Skip to content
Snippets Groups Projects
Select Git revision
  • 1f7fdcd1f4d390dab008edcb32197bb12bbd9908
  • deploy/production default
  • deploy/test
3 results

SprintListController.php

Blame
  • lrw.c 13.23 KiB
    /* LRW: as defined by Cyril Guyot in
     *	http://grouper.ieee.org/groups/1619/email/pdf00017.pdf
     *
     * Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
     *
     * Based on ecb.c
     * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
     *
     * This program 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 2 of the License, or (at your option)
     * any later version.
     */
    /* This implementation is checked against the test vectors in the above
     * document and by a test vector provided by Ken Buchanan at
     * http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
     *
     * The test vectors are included in the testing module tcrypt.[ch] */
    
    #include <crypto/internal/skcipher.h>
    #include <crypto/scatterwalk.h>
    #include <linux/err.h>
    #include <linux/init.h>
    #include <linux/kernel.h>
    #include <linux/module.h>
    #include <linux/scatterlist.h>
    #include <linux/slab.h>
    
    #include <crypto/b128ops.h>
    #include <crypto/gf128mul.h>
    
    #define LRW_BUFFER_SIZE 128u
    
    #define LRW_BLOCK_SIZE 16
    
    struct priv {
    	struct crypto_skcipher *child;
    
    	/*
    	 * optimizes multiplying a random (non incrementing, as at the
    	 * start of a new sector) value with key2, we could also have
    	 * used 4k optimization tables or no optimization at all. In the
    	 * latter case we would have to store key2 here
    	 */
    	struct gf128mul_64k *table;
    
    	/*
    	 * stores:
    	 *  key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
    	 *  key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
    	 *  key2*{ 0,0,...1,1,1,1,1 }, etc
    	 * needed for optimized multiplication of incrementing values
    	 * with key2
    	 */
    	be128 mulinc[128];
    };
    
    struct rctx {
    	be128 buf[LRW_BUFFER_SIZE / sizeof(be128)];
    
    	be128 t;
    
    	be128 *ext;
    
    	struct scatterlist srcbuf[2];
    	struct scatterlist dstbuf[2];
    	struct scatterlist *src;
    	struct scatterlist *dst;
    
    	unsigned int left;
    
    	struct skcipher_request subreq;
    };
    
    static inline void setbit128_bbe(void *b, int bit)
    {
    	__set_bit(bit ^ (0x80 -
    #ifdef __BIG_ENDIAN
    			 BITS_PER_LONG
    #else
    			 BITS_PER_BYTE
    #endif
    			), b);
    }
    
    static int setkey(struct crypto_skcipher *parent, const u8 *key,
    		  unsigned int keylen)
    {
    	struct priv *ctx = crypto_skcipher_ctx(parent);
    	struct crypto_skcipher *child = ctx->child;
    	int err, bsize = LRW_BLOCK_SIZE;
    	const u8 *tweak = key + keylen - bsize;
    	be128 tmp = { 0 };
    	int i;
    
    	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
    	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
    					 CRYPTO_TFM_REQ_MASK);
    	err = crypto_skcipher_setkey(child, key, keylen - bsize);
    	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
    					  CRYPTO_TFM_RES_MASK);
    	if (err)
    		return err;
    
    	if (ctx->table)
    		gf128mul_free_64k(ctx->table);
    
    	/* initialize multiplication table for Key2 */
    	ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
    	if (!ctx->table)
    		return -ENOMEM;
    
    	/* initialize optimization table */
    	for (i = 0; i < 128; i++) {
    		setbit128_bbe(&tmp, i);
    		ctx->mulinc[i] = tmp;
    		gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
    	}
    
    	return 0;
    }
    
    static inline void inc(be128 *iv)
    {
    	be64_add_cpu(&iv->b, 1);
    	if (!iv->b)
    		be64_add_cpu(&iv->a, 1);
    }
    
