diff options
Diffstat (limited to 'crypto/lrw.c')
| -rw-r--r-- | crypto/lrw.c | 61 |
1 files changed, 37 insertions, 24 deletions
diff --git a/crypto/lrw.c b/crypto/lrw.c index 5504d1325a56..7377b5b486fd 100644 --- a/crypto/lrw.c +++ b/crypto/lrw.c @@ -120,27 +120,28 @@ static int setkey(struct crypto_skcipher *parent, const u8 *key, 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) +/* + * Returns the number of trailing '1' bits in the words of the counter, which is + * represented by 4 32-bit words, arranged from least to most significant. + * At the same time, increments the counter by one. + * + * For example: + * + * u32 counter[4] = { 0xFFFFFFFF, 0x1, 0x0, 0x0 }; + * int i = next_index(&counter); + * // i == 33, counter == { 0x0, 0x2, 0x0, 0x0 } + */ +static int next_index(u32 *counter) { - int x; - __be32 *p = (__be32 *) block; + int i, res = 0; - for (p += 3, x = 0; x < 128; p--, x += 32) { - u32 val = be32_to_cpup(p); - - if (!~val) - continue; - - return x + ffz(val); + for (i = 0; i < 4; i++) { + if (counter[i] + 1 != 0) { + res += ffz(counter[i]++); + break; + } + counter[i] = 0; + res += 32; } /* @@ -214,8 +215,9 @@ static int pre_crypt(struct skcipher_request *req) struct scatterlist *sg; unsigned cryptlen; unsigned offset; - be128 *iv; bool more; + __be32 *iv; + u32 counter[4]; int err; subreq = &rctx->subreq; @@ -230,7 +232,12 @@ static int pre_crypt(struct skcipher_request *req) cryptlen, req->iv); err = skcipher_walk_virt(&w, subreq, false); - iv = w.iv; + iv = (__be32 *)w.iv; + + counter[0] = be32_to_cpu(iv[3]); + counter[1] = be32_to_cpu(iv[2]); + counter[2] = be32_to_cpu(iv[1]); + counter[3] = be32_to_cpu(iv[0]); while (w.nbytes) { unsigned int avail = w.nbytes; @@ -247,10 +254,16 @@ static int pre_crypt(struct skcipher_request *req) /* T <- I*Key2, using the optimization * discussed in the specification */ be128_xor(&rctx->t, &rctx->t, - &ctx->mulinc[get_index128(iv)]); - inc(iv); + &ctx->mulinc[next_index(counter)]); } while ((avail -= bs) >= bs); + if (w.nbytes == w.total) { + iv[0] = cpu_to_be32(counter[3]); + iv[1] = cpu_to_be32(counter[2]); + iv[2] = cpu_to_be32(counter[1]); + iv[3] = cpu_to_be32(counter[0]); + } + err = skcipher_walk_done(&w, avail); } @@ -548,7 +561,7 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb) 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); + (__alignof__(__be32) - 1); inst->alg.ivsize = LRW_BLOCK_SIZE; inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) + |