linux - Contrib clone of linux

Age	Commit message (Expand)	Author
2012-03-23	prio_tree: introduce prio_set_parent()	Xiao Guangrong
2012-03-23	prio_tree: simplify prio_tree_expand()	Xiao Guangrong
2012-03-23	prio_tree: cleanup prio_tree_left()/prio_tree_right()	Xiao Guangrong
2012-03-23	prio_tree: remove unnecessary code in prio_tree_replace	Xiao Guangrong
2005-04-16	Linux-2.6.12-rc2	Linus Torvalds

/* Diffie-Hellman Key Agreement Method [RFC2631] * * Copyright (c) 2016, Intel Corporation * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com> * * 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 <linux/module.h> #include <crypto/internal/kpp.h> #include <crypto/kpp.h> #include <crypto/dh.h> #include <linux/mpi.h> struct dh_ctx { MPI p; /* Value is guaranteed to be set. */ MPI q; /* Value is optional. */ MPI g; /* Value is guaranteed to be set. */ MPI xa; /* Value is guaranteed to be set. */ }; static void dh_clear_ctx(struct dh_ctx *ctx) { mpi_free(ctx->p); mpi_free(ctx->q); mpi_free(ctx->g); mpi_free(ctx->xa); memset(ctx, 0, sizeof(*ctx)); } /* * If base is g we compute the public key * ya = g^xa mod p; [RFC2631 sec 2.1.1] * else if base if the counterpart public key we compute the shared secret * ZZ = yb^xa mod p; [RFC2631 sec 2.1.1] */ static int _compute_val(const struct dh_ctx *ctx, MPI base, MPI val) { /* val = base^xa mod p */ return mpi_powm(val, base, ctx->xa, ctx->p); } static inline struct dh_ctx *dh_get_ctx(struct crypto_kpp *tfm) { return kpp_tfm_ctx(tfm); } static int dh_check_params_length(unsigned int p_len) { return (p_len < 1536) ? -EINVAL : 0; } static int dh_set_params(struct dh_ctx *ctx, struct dh *params) { if (dh_check_params_length(params->p_size << 3)) return -EINVAL; ctx->p = mpi_read_raw_data(params->p, params->p_size); if (!ctx->p) return -EINVAL; if (params->q && params->q_size) { ctx->q = mpi_read_raw_data(params->q, params->q_size); if (!ctx->q) return -EINVAL; } ctx->g = mpi_read_raw_data(params->g, params->g_size); if (!ctx->g) return -EINVAL; return 0; } static int dh_set_secret(struct crypto_kpp *tfm, const void *buf, unsigned int len) { struct dh_ctx *ctx = dh_get_ctx(tfm); struct dh params; /* Free the old MPI key if any */ dh_clear_ctx(ctx); if (crypto_dh_decode_key(buf, len, &params) < 0) goto err_clear_ctx; if (dh_set_params(ctx, &params) < 0) goto err_clear_ctx; ctx->xa = mpi_read_raw_data(params.key, params.key_size); if (!ctx->xa) goto err_clear_ctx; return 0; err_clear_ctx: dh_clear_ctx(ctx); return -EINVAL; } /* * SP800-56A public key verification: * * * If Q is provided as part of the domain paramenters, a full validation * according to SP800-56A section 5.6.2.3.1 is performed. * * * If Q is not provided, a partial validation according to SP800-56A section * 5.6.2.3.2 is performed. */ static int dh_is_pubkey_valid(struct dh_ctx *ctx, MPI y) { if (unlikely(!ctx->p)) return -EINVAL; /* * Step 1: Verify that 2 <= y <= p - 2. * * The upper limit check is actually y < p instead of y < p - 1 * as the mpi_sub_ui function is yet missing. */ if (mpi_cmp_ui(y, 1) < 1 || mpi_cmp(y, ctx->p) >= 0) return -EINVAL; /* Step 2: Verify that 1 = y^q mod p */ if (ctx->q) { MPI val = mpi_alloc(0); int ret; if (!val) return -ENOMEM; ret = mpi_powm(val, y, ctx->q, ctx->p); if (ret) { mpi_free(val); return ret; } ret = mpi_cmp_ui(val, 1); mpi_free(val); if (ret != 0) return -EINVAL; } return 0; } static int dh_compute_value(struct kpp_request *req) { struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); struct dh_ctx *ctx = dh_get_ctx(tfm); MPI base, val = mpi_alloc(0); int ret = 0; int sign; if (!val) return -ENOMEM; if (unlikely(!ctx->xa)) { ret = -EINVAL; goto err_free_val; } if (req->src) { base = mpi_read_raw_from_sgl(req->src, req->src_len); if (!base) { ret = -EINVAL; goto err_free_val; } ret = dh_is_pubkey_valid(ctx, base); if (ret) goto err_free_base; } else { base = ctx->g; } ret = _compute_val(ctx, base, val); if (ret) goto err_free_base; ret = mpi_write_to_sgl(val, req->dst, req->dst_len, &sign); if (ret) goto err_free_base; if (sign < 0) ret = -EBADMSG; err_free_base: if (req->src) mpi_free(base); err_free_val: mpi_free(val); return ret; } static unsigned int dh_max_size(struct crypto_kpp *tfm) { struct dh_ctx *ctx = dh_get_ctx(tfm); return mpi_get_size(ctx->p); } static void dh_exit_tfm(struct crypto_kpp *tfm) { struct dh_ctx *ctx = dh_get_ctx(tfm); dh_clear_ctx(ctx); } static struct kpp_alg dh = { .set_secret = dh_set_secret, .generate_public_key = dh_compute_value, .compute_shared_secret = dh_compute_value, .max_size = dh_max_size, .exit = dh_exit_tfm, .base = { .cra_name = "dh", .cra_driver_name = "dh-generic", .cra_priority = 100, .cra_module = THIS_MODULE, .cra_ctxsize = sizeof(struct dh_ctx), }, }; static int dh_init(void) { return crypto_register_kpp(&dh); } static void dh_exit(void) { crypto_unregister_kpp(&dh); } module_init(dh_init); module_exit(dh_exit); MODULE_ALIAS_CRYPTO("dh"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("DH generic algorithm");