    /* this returns the number of consequative 1 bits starting
     * from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */
    static inline int get_index128(be128 *block)
    {
    	int x;
    	__be32 *p = (__be32 *) block;
    
    	for (p += 3, x = 0; x < 128; p--, x += 32) {
    		u32 val = be32_to_cpup(p);
    
    		if (!~val)
    			continue;
    
    		return x + ffz(val);
    	}
    
    	return x;
    }
    
    static int post_crypt(struct skcipher_request *req)
    {
    	struct rctx *rctx = skcipher_request_ctx(req);
    	be128 *buf = rctx->ext ?: rctx->buf;
    	struct skcipher_request *subreq;
    	const int bs = LRW_BLOCK_SIZE;
    	struct skcipher_walk w;
    	struct scatterlist *sg;
    	unsigned offset;
    	int err;
    
    	subreq = &rctx->subreq;
    	err = skcipher_walk_virt(&w, subreq, false);
    
    	while (w.nbytes) {
    		unsigned int avail = w.nbytes;
    		be128 *wdst;
    
    		wdst = w.dst.virt.addr;
    
    		do {
    			be128_xor(wdst, buf++, wdst);
    			wdst++;
    		} while ((avail -= bs) >= bs);
    
    		err = skcipher_walk_done(&w, avail);
    	}
    
    	rctx->left -= subreq->cryptlen;
    
    	if (err || !rctx->left)
    		goto out;
    
    	rctx->dst = rctx->dstbuf;
    
    	scatterwalk_done(&w.out, 0, 1);
    	sg = w.out.sg;
    	offset = w.out.offset;
    
    	if (rctx->dst != sg) {
    		rctx->dst[0] = *sg;
    		sg_unmark_end(rctx->dst);
    		scatterwalk_crypto_chain(rctx->dst, sg_next(sg), 0, 2);
    	}
    	rctx->dst[0].length -= offset - sg->offset;
    	rctx->dst[0].offset = offset;
    
    out:
    	return err;
    }
    
    static int pre_crypt(struct skcipher_request *req)
    {
    	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
    	struct rctx *rctx = skcipher_request_ctx(req);
    	struct priv *ctx = crypto_skcipher_ctx(tfm);
    	be128 *buf = rctx->ext ?: rctx->buf;
    	struct skcipher_request *subreq;
    	const int bs = LRW_BLOCK_SIZE;
    	struct skcipher_walk w;
    	struct scatterlist *sg;
    	unsigned cryptlen;
    	unsigned offset;
    	be128 *iv;
    	bool more;
    	int err;
    
    	subreq = &rctx->subreq;
    	skcipher_request_set_tfm(subreq, tfm);
    
    	cryptlen = subreq->cryptlen;
    	more = rctx->left > cryptlen;
    	if (!more)
    		cryptlen = rctx->left;
    
    	skcipher_request_set_crypt(subreq, rctx->src, rctx->dst,
    				   cryptlen, req->iv);
    
    	err = skcipher_walk_virt(&w, subreq, false);
    	iv = w.iv;
    
    	while (w.nbytes) {
    		unsigned int avail = w.nbytes;
    		be128 *wsrc;
    		be128 *wdst;
    
    		wsrc = w.src.virt.addr;
    		wdst = w.dst.virt.addr;
    
    		do {
    			*buf++ = rctx->t;
    			be128_xor(wdst++, &rctx->t, wsrc++);
    
    			/* T <- I*Key2, using the optimization
    			 * discussed in the specification */
    			be128_xor(&rctx->t, &rctx->t,
    				  &ctx->mulinc[get_index128(iv)]);
    			inc(iv);
    		} while ((avail -= bs) >= bs);
    
    		err = skcipher_walk_done(&w, avail);
    	}
    
    	skcipher_request_set_tfm(subreq, ctx->child);
    	skcipher_request_set_crypt(subreq, rctx->dst, rctx->dst,
    				   cryptlen, NULL);
    
    	if (err || !more)
    		goto out;
    
    	rctx->src = rctx->srcbuf;
    
    	scatterwalk_done(&w.in, 0, 1);
    	sg = w.in.sg;
    	offset = w.in.offset;
    
    	if (rctx->src != sg) {
    		rctx->src[0] = *sg;
    		sg_unmark_end(rctx->src);
    		scatterwalk_crypto_chain(rctx->src, sg_next(sg), 0, 2);
    	}
    	rctx->src[0].length -= offset - sg->offset;
    	rctx->src[0].offset = offset;
    
    out:
    	return err;
    }
    
    static int init_crypt(struct skcipher_request *req, crypto_completion_t done)
    {
    	struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
    	struct rctx *rctx = skcipher_request_ctx(req);
    	struct skcipher_request *subreq;
    	gfp_t gfp;
    
    	subreq = &rctx->subreq;
    	skcipher_request_set_callback(subreq, req->base.flags, done, req);
    
    	gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
    							   GFP_ATOMIC;
    	rctx->ext = NULL;
    
    	subreq->cryptlen = LRW_BUFFER_SIZE;
    	if (req->cryptlen > LRW_BUFFER_SIZE) {
    		unsigned int n = min(req->cryptlen, (unsigned int)PAGE_SIZE);
    
    		rctx->ext = kmalloc(n, gfp);
    		if (rctx->ext)
    			subreq->cryptlen = n;
    	}
    
    	rctx->src = req->src;
    	rctx->dst = req->dst;
    	rctx->left = req->cryptlen;
    
