-static __u8 zero_iv[CIPHER_MAX_BLKSIZE] = { 0, };
-
-static void buf_to_sl(struct scatterlist *sl,
- void *buf, unsigned int len)
-{
- sl->page = virt_to_page(buf);
- sl->offset = offset_in_page(buf);
- sl->length = len;
-}
-
-/*
- * CTS CBC encryption:
- * 1. X(n-1) = P(n-1)
- * 2. E(n-1) = Encrypt(K, X(n-1))
- * 3. C(n) = HEAD(E(n-1))
- * 4. P = P(n) | 0
- * 5. D(n) = E(n-1) XOR P
- * 6. C(n-1) = Encrypt(K, D(n))
- *
- * CTS encryption using standard CBC interface:
- * 1. pad the last partial block with 0.
- * 2. do CBC encryption.
- * 3. swap the last two ciphertext blocks.
- * 4. truncate to original plaintext size.
- */
-static int cbc_cts_encrypt(struct ll_crypto_cipher *tfm,
- struct scatterlist *sld,
- struct scatterlist *sls)
-{
- struct scatterlist slst, sldt;
- struct blkcipher_desc desc;
- void *data;
- __u8 sbuf[CIPHER_MAX_BLKSIZE];
- __u8 dbuf[CIPHER_MAX_BLKSIZE];
- unsigned int blksize, blks, tail;
- int rc;
-
- blksize = ll_crypto_blkcipher_blocksize(tfm);
- blks = sls->length / blksize;
- tail = sls->length % blksize;
- LASSERT(blks > 0 && tail > 0);
-
- /* pad tail block with 0, copy to sbuf */
- data = cfs_kmap(sls->page);
- memcpy(sbuf, data + sls->offset + blks * blksize, tail);
- memset(sbuf + tail, 0, blksize - tail);
- cfs_kunmap(sls->page);
-
- buf_to_sl(&slst, sbuf, blksize);
- buf_to_sl(&sldt, dbuf, blksize);
- desc.tfm = tfm;
- desc.flags = 0;
-
- /* encrypt head */
- rc = ll_crypto_blkcipher_encrypt(&desc, sld, sls, sls->length - tail);
- if (unlikely(rc)) {
- CERROR("encrypt head (%u) data: %d\n", sls->length - tail, rc);
- return rc;
- }
- /* encrypt tail */
- rc = ll_crypto_blkcipher_encrypt(&desc, &sldt, &slst, blksize);
- if (unlikely(rc)) {
- CERROR("encrypt tail (%u) data: %d\n", slst.length, rc);
- return rc;
- }
-
- /* swab C(n) and C(n-1), if n == 1, then C(n-1) is the IV */
- data = cfs_kmap(sld->page);
-
- memcpy(data + sld->offset + blks * blksize,
- data + sld->offset + (blks - 1) * blksize, tail);
- memcpy(data + sld->offset + (blks - 1) * blksize, dbuf, blksize);
- cfs_kunmap(sld->page);
-
- return 0;
-}
-
-/*
- * CTS CBC decryption:
- * 1. D(n) = Decrypt(K, C(n-1))
- * 2. C = C(n) | 0
- * 3. X(n) = D(n) XOR C
- * 4. P(n) = HEAD(X(n))
- * 5. E(n-1) = C(n) | TAIL(X(n))
- * 6. X(n-1) = Decrypt(K, E(n-1))
- * 7. P(n-1) = X(n-1) XOR C(n-2)
- *
- * CTS decryption using standard CBC interface:
- * 1. D(n) = Decrypt(K, C(n-1))
- * 2. C(n) = C(n) | TAIL(D(n))
- * 3. swap the last two ciphertext blocks.
- * 4. do CBC decryption.
- * 5. truncate to original ciphertext size.
