net/ceph/crypto.c - pub/scm/linux/kernel/git/linville/wireless - Git at Google


 #include <linux/ceph/ceph_debug.h>

 #include <linux/err.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <crypto/hash.h>
 #include <linux/key-type.h>

 #include <keys/ceph-type.h>
 #include <keys/user-type.h>
 #include <linux/ceph/decode.h>
 #include "crypto.h"

 int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
 			  const struct ceph_crypto_key *src)
 {
 	memcpy(dst, src, sizeof(struct ceph_crypto_key));
 	dst->key = kmemdup(src->key, src->len, GFP_NOFS);
 	if (!dst->key)
 		return -ENOMEM;
 	return 0;
 }

 int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end)
 {
 	if (*p + sizeof(u16) + sizeof(key->created) +
 	    sizeof(u16) + key->len > end)
 		return -ERANGE;
 	ceph_encode_16(p, key->type);
 	ceph_encode_copy(p, &key->created, sizeof(key->created));
 	ceph_encode_16(p, key->len);
 	ceph_encode_copy(p, key->key, key->len);
 	return 0;
 }

 int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
 {
 	ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
 	key->type = ceph_decode_16(p);
 	ceph_decode_copy(p, &key->created, sizeof(key->created));
 	key->len = ceph_decode_16(p);
 	ceph_decode_need(p, end, key->len, bad);
 	key->key = kmalloc(key->len, GFP_NOFS);
 	if (!key->key)
 		return -ENOMEM;
 	ceph_decode_copy(p, key->key, key->len);
 	return 0;

 bad:
 	dout("failed to decode crypto key\n");
 	return -EINVAL;
 }

 int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
 {
 	int inlen = strlen(inkey);
 	int blen = inlen * 3 / 4;
 	void *buf, *p;
 	int ret;

 	dout("crypto_key_unarmor %s\n", inkey);
 	buf = kmalloc(blen, GFP_NOFS);
 	if (!buf)
 		return -ENOMEM;
 	blen = ceph_unarmor(buf, inkey, inkey+inlen);
 	if (blen < 0) {
 		kfree(buf);
 		return blen;
 	}

 	p = buf;
 	ret = ceph_crypto_key_decode(key, &p, p + blen);
 	kfree(buf);
 	if (ret)
 		return ret;
 	dout("crypto_key_unarmor key %p type %d len %d\n", key,
 	     key->type, key->len);
 	return 0;
 }


 #define AES_KEY_SIZE 16

 static struct crypto_blkcipher *ceph_crypto_alloc_cipher(void)
 {
 	return crypto_alloc_blkcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
 }

 static const u8 *aes_iv = (u8 *)CEPH_AES_IV;

 /*
  * Should be used for buffers allocated with ceph_kvmalloc().
  * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
  * in-buffer (msg front).
  *
  * Dispose of @sgt with teardown_sgtable().
  *
  * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
  * in cases where a single sg is sufficient.  No attempt to reduce the
  * number of sgs by squeezing physically contiguous pages together is
  * made though, for simplicity.
  */
 static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
 			 const void *buf, unsigned int buf_len)
 {
 	struct scatterlist *sg;
 	const bool is_vmalloc = is_vmalloc_addr(buf);
 	unsigned int off = offset_in_page(buf);
 	unsigned int chunk_cnt = 1;
 	unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
 	int i;
 	int ret;

 	if (buf_len == 0) {
 		memset(sgt, 0, sizeof(*sgt));
 		return -EINVAL;
 	}

 	if (is_vmalloc) {
 		chunk_cnt = chunk_len >> PAGE_SHIFT;
 		chunk_len = PAGE_SIZE;
 	}

 	if (chunk_cnt > 1) {
 		ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
 		if (ret)
 			return ret;
 	} else {
 		WARN_ON(chunk_cnt != 1);
 		sg_init_table(prealloc_sg, 1);
 		sgt->sgl = prealloc_sg;
 		sgt->nents = sgt->orig_nents = 1;
 	}

 	for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
 		struct page *page;
 		unsigned int len = min(chunk_len - off, buf_len);

 		if (is_vmalloc)
 			page = vmalloc_to_page(buf);
 		else
 			page = virt_to_page(buf);

 		sg_set_page(sg, page, len, off);

 		off = 0;
 		buf += len;
 		buf_len -= len;
 	}
 	WARN_ON(buf_len != 0);

 	return 0;
 }

 static void teardown_sgtable(struct sg_table *sgt)
 {
 	if (sgt->orig_nents > 1)
 		sg_free_table(sgt);
 }

 static int ceph_aes_encrypt(const void *key, int key_len,
 			    void *dst, size_t *dst_len,
 			    const void *src, size_t src_len)
 {
 	struct scatterlist sg_in[2], prealloc_sg;
 	struct sg_table sg_out;
 	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
 	struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 };
 	int ret;
 	void *iv;
 	int ivsize;
 	size_t zero_padding = (0x10 - (src_len & 0x0f));
 	char pad[16];

 	if (IS_ERR(tfm))
 		return PTR_ERR(tfm);

 	memset(pad, zero_padding, zero_padding);