    	/* calculate first value of T */
    	memcpy(&rctx->t, req->iv, sizeof(rctx->t));
    
    	/* T <- I*Key2 */
    	gf128mul_64k_bbe(&rctx->t, ctx->table);
    
    	return 0;
    }
    
    static void exit_crypt(struct skcipher_request *req)
    {
    	struct rctx *rctx = skcipher_request_ctx(req);
    
    	rctx->left = 0;
    
    	if (rctx->ext)
    		kzfree(rctx->ext);
    }
    
    static int do_encrypt(struct skcipher_request *req, int err)
    {
    	struct rctx *rctx = skcipher_request_ctx(req);
    	struct skcipher_request *subreq;
    
    	subreq = &rctx->subreq;
    
    	while (!err && rctx->left) {
    		err = pre_crypt(req) ?:
    		      crypto_skcipher_encrypt(subreq) ?:
    		      post_crypt(req);
    
    		if (err == -EINPROGRESS || err == -EBUSY)
    			return err;
    	}
    
    	exit_crypt(req);
    	return err;
    }
    
    static void encrypt_done(struct crypto_async_request *areq, int err)
    {
    	struct skcipher_request *req = areq->data;
    	struct skcipher_request *subreq;
    	struct rctx *rctx;
    
    	rctx = skcipher_request_ctx(req);
    
    	if (err == -EINPROGRESS) {
    		if (rctx->left != req->cryptlen)
    			return;
    		goto out;
    	}
    
    	subreq = &rctx->subreq;
    	subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
    
    	err = do_encrypt(req, err ?: post_crypt(req));
    	if (rctx->left)
    		return;
    
    out:
    	skcipher_request_complete(req, err);
    }
    
    static int encrypt(struct skcipher_request *req)
    {
    	return do_encrypt(req, init_crypt(req, encrypt_done));
    }
    
    static int do_decrypt(struct skcipher_request *req, int err)
    {
    	struct rctx *rctx = skcipher_request_ctx(req);
    	struct skcipher_request *subreq;
    
    	subreq = &rctx->subreq;
    
    	while (!err && rctx->left) {
    		err = pre_crypt(req) ?:
    		      crypto_skcipher_decrypt(subreq) ?:
    		      post_crypt(req);
    
    		if (err == -EINPROGRESS || err == -EBUSY)
    			return err;
    	}
    
    	exit_crypt(req);
    	return err;
    }
    
    static void decrypt_done(struct crypto_async_request *areq, int err)
    {
    	struct skcipher_request *req = areq->data;
    	struct skcipher_request *subreq;
    	struct rctx *rctx;
    
    	rctx = skcipher_request_ctx(req);
    
    	if (err == -EINPROGRESS) {
    		if (rctx->left != req->cryptlen)
    			return;
    		goto out;
    	}
    
    	subreq = &rctx->subreq;
    	subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
    
    	err = do_decrypt(req, err ?: post_crypt(req));
    	if (rctx->left)
    		return;
    
    out:
    	skcipher_request_complete(req, err);
    }
    
    static int decrypt(struct skcipher_request *req)
    {
    	return do_decrypt(req, init_crypt(req, decrypt_done));
    }
    
    static int init_tfm(struct crypto_skcipher *tfm)
    {
    	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
    	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
    	struct priv *ctx = crypto_skcipher_ctx(tfm);
    	struct crypto_skcipher *cipher;
    
    	cipher = crypto_spawn_skcipher(spawn);
    	if (IS_ERR(cipher))
    		return PTR_ERR(cipher);
    
    	ctx->child = cipher;
    
    	crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(cipher) +
    					 sizeof(struct rctx));
    
    	return 0;
    }
    
    static void exit_tfm(struct crypto_skcipher *tfm)
    {
    	struct priv *ctx = crypto_skcipher_ctx(tfm);
    
    	if (ctx->table)
    		gf128mul_free_64k(ctx->table);
    	crypto_free_skcipher(ctx->child);
    }
    
    static void free(struct skcipher_instance *inst)
    {
    	crypto_drop_skcipher(skcipher_instance_ctx(inst));
    	kfree(inst);
    }
    
    static int create(struct crypto_template *tmpl, struct rtattr **tb)
    {
    	struct crypto_skcipher_spawn *spawn;
    	struct skcipher_instance *inst;
    	struct crypto_attr_type *algt;
    	struct skcipher_alg *alg;
    	const char *cipher_name;
    	char ecb_name[CRYPTO_MAX_ALG_NAME];
    	int err;
    
    	algt = crypto_get_attr_type(tb);
    	if (IS_ERR(algt))
    		return PTR_ERR(algt);
    
