diff options
Diffstat (limited to 'drivers/crypto/nx/nx-aes-ccm.c')
-rw-r--r-- | drivers/crypto/nx/nx-aes-ccm.c | 595 |
1 files changed, 595 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 000000000..7038f364a --- /dev/null +++ b/drivers/crypto/nx/nx-aes-ccm.c @@ -0,0 +1,595 @@ +/** + * 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; + } + + 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; + } + + 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, + unsigned int assoclen, + 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; + u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL; + int rc; + unsigned int max_sg_len; + + /* zero the ctr value */ + memset(iv + 15 - iv[0], 0, iv[0] + 1); + + /* page 78 of nx_wb.pdf has, + * Note: RFC3610 allows the AAD data to be up to 2^64 -1 bytes + * in length. If a full message is used, the AES CCA implementation + * restricts the maximum AAD length to 2^32 -1 bytes. + * If partial messages are used, the implementation supports + * 2^64 -1 bytes maximum AAD length. + * + * However, in the cryptoapi's aead_request structure, + * assoclen is an unsigned int, thus it cannot hold a length + * value greater than 2^32 - 1. + * Thus the AAD is further constrained by this and is never + * greater than 2^32. + */ + + if (!assoclen) { + b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; + } else if (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 = assoclen; + } else if (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; + } else { + b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0; + b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1; + iauth_len = 10; + } + + /* generate B0 */ + rc = generate_b0(iv, assoclen, authsize, nbytes, b0); + if (rc) + return rc; + + /* generate B1: + * add control info for associated data + * RFC 3610 and NIST Special Publication 800-38C + */ + if (b1) { + memset(b1, 0, 16); + if (assoclen <= 65280) { + *(u16 *)b1 = assoclen; + scatterwalk_map_and_copy(b1 + 2, req->src, 0, + iauth_len, SCATTERWALK_FROM_SG); + } else { + *(u16 *)b1 = (u16)(0xfffe); + *(u32 *)&b1[2] = assoclen; + scatterwalk_map_and_copy(b1 + 6, req->src, 0, + iauth_len, SCATTERWALK_FROM_SG); + } + } + + /* now copy any remaining AAD to scatterlist and call nx... */ + if (!assoclen) { + return rc; + } else if (assoclen <= 14) { + unsigned int len = 16; + + nx_insg = nx_build_sg_list(nx_insg, b1, &len, nx_ctx->ap->sglen); + + if (len != 16) + return -EINVAL; + + nx_outsg = nx_build_sg_list(nx_outsg, tmp, &len, + nx_ctx->ap->sglen); + + if (len != 16) + return -EINVAL; + + /* 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; + + result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac; + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + return rc; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(assoclen, &nx_ctx->stats->aes_bytes); + + } else { + unsigned int processed = 0, to_process; + + processed += iauth_len; + + /* page_limit: number of sg entries that fit on one page */ + max_sg_len = min_t(u64, nx_ctx->ap->sglen, + nx_driver.of.max_sg_len/sizeof(struct nx_sg)); + max_sg_len = min_t(u64, max_sg_len, + nx_ctx->ap->databytelen/NX_PAGE_SIZE); + + do { + to_process = min_t(u32, assoclen - processed, + nx_ctx->ap->databytelen); + + nx_insg = nx_walk_and_build(nx_ctx->in_sg, + nx_ctx->ap->sglen, + req->src, processed, + &to_process); + + if ((to_process + processed) < assoclen) { + NX_CPB_FDM(nx_ctx->csbcpb_aead) |= + NX_FDM_INTERMEDIATE; + } else { + NX_CPB_FDM(nx_ctx->csbcpb_aead) &= + ~NX_FDM_INTERMEDIATE; + } + + + nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) * + sizeof(struct nx_sg); + + result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0; + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + return rc; + + memcpy(nx_ctx->csbcpb_aead->cpb.aes_cca.b0, + nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0, + AES_BLOCK_SIZE); + + NX_CPB_FDM(nx_ctx->csbcpb_aead) |= NX_FDM_CONTINUATION; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(assoclen, &nx_ctx->stats->aes_bytes); + + processed += to_process; + } while (processed < assoclen); + + result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0; + } + + memcpy(out, result, AES_BLOCK_SIZE); + + return rc; +} + +static int ccm_nx_decrypt(struct aead_request *req, + struct blkcipher_desc *desc, + unsigned int assoclen) +{ + 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; + unsigned long irq_flags; + unsigned int processed = 0, to_process; + int rc = -1; + + spin_lock_irqsave(&nx_ctx->lock, irq_flags); + + nbytes -= authsize; + + /* copy out the auth tag to compare with later */ + scatterwalk_map_and_copy(priv->oauth_tag, + req->src, nbytes + req->assoclen, authsize, + SCATTERWALK_FROM_SG); + + rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, assoclen, + csbcpb->cpb.aes_ccm.in_pat_or_b0); + if (rc) + goto out; + + do { + + /* to_process: the AES_BLOCK_SIZE data chunk to process in this + * update. This value is bound by sg list limits. + */ + to_process = nbytes - processed; + + if ((to_process + processed) < nbytes) + NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE; + else + NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; + + NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT; + + rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, + &to_process, processed + req->assoclen, + csbcpb->cpb.aes_ccm.iv_or_ctr); + if (rc) + goto out; + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + /* for partial completion, copy following for next + * entry into loop... + */ + memcpy(desc->info, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE); + memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0, + csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE); + memcpy(csbcpb->cpb.aes_ccm.in_s0, + csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE); + + NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION; + + /* update stats */ + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(csbcpb->csb.processed_byte_count, + &(nx_ctx->stats->aes_bytes)); + + processed += to_process; + } while (processed < nbytes); + + rc = crypto_memneq(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag, + authsize) ? -EBADMSG : 0; +out: + spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); + return rc; +} + +static int ccm_nx_encrypt(struct aead_request *req, + struct blkcipher_desc *desc, + unsigned int assoclen) +{ + 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)); + unsigned long irq_flags; + unsigned int processed = 0, to_process; + int rc = -1; + + spin_lock_irqsave(&nx_ctx->lock, irq_flags); + + rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, assoclen, + csbcpb->cpb.aes_ccm.in_pat_or_b0); + if (rc) + goto out; + + do { + /* to process: the AES_BLOCK_SIZE data chunk to process in this + * update. This value is bound by sg list limits. + */ + to_process = nbytes - processed; + + if ((to_process + processed) < nbytes) + NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE; + else + NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; + + NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; + + rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, + &to_process, processed + req->assoclen, + csbcpb->cpb.aes_ccm.iv_or_ctr); + if (rc) + goto out; + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + /* for partial completion, copy following for next + * entry into loop... + */ + memcpy(desc->info, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE); + memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0, + csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE); + memcpy(csbcpb->cpb.aes_ccm.in_s0, + csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE); + + NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION; + + /* update stats */ + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(csbcpb->csb.processed_byte_count, + &(nx_ctx->stats->aes_bytes)); + + processed += to_process; + + } while (processed < nbytes); + + /* copy out the auth tag */ + scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac, + req->dst, nbytes + req->assoclen, authsize, + SCATTERWALK_TO_SG); + +out: + spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); + 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 nx_gcm_rctx *rctx = aead_request_ctx(req); + struct blkcipher_desc desc; + u8 *iv = rctx->iv; + + iv[0] = 3; + memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); + memcpy(iv + 4, req->iv, 8); + + desc.info = iv; + + return ccm_nx_encrypt(req, &desc, req->assoclen - 8); +} + +static int ccm_aes_nx_encrypt(struct aead_request *req) +{ + struct blkcipher_desc desc; + int rc; + + desc.info = req->iv; + + rc = crypto_ccm_check_iv(desc.info); + if (rc) + return rc; + + return ccm_nx_encrypt(req, &desc, req->assoclen); +} + +static int ccm4309_aes_nx_decrypt(struct aead_request *req) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); + struct nx_gcm_rctx *rctx = aead_request_ctx(req); + struct blkcipher_desc desc; + u8 *iv = rctx->iv; + + iv[0] = 3; + memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); + memcpy(iv + 4, req->iv, 8); + + desc.info = iv; + + return ccm_nx_decrypt(req, &desc, req->assoclen - 8); +} + +static int ccm_aes_nx_decrypt(struct aead_request *req) +{ + struct blkcipher_desc desc; + int rc; + + desc.info = req->iv; + + rc = crypto_ccm_check_iv(desc.info); + if (rc) + return rc; + + return ccm_nx_decrypt(req, &desc, req->assoclen); +} + +/* 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 aead_alg nx_ccm_aes_alg = { + .base = { + .cra_name = "ccm(aes)", + .cra_driver_name = "ccm-aes-nx", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct nx_crypto_ctx), + .cra_module = THIS_MODULE, + }, + .init = nx_crypto_ctx_aes_ccm_init, + .exit = nx_crypto_ctx_aead_exit, + .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 aead_alg nx_ccm4309_aes_alg = { + .base = { + .cra_name = "rfc4309(ccm(aes))", + .cra_driver_name = "rfc4309-ccm-aes-nx", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_NEED_FALLBACK, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct nx_crypto_ctx), + .cra_module = THIS_MODULE, + }, + .init = nx_crypto_ctx_aes_ccm_init, + .exit = nx_crypto_ctx_aead_exit, + .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, +}; |