 	*dst_len = src_len + zero_padding;

 	sg_init_table(sg_in, 2);
 	sg_set_buf(&sg_in[0], src, src_len);
 	sg_set_buf(&sg_in[1], pad, zero_padding);
 	ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len);
 	if (ret)
 		goto out_tfm;

 	crypto_blkcipher_setkey((void *)tfm, key, key_len);
 	iv = crypto_blkcipher_crt(tfm)->iv;
 	ivsize = crypto_blkcipher_ivsize(tfm);
 	memcpy(iv, aes_iv, ivsize);

 	/*
 	print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1,
 		       key, key_len, 1);
 	print_hex_dump(KERN_ERR, "enc src: ", DUMP_PREFIX_NONE, 16, 1,
 			src, src_len, 1);
 	print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1,
 			pad, zero_padding, 1);
 	*/
 	ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in,
 				     src_len + zero_padding);
 	if (ret < 0) {
 		pr_err("ceph_aes_crypt failed %d\n", ret);
 		goto out_sg;
 	}
 	/*
 	print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1,
 		       dst, *dst_len, 1);
 	*/

 out_sg:
 	teardown_sgtable(&sg_out);
 out_tfm:
 	crypto_free_blkcipher(tfm);
 	return ret;
 }

 static int ceph_aes_encrypt2(const void *key, int key_len, void *dst,
 			     size_t *dst_len,
 			     const void *src1, size_t src1_len,
 			     const void *src2, size_t src2_len)
 {
 	struct scatterlist sg_in[3], prealloc_sg;
 	struct sg_table sg_out;
 	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
 	struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 };
 	int ret;
 	void *iv;
 	int ivsize;
 	size_t zero_padding = (0x10 - ((src1_len + src2_len) & 0x0f));
 	char pad[16];

 	if (IS_ERR(tfm))
 		return PTR_ERR(tfm);

 	memset(pad, zero_padding, zero_padding);

 	*dst_len = src1_len + src2_len + zero_padding;

 	sg_init_table(sg_in, 3);
 	sg_set_buf(&sg_in[0], src1, src1_len);
 	sg_set_buf(&sg_in[1], src2, src2_len);
 	sg_set_buf(&sg_in[2], pad, zero_padding);
 	ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len);
 	if (ret)
 		goto out_tfm;

 	crypto_blkcipher_setkey((void *)tfm, key, key_len);
 	iv = crypto_blkcipher_crt(tfm)->iv;
 	ivsize = crypto_blkcipher_ivsize(tfm);
 	memcpy(iv, aes_iv, ivsize);

 	/*
 	print_hex_dump(KERN_ERR, "enc  key: ", DUMP_PREFIX_NONE, 16, 1,
 		       key, key_len, 1);
 	print_hex_dump(KERN_ERR, "enc src1: ", DUMP_PREFIX_NONE, 16, 1,
 			src1, src1_len, 1);
 	print_hex_dump(KERN_ERR, "enc src2: ", DUMP_PREFIX_NONE, 16, 1,
 			src2, src2_len, 1);
 	print_hex_dump(KERN_ERR, "enc  pad: ", DUMP_PREFIX_NONE, 16, 1,
 			pad, zero_padding, 1);
 	*/
 	ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in,
 				     src1_len + src2_len + zero_padding);
 	if (ret < 0) {
 		pr_err("ceph_aes_crypt2 failed %d\n", ret);
 		goto out_sg;
 	}
 	/*
 	print_hex_dump(KERN_ERR, "enc  out: ", DUMP_PREFIX_NONE, 16, 1,
 		       dst, *dst_len, 1);
 	*/

 out_sg:
 	teardown_sgtable(&sg_out);
 out_tfm:
 	crypto_free_blkcipher(tfm);
 	return ret;
 }

 static int ceph_aes_decrypt(const void *key, int key_len,
 			    void *dst, size_t *dst_len,
 			    const void *src, size_t src_len)
 {
 	struct sg_table sg_in;
 	struct scatterlist sg_out[2], prealloc_sg;
 	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
 	struct blkcipher_desc desc = { .tfm = tfm };
 	char pad[16];
 	void *iv;
 	int ivsize;
 	int ret;
 	int last_byte;

 	if (IS_ERR(tfm))
 		return PTR_ERR(tfm);

 	sg_init_table(sg_out, 2);
 	sg_set_buf(&sg_out[0], dst, *dst_len);
 	sg_set_buf(&sg_out[1], pad, sizeof(pad));
 	ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len);
 	if (ret)
 		goto out_tfm;

 	crypto_blkcipher_setkey((void *)tfm, key, key_len);
 	iv = crypto_blkcipher_crt(tfm)->iv;
 	ivsize = crypto_blkcipher_ivsize(tfm);
 	memcpy(iv, aes_iv, ivsize);