    	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
    		return -EINVAL;
    
    	cipher_name = crypto_attr_alg_name(tb[1]);
    	if (IS_ERR(cipher_name))
    		return PTR_ERR(cipher_name);
    
    	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
    	if (!inst)
    		return -ENOMEM;
    
    	spawn = skcipher_instance_ctx(inst);
    
    	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
    	err = crypto_grab_skcipher(spawn, cipher_name, 0,
    				   crypto_requires_sync(algt->type,
    							algt->mask));
    	if (err == -ENOENT) {
    		err = -ENAMETOOLONG;
    		if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
    			     cipher_name) >= CRYPTO_MAX_ALG_NAME)
    			goto err_free_inst;
    
    		err = crypto_grab_skcipher(spawn, ecb_name, 0,
    					   crypto_requires_sync(algt->type,
    								algt->mask));
    	}
    
    	if (err)
    		goto err_free_inst;
    
    	alg = crypto_skcipher_spawn_alg(spawn);
    
    	err = -EINVAL;
    	if (alg->base.cra_blocksize != LRW_BLOCK_SIZE)
    		goto err_drop_spawn;
    
    	if (crypto_skcipher_alg_ivsize(alg))
    		goto err_drop_spawn;
    
    	err = crypto_inst_setname(skcipher_crypto_instance(inst), "lrw",
    				  &alg->base);
    	if (err)
    		goto err_drop_spawn;
    
    	err = -EINVAL;
    	cipher_name = alg->base.cra_name;
    
    	/* Alas we screwed up the naming so we have to mangle the
    	 * cipher name.
    	 */
    	if (!strncmp(cipher_name, "ecb(", 4)) {
    		unsigned len;
    
    		len = strlcpy(ecb_name, cipher_name + 4, sizeof(ecb_name));
    		if (len < 2 || len >= sizeof(ecb_name))
    			goto err_drop_spawn;
    
    		if (ecb_name[len - 1] != ')')
    			goto err_drop_spawn;
    
    		ecb_name[len - 1] = 0;
    
    		if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
    			     "lrw(%s)", ecb_name) >= CRYPTO_MAX_ALG_NAME) {
    			err = -ENAMETOOLONG;
    			goto err_drop_spawn;
    		}
    	} else
    		goto err_drop_spawn;
    
    	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
    	inst->alg.base.cra_priority = alg->base.cra_priority;
    	inst->alg.base.cra_blocksize = LRW_BLOCK_SIZE;
    	inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
    				       (__alignof__(u64) - 1);
    
    	inst->alg.ivsize = LRW_BLOCK_SIZE;
    	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
    				LRW_BLOCK_SIZE;
    	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
    				LRW_BLOCK_SIZE;
    
    	inst->alg.base.cra_ctxsize = sizeof(struct priv);
    
    	inst->alg.init = init_tfm;
    	inst->alg.exit = exit_tfm;
    
    	inst->alg.setkey = setkey;
    	inst->alg.encrypt = encrypt;
    	inst->alg.decrypt = decrypt;
    
    	inst->free = free;
    
    	err = skcipher_register_instance(tmpl, inst);
    	if (err)
    		goto err_drop_spawn;
    
    out:
    	return err;
    
    err_drop_spawn:
    	crypto_drop_skcipher(spawn);
    err_free_inst:
    	kfree(inst);
    	goto out;
    }
    
    static struct crypto_template crypto_tmpl = {
    	.name = "lrw",
    	.create = create,
    	.module = THIS_MODULE,
    };
    
    static int __init crypto_module_init(void)
    {
    	return crypto_register_template(&crypto_tmpl);
    }
    
    static void __exit crypto_module_exit(void)
    {
    	crypto_unregister_template(&crypto_tmpl);
    }
    
    module_init(crypto_module_init);
    module_exit(crypto_module_exit);
    
    MODULE_LICENSE("GPL");
    MODULE_DESCRIPTION("LRW block cipher mode");
    MODULE_ALIAS_CRYPTO("lrw");