From: Alex Ousherovitch <[email protected]> Register ECDH and X25519 kpp algorithms using the CMH PKE core. Supports P-256, P-384, and Curve25519 for key agreement.
Co-developed-by: Saravanakrishnan Krishnamoorthy <[email protected]> Signed-off-by: Saravanakrishnan Krishnamoorthy <[email protected]> Signed-off-by: Alex Ousherovitch <[email protected]> Reviewed-by: Joel Wittenauer <[email protected]> Reviewed-by: Thi Nguyen <[email protected]> --- drivers/crypto/cmh/Makefile | 3 +- drivers/crypto/cmh/cmh_main.c | 8 + drivers/crypto/cmh/cmh_pke_ecdh.c | 698 ++++++++++++++++++++++++++++++ 3 files changed, 708 insertions(+), 1 deletion(-) create mode 100644 drivers/crypto/cmh/cmh_pke_ecdh.c diff --git a/drivers/crypto/cmh/Makefile b/drivers/crypto/cmh/Makefile index fdbf66b13628..a4cea0a56fc1 100644 --- a/drivers/crypto/cmh/Makefile +++ b/drivers/crypto/cmh/Makefile @@ -32,7 +32,8 @@ cmh-y := \ cmh_rng.o \ cmh_pke_common.o \ cmh_pke_rsa.o \ - cmh_pke_ecdsa.o + cmh_pke_ecdsa.o \ + cmh_pke_ecdh.o # Management ioctl device (/dev/cmh_mgmt): key lifecycle, PKE, PQC ioctls. cmh-$(CONFIG_CRYPTO_DEV_CMH_MGMT) += \ diff --git a/drivers/crypto/cmh/cmh_main.c b/drivers/crypto/cmh/cmh_main.c index 2191682f3d54..dd4e8812c457 100644 --- a/drivers/crypto/cmh/cmh_main.c +++ b/drivers/crypto/cmh/cmh_main.c @@ -292,6 +292,11 @@ static int cmh_probe(struct platform_device *pdev) if (ret) goto err_pke_ecdsa_register; + /* Register PKE ECDH/X25519 kpp */ + ret = cmh_pke_ecdh_register(); + if (ret) + goto err_pke_ecdh_register; + /* Register key management device (/dev/cmh_mgmt) */ ret = cmh_mgmt_register(); if (ret) @@ -304,6 +309,8 @@ static int cmh_probe(struct platform_device *pdev) return 0; err_mgmt_register: + cmh_pke_ecdh_unregister(); +err_pke_ecdh_register: cmh_pke_ecdsa_unregister(); err_pke_ecdsa_register: cmh_pke_rsa_unregister(); @@ -364,6 +371,7 @@ static void cmh_remove(struct platform_device *pdev) cfg = &dev->config; cmh_mgmt_unregister(); + cmh_pke_ecdh_unregister(); cmh_pke_ecdsa_unregister(); cmh_pke_rsa_unregister(); cmh_ccp_poly_unregister(); diff --git a/drivers/crypto/cmh/cmh_pke_ecdh.c b/drivers/crypto/cmh/cmh_pke_ecdh.c new file mode 100644 index 000000000000..d8b821cc4217 --- /dev/null +++ b/drivers/crypto/cmh/cmh_pke_ecdh.c @@ -0,0 +1,698 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2026 Cryptography Research, Inc. (CRI). + * CMH LKM -- ECDH / X25519 kpp Driver + * + * Registers "ecdh-nist-p256", "ecdh-nist-p384", and "curve25519" + * kpp algorithms with priority 300. + * + * - set_secret: decodes private key from kpp_secret + ecdh struct + * (NIST curves) or raw 32-byte scalar (Curve25519). + * Stores in cmh_key_ctx: raw keys written via SYS_REF_TEMP. + * Datastore-referenced keys are only reachable through the ioctl + * path (cmh_mgmt.c). + * + * - generate_public_key: PKE_CMD_ECDH_KEYGEN -> outputs X coordinate + * (NIST Weierstrass) or full public key (Edwards/Montgomery). + * For NIST curves, we generate X||Y by calling ECDSA_PUBGEN instead, + * matching the kernel ecdh.c pattern that outputs uncompressed X||Y. + * + * - compute_shared_secret: PKE_CMD_ECDH -> shared secret X coordinate. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/scatterlist.h> +#include <crypto/kpp.h> +#include <crypto/ecdh.h> +#include <crypto/internal/kpp.h> +#include <crypto/internal/ecc.h> + +#include "cmh_pke.h" +#include "cmh_sys.h" +#include "cmh_sys_abi.h" +#include "cmh_txn.h" +#include "cmh_dma.h" +#include "cmh_key.h" + +/* + * ECDH key format: kpp_secret header + key_size(u16) + key data. + * We decode this inline to avoid depending on CONFIG_CRYPTO_ECDH. + */ +#define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + sizeof(unsigned short)) + +struct cmh_ecdh_tfm_ctx { + struct cmh_key_ctx key; + u32 curve; /* PKE_CURVE_* */ + u32 clen; /* coordinate length in bytes */ +}; + +static inline struct cmh_ecdh_tfm_ctx *cmh_ecdh_ctx(struct crypto_kpp *tfm) +{ + return kpp_tfm_ctx(tfm); +} + +/* + * Per-request context for ECDH/X25519 operations. + * + * generate_public_key: single-phase async VCQ. + * compute_shared_secret: 2-phase async VCQ with callback chaining. + * Phase 1: sys_write(sk) + sys_new(ref) + ecdh(peer) + pflush + * -> phase1 callback reads ref, submits Phase 2. + * Phase 2: sys_data(ref, ss_dma) + sys_flush + * -> phase2 callback extracts shared secret, completes req. + * + * Both phases target the same mbx_idx so the DS reference remains + * valid, since DS objects are MBX-scoped. + */ +struct cmh_ecdh_reqctx { + /* Buffers */ + u8 *pk_buf; /* keygen: output public key */ + u8 *sk_buf; /* private key copy */ + u8 *peer_buf; /* compute: peer public key */ + u8 *ss_buf; /* compute: shared secret output */ + u64 *ref_buf; /* compute: DS ref from Phase 1 */ + /* DMA handles */ + dma_addr_t pk_dma; + dma_addr_t sk_dma; + dma_addr_t peer_dma; + dma_addr_t ss_dma; + dma_addr_t ref_dma; + /* Sizes and params for Phase 2 re-submit */ + u32 out_len; /* keygen: public key size */ + u32 clen; + u32 peer_len; + u32 sk_len; + u32 dma_swap; + int mbx_idx; /* pinned MBX for Phase 2 */ +}; + +/* + * set_secret: NIST curves decode kpp_secret + u16 key_size + raw scalar. + * Curve25519 uses raw 32-byte scalar directly. + */ +static int cmh_ecdh_set_secret_nist(struct crypto_kpp *tfm, + const void *buf, unsigned int len) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + const u8 *ptr = buf; + struct kpp_secret secret; + unsigned short key_size; + int ret; + + if (!buf || len < ECDH_KPP_SECRET_MIN_SIZE) + return -EINVAL; + + memcpy(&secret, ptr, sizeof(secret)); + ptr += sizeof(secret); + + if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH) + return -EINVAL; + if (len < secret.len) + return -EINVAL; + + memcpy(&key_size, ptr, sizeof(key_size)); + ptr += sizeof(key_size); + + if (key_size == 0) { + /* + * key_size == 0: generate a validated random private key. + * Uses the kernel ECC library (FIPS 186-5 A.2.2) to ensure + * the scalar is in the valid range [2, n-3] for the curve. + */ + u64 priv[ECC_MAX_DIGITS]; + unsigned int ndigits = ctx->clen / sizeof(u64); + unsigned int curve_id; + u8 *rnd; + + if (secret.len != ECDH_KPP_SECRET_MIN_SIZE) + return -EINVAL; + if (ndigits > ECC_MAX_DIGITS) + return -EINVAL; + /* Reject non-limb-aligned clen to prevent ndigits truncation */ + if (ctx->clen % sizeof(u64)) + return -EINVAL; + + if (ctx->curve == PKE_CURVE_P256) + curve_id = ECC_CURVE_NIST_P256; + else if (ctx->curve == PKE_CURVE_P384) + curve_id = ECC_CURVE_NIST_P384; + else + return -EINVAL; + + ret = ecc_gen_privkey(curve_id, ndigits, priv); + if (ret) { + memzero_explicit(priv, sizeof(priv)); + return ret; + } + + rnd = kmalloc(ctx->clen, GFP_KERNEL); + if (!rnd) { + memzero_explicit(priv, sizeof(priv)); + return -ENOMEM; + } + + /* Convert VLI (native LE-digit-order) to big-endian bytes */ + ecc_swap_digits(priv, (u64 *)rnd, ndigits); + memzero_explicit(priv, sizeof(priv)); + + ret = cmh_key_setkey_raw(&ctx->key, rnd, ctx->clen, + CORE_ID_PKE); + kfree_sensitive(rnd); + return ret; + } + + if (key_size != ctx->clen) + return -EINVAL; + + if (secret.len != ECDH_KPP_SECRET_MIN_SIZE + key_size) + return -EINVAL; + + return cmh_key_setkey_raw(&ctx->key, ptr, key_size, CORE_ID_PKE); +} + +static int cmh_ecdh_set_secret_x25519(struct crypto_kpp *tfm, + const void *buf, unsigned int len) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + + if (len != pke_curve_clen(PKE_CURVE_25519)) + return -EINVAL; + + return cmh_key_setkey_raw(&ctx->key, buf, len, CORE_ID_PKE); +} + +static void cmh_ecdh_keygen_complete(void *data, int error) +{ + struct kpp_request *req = data; + struct cmh_ecdh_reqctx *rctx = kpp_request_ctx(req); + + if (error == -EINPROGRESS) { + cmh_complete(&req->base, error); + return; + } + + if (!cmh_dma_map_error(rctx->sk_dma)) + cmh_dma_unmap_single(rctx->sk_dma, rctx->sk_len, + DMA_TO_DEVICE); + if (!cmh_dma_map_error(rctx->pk_dma)) + cmh_dma_unmap_single(rctx->pk_dma, rctx->out_len, + DMA_FROM_DEVICE); + + if (!error) { + int nents; + + nents = sg_nents_for_len(req->dst, rctx->out_len); + if (nents < 0 || + sg_copy_from_buffer(req->dst, nents, + rctx->pk_buf, + rctx->out_len) != rctx->out_len) + error = -EINVAL; + else + req->dst_len = rctx->out_len; + } + + kfree_sensitive(rctx->sk_buf); + rctx->sk_buf = NULL; + kfree(rctx->pk_buf); + rctx->pk_buf = NULL; + cmh_complete(&req->base, error); +} + +/* + * generate_public_key: For NIST ECDH, use ECDH_KEYGEN which outputs + * the public key X-coordinate. But the kernel kpp interface expects + * uncompressed X||Y, so we use ECDSA_PUBGEN which gives us (X,Y). + * For Curve25519, ECDH_KEYGEN gives us the Montgomery u-coordinate + * which is the full public key. + */ +static int cmh_ecdh_generate_public_key(struct kpp_request *req) +{ + struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + struct cmh_ecdh_reqctx *rctx = kpp_request_ctx(req); + u32 clen = ctx->clen; + bool is_25519 = (ctx->curve == PKE_CURVE_25519); + u32 out_len = is_25519 ? clen : 2 * clen; + struct vcq_cmd vcq[PKE_VCQ_CMDS_MAX]; + struct core_dispatch dd; + u32 swap, dma_swap; + int