- */
-static int cbc_cts_decrypt(struct ll_crypto_cipher *tfm,
- struct scatterlist *sld,
- struct scatterlist *sls)
-{
- struct blkcipher_desc desc;
- struct scatterlist slst, sldt;
- void *data;
- __u8 sbuf[CIPHER_MAX_BLKSIZE];
- __u8 dbuf[CIPHER_MAX_BLKSIZE];
- unsigned int blksize, blks, tail;
- int rc;
-
- blksize = ll_crypto_blkcipher_blocksize(tfm);
- blks = sls->length / blksize;
- tail = sls->length % blksize;
- LASSERT(blks > 0 && tail > 0);
-
- /* save current IV, and set IV to zero */
- ll_crypto_blkcipher_get_iv(tfm, sbuf, blksize);
- ll_crypto_blkcipher_set_iv(tfm, zero_iv, blksize);
-
- /* D(n) = Decrypt(K, C(n-1)) */
- slst = *sls;
- slst.offset += (blks - 1) * blksize;
- slst.length = blksize;
-
- buf_to_sl(&sldt, dbuf, blksize);
- desc.tfm = tfm;
- desc.flags = 0;
-
- rc = ll_crypto_blkcipher_decrypt(&desc, &sldt, &slst, blksize);
- if (unlikely(rc)) {
- CERROR("decrypt C(n-1) (%u): %d\n", slst.length, rc);
- return rc;
- }
-
- /* restore IV */
- ll_crypto_blkcipher_set_iv(tfm, sbuf, blksize);
-
- data = cfs_kmap(sls->page);
- /* C(n) = C(n) | TAIL(D(n)) */
- memcpy(dbuf, data + sls->offset + blks * blksize, tail);
- /* swab C(n) and C(n-1) */
- memcpy(sbuf, data + sls->offset + (blks - 1) * blksize, blksize);
- memcpy(data + sls->offset + (blks - 1) * blksize, dbuf, blksize);
- cfs_kunmap(sls->page);
-
- /* do cbc decrypt */
- buf_to_sl(&slst, sbuf, blksize);
- buf_to_sl(&sldt, dbuf, blksize);
-
- /* decrypt head */
- rc = ll_crypto_blkcipher_decrypt(&desc, sld, sls, sls->length - tail);
- if (unlikely(rc)) {
- CERROR("decrypt head (%u) data: %d\n", sls->length - tail, rc);
- return rc;
- }
- /* decrypt tail */
- rc = ll_crypto_blkcipher_decrypt(&desc, &sldt, &slst, blksize);
- if (unlikely(rc)) {
- CERROR("decrypt tail (%u) data: %d\n", slst.length, rc);
- return rc;
- }
-
- /* truncate to original ciphertext size */
- data = cfs_kmap(sld->page);
- memcpy(data + sld->offset + blks * blksize, dbuf, tail);
- cfs_kunmap(sld->page);
-
- return 0;
-}
-
-static inline int do_cts_tfm(struct ll_crypto_cipher *tfm,
- int encrypt,
- struct scatterlist *sld,
- struct scatterlist *sls)
-{
-#ifndef HAVE_ASYNC_BLOCK_CIPHER
- LASSERT(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_CBC);
-#endif
-
- if (encrypt)
- return cbc_cts_encrypt(tfm, sld, sls);
- else
- return cbc_cts_decrypt(tfm, sld, sls);
-}
-
-/*
- * normal encrypt/decrypt of data of even blocksize
- */
-static inline int do_cipher_tfm(struct ll_crypto_cipher *tfm,
- int encrypt,
- struct scatterlist *sld,
- struct scatterlist *sls)
-{
- struct blkcipher_desc desc;
- desc.tfm = tfm;
- desc.flags = 0;
- if (encrypt)
- return ll_crypto_blkcipher_encrypt(&desc, sld, sls, sls->length);
- else
- return ll_crypto_blkcipher_decrypt(&desc, sld, sls, sls->length);
-}
-
-static struct ll_crypto_cipher *get_stream_cipher(__u8 *key, unsigned int keylen)
-{
- const struct sptlrpc_ciph_type *ct;
- struct ll_crypto_cipher *tfm;
- int rc;
-
- /* using ARC4, the only stream cipher in linux for now */
- ct = sptlrpc_get_ciph_type(BULK_CIPH_ALG_ARC4);
- LASSERT(ct);
-
- tfm = ll_crypto_alloc_blkcipher(ct->sct_tfm_name, 0, 0);
- if (tfm == NULL) {
- CERROR("Failed to allocate stream TFM %s\n", ct->sct_name);
- return NULL;
- }
- LASSERT(ll_crypto_blkcipher_blocksize(tfm));
-
- if (keylen > ct->sct_keysize)
- keylen = ct->sct_keysize;
-
- LASSERT(keylen >= crypto_tfm_alg_min_keysize(tfm));
- LASSERT(keylen <= crypto_tfm_alg_max_keysize(tfm));
-
- rc = ll_crypto_blkcipher_setkey(tfm, key, keylen);
- if (rc) {
- CERROR("Failed to set key for TFM %s: %d\n", ct->sct_name, rc);
- ll_crypto_free_blkcipher(tfm);
- return NULL;
- }
-
- return tfm;
-}
-
-static int do_bulk_privacy(struct gss_ctx *gctx,
- struct ptlrpc_bulk_desc *desc,
- int encrypt, __u32 alg,
- struct ptlrpc_bulk_sec_desc *bsd)
-{
- const struct sptlrpc_ciph_type *ct = sptlrpc_get_ciph_type(alg);
- struct ll_crypto_cipher *tfm;
- struct ll_crypto_cipher *stfm = NULL; /* backup stream cipher */
- struct scatterlist sls, sld, *sldp;
- unsigned int blksize, keygen_size;
- int i, rc;
- __u8 key[CIPHER_MAX_KEYSIZE];
-
- LASSERT(ct);
-
- if (encrypt)
- bsd->bsd_ciph_alg = BULK_CIPH_ALG_NULL;
-
- if (alg == BULK_CIPH_ALG_NULL)
- return 0;
-
- if (desc->bd_iov_count <= 0) {
- if (encrypt)
- bsd->bsd_ciph_alg = alg;
- return 0;
- }
-
- tfm = ll_crypto_alloc_blkcipher(ct->sct_tfm_name, 0, 0 );
- if (tfm == NULL) {
- CERROR("Failed to allocate TFM %s\n", ct->sct_name);
- return -ENOMEM;
- }
- blksize = ll_crypto_blkcipher_blocksize(tfm);
-
- LASSERT(crypto_tfm_alg_max_keysize(tfm) >= ct->sct_keysize);
- LASSERT(crypto_tfm_alg_min_keysize(tfm) <= ct->sct_keysize);
- LASSERT(ct->sct_ivsize == 0 ||
- ll_crypto_blkcipher_ivsize(tfm) == ct->sct_ivsize);
- LASSERT(ct->sct_keysize <= CIPHER_MAX_KEYSIZE);
- LASSERT(blksize <= CIPHER_MAX_BLKSIZE);
-
- /* generate ramdom key seed and compute the secret key based on it.
- * note determined by algorithm which lgss_plain_encrypt use, it
- * might require the key size be its (blocksize * n). so here for
- * simplicity, we force it's be n * MAX_BLKSIZE by padding 0 */
- keygen_size = (ct->sct_keysize + CIPHER_MAX_BLKSIZE - 1) &
- ~(CIPHER_MAX_BLKSIZE - 1);
- if (encrypt) {
- get_random_bytes(bsd->bsd_key, ct->sct_keysize);
- if (ct->sct_keysize < keygen_size)
- memset(bsd->bsd_key + ct->sct_keysize, 0,
- keygen_size - ct->sct_keysize);
- }
-
- rc = lgss_plain_encrypt(gctx, 0, keygen_size, bsd->bsd_key, key);
- if (rc) {
- CERROR("failed to compute secret key: %d\n", rc);
- goto out;
- }
-
- rc = ll_crypto_blkcipher_setkey(tfm, key, ct->sct_keysize);
- if (rc) {
- CERROR("Failed to set key for TFM %s: %d\n", ct->sct_name, rc);
- goto out;
- }
-
- /* stream cipher doesn't need iv */
- if (blksize > 1)
- ll_crypto_blkcipher_set_iv(tfm, zero_iv, blksize);
-
- for (i = 0; i < desc->bd_iov_count; i++) {
- sls.page = desc->bd_iov[i].kiov_page;
- sls.offset = desc->bd_iov[i].kiov_offset;
- sls.length = desc->bd_iov[i].kiov_len;
-
- if (unlikely(sls.length == 0)) {
- CWARN("page %d with 0 length data?\n", i);
- continue;
- }
-
- if (unlikely(sls.offset % blksize)) {
- CERROR("page %d with odd offset %u, TFM %s\n",
- i, sls.offset, ct->sct_name);
- rc = -EINVAL;
- goto out;
- }
-
- if (desc->bd_enc_pages) {
- sld.page = desc->bd_enc_pages[i];
- sld.offset = desc->bd_iov[i].kiov_offset;
- sld.length = desc->bd_iov[i].kiov_len;
-
- sldp = &sld;
- } else {
- sldp = &sls;
- }
-
- if (likely(sls.length % blksize == 0)) {
- /* data length is n * blocksize, do the normal tfm */
- rc = do_cipher_tfm(tfm, encrypt, sldp, &sls);
- } else if (sls.length < blksize) {
- /* odd data length, and smaller than 1 block, CTS
- * doesn't work in this case because it requires
- * transfer a modified IV to peer. here we use a
- * "backup" stream cipher to do the tfm */
- if (stfm == NULL) {
- stfm = get_stream_cipher(key, ct->sct_keysize);
- if (tfm == NULL) {
- rc = -ENOMEM;
- goto out;
- }
- }
- rc = do_cipher_tfm(stfm, encrypt, sldp, &sls);
- } else {
- /* odd data length but > 1 block, do CTS tfm */
- rc = do_cts_tfm(tfm, encrypt, sldp, &sls);
- }
-
- if (unlikely(rc)) {
- CERROR("error %s page %d/%d: %d\n",
- encrypt ? "encrypt" : "decrypt",
- i + 1, desc->bd_iov_count, rc);
- goto out;
- }
-
- if (desc->bd_enc_pages)
- desc->bd_iov[i].kiov_page = desc->bd_enc_pages[i];
- }
-
- if (encrypt)
- bsd->bsd_ciph_alg = alg;
-
-out:
- if (stfm)
- ll_crypto_free_blkcipher(stfm);
-
- ll_crypto_free_blkcipher(tfm);
- return rc;
-}
-