
+		}
+	}
+
+	src = cop->src;
+	dst = cop->dst;
+
+
+	while(nbytes > 0) {
+		size_t current_len = nbytes > bufsize ? bufsize : nbytes;
+
+		copy_from_user(data, src, current_len);
+
+		sg_set_buf(&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 (hdesc.tfm) {
+				ret = crypto_hash_update(&hdesc, &sg, current_len);
+				if (unlikely(ret)) {
+					dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret);
+					goto out;
+				}
+			}
+			if (bdesc.tfm) {
+				ret = crypto_blkcipher_encrypt(&bdesc, &sg, &sg, current_len);
+
+				if (unlikely(ret)) {
+					dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret);
+					goto out;
+				}
+				copy_to_user(dst, data, current_len);
+				dst += current_len;
+			}
+		} else {
+			if (bdesc.tfm) {
+				ret = crypto_blkcipher_decrypt(&bdesc, &sg, &sg, current_len);
+
+				if (unlikely(ret)) {
+					dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret);
+					goto out;
+				}
+				copy_to_user(dst, data, current_len);
+				dst += current_len;
+
+			}
+
+			if (hdesc.tfm) {
+				ret = crypto_hash_update(&hdesc, &sg, current_len);
+				if (unlikely(ret)) {
+					dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret);
+					goto out;
+				}
+			}
+		}
+
+		nbytes -= current_len;
+		src += current_len;
+	}
+	
+	if (hdesc.tfm) {
+		ret = crypto_hash_final(&hdesc, hash_output);
+		if (unlikely(ret)) {
+			dprintk(0, KERN_ERR, "CryptoAPI failure: %d\n",ret);
+			goto out;
+		}
+
+		copy_to_user(cop->mac, hash_output, crypto_hash_digestsize(ses_ptr->hash_tfm));
+	}
+
+#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 fcrypt *fcr;
+
+	fcr = kmalloc(sizeof(*fcr), GFP_KERNEL);
+	if(!fcr)
+		return -ENOMEM;
+
+	memset(fcr, 0, sizeof(*fcr));
+	init_MUTEX(&fcr->sem);
+	INIT_LIST_HEAD(&fcr->list);
+	filp->private_data = fcr;
+
+	return 0;
+}
+
+static int
+cryptodev_release(struct inode *inode, struct file *filp)
+{
+	struct fcrypt *fcr = filp->private_data;
+
+	if(fcr) {
+		crypto_finish_all_sessions(fcr);
+		kfree(fcr);
+		filp->private_data = NULL;
+	}
+	
+	return 0;
+}
+
+static int
+clonefd(struct file *filp)
+{
+	struct fdtable *fdt = files_fdtable(current->files);
+	int ret;
+	ret = get_unused_fd();
+	if (ret >= 0) {
+			get_file(filp);
+			FD_SET(ret, fdt->open_fds);
+			fd_install(ret, filp);
+	}
+
+	return ret;
+}
+
+static int
+cryptodev_ioctl(struct inode *inode, struct file *filp,
+		unsigned int cmd, unsigned long arg)
+{
+	int __user *p = (void __user *)arg;
+	struct session_op sop;
+	struct crypt_op cop;
+	struct fcrypt *fcr = filp->private_data;
+	uint32_t ses;
+	int ret, fd;
+
+	if (!fcr)
+		BUG();
+
+	switch (cmd) {
+		case CIOCASYMFEAT:
+			put_user(0, p);
+			return 0;
+		case CRIOGET:
+			fd = clonefd(filp);
+			put_user(fd, p);
+			return 0;
+			
+		case CIOCGSESSION:
+			copy_from_user(&sop, (void*)arg, sizeof(sop));
+			ret = crypto_create_session(fcr, &sop);
+			if (ret)
+				return ret;
+			copy_to_user((void*)arg, &sop, sizeof(sop));
+			return 0;
+
+		case CIOCFSESSION:
+			get_user(ses, (uint32_t*)arg);
+			ret = crypto_finish_session(fcr, ses);
+			return ret;
+
+		case CIOCCRYPT:
+			copy_from_user(&cop, (void*)arg, sizeof(cop));
+			ret = crypto_run(fcr, &cop);
+			copy_to_user((void*)arg, &cop, sizeof(cop));
+			return ret;
+
+		default:
+			return -EINVAL;
+	}
+}
+
+struct file_operations cryptodev_fops = {
+	.owner = THIS_MODULE,
+	.open = cryptodev_open,
+	.release = cryptodev_release,
+	.ioctl = cryptodev_ioctl,
+};
+
+struct miscdevice cryptodev = {
+	.minor = CRYPTODEV_MINOR,
+	.name = "crypto",
+	.fops = &cryptodev_fops,
+};
+
+static int
+cryptodev_register(void)
+{
+	int rc;
+
+	rc = misc_register (&cryptodev);
+	if (rc) {
+		printk(KERN_ERR PFX "registeration of /dev/crypto failed\n");
+		return rc;
+	}
+
+	return 0;
+}
+
+static void
+cryptodev_deregister(void)
+{
+	misc_deregister(&cryptodev);
+}
+
+/* ====== Module init/exit ====== */
+
+int __init init_cryptodev(void)
+{
+	int rc;
+	
+	rc = cryptodev_register();
+	if (rc)
+		return rc;
+
+	printk(KERN_INFO PFX "driver loaded.\n");
+
+	return 0;
+}
+
+void __exit exit_cryptodev(void)
+{
+	cryptodev_deregister();
+	printk(KERN_INFO PFX "driver unloaded.\n");
+}
+
+module_init(init_cryptodev);
+module_exit(exit_cryptodev);