ret, idx; + gfp_t gfp; + + if (ctx->key.mode != CMH_KEY_RAW) + return -EINVAL; + if (req->dst_len < out_len) + return -EINVAL; + + gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? + GFP_KERNEL : GFP_ATOMIC; + + memset(rctx, 0, sizeof(*rctx)); + rctx->out_len = out_len; + rctx->sk_len = ctx->key.raw.len; + rctx->pk_dma = DMA_MAPPING_ERROR; + rctx->sk_dma = DMA_MAPPING_ERROR; + + rctx->pk_buf = kzalloc(out_len, gfp); + if (!rctx->pk_buf) + return -ENOMEM; + + rctx->pk_dma = cmh_dma_map_single(rctx->pk_buf, out_len, + DMA_FROM_DEVICE); + if (cmh_dma_map_error(rctx->pk_dma)) { + ret = -ENOMEM; + goto out_free; + } + + swap = PKE_SWAP_FLAGS; + dma_swap = pke_swap_flags(ctx->curve); + + dd = cmh_core_select_instance(CMH_CORE_PKE); + + rctx->sk_buf = kmemdup(ctx->key.raw.data, ctx->key.raw.len, gfp); + if (!rctx->sk_buf) { + ret = -ENOMEM; + goto out_unmap; + } + rctx->sk_dma = cmh_dma_map_single(rctx->sk_buf, ctx->key.raw.len, + DMA_TO_DEVICE); + if (cmh_dma_map_error(rctx->sk_dma)) { + ret = -ENOMEM; + goto out_unmap; + } + + vcq_set_header(&vcq[0], PKE_VCQ_CMDS_MAX); + idx = 1; + vcq_add_sys_write(&vcq[idx], SYS_REF_TEMP, rctx->sk_dma, + SYS_REF_NONE, ctx->key.raw.len, + ctx->key.raw.sys_type); + vcq[idx].id |= dma_swap; + idx++; + if (is_25519) + vcq_add_pke_ecdh_keygen(&vcq[idx++], dd.core_id, ctx->curve, + clen, rctx->pk_dma, SYS_REF_TEMP, + swap); + else + vcq_add_pke_ecdsa_pubgen(&vcq[idx++], dd.core_id, + ctx->curve, clen, rctx->pk_dma, + SYS_REF_TEMP, swap); + vcq_add_pke_flush(&vcq[idx++], dd.core_id); + + ret = cmh_tm_submit_async(vcq, PKE_VCQ_CMDS_MAX, 1, dd.mbx_idx, + cmh_ecdh_keygen_complete, req, + !!(req->base.flags & + CRYPTO_TFM_REQ_MAY_BACKLOG), 0); + if (ret == -EBUSY) + return -EBUSY; + if (!ret) + return -EINPROGRESS; + +out_unmap: + if (!cmh_dma_map_error(rctx->sk_dma)) + cmh_dma_unmap_single(rctx->sk_dma, ctx->key.raw.len, + DMA_TO_DEVICE); + if (!cmh_dma_map_error(rctx->pk_dma)) + cmh_dma_unmap_single(rctx->pk_dma, out_len, + DMA_FROM_DEVICE); + +out_free: + kfree_sensitive(rctx->sk_buf); + kfree(rctx->pk_buf); + return ret; +} + +static void cmh_ecdh_ss_phase2_complete(void *data, int error) +{ + struct kpp_request *req = data; + struct cmh_ecdh_reqctx *rctx = kpp_request_ctx(req); + + if (error == -EINPROGRESS) { + cmh_complete(&req->base, error); + return; + } + + if (!cmh_dma_map_error(rctx->ss_dma)) + cmh_dma_unmap_single(rctx->ss_dma, rctx->clen, + DMA_FROM_DEVICE); + + if (!error) { + int nents; + + nents = sg_nents_for_len(req->dst, rctx->clen); + if (nents < 0 || + sg_copy_from_buffer(req->dst, nents, + rctx->ss_buf, + rctx->clen) != rctx->clen) + error = -EINVAL; + else + req->dst_len = rctx->clen; + } + + kfree(rctx->ref_buf); + rctx->ref_buf = NULL; + kfree_sensitive(rctx->ss_buf); + rctx->ss_buf = NULL; + cmh_complete(&req->base, error); +} + +static void cmh_ecdh_ss_phase1_complete(void *data, int error) +{ + struct kpp_request *req = data; + struct cmh_ecdh_reqctx *rctx = kpp_request_ctx(req); + struct vcq_cmd vcq[3]; + int ret; + + if (error == -EINPROGRESS) { + cmh_complete(&req->base, error); + return; + } + + /* Phase 1-only resources: sk, peer -- always clean up */ + if (!cmh_dma_map_error(rctx->sk_dma)) + cmh_dma_unmap_single(rctx->sk_dma, rctx->sk_len, + DMA_TO_DEVICE); + kfree_sensitive(rctx->sk_buf); + rctx->sk_buf = NULL; + + if (!cmh_dma_map_error(rctx->peer_dma)) + cmh_dma_unmap_single(rctx->peer_dma, rctx->peer_len, + DMA_TO_DEVICE); + kfree(rctx->peer_buf); + rctx->peer_buf = NULL; + + if (error) + goto out_cleanup; + + /* Read the DS reference written by Phase 1 */ + cmh_dma_sync_for_cpu(rctx->ref_dma, sizeof(u64), DMA_FROM_DEVICE); + cmh_dma_unmap_single(rctx->ref_dma, sizeof(u64), DMA_FROM_DEVICE); + rctx->ref_dma = DMA_MAPPING_ERROR; + + /* Phase 2: extract shared secret from DS */ + vcq_set_header(&vcq[0], 3); + vcq_add_sys_data(&vcq[1], *rctx->ref_buf, rctx->ss_dma, + rctx->clen); + vcq[1].id |= rctx->dma_swap; + vcq_add_sys_flush(&vcq[2]); + + ret = cmh_tm_submit_async(vcq, 3, 1, rctx->mbx_idx, + cmh_ecdh_ss_phase2_complete, req, + true, 0); + if (ret == -EBUSY || !ret) + return; + + error = ret; + +out_cleanup: + if (!cmh_dma_map_error(rctx->ref_dma)) + cmh_dma_unmap_single(rctx->ref_dma, sizeof(u64), + DMA_FROM_DEVICE); + if (!cmh_dma_map_error(rctx->ss_dma)) + cmh_dma_unmap_single(rctx->ss_dma, rctx->clen, + DMA_FROM_DEVICE); + kfree(rctx->ref_buf); + rctx->ref_buf = NULL; + kfree_sensitive(rctx->ss_buf); + rctx->ss_buf = NULL; + cmh_complete(&req->base, error); +} + +/* + * compute_shared_secret: PKE_CMD_ECDH. + * + * req->src = peer public key (X||Y for NIST, raw 32B for Curve25519). + * Output = shared secret X coordinate (clen bytes). + * + * The CMH ECDH command stores the shared secret in a DS object, + * not directly to DMA. We create a DS slot with SYS_CMD_NEW, + * reference it via SYS_REF_LAST, then extract the result with a + * second VCQ submission using SYS_CMD_DATA with the actual ref. + */ +static int cmh_ecdh_compute_shared_secret(struct kpp_request *req) +{ + struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + struct cmh_ecdh_reqctx *rctx = kpp_request_ctx(req); + u32 clen = ctx->clen; + bool is_25519 = (ctx->curve == PKE_CURVE_25519); + u32 peer_len = is_25519 ? clen : 2 * clen; + u32 ss_type = SYS_TYPE_SET(SYS_TYPE_FLAG_PT, CORE_ID_PKE); + struct vcq_cmd vcq[5]; + struct core_dispatch dd; + u32 swap, dma_swap; + int ret, idx, nents; + gfp_t gfp; + + if (ctx->key.mode != CMH_KEY_RAW) + return -EINVAL; + if (req->src_len < peer_len || req->dst_len < clen) + return -EINVAL; + + gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? + GFP_KERNEL : GFP_ATOMIC; + + memset(rctx, 0, sizeof(*rctx)); + rctx->clen = clen; + rctx->peer_len = peer_len; + rctx->sk_len = ctx->key.raw.len; + rctx->pk_dma = DMA_MAPPING_ERROR; + rctx->sk_dma = DMA_MAPPING_ERROR; + rctx->peer_dma = DMA_MAPPING_ERROR; + rctx->ss_dma = DMA_MAPPING_ERROR; + rctx->ref_dma = DMA_MAPPING_ERROR; + + rctx->peer_buf = kmalloc(peer_len, gfp); + rctx->ss_buf = kzalloc(clen, gfp); + rctx->ref_buf = kzalloc_obj(u64, gfp); + if (!rctx->peer_buf || !rctx->ss_buf || !rctx->ref_buf) { + ret = -ENOMEM; + goto out_free; + } + + nents = sg_nents_for_len(req->src, peer_len); + if (nents < 0 || + sg_pcopy_to_buffer(req->src, nents, rctx->peer_buf, + peer_len, 0) != peer_len) { + ret = -EINVAL; + goto out_free; + } + + rctx->peer_dma = cmh_dma_map_single(rctx->peer_buf, peer_len, + DMA_TO_DEVICE); + rctx->ss_dma = cmh_dma_map_single(rctx->ss_buf, clen, + DMA_FROM_DEVICE); + rctx->ref_dma = cmh_dma_map_single(rctx->ref_buf, sizeof(u64), + DMA_FROM_DEVICE); + + if (cmh_dma_map_error(rctx->peer_dma) || + cmh_dma_map_error(rctx->ss_dma) || + cmh_dma_map_error(rctx->ref_dma)) { + ret = -ENOMEM; + goto out_unmap; + } + + swap = PKE_SWAP_FLAGS; + dma_swap = pke_swap_flags(ctx->curve); + rctx->dma_swap = dma_swap; + + dd = cmh_core_select_instance(CMH_CORE_PKE); + rctx->mbx_idx = dd.mbx_idx; + + rctx->sk_buf = kmemdup(ctx->key.raw.data, ctx->key.raw.len, gfp); + if (!rctx->sk_buf) { + ret = -ENOMEM; + goto out_unmap; + } + rctx->sk_dma = cmh_dma_map_single(rctx->sk_buf, ctx->key.raw.len, + DMA_TO_DEVICE); + if (cmh_dma_map_error(rctx->sk_dma)) { + ret = -ENOMEM; + goto out_unmap; + } + + vcq_set_header(&vcq[0], 5); + idx = 1; + vcq_add_sys_write(&vcq[idx], SYS_REF_TEMP, rctx->sk_dma, + SYS_REF_NONE, ctx->key.raw.len, + ctx->key.raw.sys_type); + vcq[idx].id |= dma_swap; + idx++; + vcq_add_sys_new(&vcq[idx++], 0, rctx->ref_dma, clen); + vcq_add_pke_ecdh(&vcq[idx++], dd.core_id, ctx->curve, clen, + clen, ss_type, rctx->peer_dma, + SYS_REF_TEMP, SYS_REF_LAST, swap); + vcq_add_pke_flush(&vcq[idx++], dd.core_id); + + ret = cmh_tm_submit_async(vcq, 5, 1, dd.mbx_idx, + cmh_ecdh_ss_phase1_complete, req, + !!(req->base.flags & + CRYPTO_TFM_REQ_MAY_BACKLOG), 0); + if (ret == -EBUSY) + return -EBUSY; + if (!ret) + return -EINPROGRESS; + +out_unmap: + if (!cmh_dma_map_error(rctx->sk_dma)) + cmh_dma_unmap_single(rctx->sk_dma, rctx->sk_len, + DMA_TO_DEVICE); + if (!cmh_dma_map_error(rctx->ss_dma)) + cmh_dma_unmap_single(rctx->ss_dma, clen, + DMA_FROM_DEVICE); + if (!cmh_dma_map_error(rctx->ref_dma)) + cmh_dma_unmap_single(rctx->ref_dma, sizeof(u64), + DMA_FROM_DEVICE); + if (!cmh_dma_map_error(rctx->peer_dma)) + cmh_dma_unmap_single(rctx->peer_dma, peer_len, + DMA_TO_DEVICE); + +out_free: + kfree_sensitive(rctx->sk_buf); + kfree(rctx->ref_buf); + kfree_sensitive(rctx->ss_buf); + kfree(rctx->peer_buf); + return ret; +} + +static unsigned int cmh_ecdh_max_size(struct crypto_kpp *tfm) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + + /* Max output = X||Y for generate_public_key (NIST) */ + return 2 * ctx->clen; +} + +static unsigned int cmh_x25519_max_size(struct crypto_kpp *tfm) +{ + return pke_curve_clen(PKE_CURVE_25519); /* single coordinate */ +} + +static int cmh_ecdh_p256_init(struct crypto_kpp *tfm) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + + memset(ctx, 0, sizeof(*ctx)); + ctx->curve = PKE_CURVE_P256; + ctx->clen = pke_curve_clen(PKE_CURVE_P256); + tfm->reqsize = sizeof(struct cmh_ecdh_reqctx); + return 