| /* |
| * AMD Cryptographic Coprocessor (CCP) RSA crypto API support |
| * |
| * Copyright (C) 2017 Advanced Micro Devices, Inc. |
| * |
| * Author: Gary R Hook <gary.hook@amd.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/scatterlist.h> |
| #include <linux/crypto.h> |
| #include <crypto/algapi.h> |
| #include <crypto/internal/rsa.h> |
| #include <crypto/internal/akcipher.h> |
| #include <crypto/akcipher.h> |
| #include <crypto/scatterwalk.h> |
| |
| #include "ccp-crypto.h" |
| |
| static inline struct akcipher_request *akcipher_request_cast( |
| struct crypto_async_request *req) |
| { |
| return container_of(req, struct akcipher_request, base); |
| } |
| |
| static inline int ccp_copy_and_save_keypart(u8 **kpbuf, unsigned int *kplen, |
| const u8 *buf, size_t sz) |
| { |
| int nskip; |
| |
| for (nskip = 0; nskip < sz; nskip++) |
| if (buf[nskip]) |
| break; |
| *kplen = sz - nskip; |
| *kpbuf = kmemdup(buf + nskip, *kplen, GFP_KERNEL); |
| if (!*kpbuf) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| static int ccp_rsa_complete(struct crypto_async_request *async_req, int ret) |
| { |
| struct akcipher_request *req = akcipher_request_cast(async_req); |
| struct ccp_rsa_req_ctx *rctx = akcipher_request_ctx(req); |
| |
| if (ret) |
| return ret; |
| |
| req->dst_len = rctx->cmd.u.rsa.key_size >> 3; |
| |
| return 0; |
| } |
| |
| static unsigned int ccp_rsa_maxsize(struct crypto_akcipher *tfm) |
| { |
| struct ccp_ctx *ctx = akcipher_tfm_ctx(tfm); |
| |
| return ctx->u.rsa.n_len; |
| } |
| |
| static int ccp_rsa_crypt(struct akcipher_request *req, bool encrypt) |
| { |
| struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); |
| struct ccp_ctx *ctx = akcipher_tfm_ctx(tfm); |
| struct ccp_rsa_req_ctx *rctx = akcipher_request_ctx(req); |
| int ret = 0; |
| |
| memset(&rctx->cmd, 0, sizeof(rctx->cmd)); |
| INIT_LIST_HEAD(&rctx->cmd.entry); |
| rctx->cmd.engine = CCP_ENGINE_RSA; |
| |
| rctx->cmd.u.rsa.key_size = ctx->u.rsa.key_len; /* in bits */ |
| if (encrypt) { |
| rctx->cmd.u.rsa.exp = &ctx->u.rsa.e_sg; |
| rctx->cmd.u.rsa.exp_len = ctx->u.rsa.e_len; |
| } else { |
| rctx->cmd.u.rsa.exp = &ctx->u.rsa.d_sg; |
| rctx->cmd.u.rsa.exp_len = ctx->u.rsa.d_len; |
| } |
| rctx->cmd.u.rsa.mod = &ctx->u.rsa.n_sg; |
| rctx->cmd.u.rsa.mod_len = ctx->u.rsa.n_len; |
| rctx->cmd.u.rsa.src = req->src; |
| rctx->cmd.u.rsa.src_len = req->src_len; |
| rctx->cmd.u.rsa.dst = req->dst; |
| |
| ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); |
| |
| return ret; |
| } |
| |
| static int ccp_rsa_encrypt(struct akcipher_request *req) |
| { |
| return ccp_rsa_crypt(req, true); |
| } |
| |
| static int ccp_rsa_decrypt(struct akcipher_request *req) |
| { |
| return ccp_rsa_crypt(req, false); |
| } |
| |
| static int ccp_check_key_length(unsigned int len) |
| { |
| /* In bits */ |
| if (len < 8 || len > 4096) |
| return -EINVAL; |
| return 0; |
| } |
| |
| static void ccp_rsa_free_key_bufs(struct ccp_ctx *ctx) |
| { |
| /* Clean up old key data */ |
| kzfree(ctx->u.rsa.e_buf); |
| ctx->u.rsa.e_buf = NULL; |
| ctx->u.rsa.e_len = 0; |
| kzfree(ctx->u.rsa.n_buf); |
| ctx->u.rsa.n_buf = NULL; |
| ctx->u.rsa.n_len = 0; |
| kzfree(ctx->u.rsa.d_buf); |
| ctx->u.rsa.d_buf = NULL; |
| ctx->u.rsa.d_len = 0; |
| } |
| |
| static int ccp_rsa_setkey(struct crypto_akcipher *tfm, const void *key, |
| unsigned int keylen, bool private) |
| { |
| struct ccp_ctx *ctx = akcipher_tfm_ctx(tfm); |
| struct rsa_key raw_key; |
| int ret; |
| |
| ccp_rsa_free_key_bufs(ctx); |
| memset(&raw_key, 0, sizeof(raw_key)); |
| |
| /* Code borrowed from crypto/rsa.c */ |
| if (private) |
| ret = rsa_parse_priv_key(&raw_key, key, keylen); |
| else |
| ret = rsa_parse_pub_key(&raw_key, key, keylen); |
| if (ret) |
| goto n_key; |
| |