 	/*
 	print_hex_dump(KERN_ERR, "dec key: ", DUMP_PREFIX_NONE, 16, 1,
 		       key, key_len, 1);
 	print_hex_dump(KERN_ERR, "dec  in: ", DUMP_PREFIX_NONE, 16, 1,
 		       src, src_len, 1);
 	*/
 	ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len);
 	if (ret < 0) {
 		pr_err("ceph_aes_decrypt failed %d\n", ret);
 		goto out_sg;
 	}

 	if (src_len <= *dst_len)
 		last_byte = ((char *)dst)[src_len - 1];
 	else
 		last_byte = pad[src_len - *dst_len - 1];
 	if (last_byte <= 16 && src_len >= last_byte) {
 		*dst_len = src_len - last_byte;
 	} else {
 		pr_err("ceph_aes_decrypt got bad padding %d on src len %d\n",
 		       last_byte, (int)src_len);
 		return -EPERM;  /* bad padding */
 	}
 	/*
 	print_hex_dump(KERN_ERR, "dec out: ", DUMP_PREFIX_NONE, 16, 1,
 		       dst, *dst_len, 1);
 	*/

 out_sg:
 	teardown_sgtable(&sg_in);
 out_tfm:
 	crypto_free_blkcipher(tfm);
 	return ret;
 }

 static int ceph_aes_decrypt2(const void *key, int key_len,
 			     void *dst1, size_t *dst1_len,
 			     void *dst2, size_t *dst2_len,
 			     const void *src, size_t src_len)
 {
 	struct sg_table sg_in;
 	struct scatterlist sg_out[3], prealloc_sg;
 	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
 	struct blkcipher_desc desc = { .tfm = tfm };
 	char pad[16];
 	void *iv;
 	int ivsize;
 	int ret;
 	int last_byte;

 	if (IS_ERR(tfm))
 		return PTR_ERR(tfm);

 	sg_init_table(sg_out, 3);
 	sg_set_buf(&sg_out[0], dst1, *dst1_len);
 	sg_set_buf(&sg_out[1], dst2, *dst2_len);
 	sg_set_buf(&sg_out[2], pad, sizeof(pad));
 	ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len);
 	if (ret)
 		goto out_tfm;

 	crypto_blkcipher_setkey((void *)tfm, key, key_len);
 	iv = crypto_blkcipher_crt(tfm)->iv;
 	ivsize = crypto_blkcipher_ivsize(tfm);
 	memcpy(iv, aes_iv, ivsize);

 	/*
 	print_hex_dump(KERN_ERR, "dec  key: ", DUMP_PREFIX_NONE, 16, 1,
 		       key, key_len, 1);
 	print_hex_dump(KERN_ERR, "dec   in: ", DUMP_PREFIX_NONE, 16, 1,
 		       src, src_len, 1);
 	*/
 	ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len);
 	if (ret < 0) {
 		pr_err("ceph_aes_decrypt failed %d\n", ret);
 		goto out_sg;
 	}

 	if (src_len <= *dst1_len)
 		last_byte = ((char *)dst1)[src_len - 1];
 	else if (src_len <= *dst1_len + *dst2_len)
 		last_byte = ((char *)dst2)[src_len - *dst1_len - 1];
 	else
 		last_byte = pad[src_len - *dst1_len - *dst2_len - 1];
 	if (last_byte <= 16 && src_len >= last_byte) {
 		src_len -= last_byte;
 	} else {
 		pr_err("ceph_aes_decrypt got bad padding %d on src len %d\n",
 		       last_byte, (int)src_len);
 		return -EPERM;  /* bad padding */
 	}

 	if (src_len < *dst1_len) {
 		*dst1_len = src_len;
 		*dst2_len = 0;
 	} else {
 		*dst2_len = src_len - *dst1_len;
 	}
 	/*
 	print_hex_dump(KERN_ERR, "dec  out1: ", DUMP_PREFIX_NONE, 16, 1,
 		       dst1, *dst1_len, 1);
 	print_hex_dump(KERN_ERR, "dec  out2: ", DUMP_PREFIX_NONE, 16, 1,
 		       dst2, *dst2_len, 1);
 	*/