0; +} + +static int cmh_ecdh_p384_init(struct crypto_kpp *tfm) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + + memset(ctx, 0, sizeof(*ctx)); + ctx->curve = PKE_CURVE_P384; + ctx->clen = pke_curve_clen(PKE_CURVE_P384); + tfm->reqsize = sizeof(struct cmh_ecdh_reqctx); + return 0; +} + +static int cmh_x25519_init(struct crypto_kpp *tfm) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + + memset(ctx, 0, sizeof(*ctx)); + ctx->curve = PKE_CURVE_25519; + ctx->clen = pke_curve_clen(PKE_CURVE_25519); + tfm->reqsize = sizeof(struct cmh_ecdh_reqctx); + return 0; +} + +static void cmh_ecdh_exit(struct crypto_kpp *tfm) +{ + struct cmh_ecdh_tfm_ctx *ctx = cmh_ecdh_ctx(tfm); + + cmh_key_destroy(&ctx->key); +} + +static struct kpp_alg cmh_ecdh_algs[] = { + { + .set_secret = cmh_ecdh_set_secret_nist, + .generate_public_key = cmh_ecdh_generate_public_key, + .compute_shared_secret = cmh_ecdh_compute_shared_secret, + .max_size = cmh_ecdh_max_size, + .init = cmh_ecdh_p256_init, + .exit = cmh_ecdh_exit, + .base = { + .cra_name = "ecdh-nist-p256", + .cra_driver_name = "cri-cmh-ecdh-nist-p256", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_ASYNC, + .cra_module = THIS_MODULE, + .cra_ctxsize = sizeof(struct cmh_ecdh_tfm_ctx), + }, + }, + { + .set_secret = cmh_ecdh_set_secret_nist, + .generate_public_key = cmh_ecdh_generate_public_key, + .compute_shared_secret = cmh_ecdh_compute_shared_secret, + .max_size = cmh_ecdh_max_size, + .init = cmh_ecdh_p384_init, + .exit = cmh_ecdh_exit, + .base = { + .cra_name = "ecdh-nist-p384", + .cra_driver_name = "cri-cmh-ecdh-nist-p384", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_ASYNC, + .cra_module = THIS_MODULE, + .cra_ctxsize = sizeof(struct cmh_ecdh_tfm_ctx), + }, + }, + { + .set_secret = cmh_ecdh_set_secret_x25519, + .generate_public_key = cmh_ecdh_generate_public_key, + .compute_shared_secret = cmh_ecdh_compute_shared_secret, + .max_size = cmh_x25519_max_size, + .init = cmh_x25519_init, + .exit = cmh_ecdh_exit, + .base = { + .cra_name = "curve25519", + .cra_driver_name = "cri-cmh-curve25519", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_ASYNC, + .cra_module = THIS_MODULE, + .cra_ctxsize = sizeof(struct cmh_ecdh_tfm_ctx), + }, + }, +}; + +/** + * cmh_pke_ecdh_register() - Register ECDH kpp algorithms with the crypto framework + * + * Return: 0 on success, negative errno on failure. + */ +int cmh_pke_ecdh_register(void) +{ + int ret, i; + + for (i = 0; i < ARRAY_SIZE(cmh_ecdh_algs); i++) { + ret = crypto_register_kpp(&cmh_ecdh_algs[i]); + if (ret) { + dev_err(cmh_dev(), "cmh: failed to register %s (%d)\n", + cmh_ecdh_algs[i].base.cra_name, ret); + goto err_unregister; + } + } + + return 0; + +err_unregister: + while (i--) + crypto_unregister_kpp(&cmh_ecdh_algs[i]); + return ret; +} + +/** + * cmh_pke_ecdh_unregister() - Unregister ECDH kpp algorithms from the crypto framework + */ +void cmh_pke_ecdh_unregister(void) +{ + int i = ARRAY_SIZE(cmh_ecdh_algs); + + while (i--) + crypto_unregister_kpp(&cmh_ecdh_algs[i]); +} -- 2.43.7
