C++ crypto_blkcipher_blocksize函数代码示例

u32
krb5_encrypt(
	struct crypto_blkcipher *tfm,
	void * iv,
	void * in,
	void * out,
	int length)
{
	u32 ret = -EINVAL;
	struct scatterlist sg[1];
	u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };

	if (length % crypto_blkcipher_blocksize(tfm) != 0)
		goto out;

	if (crypto_blkcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
		dprintk("RPC:       gss_k5encrypt: tfm iv size too large %d\n",
			crypto_blkcipher_ivsize(tfm));
		goto out;
	}

	if (iv)
		memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm));

	memcpy(out, in, length);
	sg_init_one(sg, out, length);

	ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, length);
out:
	dprintk("RPC:       krb5_encrypt returns %d\n", ret);
	return ret;
}

u32
krb5_decrypt(
     struct crypto_blkcipher *tfm,
     void * iv,
     void * in,
     void * out,
     int length)
{
	u32 ret = -EINVAL;
	struct scatterlist sg[1];
	u8 local_iv[16] = {0};
	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };

	if (length % crypto_blkcipher_blocksize(tfm) != 0)
		goto out;

	if (crypto_blkcipher_ivsize(tfm) > 16) {
		dprintk("RPC:       gss_k5decrypt: tfm iv size to large %d\n",
			crypto_blkcipher_ivsize(tfm));
		goto out;
	}
	if (iv)
		memcpy(local_iv,iv, crypto_blkcipher_ivsize(tfm));

	memcpy(out, in, length);
	sg_set_buf(sg, out, length);

	ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, length);
out:
	dprintk("RPC:       gss_k5decrypt returns %d\n",ret);
	return ret;
}

static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
{
	struct esp_data *esp = x->data;
	u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
	u32 align = max_t(u32, blksize, esp->conf.padlen);
	u32 rem;

	mtu -= x->props.header_len + esp->auth.icv_trunc_len;
	rem = mtu & (align - 1);
	mtu &= ~(align - 1);

	switch (x->props.mode) {
	case XFRM_MODE_TUNNEL:
		break;
	default:
	case XFRM_MODE_TRANSPORT:
		/* The worst case */
		mtu -= blksize - 4;
		mtu += min_t(u32, blksize - 4, rem);
		break;
	case XFRM_MODE_BEET:
		/* The worst case. */
		mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
		break;
	}

	return mtu - 2;
}

int blkcipher_walk_phys(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk)
{
	walk->flags |= BLKCIPHER_WALK_PHYS;
	walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
	return blkcipher_walk_first(desc, walk);
}

static u32 esp4_get_max_size(struct xfrm_state *x, int mtu)
{
	struct esp_data *esp = x->data;
	u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
	int enclen = 0;

	switch (x->props.mode) {
	case XFRM_MODE_TUNNEL:
		mtu = ALIGN(mtu +2, blksize);
		break;
	default:
	case XFRM_MODE_TRANSPORT:
		/* The worst case */
		mtu = ALIGN(mtu + 2, 4) + blksize - 4;
		break;
	case XFRM_MODE_BEET:
 		/* The worst case. */
		enclen = IPV4_BEET_PHMAXLEN;
		mtu = ALIGN(mtu + enclen + 2, blksize);
		break;
	}

	if (esp->conf.padlen)
		mtu = ALIGN(mtu, esp->conf.padlen);

	return mtu + x->props.header_len + esp->auth.icv_trunc_len - enclen;
}

static int crypto_cts_decrypt(struct blkcipher_desc *desc,
			      struct scatterlist *dst, struct scatterlist *src,
			      unsigned int nbytes)
{
	struct crypto_cts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	int bsize = crypto_blkcipher_blocksize(desc->tfm);
	int tot_blocks = (nbytes + bsize - 1) / bsize;
	int cbc_blocks = tot_blocks > 2 ? tot_blocks - 2 : 0;
	struct blkcipher_desc lcldesc;
	int err;

	lcldesc.tfm = ctx->child;
	lcldesc.info = desc->info;
	lcldesc.flags = desc->flags;

	if (tot_blocks == 1) {
		err = crypto_blkcipher_decrypt_iv(&lcldesc, dst, src, bsize);
	} else if (nbytes <= bsize * 2) {
		err = cts_cbc_decrypt(ctx, desc, dst, src, 0, nbytes);
	} else {
		/* do normal function for tot_blocks - 2 */
		err = crypto_blkcipher_decrypt_iv(&lcldesc, dst, src,
							cbc_blocks * bsize);
		if (err == 0) {
			/* do cts for final two blocks */
			err = cts_cbc_decrypt(ctx, desc, dst, src,
						cbc_blocks * bsize,
						nbytes - (cbc_blocks * bsize));
		}
	}
	return err;
}