 out_sg:
 	teardown_sgtable(&sg_in);
 out_tfm:
 	crypto_free_blkcipher(tfm);
 	return ret;
 }


 int ceph_decrypt(struct ceph_crypto_key *secret, void *dst, size_t *dst_len,
 		 const void *src, size_t src_len)
 {
 	switch (secret->type) {
 	case CEPH_CRYPTO_NONE:
 		if (*dst_len < src_len)
 			return -ERANGE;
 		memcpy(dst, src, src_len);
 		*dst_len = src_len;
 		return 0;

 	case CEPH_CRYPTO_AES:
 		return ceph_aes_decrypt(secret->key, secret->len, dst,
 					dst_len, src, src_len);

 	default:
 		return -EINVAL;
 	}
 }

 int ceph_decrypt2(struct ceph_crypto_key *secret,
 			void *dst1, size_t *dst1_len,
 			void *dst2, size_t *dst2_len,
 			const void *src, size_t src_len)
 {
 	size_t t;

 	switch (secret->type) {
 	case CEPH_CRYPTO_NONE:
 		if (*dst1_len + *dst2_len < src_len)
 			return -ERANGE;
 		t = min(*dst1_len, src_len);
 		memcpy(dst1, src, t);
 		*dst1_len = t;
 		src += t;
 		src_len -= t;
 		if (src_len) {
 			t = min(*dst2_len, src_len);
 			memcpy(dst2, src, t);
 			*dst2_len = t;
 		}
 		return 0;

 	case CEPH_CRYPTO_AES:
 		return ceph_aes_decrypt2(secret->key, secret->len,
 					 dst1, dst1_len, dst2, dst2_len,
 					 src, src_len);

 	default:
 		return -EINVAL;
 	}
 }

 int ceph_encrypt(struct ceph_crypto_key *secret, void *dst, size_t *dst_len,
 		 const void *src, size_t src_len)
 {
 	switch (secret->type) {
 	case CEPH_CRYPTO_NONE:
 		if (*dst_len < src_len)
 			return -ERANGE;
 		memcpy(dst, src, src_len);
 		*dst_len = src_len;
 		return 0;

 	case CEPH_CRYPTO_AES:
 		return ceph_aes_encrypt(secret->key, secret->len, dst,
 					dst_len, src, src_len);

 	default:
 		return -EINVAL;
 	}
 }

 int ceph_encrypt2(struct ceph_crypto_key *secret, void *dst, size_t *dst_len,
 		  const void *src1, size_t src1_len,
 		  const void *src2, size_t src2_len)
 {
 	switch (secret->type) {
 	case CEPH_CRYPTO_NONE:
 		if (*dst_len < src1_len + src2_len)
 			return -ERANGE;
 		memcpy(dst, src1, src1_len);
 		memcpy(dst + src1_len, src2, src2_len);
 		*dst_len = src1_len + src2_len;
 		return 0;

 	case CEPH_CRYPTO_AES:
 		return ceph_aes_encrypt2(secret->key, secret->len, dst, dst_len,
 					 src1, src1_len, src2, src2_len);

 	default:
 		return -EINVAL;
 	}
 }

 static int ceph_key_preparse(struct key_preparsed_payload *prep)
 {
 	struct ceph_crypto_key *ckey;
 	size_t datalen = prep->datalen;
 	int ret;
 	void *p;

 	ret = -EINVAL;
 	if (datalen <= 0 || datalen > 32767 || !prep->data)
 		goto err;

 	ret = -ENOMEM;
 	ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
 	if (!ckey)
 		goto err;

 	/* TODO ceph_crypto_key_decode should really take const input */
 	p = (void *)prep->data;
 	ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
 	if (ret < 0)
 		goto err_ckey;

 	prep->payload[0] = ckey;
 	prep->quotalen = datalen;
 	return 0;

 err_ckey:
 	kfree(ckey);
 err:
 	return ret;
 }

 static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
 {
 	struct ceph_crypto_key *ckey = prep->payload[0];
 	ceph_crypto_key_destroy(ckey);
 	kfree(ckey);
 }

 static void ceph_key_destroy(struct key *key)
 {
 	struct ceph_crypto_key *ckey = key->payload.data;

 	ceph_crypto_key_destroy(ckey);
 	kfree(ckey);
 }

 struct key_type key_type_ceph = {
 	.name		= "ceph",
 	.preparse	= ceph_key_preparse,
 	.free_preparse	= ceph_key_free_preparse,
 	.instantiate	= generic_key_instantiate,
 	.destroy	= ceph_key_destroy,
 };

 int ceph_crypto_init(void) {
 	return register_key_type(&key_type_ceph);
 }

 void ceph_crypto_shutdown(void) {
 	unregister_key_type(&key_type_ceph);
 }

	#include <linux/ceph/ceph_debug.h>

	#include <linux/err.h>
	#include <linux/scatterlist.h>
	#include <linux/slab.h>
	#include <crypto/hash.h>
	#include <linux/key-type.h>

