diff options
Diffstat (limited to 'drivers/crypto/nx/nx-aes-xcbc.c')
| -rw-r--r-- | drivers/crypto/nx/nx-aes-xcbc.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/drivers/crypto/nx/nx-aes-xcbc.c b/drivers/crypto/nx/nx-aes-xcbc.c new file mode 100644 index 00000000000..03c4bf57d06 --- /dev/null +++ b/drivers/crypto/nx/nx-aes-xcbc.c @@ -0,0 +1,333 @@ +/** + * AES XCBC routines supporting the Power 7+ Nest Accelerators driver + * + * Copyright (C) 2011-2012 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/hash.h> +#include <crypto/aes.h> +#include <crypto/algapi.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/crypto.h> +#include <asm/vio.h> + +#include "nx_csbcpb.h" +#include "nx.h" + + +struct xcbc_state { + u8 state[AES_BLOCK_SIZE]; + unsigned int count; + u8 buffer[AES_BLOCK_SIZE]; +}; + +static int nx_xcbc_set_key(struct crypto_shash *desc, + const u8 *in_key, + unsigned int key_len) +{ + struct nx_crypto_ctx *nx_ctx = crypto_shash_ctx(desc); + + switch (key_len) { + case AES_KEYSIZE_128: + nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128]; + break; + default: + return -EINVAL; + } + + memcpy(nx_ctx->priv.xcbc.key, in_key, key_len); + + return 0; +} + +/* + * Based on RFC 3566, for a zero-length message: + * + * n = 1 + * K1 = E(K, 0x01010101010101010101010101010101) + * K3 = E(K, 0x03030303030303030303030303030303) + * E[0] = 0x00000000000000000000000000000000 + * M[1] = 0x80000000000000000000000000000000 (0 length message with padding) + * E[1] = (K1, M[1] ^ E[0] ^ K3) + * Tag = M[1] + */ +static int nx_xcbc_empty(struct shash_desc *desc, u8 *out) +{ + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + struct nx_sg *in_sg, *out_sg; + u8 keys[2][AES_BLOCK_SIZE]; + u8 key[32]; + int rc = 0; + + /* Change to ECB mode */ + csbcpb->cpb.hdr.mode = NX_MODE_AES_ECB; + memcpy(key, csbcpb->cpb.aes_xcbc.key, AES_BLOCK_SIZE); + memcpy(csbcpb->cpb.aes_ecb.key, key, AES_BLOCK_SIZE); + NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; + + /* K1 and K3 base patterns */ + memset(keys[0], 0x01, sizeof(keys[0])); + memset(keys[1], 0x03, sizeof(keys[1])); + + /* Generate K1 and K3 encrypting the patterns */ + in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) keys, sizeof(keys), + nx_ctx->ap->sglen); + out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) keys, sizeof(keys), + nx_ctx->ap->sglen); + nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg); + nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg); + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + atomic_inc(&(nx_ctx->stats->aes_ops)); + + /* XOr K3 with the padding for a 0 length message */ + keys[1][0] ^= 0x80; + + /* Encrypt the final result */ + memcpy(csbcpb->cpb.aes_ecb.key, keys[0], AES_BLOCK_SIZE); + in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) keys[1], sizeof(keys[1]), + nx_ctx->ap->sglen); + out_sg = nx_build_sg_list(nx_ctx->out_sg, out, AES_BLOCK_SIZE, + nx_ctx->ap->sglen); + nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg); + nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg); + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + atomic_inc(&(nx_ctx->stats->aes_ops)); + +out: + /* Restore XCBC mode */ + csbcpb->cpb.hdr.mode = NX_MODE_AES_XCBC_MAC; + memcpy(csbcpb->cpb.aes_xcbc.key, key, AES_BLOCK_SIZE); + NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT; + + return rc; +} + +static int nx_xcbc_init(struct shash_desc *desc) +{ + struct xcbc_state *sctx = shash_desc_ctx(desc); + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + struct nx_sg *out_sg; + + nx_ctx_init(nx_ctx, HCOP_FC_AES); + + memset(sctx, 0, sizeof *sctx); + + NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128); + csbcpb->cpb.hdr.mode = NX_MODE_AES_XCBC_MAC; + + memcpy(csbcpb->cpb.aes_xcbc.key, nx_ctx->priv.xcbc.key, AES_BLOCK_SIZE); + memset(nx_ctx->priv.xcbc.key, 0, sizeof *nx_ctx->priv.xcbc.key); + + out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state, + AES_BLOCK_SIZE, nx_ctx->ap->sglen); + nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg); + + return 0; +} + +static int nx_xcbc_update(struct shash_desc *desc, + const u8 *data, + unsigned int len) +{ + struct xcbc_state *sctx = shash_desc_ctx(desc); + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + struct nx_sg *in_sg; + u32 to_process, leftover, total; + u32 max_sg_len; + unsigned long irq_flags; + int rc = 0; + + spin_lock_irqsave(&nx_ctx->lock, irq_flags); + + + total = sctx->count + len; + + /* 2 cases for total data len: + * 1: <= AES_BLOCK_SIZE: copy into state, return 0 + * 2: > AES_BLOCK_SIZE: process X blocks, copy in leftover + */ + if (total <= AES_BLOCK_SIZE) { + memcpy(sctx->buffer + sctx->count, data, len); + sctx->count += len; + goto out; + } + + in_sg = nx_ctx->in_sg; + max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg), + nx_ctx->ap->sglen); + + do { + + /* to_process: the AES_BLOCK_SIZE data chunk to process in this + * update */ + to_process = min_t(u64, total, nx_ctx->ap->databytelen); + to_process = min_t(u64, to_process, + NX_PAGE_SIZE * (max_sg_len - 1)); + to_process = to_process & ~(AES_BLOCK_SIZE - 1); + leftover = total - to_process; + + /* the hardware will not accept a 0 byte operation for this + * algorithm and the operation MUST be finalized to be correct. + * So if we happen to get an update that falls on a block sized + * boundary, we must save off the last block to finalize with + * later. */ + if (!leftover) { + to_process -= AES_BLOCK_SIZE; + leftover = AES_BLOCK_SIZE; + } + + if (sctx->count) { + in_sg = nx_build_sg_list(nx_ctx->in_sg, + (u8 *) sctx->buffer, + sctx->count, + max_sg_len); + } + in_sg = nx_build_sg_list(in_sg, + (u8 *) data, + to_process - sctx->count, + max_sg_len); + nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * + sizeof(struct nx_sg); + + /* we've hit the nx chip previously and we're updating again, + * so copy over the partial digest */ + if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) { + memcpy(csbcpb->cpb.aes_xcbc.cv, + csbcpb->cpb.aes_xcbc.out_cv_mac, + AES_BLOCK_SIZE); + } + + NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE; + if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) { + rc = -EINVAL; + goto out; + } + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + + /* everything after the first update is continuation */ + NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION; + + total -= to_process; + data += to_process - sctx->count; + sctx->count = 0; + in_sg = nx_ctx->in_sg; + } while (leftover > AES_BLOCK_SIZE); + + /* copy the leftover back into the state struct */ + memcpy(sctx->buffer, data, leftover); + sctx->count = leftover; + +out: + spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); + return rc; +} + +static int nx_xcbc_final(struct shash_desc *desc, u8 *out) +{ + struct xcbc_state *sctx = shash_desc_ctx(desc); + struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base); + struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; + struct nx_sg *in_sg, *out_sg; + unsigned long irq_flags; + int rc = 0; + + spin_lock_irqsave(&nx_ctx->lock, irq_flags); + + if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) { + /* we've hit the nx chip previously, now we're finalizing, + * so copy over the partial digest */ + memcpy(csbcpb->cpb.aes_xcbc.cv, + csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE); + } else if (sctx->count == 0) { + /* + * we've never seen an update, so this is a 0 byte op. The + * hardware cannot handle a 0 byte op, so just ECB to + * generate the hash. + */ + rc = nx_xcbc_empty(desc, out); + goto out; + } + + /* final is represented by continuing the operation and indicating that + * this is not an intermediate operation */ + NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; + + in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buffer, + sctx->count, nx_ctx->ap->sglen); + out_sg = nx_build_sg_list(nx_ctx->out_sg, out, AES_BLOCK_SIZE, + nx_ctx->ap->sglen); + + nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg); + nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg); + + if (!nx_ctx->op.outlen) { + rc = -EINVAL; + goto out; + } + + rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, + desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + + memcpy(out, csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE); +out: + spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); + return rc; +} + +struct shash_alg nx_shash_aes_xcbc_alg = { + .digestsize = AES_BLOCK_SIZE, + .init = nx_xcbc_init, + .update = nx_xcbc_update, + .final = nx_xcbc_final, + .setkey = nx_xcbc_set_key, + .descsize = sizeof(struct xcbc_state), + .statesize = sizeof(struct xcbc_state), + .base = { + .cra_name = "xcbc(aes)", + .cra_driver_name = "xcbc-aes-nx", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_SHASH, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_module = THIS_MODULE, + .cra_ctxsize = sizeof(struct nx_crypto_ctx), + .cra_init = nx_crypto_ctx_aes_xcbc_init, + .cra_exit = nx_crypto_ctx_exit, + } +}; |