static int cts_cbc_decrypt(struct crypto_cts_ctx *ctx,
			   struct blkcipher_desc *desc,
			   struct scatterlist *dst,
			   struct scatterlist *src,
			   unsigned int offset,
			   unsigned int nbytes)
{
	int bsize = crypto_blkcipher_blocksize(desc->tfm);
	u8 tmp[bsize];
	struct blkcipher_desc lcldesc;
	struct scatterlist sgsrc[1], sgdst[1];
	int lastn = nbytes - bsize;
	u8 iv[bsize];
	u8 s[bsize * 2], d[bsize * 2];
	int err;

	if (lastn < 0)
		return -EINVAL;

	sg_init_table(sgsrc, 1);
	sg_init_table(sgdst, 1);

	scatterwalk_map_and_copy(s, src, offset, nbytes, 0);

	lcldesc.tfm = ctx->child;
	lcldesc.info = iv;
	lcldesc.flags = desc->flags;

	/* 1. Decrypt Cn-1 (s) to create Dn (tmp)*/
	memset(iv, 0, sizeof(iv));
	sg_set_buf(&sgsrc[0], s, bsize);
	sg_set_buf(&sgdst[0], tmp, bsize);
	err = crypto_blkcipher_decrypt_iv(&lcldesc, sgdst, sgsrc, bsize);
	if (err)
		return err;
	/* 2. Pad Cn with zeros at the end to create C of length BB */
	memset(iv, 0, sizeof(iv));
	memcpy(iv, s + bsize, lastn);
	/* 3. Exclusive-or Dn (tmp) with C (iv) to create Xn (tmp) */
	crypto_xor(tmp, iv, bsize);
	/* 4. Select the first Ln bytes of Xn (tmp) to create Pn */
	memcpy(d + bsize, tmp, lastn);

	/* 5. Append the tail (BB - Ln) bytes of Xn (tmp) to Cn to create En */
	memcpy(s + bsize + lastn, tmp + lastn, bsize - lastn);
	/* 6. Decrypt En to create Pn-1 */
	memset(iv, 0, sizeof(iv));
	sg_set_buf(&sgsrc[0], s + bsize, bsize);
	sg_set_buf(&sgdst[0], d, bsize);
	err = crypto_blkcipher_decrypt_iv(&lcldesc, sgdst, sgsrc, bsize);

	/* XOR with previous block */
	crypto_xor(d, desc->info, bsize);

	scatterwalk_map_and_copy(d, dst, offset, nbytes, 1);

	memcpy(desc->info, s, bsize);
	return err;
}

int blkcipher_walk_phys(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk)
{
	walk->flags |= BLKCIPHER_WALK_PHYS;
	walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
	walk->cipher_blocksize = walk->walk_blocksize;
	walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
	walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
	return blkcipher_walk_first(desc, walk);
}

int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
			      struct blkcipher_walk *walk,
			      unsigned int blocksize)
{
	walk->flags &= ~BLKCIPHER_WALK_PHYS;
	walk->walk_blocksize = blocksize;
	walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
	walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
	walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
	return blkcipher_walk_first(desc, walk);
}

static int blkcipher_walk_next(struct blkcipher_desc *desc,
			       struct blkcipher_walk *walk)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
	unsigned int bsize;
	unsigned int n;
	int err;

	n = walk->total;
	if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
		desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return blkcipher_walk_done(desc, walk, -EINVAL);
	}

	walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
			 BLKCIPHER_WALK_DIFF);
	if (!scatterwalk_aligned(&walk->in, alignmask) ||
	    !scatterwalk_aligned(&walk->out, alignmask) ||
	    (walk->flags & AMBA_CIPHER_COPY)) {
		walk->flags |= BLKCIPHER_WALK_COPY;
		if (!walk->page) {
			walk->page = (void *)__get_free_page(GFP_ATOMIC);
			if (!walk->page)
				n = 0;
		}
	}

	bsize = min(walk->blocksize, n);
	n = scatterwalk_clamp(&walk->in, n);
	n = scatterwalk_clamp(&walk->out, n);

	if (unlikely(n < bsize)) {
		err = blkcipher_next_slow(desc, walk, bsize, alignmask);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;
	if (walk->flags & BLKCIPHER_WALK_COPY) {
		err = blkcipher_next_copy(walk);
		goto set_phys_lowmem;
	}

	return blkcipher_next_fast(desc, walk);

set_phys_lowmem:
	if (walk->flags & BLKCIPHER_WALK_PHYS) {
		walk->src.phys.page = virt_to_page(walk->src.virt.addr);
		walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
		walk->src.phys.offset &= PAGE_SIZE - 1;
		walk->dst.phys.offset &= PAGE_SIZE - 1;
	}
	return err;
}

static int cts_cbc_encrypt(struct crypto_cts_ctx *ctx,
			   struct blkcipher_desc *desc,
			   struct scatterlist *dst,
			   struct scatterlist *src,
			   unsigned int offset,
			   unsigned int nbytes)
{
	int bsize = crypto_blkcipher_blocksize(desc->tfm);
	u8 tmp[bsize], tmp2[bsize];
	struct blkcipher_desc lcldesc;
	struct scatterlist sgsrc[1], sgdst[1];
	int lastn = nbytes - bsize;
	u8 iv[bsize];
	u8 s[bsize * 2], d[bsize * 2];
	int err;

	if (lastn < 0)
		return -EINVAL;

	sg_init_table(sgsrc, 1);
	sg_init_table(sgdst, 1);

	memset(s, 0, sizeof(s));
	scatterwalk_map_and_copy(s, src, offset, nbytes, 0);

	memcpy(iv, desc->info, bsize);

	lcldesc.tfm = ctx->child;
	lcldesc.info = iv;
	lcldesc.flags = desc->flags;

	sg_set_buf(&sgsrc[0], s, bsize);
	sg_set_buf(&sgdst[0], tmp, bsize);
	err = crypto_blkcipher_encrypt_iv(&lcldesc, sgdst, sgsrc, bsize);

	memcpy(d + bsize, tmp, lastn);

	lcldesc.info = tmp;

	sg_set_buf(&sgsrc[0], s + bsize, bsize);
	sg_set_buf(&sgdst[0], tmp2, bsize);
	err = crypto_blkcipher_encrypt_iv(&lcldesc, sgdst, sgsrc, bsize);

	memcpy(d, tmp2, bsize);

	scatterwalk_map_and_copy(d, dst, offset, nbytes, 1);

	memcpy(desc->info, tmp2, bsize);

	return err;
}

static int aes_get_sizes(void)
{
	struct crypto_blkcipher *tfm;

	tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm)) {
		pr_err("encrypted_key: failed to alloc_cipher (%ld)\n",
		       PTR_ERR(tfm));
		return PTR_ERR(tfm);
	}
	ivsize = crypto_blkcipher_ivsize(tfm);
	blksize = crypto_blkcipher_blocksize(tfm);
	crypto_free_blkcipher(tfm);
	return 0;
}

int dek_aes_decrypt(struct crypto_blkcipher *sdp_tfm, char *src, char *dst, int len) {
	struct blkcipher_desc desc;
	struct scatterlist src_sg, dst_sg;
	int bsize = crypto_blkcipher_blocksize(sdp_tfm);
	u8 iv[bsize];

	memset(&iv, 0, sizeof(iv));
	desc.tfm = sdp_tfm;
	desc.info = iv;
	desc.flags = 0;

	sg_init_one(&src_sg, src, len);
	sg_init_one(&dst_sg, dst, len);

	return crypto_blkcipher_decrypt_iv(&desc, &dst_sg, &src_sg, len);
}

static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
{
	struct esp_data *esp = x->data;
	u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);

	if (x->props.mode == XFRM_MODE_TUNNEL) {
		mtu = ALIGN(mtu + 2, blksize);
	} else {
		/* The worst case. */
		u32 padsize = ((blksize - 1) & 7) + 1;
		mtu = ALIGN(mtu + 2, padsize) + blksize - padsize;
	}
	if (esp->conf.padlen)
		mtu = ALIGN(mtu, esp->conf.padlen);

	return mtu + x->props.header_len + esp->auth.icv_trunc_len;
}

static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
{
    struct esp_data *esp = x->data;
    u32 blksize = ALIGN(crypto_blkcipher_blocksize(esp->conf.tfm), 4);
    u32 align = max_t(u32, blksize, esp->conf.padlen);
    u32 rem;

    mtu -= x->props.header_len + esp->auth.icv_trunc_len;
    rem = mtu & (align - 1);
    mtu &= ~(align - 1);

    if (x->props.mode != XFRM_MODE_TUNNEL) {
        u32 padsize = ((blksize - 1) & 7) + 1;
        mtu -= blksize - padsize;
        mtu += min_t(u32, blksize - padsize, rem);
    }

    return mtu - 2;
}