diff options
Diffstat (limited to 'crypto/rsa-pkcs1pad.c')
| -rw-r--r-- | crypto/rsa-pkcs1pad.c | 628 |
1 files changed, 628 insertions, 0 deletions
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c new file mode 100644 index 000000000000..50f5c97e1087 --- /dev/null +++ b/crypto/rsa-pkcs1pad.c @@ -0,0 +1,628 @@ +/* + * 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); + size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len; + size_t chunk_len, pad_left; + struct sg_mapping_iter miter; + + if (!err) { + if (pad_len) { + sg_miter_start(&miter, req->dst, + sg_nents_for_len(req->dst, pad_len), + SG_MITER_ATOMIC | SG_MITER_TO_SG); + + pad_left = pad_len; + while (pad_left) { + sg_miter_next(&miter); + + chunk_len = min(miter.length, pad_left); + memset(miter.addr, 0, chunk_len); + pad_left -= chunk_len; + } + + sg_miter_stop(&miter); + } + + 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, + pad_len); + } + 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, +}; |