--- /dev/null
+/*
+ * RSA padding templates.
+ *
+ * Copyright (c) 2015 Intel Corporation
+ *
+ * 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; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/akcipher.h>
+#include <crypto/internal/akcipher.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/random.h>
+
+struct pkcs1pad_ctx {
+ struct crypto_akcipher *child;
+
+ unsigned int key_size;
+};
+
+struct pkcs1pad_request {
+ struct akcipher_request child_req;
+
+ struct scatterlist in_sg[3], out_sg[2];
+ uint8_t *in_buf, *out_buf;
+};
+
+static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
+ unsigned int keylen)
+{
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ int err, size;
+
+ err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
+
+ if (!err) {
+ /* Find out new modulus size from rsa implementation */
+ size = crypto_akcipher_maxsize(ctx->child);
+
+ ctx->key_size = size > 0 ? size : 0;
+ if (size <= 0)
+ err = size;
+ }
+
+ return err;
+}
+
+static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
+ unsigned int keylen)
+{
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ int err, size;
+
+ err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
+
+ if (!err) {
+ /* Find out new modulus size from rsa implementation */
+ size = crypto_akcipher_maxsize(ctx->child);
+
+ ctx->key_size = size > 0 ? size : 0;
+ if (size <= 0)
+ err = size;
+ }
+
+ return err;
+}
+
+static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
+{
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+
+ /*
+ * The maximum destination buffer size for the encrypt/sign operations
+ * will be the same as for RSA, even though it's smaller for
+ * decrypt/verify.
+ */
+
+ return ctx->key_size ?: -EINVAL;
+}
+
+static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
+ struct scatterlist *next)
+{
+ int nsegs = next ? 1 : 0;
+
+ if (offset_in_page(buf) + len <= PAGE_SIZE) {
+ nsegs += 1;
+ sg_init_table(sg, nsegs);
+ sg_set_buf(sg, buf, len);
+ } else {
+ nsegs += 2;
+ sg_init_table(sg, nsegs);
+ sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf));
+ sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf),
+ offset_in_page(buf) + len - PAGE_SIZE);
+ }
+
+ if (next)
+ sg_chain(sg, nsegs, next);
+}
+
+static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ uint8_t zeros[ctx->key_size - req_ctx->child_req.dst_len];
+
+ if (!err) {
+ if (req_ctx->child_req.dst_len < ctx->key_size) {
+ memset(zeros, 0, sizeof(zeros));
+ sg_copy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst,
+ sizeof(zeros)),
+ zeros, sizeof(zeros));
+ }
+
+ sg_pcopy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst, ctx->key_size),
+ req_ctx->out_buf, req_ctx->child_req.dst_len,
+ sizeof(zeros));
+ }
+ req->dst_len = ctx->key_size;
+
+ kfree(req_ctx->in_buf);
+ kzfree(req_ctx->out_buf);
+
+ return err;
+}
+
+static void pkcs1pad_encrypt_sign_complete_cb(
+ struct crypto_async_request *child_async_req, int err)
+{
+ struct akcipher_request *req = child_async_req->data;
+ struct crypto_async_request async_req;
+
+ if (err == -EINPROGRESS)
+ return;
+
+ async_req.data = req->base.data;
+ async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
+ async_req.flags = child_async_req->flags;
+ req->base.complete(&async_req,
+ pkcs1pad_encrypt_sign_complete(req, err));
+}
+
+static int pkcs1pad_encrypt(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ int err;
+ unsigned int i, ps_end;
+
+ if (!ctx->key_size)
+ return -EINVAL;
+
+ if (req->src_len > ctx->key_size - 11)
+ return -EOVERFLOW;
+
+ if (req->dst_len < ctx->key_size) {
+ req->dst_len = ctx->key_size;
+ return -EOVERFLOW;
+ }
+
+ if (ctx->key_size > PAGE_SIZE)
+ return -ENOTSUPP;
+
+ /*
+ * Replace both input and output to add the padding in the input and
+ * the potential missing leading zeros in the output.