	#include <keys/ceph-type.h>
	#include <keys/user-type.h>
	#include <linux/ceph/decode.h>
	#include "crypto.h"

	int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
	const struct ceph_crypto_key *src)
	{
	memcpy(dst, src, sizeof(struct ceph_crypto_key));
	dst->key = kmemdup(src->key, src->len, GFP_NOFS);
	if (!dst->key)
	return -ENOMEM;
	return 0;
	}

	int ceph_crypto_key_encode(struct ceph_crypto_key key, void p, void end)
	{
	if (*p + sizeof(u16) + sizeof(key->created) +
	sizeof(u16) + key->len > end)
	return -ERANGE;
	ceph_encode_16(p, key->type);
	ceph_encode_copy(p, &key->created, sizeof(key->created));
	ceph_encode_16(p, key->len);
	ceph_encode_copy(p, key->key, key->len);
	return 0;
	}

	int ceph_crypto_key_decode(struct ceph_crypto_key key, void p, void end)
	{
	ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
	key->type = ceph_decode_16(p);
	ceph_decode_copy(p, &key->created, sizeof(key->created));
	key->len = ceph_decode_16(p);
	ceph_decode_need(p, end, key->len, bad);
	key->key = kmalloc(key->len, GFP_NOFS);
	if (!key->key)
	return -ENOMEM;
	ceph_decode_copy(p, key->key, key->len);
	return 0;

	bad:
	dout("failed to decode crypto key\n");
	return -EINVAL;
	}

	int ceph_crypto_key_unarmor(struct ceph_crypto_key key, const char inkey)
	{
	int inlen = strlen(inkey);
	int blen = inlen * 3 / 4;
	void buf, p;
	int ret;

	dout("crypto_key_unarmor %s\n", inkey);
	buf = kmalloc(blen, GFP_NOFS);
	if (!buf)
	return -ENOMEM;
	blen = ceph_unarmor(buf, inkey, inkey+inlen);
	if (blen < 0) {
	kfree(buf);
	return blen;
	}

	p = buf;
	ret = ceph_crypto_key_decode(key, &p, p + blen);
	kfree(buf);
	if (ret)
	return ret;
	dout("crypto_key_unarmor key %p type %d len %d\n", key,
	key->type, key->len);
	return 0;
	}



	#define AES_KEY_SIZE 16

	static struct crypto_blkcipher *ceph_crypto_alloc_cipher(void)
	{
	return crypto_alloc_blkcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
	}

	static const u8 aes_iv = (u8 )CEPH_AES_IV;

	/*
	* Should be used for buffers allocated with ceph_kvmalloc().
	* Currently these are encrypt out-buffer (ceph_buffer) and decrypt
	* in-buffer (msg front).
	*
	* Dispose of @sgt with teardown_sgtable().
	*
	* @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
	* in cases where a single sg is sufficient. No attempt to reduce the
	* number of sgs by squeezing physically contiguous pages together is
	* made though, for simplicity.
	*/
	static int setup_sgtable(struct sg_table sgt, struct scatterlist prealloc_sg,
	const void *buf, unsigned int buf_len)
	{
	struct scatterlist *sg;
	const bool is_vmalloc = is_vmalloc_addr(buf);
	unsigned int off = offset_in_page(buf);
	unsigned int chunk_cnt = 1;
	unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
	int i;
	int ret;

	if (buf_len == 0) {
	memset(sgt, 0, sizeof(*sgt));
	return -EINVAL;
	}

	if (is_vmalloc) {
	chunk_cnt = chunk_len >> PAGE_SHIFT;
	chunk_len = PAGE_SIZE;
	}

	if (chunk_cnt > 1) {
	ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
	if (ret)
	return ret;
	} else {
	WARN_ON(chunk_cnt != 1);
	sg_init_table(prealloc_sg, 1);
	sgt->sgl = prealloc_sg;
	sgt->nents = sgt->orig_nents = 1;
	}

	for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
	struct page *page;
	unsigned int len = min(chunk_len - off, buf_len);

	if (is_vmalloc)
	page = vmalloc_to_page(buf);
	else
	page = virt_to_page(buf);

	sg_set_page(sg, page, len, off);

