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author | Kent Yoder <key@linux.vnet.ibm.com> | 2012-05-14 11:05:23 +0000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-05-16 15:05:42 +1000 |
commit | a00bd6e60a341d6d21f9dfed89a8a7cf82383389 (patch) | |
tree | ce6129c627296d7b92cd16ea2a2f82fd3a7a742e /drivers/crypto/nx/nx-aes-ccm.c | |
parent | 856d673476e31c1dfe568777956036637d53902d (diff) | |
download | op-kernel-dev-a00bd6e60a341d6d21f9dfed89a8a7cf82383389.zip op-kernel-dev-a00bd6e60a341d6d21f9dfed89a8a7cf82383389.tar.gz |
powerpc/crypto: AES-CCM mode routines for nx encryption
These routines add support for AES in CCM mode on the Power7+ CPU's
in-Nest accelerator driver.
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'drivers/crypto/nx/nx-aes-ccm.c')
-rw-r--r-- | drivers/crypto/nx/nx-aes-ccm.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/drivers/crypto/nx/nx-aes-ccm.c b/drivers/crypto/nx/nx-aes-ccm.c new file mode 100644 index 0000000..7aeac67 --- /dev/null +++ b/drivers/crypto/nx/nx-aes-ccm.c @@ -0,0 +1,468 @@ +/** + * AES CCM routines supporting the Power 7+ Nest Accelerators driver + * + * Copyright (C) 2012 International Business Machines Inc. + * + * 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; version 2 only. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Author: Kent Yoder <yoder1@us.ibm.com> + */ + +#include <crypto/internal/aead.h> +#include <crypto/aes.h> +#include <crypto/algapi.h> +#include <crypto/scatterwalk.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/crypto.h> +#include <asm/vio.h> + +#include "nx_csbcpb.h" +#include "nx.h" + + +static int ccm_aes_nx_set_key(struct crypto_aead *tfm, + const u8 *in_key, + unsigned int key_len) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead; + + nx_ctx_init(nx_ctx, HCOP_FC_AES); + + switch (key_len) { + case AES_KEYSIZE_128: + NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128); + NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128); + nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128]; + break; + default: + return -EINVAL; + } + + csbcpb->cpb.hdr.mode = NX_MODE_AES_CCM; + memcpy(csbcpb->cpb.aes_ccm.key, in_key, key_len); + + csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_CCA; + memcpy(csbcpb_aead->cpb.aes_cca.key, in_key, key_len); + + return 0; + +} + +static int ccm4309_aes_nx_set_key(struct crypto_aead *tfm, + const u8 *in_key, + unsigned int key_len) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); + + if (key_len < 3) + return -EINVAL; + + key_len -= 3; + + memcpy(nx_ctx->priv.ccm.nonce, in_key + key_len, 3); + + return ccm_aes_nx_set_key(tfm, in_key, key_len); +} + +static int ccm_aes_nx_setauthsize(struct crypto_aead *tfm, + unsigned int authsize) +{ + switch (authsize) { + case 4: + case 6: + case 8: + case 10: + case 12: + case 14: + case 16: + break; + default: + return -EINVAL; + } + + crypto_aead_crt(tfm)->authsize = authsize; + + return 0; +} + +static int ccm4309_aes_nx_setauthsize(struct crypto_aead *tfm, + unsigned int authsize) +{ + switch (authsize) { + case 8: + case 12: + case 16: + break; + default: + return -EINVAL; + } + + crypto_aead_crt(tfm)->authsize = authsize; + + return 0; +} + +/* taken from crypto/ccm.c */ +static int set_msg_len(u8 *block, unsigned int msglen, int csize) +{ + __be32 data; + + memset(block, 0, csize); + block += csize; + + if (csize >= 4) + csize = 4; + else if (msglen > (unsigned int)(1 << (8 * csize))) + return -EOVERFLOW; + + data = cpu_to_be32(msglen); + memcpy(block - csize, (u8 *)&data + 4 - csize, csize); + + return 0; +} + +/* taken from crypto/ccm.c */ +static inline int crypto_ccm_check_iv(const u8 *iv) +{ + /* 2 <= L <= 8, so 1 <= L' <= 7. */ + if (1 > iv[0] || iv[0] > 7) + return -EINVAL; + + return 0; +} + +/* based on code from crypto/ccm.c */ +static int generate_b0(u8 *iv, unsigned int assoclen, unsigned int authsize, + unsigned int cryptlen, u8 *b0) +{ + unsigned int l, lp, m = authsize; + int rc; + + memcpy(b0, iv, 16); + + lp = b0[0]; + l = lp + 1; + + /* set m, bits 3-5 */ + *b0 |= (8 * ((m - 2) / 