+ */
+ req_ctx->child_req.src = req_ctx->in_sg;
+ req_ctx->child_req.src_len = ctx->key_size - 1;
+ req_ctx->child_req.dst = req_ctx->out_sg;
+ req_ctx->child_req.dst_len = ctx->key_size;
+
+ req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
+ (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+ GFP_KERNEL : GFP_ATOMIC);
+ if (!req_ctx->in_buf)
+ return -ENOMEM;
+
+ ps_end = ctx->key_size - req->src_len - 2;
+ req_ctx->in_buf[0] = 0x02;
+ for (i = 1; i < ps_end; i++)
+ req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
+ req_ctx->in_buf[ps_end] = 0x00;
+
+ pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
+ ctx->key_size - 1 - req->src_len, req->src);
+
+ req_ctx->out_buf = kmalloc(ctx->key_size,
+ (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+ GFP_KERNEL : GFP_ATOMIC);
+ if (!req_ctx->out_buf) {
+ kfree(req_ctx->in_buf);
+ return -ENOMEM;
+ }
+
+ pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
+ ctx->key_size, NULL);
+
+ akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
+ akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
+ pkcs1pad_encrypt_sign_complete_cb, req);
+
+ err = crypto_akcipher_encrypt(&req_ctx->child_req);
+ if (err != -EINPROGRESS &&
+ (err != -EBUSY ||
+ !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return pkcs1pad_encrypt_sign_complete(req, err);
+
+ return err;
+}
+
+static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ unsigned int pos;
+
+ if (err == -EOVERFLOW)
+ /* Decrypted value had no leading 0 byte */
+ err = -EINVAL;
+
+ if (err)
+ goto done;
+
+ if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
+ err = -EINVAL;
+ goto done;
+ }
+
+ if (req_ctx->out_buf[0] != 0x02) {
+ err = -EINVAL;
+ goto done;
+ }
+ for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
+ if (req_ctx->out_buf[pos] == 0x00)
+ break;
+ if (pos < 9 || pos == req_ctx->child_req.dst_len) {
+ err = -EINVAL;
+ goto done;
+ }
+ pos++;
+
+ if (req->dst_len < req_ctx->child_req.dst_len - pos)
+ err = -EOVERFLOW;
+ req->dst_len = req_ctx->child_req.dst_len - pos;
+
+ if (!err)
+ sg_copy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst, req->dst_len),
+ req_ctx->out_buf + pos, req->dst_len);
+
+done:
+ kzfree(req_ctx->out_buf);
+
+ return err;
+}
+
+static void pkcs1pad_decrypt_complete_cb(
+ struct crypto_async_request *child_async_req, int err)
+{
+ struct akcipher_request *req = child_async_req->data;
+ struct crypto_async_request async_req;
+
+ if (err == -EINPROGRESS)
+ return;
+
+ async_req.data = req->base.data;
+ async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
+ async_req.flags = child_async_req->flags;
+ req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
+}
+
+static int pkcs1pad_decrypt(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ int err;
+
+ if (!ctx->key_size || req->src_len != ctx->key_size)
+ return -EINVAL;
+
+ if (ctx->key_size > PAGE_SIZE)
+ return -ENOTSUPP;
+
+ /* Reuse input buffer, output to a new buffer */
+ req_ctx->child_req.src = req->src;
+ req_ctx->child_req.src_len = req->src_len;
+ req_ctx->child_req.dst = req_ctx->out_sg;
+ req_ctx->child_req.dst_len = ctx->key_size - 1;
+
+ req_ctx->out_buf = kmalloc(ctx->key_size - 1,
+ (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+ GFP_KERNEL : GFP_ATOMIC);
+ if (!req_ctx->out_buf)
+ return -ENOMEM;
+
+ pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
+ ctx->key_size - 1, NULL);
+
+ akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
+ akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
+ pkcs1pad_decrypt_complete_cb, req);
+
+ err = crypto_akcipher_decrypt(&req_ctx->child_req);
+ if (err != -EINPROGRESS &&
+ (err != -EBUSY ||
+ !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return pkcs1pad_decrypt_complete(req, err);
+
+ return err;
+}
+
+static int pkcs1pad_sign(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ int err;
+ unsigned int ps_end;
+
+ if (!ctx->key_size)
+ return -EINVAL;
+
+ if (req->src_len > ctx->key_size - 11)
+ return -EOVERFLOW;
+
+ if (req->dst_len < ctx->key_size) {
+ req->dst_len = ctx->key_size;
+ return -EOVERFLOW;
+ }
+
+ if (ctx->key_size > PAGE_SIZE)
+ return -ENOTSUPP;
+
+ /*
+ * Replace both input and output to add the padding in the input and
+ * the potential missing leading zeros in the output.
+ */
+ req_ctx->child_req.src = req_ctx->in_sg;
+ req_ctx->child_req.src_len = ctx->key_size - 1;
+ req_ctx->child_req.dst = req_ctx->out_sg;
+ req_ctx->child_req.dst_len = ctx->key_size;
+
+ req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
+ (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+ GFP_KERNEL : GFP_ATOMIC);
+ if (!req_ctx->in_buf)
+ return -ENOMEM;
+
+ ps_end = ctx->key_size - req->src_len - 2;
+ req_ctx->in_buf[0] = 0x01;
+ memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
+ req_ctx->in_buf[ps_end] = 0x00;
+
+ pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
+ ctx->key_size - 1 - req->src_len, req->src);
+
+ req_ctx->out_buf = kmalloc(ctx->key_size,
+ (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+ GFP_KERNEL : GFP_ATOMIC);
+ if (!req_ctx->out_buf) {
+ kfree(req_ctx->in_buf);
+ return -ENOMEM;
+ }
+
+ pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
+ ctx->key_size, NULL);
+
+ akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
+ akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
+ pkcs1pad_encrypt_sign_complete_cb, req);
+
+ err = crypto_akcipher_sign(&req_ctx->child_req);
+ if (err != -EINPROGRESS &&
+ (err != -EBUSY ||
+ !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return pkcs1pad_encrypt_sign_complete(req, err);
+
+ return err;
+}
+
+static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ unsigned int pos;
+
+ if (err == -EOVERFLOW)
+ /* Decrypted value had no leading 0 byte */
+ err = -EINVAL;
+
+ if (err)
+ goto done;
+
+ if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
+ err = -EINVAL;
+ goto done;
+ }
+
+ if (req_ctx->out_buf[0] != 0x01) {
+ err = -EINVAL;
+ goto done;
+ }
+ for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
+ if (req_ctx->out_buf[pos] != 0xff)
+ break;
+ if (pos < 9 || pos == req_ctx->child_req.dst_len ||
+ req_ctx->out_buf[pos] != 0x00) {
+ err = -EINVAL;
+ goto done;
+ }
+ pos++;
+
+ if (req->dst_len < req_ctx->child_req.dst_len - pos)
+ err = -EOVERFLOW;
+ req->dst_len = req_ctx->child_req.dst_len - pos;
+
+ if (!err)
+ sg_copy_from_buffer(req->dst,
+ sg_nents_for_len(req->dst, req->dst_len),
+ req_ctx->out_buf + pos, req->dst_len);
+
+done:
+ kzfree(req_ctx->out_buf);
+
+ return err;
+}
+
+static void pkcs1pad_verify_complete_cb(
+ struct crypto_async_request *child_async_req, int err)
+{
+ struct akcipher_request *req = child_async_req->data;
+ struct crypto_async_request async_req;
+
+ if (err == -EINPROGRESS)
+ return;
+
+ async_req.data = req->base.data;
+ async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
+ async_req.flags = child_async_req->flags;
+ req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
+}
+
+/*
+ * The verify operation is here for completeness similar to the verification
+ * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
+ * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
+ * retrieve the DigestInfo from a signature, instead the user is expected
+ * to call the sign operation to generate the expected signature and compare
+ * signatures instead of the message-digests.