	off = 0;
	buf += len;
	buf_len -= len;
	}
	WARN_ON(buf_len != 0);

	return 0;
	}

	static void teardown_sgtable(struct sg_table *sgt)
	{
	if (sgt->orig_nents > 1)
	sg_free_table(sgt);
	}

	static int ceph_aes_encrypt(const void *key, int key_len,
	void dst, size_t dst_len,
	const void *src, size_t src_len)
	{
	struct scatterlist sg_in[2], prealloc_sg;
	struct sg_table sg_out;
	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
	struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 };
	int ret;
	void *iv;
	int ivsize;
	size_t zero_padding = (0x10 - (src_len & 0x0f));
	char pad[16];

	if (IS_ERR(tfm))
	return PTR_ERR(tfm);

	memset(pad, zero_padding, zero_padding);

	*dst_len = src_len + zero_padding;

	sg_init_table(sg_in, 2);
	sg_set_buf(&sg_in[0], src, src_len);
	sg_set_buf(&sg_in[1], pad, zero_padding);
	ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len);
	if (ret)
	goto out_tfm;

	crypto_blkcipher_setkey((void *)tfm, key, key_len);
	iv = crypto_blkcipher_crt(tfm)->iv;
	ivsize = crypto_blkcipher_ivsize(tfm);
	memcpy(iv, aes_iv, ivsize);

	/*
	print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1,
	key, key_len, 1);
	print_hex_dump(KERN_ERR, "enc src: ", DUMP_PREFIX_NONE, 16, 1,
	src, src_len, 1);
	print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1,
	pad, zero_padding, 1);
	*/
	ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in,
	src_len + zero_padding);
	if (ret < 0) {
	pr_err("ceph_aes_crypt failed %d\n", ret);
	goto out_sg;
	}
	/*
	print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1,
	dst, *dst_len, 1);
	*/

	out_sg:
	teardown_sgtable(&sg_out);
	out_tfm:
	crypto_free_blkcipher(tfm);
	return ret;
	}

	static int ceph_aes_encrypt2(const void key, int key_len, void dst,
	size_t *dst_len,
	const void *src1, size_t src1_len,
	const void *src2, size_t src2_len)
	{
	struct scatterlist sg_in[3], prealloc_sg;
	struct sg_table sg_out;
	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
	struct blkcipher_desc desc = { .tfm = tfm, .flags = 0 };
	int ret;
	void *iv;
	int ivsize;
	size_t zero_padding = (0x10 - ((src1_len + src2_len) & 0x0f));
	char pad[16];

	if (IS_ERR(tfm))
	return PTR_ERR(tfm);

	memset(pad, zero_padding, zero_padding);

	*dst_len = src1_len + src2_len + zero_padding;

	sg_init_table(sg_in, 3);
	sg_set_buf(&sg_in[0], src1, src1_len);
	sg_set_buf(&sg_in[1], src2, src2_len);
	sg_set_buf(&sg_in[2], pad, zero_padding);
	ret = setup_sgtable(&sg_out, &prealloc_sg, dst, *dst_len);
	if (ret)
	goto out_tfm;

	crypto_blkcipher_setkey((void *)tfm, key, key_len);
	iv = crypto_blkcipher_crt(tfm)->iv;
	ivsize = crypto_blkcipher_ivsize(tfm);
	memcpy(iv, aes_iv, ivsize);

	/*
	print_hex_dump(KERN_ERR, "enc key: ", DUMP_PREFIX_NONE, 16, 1,
	key, key_len, 1);
	print_hex_dump(KERN_ERR, "enc src1: ", DUMP_PREFIX_NONE, 16, 1,
	src1, src1_len, 1);
	print_hex_dump(KERN_ERR, "enc src2: ", DUMP_PREFIX_NONE, 16, 1,
	src2, src2_len, 1);
	print_hex_dump(KERN_ERR, "enc pad: ", DUMP_PREFIX_NONE, 16, 1,
	pad, zero_padding, 1);
	*/
	ret = crypto_blkcipher_encrypt(&desc, sg_out.sgl, sg_in,
	src1_len + src2_len + zero_padding);
	if (ret < 0) {
	pr_err("ceph_aes_crypt2 failed %d\n", ret);
	goto out_sg;
	}
	/*
	print_hex_dump(KERN_ERR, "enc out: ", DUMP_PREFIX_NONE, 16, 1,
	dst, *dst_len, 1);
	*/

	out_sg:
	teardown_sgtable(&sg_out);
	out_tfm:
	crypto_free_blkcipher(tfm);
	return ret;
	}