2)); + + /* set adata, bit 6, if associated data is used */ + if (assoclen) + *b0 |= 64; + + rc = set_msg_len(b0 + 16 - l, cryptlen, l); + + return rc; +} + +static int generate_pat(u8 *iv, + struct aead_request *req, + struct nx_crypto_ctx *nx_ctx, + unsigned int authsize, + unsigned int nbytes, + u8 *out) +{ + struct nx_sg *nx_insg = nx_ctx->in_sg; + struct nx_sg *nx_outsg = nx_ctx->out_sg; + unsigned int iauth_len = 0; + struct vio_pfo_op *op = NULL; + u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL; + int rc; + + /* zero the ctr value */ + memset(iv + 15 - iv[0], 0, iv[0] + 1); + + if (!req->assoclen) { + b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; + } else if (req->assoclen <= 14) { + /* if associated data is 14 bytes or less, we do 1 GCM + * operation on 2 AES blocks, B0 (stored in the csbcpb) and B1, + * which is fed in through the source buffers here */ + b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; + b1 = nx_ctx->priv.ccm.iauth_tag; + iauth_len = req->assoclen; + + nx_insg = nx_build_sg_list(nx_insg, b1, 16, nx_ctx->ap->sglen); + nx_outsg = nx_build_sg_list(nx_outsg, tmp, 16, + nx_ctx->ap->sglen); + + /* inlen should be negative, indicating to phyp that its a + * pointer to an sg list */ + nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * + sizeof(struct nx_sg); + nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * + sizeof(struct nx_sg); + + NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT; + NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE; + + op = &nx_ctx->op; + result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac; + } else if (req->assoclen <= 65280) { + /* if associated data is less than (2^16 - 2^8), we construct + * B1 differently and feed in the associated data to a CCA + * operation */ + b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0; + b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1; + iauth_len = 14; + + /* remaining assoc data must have scatterlist built for it */ + nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen, + req->assoc, iauth_len, + req->assoclen - iauth_len); + nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) * + sizeof(struct nx_sg); + + op = &nx_ctx->op_aead; + result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0; + } else { + /* if associated data is less than (2^32), we construct B1 + * differently yet again and feed in the associated data to a + * CCA operation */ + pr_err("associated data len is %u bytes (returning -EINVAL)\n", + req->assoclen); + rc = -EINVAL; + } + + rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0); + if (rc) + goto done; + + if (b1) { + memset(b1, 0, 16); + *(u16 *)b1 = (u16)req->assoclen; + + scatterwalk_map_and_copy(b1 + 2, req->assoc, 0, + iauth_len, SCATTERWALK_FROM_SG); + + rc = nx_hcall_sync(nx_ctx, op, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto done; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes)); + + memcpy(out, result, AES_BLOCK_SIZE); + } +done: + return rc; +} + +static int ccm_nx_decrypt(struct aead_request *req, + struct blkcipher_desc *desc) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + unsigned int nbytes = req->cryptlen; + unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req)); + struct nx_ccm_priv *priv = &nx_ctx->priv.ccm; + int rc = -1; + + if (nbytes > nx_ctx->ap->databytelen) + return -EINVAL; + + nbytes -= authsize; + + /* copy out the auth tag to compare with later */ + scatterwalk_map_and_copy(priv->oauth_tag, + req->src, nbytes, authsize, + SCATTERWALK_FROM_SG); + + rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, + csbcpb->cpb.aes_ccm.in_pat_or_b0); + if (rc) + goto out; + + rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes, + csbcpb->cpb.aes_ccm.iv_or_ctr); + if (rc) + goto out; + + NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT; + NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_INTERMEDIATE; + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(csbcpb->csb.processed_byte_count, + &(nx_ctx->stats->aes_bytes)); + + rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag, + authsize) ? -EBADMSG : 0; +out: + return rc; +} + +static int ccm_nx_encrypt(struct aead_request *req, + struct blkcipher_desc *desc) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + unsigned int nbytes = req->cryptlen; + unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req)); + int rc = -1; + + if (nbytes > nx_ctx->ap->databytelen) + return -EINVAL; + + rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, + csbcpb->cpb.aes_ccm.in_pat_or_b0); + if (rc) + goto out; + + rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes, + csbcpb->cpb.aes_ccm.iv_or_ctr); + if (rc) + goto out; + + NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; + NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(csbcpb->csb.processed_byte_count, + &(nx_ctx->stats->aes_bytes)); + + /* copy out the auth tag */ + scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac, + req->dst, nbytes, authsize, + SCATTERWALK_TO_SG); +out: + return rc; +} + +static int ccm4309_aes_nx_encrypt(struct aead_request *req) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); + struct blkcipher_desc desc; + u8 *iv = nx_ctx->priv.ccm.iv; + + iv[0] = 3; + memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); + memcpy(iv + 4, req->iv, 8); + + desc.info = iv; + desc.tfm = (struct crypto_blkcipher *)req->base.tfm; + + return ccm_nx_encrypt(req, &desc); +} + +static int ccm_aes_nx_encrypt(struct aead_request *req) +{ + struct blkcipher_desc desc; + int rc; + + desc.info = req->iv; + desc.tfm = (struct crypto_blkcipher *)req->base.tfm; + + rc = crypto_ccm_check_iv(desc.info); + if (rc) + return rc; + + return ccm_nx_encrypt(req, &desc); +} + +static int ccm4309_aes_nx_decrypt(struct aead_request *req) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); + struct blkcipher_desc desc; + u8 *iv = nx_ctx->priv.ccm.iv; + + iv[0] = 3; + memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); + memcpy(iv + 4, req->iv, 8); + + desc.info = iv; + desc.tfm = (struct crypto_blkcipher *)req->base.tfm; + + return ccm_nx_decrypt(req, &desc); +} + +static int ccm_aes_nx_decrypt(struct aead_request *req) +{ + struct blkcipher_desc desc; + int rc; + + desc.info = req->iv; + desc.tfm = (struct crypto_blkcipher *)req->base.tfm; + + rc = crypto_ccm_check_iv(desc.info); + if (rc) + return rc; + + return ccm_nx_decrypt(req, &desc); +} + +/* tell the block cipher walk routines that this is a stream cipher by + * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block + * during encrypt/decrypt doesn't solve this problem, because it calls + * blkcipher_walk_done under the covers, which doesn't use walk->blocksize, + * but instead uses this tfm->blocksize. */ +struct crypto_alg nx_ccm_aes_alg = { + .cra_name = "ccm(aes)", + .cra_driver_name = "ccm-aes-nx", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_AEAD | + CRYPTO_ALG_NEED_FALLBACK, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct nx_crypto_ctx), + .cra_type = &crypto_aead_type, + .cra_module = THIS_MODULE, + .cra_list = LIST_HEAD_INIT(nx_ccm_aes_alg.cra_list), + .cra_init = nx_crypto_ctx_aes_ccm_init, + .cra_exit = nx_crypto_ctx_exit, + .cra_aead = { + .ivsize = AES_BLOCK_SIZE, + .maxauthsize = AES_BLOCK_SIZE, + .setkey = ccm_aes_nx_set_key, + .setauthsize = ccm_aes_nx_setauthsize, + .encrypt = ccm_aes_nx_encrypt, + .decrypt = ccm_aes_nx_decrypt, + } +}; + +struct crypto_alg nx_ccm4309_aes_alg = { + .cra_name = "rfc4309(ccm(aes))", + .cra_driver_name = "rfc4309-ccm-aes-nx", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_AEAD | + CRYPTO_ALG_NEED_FALLBACK, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct nx_crypto_ctx), + .cra_type = &crypto_nivaead_type, + .cra_module = THIS_MODULE, + .cra_list = LIST_HEAD_INIT(nx_ccm4309_aes_alg.cra_list), + .cra_init = nx_crypto_ctx_aes_ccm_init, + .cra_exit = nx_crypto_ctx_exit, + .cra_aead = { + .ivsize = 8, + .maxauthsize = AES_BLOCK_SIZE, + .setkey = ccm4309_aes_nx_set_key, + .setauthsize = ccm4309_aes_nx_setauthsize, + .encrypt = ccm4309_aes_nx_encrypt, + .decrypt = ccm4309_aes_nx_decrypt, + .geniv = "seqiv", + } +}; |