+ */
+static int pkcs1pad_verify(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+ int err;
+
+ if (!ctx->key_size || req->src_len != ctx->key_size)
+ return -EINVAL;
+
+ if (ctx->key_size > PAGE_SIZE)
+ return -ENOTSUPP;
+
+ /* Reuse input buffer, output to a new buffer */
+ req_ctx->child_req.src = req->src;
+ req_ctx->child_req.src_len = req->src_len;
+ req_ctx->child_req.dst = req_ctx->out_sg;
+ req_ctx->child_req.dst_len = ctx->key_size - 1;
+
+ req_ctx->out_buf = kmalloc(ctx->key_size - 1,
+ (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+ GFP_KERNEL : GFP_ATOMIC);
+ if (!req_ctx->out_buf)
+ return -ENOMEM;
+
+ pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
+ ctx->key_size - 1, NULL);
+
+ akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
+ akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
+ pkcs1pad_verify_complete_cb, req);
+
+ err = crypto_akcipher_verify(&req_ctx->child_req);
+ if (err != -EINPROGRESS &&
+ (err != -EBUSY ||
+ !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
+ return pkcs1pad_verify_complete(req, err);
+
+ return err;
+}
+
+static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
+{
+ struct akcipher_instance *inst = akcipher_alg_instance(tfm);
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct crypto_akcipher *child_tfm;
+
+ child_tfm = crypto_spawn_akcipher(akcipher_instance_ctx(inst));
+ if (IS_ERR(child_tfm))
+ return PTR_ERR(child_tfm);
+
+ ctx->child = child_tfm;
+
+ return 0;
+}
+
+static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
+{
+ struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
+
+ crypto_free_akcipher(ctx->child);
+}
+
+static void pkcs1pad_free(struct akcipher_instance *inst)
+{
+ struct crypto_akcipher_spawn *spawn = akcipher_instance_ctx(inst);
+
+ crypto_drop_akcipher(spawn);
+
+ kfree(inst);
+}
+
+static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
+{
+ struct crypto_attr_type *algt;
+ struct akcipher_instance *inst;
+ struct crypto_akcipher_spawn *spawn;
+ struct akcipher_alg *rsa_alg;
+ const char *rsa_alg_name;
+ int err;
+
+ algt = crypto_get_attr_type(tb);
+ if (IS_ERR(algt))
+ return PTR_ERR(algt);
+
+ if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
+ return -EINVAL;
+
+ rsa_alg_name = crypto_attr_alg_name(tb[1]);
+ if (IS_ERR(rsa_alg_name))
+ return PTR_ERR(rsa_alg_name);
+
+ inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+ if (!inst)
+ return -ENOMEM;
+
+ spawn = akcipher_instance_ctx(inst);
+ crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
+ err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
+ crypto_requires_sync(algt->type, algt->mask));
+ if (err)
+ goto out_free_inst;
+
+ rsa_alg = crypto_spawn_akcipher_alg(spawn);
+
+ err = -ENAMETOOLONG;
+ if (snprintf(inst->alg.base.cra_name,
+ CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
+ rsa_alg->base.cra_name) >=
+ CRYPTO_MAX_ALG_NAME ||
+ snprintf(inst->alg.base.cra_driver_name,
+ CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
+ rsa_alg->base.cra_driver_name) >=
+ CRYPTO_MAX_ALG_NAME)
+ goto out_drop_alg;
+
+ inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
+ inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
+ inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
+
+ inst->alg.init = pkcs1pad_init_tfm;
+ inst->alg.exit = pkcs1pad_exit_tfm;
+
+ inst->alg.encrypt = pkcs1pad_encrypt;
+ inst->alg.decrypt = pkcs1pad_decrypt;
+ inst->alg.sign = pkcs1pad_sign;
+ inst->alg.verify = pkcs1pad_verify;
+ inst->alg.set_pub_key = pkcs1pad_set_pub_key;
+ inst->alg.set_priv_key = pkcs1pad_set_priv_key;
+ inst->alg.max_size = pkcs1pad_get_max_size;
+ inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
+
+ inst->free = pkcs1pad_free;
+
+ err = akcipher_register_instance(tmpl, inst);
+ if (err)
+ goto out_drop_alg;
+
+ return 0;
+
+out_drop_alg:
+ crypto_drop_akcipher(spawn);
+out_free_inst:
+ kfree(inst);
+ return err;
+}
+
+struct crypto_template rsa_pkcs1pad_tmpl = {
+ .name = "pkcs1pad",
+ .create = pkcs1pad_create,
+ .module = THIS_MODULE,
+};
projects / linux-drm-fsl-dcu.git / commitdiff