	static int ceph_aes_decrypt(const void *key, int key_len,
	void dst, size_t dst_len,
	const void *src, size_t src_len)
	{
	struct sg_table sg_in;
	struct scatterlist sg_out[2], prealloc_sg;
	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
	struct blkcipher_desc desc = { .tfm = tfm };
	char pad[16];
	void *iv;
	int ivsize;
	int ret;
	int last_byte;

	if (IS_ERR(tfm))
	return PTR_ERR(tfm);

	sg_init_table(sg_out, 2);
	sg_set_buf(&sg_out[0], dst, *dst_len);
	sg_set_buf(&sg_out[1], pad, sizeof(pad));
	ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len);
	if (ret)
	goto out_tfm;

	crypto_blkcipher_setkey((void *)tfm, key, key_len);
	iv = crypto_blkcipher_crt(tfm)->iv;
	ivsize = crypto_blkcipher_ivsize(tfm);
	memcpy(iv, aes_iv, ivsize);

	/*
	print_hex_dump(KERN_ERR, "dec key: ", DUMP_PREFIX_NONE, 16, 1,
	key, key_len, 1);
	print_hex_dump(KERN_ERR, "dec in: ", DUMP_PREFIX_NONE, 16, 1,
	src, src_len, 1);
	*/
	ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len);
	if (ret < 0) {
	pr_err("ceph_aes_decrypt failed %d\n", ret);
	goto out_sg;
	}

	if (src_len <= *dst_len)
	last_byte = ((char *)dst)[src_len - 1];
	else
	last_byte = pad[src_len - *dst_len - 1];
	if (last_byte <= 16 && src_len >= last_byte) {
	*dst_len = src_len - last_byte;
	} else {
	pr_err("ceph_aes_decrypt got bad padding %d on src len %d\n",
	last_byte, (int)src_len);
	return -EPERM; /* bad padding */
	}
	/*
	print_hex_dump(KERN_ERR, "dec out: ", DUMP_PREFIX_NONE, 16, 1,
	dst, *dst_len, 1);
	*/

	out_sg:
	teardown_sgtable(&sg_in);
	out_tfm:
	crypto_free_blkcipher(tfm);
	return ret;
	}

	static int ceph_aes_decrypt2(const void *key, int key_len,
	void dst1, size_t dst1_len,
	void dst2, size_t dst2_len,
	const void *src, size_t src_len)
	{
	struct sg_table sg_in;
	struct scatterlist sg_out[3], prealloc_sg;
	struct crypto_blkcipher *tfm = ceph_crypto_alloc_cipher();
	struct blkcipher_desc desc = { .tfm = tfm };
	char pad[16];
	void *iv;
	int ivsize;
	int ret;
	int last_byte;

	if (IS_ERR(tfm))
	return PTR_ERR(tfm);

	sg_init_table(sg_out, 3);
	sg_set_buf(&sg_out[0], dst1, *dst1_len);
	sg_set_buf(&sg_out[1], dst2, *dst2_len);
	sg_set_buf(&sg_out[2], pad, sizeof(pad));
	ret = setup_sgtable(&sg_in, &prealloc_sg, src, src_len);
	if (ret)
	goto out_tfm;

	crypto_blkcipher_setkey((void *)tfm, key, key_len);
	iv = crypto_blkcipher_crt(tfm)->iv;
	ivsize = crypto_blkcipher_ivsize(tfm);
	memcpy(iv, aes_iv, ivsize);

	/*
	print_hex_dump(KERN_ERR, "dec key: ", DUMP_PREFIX_NONE, 16, 1,
	key, key_len, 1);
	print_hex_dump(KERN_ERR, "dec in: ", DUMP_PREFIX_NONE, 16, 1,
	src, src_len, 1);
	*/
	ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in.sgl, src_len);
	if (ret < 0) {
	pr_err("ceph_aes_decrypt failed %d\n", ret);
	goto out_sg;
	}

	if (src_len <= *dst1_len)
	last_byte = ((char *)dst1)[src_len - 1];
	else if (src_len <= dst1_len + dst2_len)
	last_byte = ((char )dst2)[src_len - dst1_len - 1];
	else
	last_byte = pad[src_len - dst1_len - dst2_len - 1];
	if (last_byte <= 16 && src_len >= last_byte) {
	src_len -= last_byte;
	} else {
	pr_err("ceph_aes_decrypt got bad padding %d on src len %d\n",
	last_byte, (int)src_len);
	return -EPERM; /* bad padding */
	}

	if (src_len < *dst1_len) {
	*dst1_len = src_len;
	*dst2_len = 0;
	} else {
	dst2_len = src_len - dst1_len;
	}
	/*
	print_hex_dump(KERN_ERR, "dec out1: ", DUMP_PREFIX_NONE, 16, 1,
	dst1, *dst1_len, 1);
	print_hex_dump(KERN_ERR, "dec out2: ", DUMP_PREFIX_NONE, 16, 1,
	dst2, *dst2_len, 1);
	*/