| ret = ccp_copy_and_save_keypart(&ctx->u.rsa.n_buf, &ctx->u.rsa.n_len, |
| raw_key.n, raw_key.n_sz); |
| if (ret) |
| goto key_err; |
| sg_init_one(&ctx->u.rsa.n_sg, ctx->u.rsa.n_buf, ctx->u.rsa.n_len); |
| |
| ctx->u.rsa.key_len = ctx->u.rsa.n_len << 3; /* convert to bits */ |
| if (ccp_check_key_length(ctx->u.rsa.key_len)) { |
| ret = -EINVAL; |
| goto key_err; |
| } |
| |
| ret = ccp_copy_and_save_keypart(&ctx->u.rsa.e_buf, &ctx->u.rsa.e_len, |
| raw_key.e, raw_key.e_sz); |
| if (ret) |
| goto key_err; |
| sg_init_one(&ctx->u.rsa.e_sg, ctx->u.rsa.e_buf, ctx->u.rsa.e_len); |
| |
| if (private) { |
| ret = ccp_copy_and_save_keypart(&ctx->u.rsa.d_buf, |
| &ctx->u.rsa.d_len, |
| raw_key.d, raw_key.d_sz); |
| if (ret) |
| goto key_err; |
| sg_init_one(&ctx->u.rsa.d_sg, |
| ctx->u.rsa.d_buf, ctx->u.rsa.d_len); |
| } |
| |
| return 0; |
| |
| key_err: |
| ccp_rsa_free_key_bufs(ctx); |
| |
| n_key: |
| return ret; |
| } |
| |
| static int ccp_rsa_setprivkey(struct crypto_akcipher *tfm, const void *key, |
| unsigned int keylen) |
| { |
| return ccp_rsa_setkey(tfm, key, keylen, true); |
| } |
| |
| static int ccp_rsa_setpubkey(struct crypto_akcipher *tfm, const void *key, |
| unsigned int keylen) |
| { |
| return ccp_rsa_setkey(tfm, key, keylen, false); |
| } |
| |
| static int ccp_rsa_init_tfm(struct crypto_akcipher *tfm) |
| { |
| struct ccp_ctx *ctx = akcipher_tfm_ctx(tfm); |
| |
| akcipher_set_reqsize(tfm, sizeof(struct ccp_rsa_req_ctx)); |
| ctx->complete = ccp_rsa_complete; |
| |
| return 0; |
| } |
| |
| static void ccp_rsa_exit_tfm(struct crypto_akcipher *tfm) |
| { |
| struct ccp_ctx *ctx = crypto_tfm_ctx(&tfm->base); |
| |
| ccp_rsa_free_key_bufs(ctx); |
| } |
| |
| static struct akcipher_alg ccp_rsa_defaults = { |
| .encrypt = ccp_rsa_encrypt, |
| .decrypt = ccp_rsa_decrypt, |
| .set_pub_key = ccp_rsa_setpubkey, |
| .set_priv_key = ccp_rsa_setprivkey, |
| .max_size = ccp_rsa_maxsize, |
| .init = ccp_rsa_init_tfm, |
| .exit = ccp_rsa_exit_tfm, |
| .base = { |
| .cra_name = "rsa", |
| .cra_driver_name = "rsa-ccp", |
| .cra_priority = CCP_CRA_PRIORITY, |
| .cra_module = THIS_MODULE, |
| .cra_ctxsize = 2 * sizeof(struct ccp_ctx), |
| }, |
| }; |
| |
| struct ccp_rsa_def { |
| unsigned int version; |
| const char *name; |
| const char *driver_name; |
| unsigned int reqsize; |
| struct akcipher_alg *alg_defaults; |
| }; |
| |
| static struct ccp_rsa_def rsa_algs[] = { |
| { |
| .version = CCP_VERSION(3, 0), |
| .name = "rsa", |
| .driver_name = "rsa-ccp", |
| .reqsize = sizeof(struct ccp_rsa_req_ctx), |
| .alg_defaults = &ccp_rsa_defaults, |
| } |
| }; |
| |
| static int ccp_register_rsa_alg(struct list_head *head, |
| const struct ccp_rsa_def *def) |
| { |
| struct ccp_crypto_akcipher_alg *ccp_alg; |
| struct akcipher_alg *alg; |
| int ret; |
| |
| ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); |
| if (!ccp_alg) |
| return -ENOMEM; |
| |
| INIT_LIST_HEAD(&ccp_alg->entry); |
| |
| alg = &ccp_alg->alg; |
| *alg = *def->alg_defaults; |
| snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name); |
| snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s", |
| def->driver_name); |
| ret = crypto_register_akcipher(alg); |
| if (ret) { |
| pr_err("%s akcipher algorithm registration error (%d)\n", |
| alg->base.cra_name, ret); |
| kfree(ccp_alg); |
| return ret; |
| } |
| |
| list_add(&ccp_alg->entry, head); |
| |
| return 0; |
| } |
| |
| int ccp_register_rsa_algs(struct list_head *head) |
| { |
| int i, ret; |
| unsigned int ccpversion = ccp_version(); |
| |
| /* Register the RSA algorithm in standard mode |
| * This works for CCP v3 and later |
| */ |
| for (i = 0; i < ARRAY_SIZE(rsa_algs); i++) { |
| if (rsa_algs[i].version > ccpversion) |
| continue; |
| ret = ccp_register_rsa_alg(head, &rsa_algs[i]); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |