diff options
| -rw-r--r-- | crypto/echainiv.c | 115 |
1 files changed, 24 insertions, 91 deletions
diff --git a/crypto/echainiv.c b/crypto/echainiv.c index 1b01fe98e91f..e3d889b122e0 100644 --- a/crypto/echainiv.c +++ b/crypto/echainiv.c @@ -1,8 +1,8 @@ /* * echainiv: Encrypted Chain IV Generator * - * This generator generates an IV based on a sequence number by xoring it - * with a salt and then encrypting it with the same key as used to encrypt + * This generator generates an IV based on a sequence number by multiplying + * it with a salt and then encrypting it with the same key as used to encrypt * the plain text. This algorithm requires that the block size be equal * to the IV size. It is mainly useful for CBC. * @@ -24,81 +24,17 @@ #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> -#include <linux/mm.h> #include <linux/module.h> -#include <linux/percpu.h> -#include <linux/spinlock.h> +#include <linux/slab.h> #include <linux/string.h> -#define MAX_IV_SIZE 16 - -static DEFINE_PER_CPU(u32 [MAX_IV_SIZE / sizeof(u32)], echainiv_iv); - -/* We don't care if we get preempted and read/write IVs from the next CPU. */ -static void echainiv_read_iv(u8 *dst, unsigned size) -{ - u32 *a = (u32 *)dst; - u32 __percpu *b = echainiv_iv; - - for (; size >= 4; size -= 4) { - *a++ = this_cpu_read(*b); - b++; - } -} - -static void echainiv_write_iv(const u8 *src, unsigned size) -{ - const u32 *a = (const u32 *)src; - u32 __percpu *b = echainiv_iv; - - for (; size >= 4; size -= 4) { - this_cpu_write(*b, *a); - a++; - b++; - } -} - -static void echainiv_encrypt_complete2(struct aead_request *req, int err) -{ - struct aead_request *subreq = aead_request_ctx(req); - struct crypto_aead *geniv; - unsigned int ivsize; - - if (err == -EINPROGRESS) - return; - - if (err) - goto out; - - geniv = crypto_aead_reqtfm(req); - ivsize = crypto_aead_ivsize(geniv); - - echainiv_write_iv(subreq->iv, ivsize); - - if (req->iv != subreq->iv) - memcpy(req->iv, subreq->iv, ivsize); - -out: - if (req->iv != subreq->iv) - kzfree(subreq->iv); -} - -static void echainiv_encrypt_complete(struct crypto_async_request *base, - int err) -{ - struct aead_request *req = base->data; - - echainiv_encrypt_complete2(req, err); - aead_request_complete(req, err); -} - static int echainiv_encrypt(struct aead_request *req) { struct crypto_aead *geniv = crypto_aead_reqtfm(req); struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv); struct aead_request *subreq = aead_request_ctx(req); - crypto_completion_t compl; - void *data; + __be64 nseqno; + u64 seqno; u8 *info; unsigned int ivsize = crypto_aead_ivsize(geniv); int err; @@ -108,8 +44,6 @@ static int echainiv_encrypt(struct aead_request *req) aead_request_set_tfm(subreq, ctx->child); - compl = echainiv_encrypt_complete; - data = req; info = req->iv; if (req->src != req->dst) { @@ -127,29 +61,30 @@ static int echainiv_encrypt(struct aead_request *req) return err; } - if (unlikely(!IS_ALIGNED((unsigned long)info, - crypto_aead_alignmask(geniv) + 1))) { - info = kmalloc(ivsize, req->base.flags & - CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL: - GFP_ATOMIC); - if (!info) - return -ENOMEM; - - memcpy(info, req->iv, ivsize); - } - - aead_request_set_callback(subreq, req->base.flags, compl, data); + aead_request_set_callback(subreq, req->base.flags, + req->base.complete, req->base.data); aead_request_set_crypt(subreq, req->dst, req->dst, req->cryptlen, info); aead_request_set_ad(subreq, req->assoclen); - crypto_xor(info, ctx->salt, ivsize); + memcpy(&nseqno, info + ivsize - 8, 8); + seqno = be64_to_cpu(nseqno); + memset(info, 0, ivsize); + scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1); - echainiv_read_iv(info, ivsize); - err = crypto_aead_encrypt(subreq); - echainiv_encrypt_complete2(req, err); - return err; + do { + u64 a; + + memcpy(&a, ctx->salt + ivsize - 8, 8); + + a |= 1; + a *= seqno; + + memcpy(info + ivsize - 8, &a, 8); + } while ((ivsize -= 8)); + + return crypto_aead_encrypt(subreq); } static int echainiv_decrypt(struct aead_request *req) @@ -196,8 +131,7 @@ static int echainiv_aead_create(struct crypto_template *tmpl, alg = crypto_spawn_aead_alg(spawn); err = -EINVAL; - if (inst->alg.ivsize & (sizeof(u32) - 1) || - inst->alg.ivsize > MAX_IV_SIZE) + if (inst->alg.ivsize & (sizeof(u64) - 1) || !inst->alg.ivsize) goto free_inst; inst->alg.encrypt = echainiv_encrypt; @@ -206,7 +140,6 @@ static int echainiv_aead_create(struct crypto_template *tmpl, inst->alg.init = aead_init_geniv; inst->alg.exit = aead_exit_geniv; - inst->alg.base.cra_alignmask |= __alignof__(u32) - 1; inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx); inst->alg.base.cra_ctxsize += inst->alg.ivsize; |