	out_sg:
	teardown_sgtable(&sg_in);
	out_tfm:
	crypto_free_blkcipher(tfm);
	return ret;
	}


	int ceph_decrypt(struct ceph_crypto_key secret, void dst, size_t *dst_len,
	const void *src, size_t src_len)
	{
	switch (secret->type) {
	case CEPH_CRYPTO_NONE:
	if (*dst_len < src_len)
	return -ERANGE;
	memcpy(dst, src, src_len);
	*dst_len = src_len;
	return 0;

	case CEPH_CRYPTO_AES:
	return ceph_aes_decrypt(secret->key, secret->len, dst,
	dst_len, src, src_len);

	default:
	return -EINVAL;
	}
	}

	int ceph_decrypt2(struct ceph_crypto_key *secret,
	void dst1, size_t dst1_len,
	void dst2, size_t dst2_len,
	const void *src, size_t src_len)
	{
	size_t t;

	switch (secret->type) {
	case CEPH_CRYPTO_NONE:
	if (dst1_len + dst2_len < src_len)
	return -ERANGE;
	t = min(*dst1_len, src_len);
	memcpy(dst1, src, t);
	*dst1_len = t;
	src += t;
	src_len -= t;
	if (src_len) {
	t = min(*dst2_len, src_len);
	memcpy(dst2, src, t);
	*dst2_len = t;
	}
	return 0;

	case CEPH_CRYPTO_AES:
	return ceph_aes_decrypt2(secret->key, secret->len,
	dst1, dst1_len, dst2, dst2_len,
	src, src_len);

	default:
	return -EINVAL;
	}
	}

	int ceph_encrypt(struct ceph_crypto_key secret, void dst, size_t *dst_len,
	const void *src, size_t src_len)
	{
	switch (secret->type) {
	case CEPH_CRYPTO_NONE:
	if (*dst_len < src_len)
	return -ERANGE;
	memcpy(dst, src, src_len);
	*dst_len = src_len;
	return 0;

	case CEPH_CRYPTO_AES:
	return ceph_aes_encrypt(secret->key, secret->len, dst,
	dst_len, src, src_len);

	default:
	return -EINVAL;
	}
	}

	int ceph_encrypt2(struct ceph_crypto_key secret, void dst, size_t *dst_len,
	const void *src1, size_t src1_len,
	const void *src2, size_t src2_len)
	{
	switch (secret->type) {
	case CEPH_CRYPTO_NONE:
	if (*dst_len < src1_len + src2_len)
	return -ERANGE;
	memcpy(dst, src1, src1_len);
	memcpy(dst + src1_len, src2, src2_len);
	*dst_len = src1_len + src2_len;
	return 0;

	case CEPH_CRYPTO_AES:
	return ceph_aes_encrypt2(secret->key, secret->len, dst, dst_len,
	src1, src1_len, src2, src2_len);

	default:
	return -EINVAL;
	}
	}

	static int ceph_key_preparse(struct key_preparsed_payload *prep)
	{
	struct ceph_crypto_key *ckey;
	size_t datalen = prep->datalen;
	int ret;
	void *p;

	ret = -EINVAL;
	if (datalen <= 0 \|\| datalen > 32767 \|\| !prep->data)
	goto err;

	ret = -ENOMEM;
	ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
	if (!ckey)
	goto err;

	/* TODO ceph_crypto_key_decode should really take const input */
	p = (void *)prep->data;
	ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
	if (ret < 0)
	goto err_ckey;

	prep->payload[0] = ckey;
	prep->quotalen = datalen;
	return 0;

	err_ckey:
	kfree(ckey);
	err:
	return ret;
	}

	static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
	{
	struct ceph_crypto_key *ckey = prep->payload[0];
	ceph_crypto_key_destroy(ckey);
	kfree(ckey);
	}

	static void ceph_key_destroy(struct key *key)
	{
	struct ceph_crypto_key *ckey = key->payload.data;

	ceph_crypto_key_destroy(ckey);
	kfree(ckey);
	}

	struct key_type key_type_ceph = {
	.name = "ceph",
	.preparse = ceph_key_preparse,
	.free_preparse = ceph_key_free_preparse,
	.instantiate = generic_key_instantiate,
	.destroy = ceph_key_destroy,
	};

	int ceph_crypto_init(void) {
	return register_key_type(&key_type_ceph);
	}

	void ceph_crypto_shutdown(void) {
	unregister_key_type(&key_type_ceph);
	}