diff options
Diffstat (limited to 'crypto/dh_helper.c')
| -rw-r--r-- | crypto/dh_helper.c | 65 |
1 files changed, 45 insertions, 20 deletions
diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c index 8ba8a3f82620..2d499879328b 100644 --- a/crypto/dh_helper.c +++ b/crypto/dh_helper.c @@ -1,11 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * 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/kernel.h> #include <linux/export.h> @@ -16,8 +12,10 @@ #define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int)) -static inline u8 *dh_pack_data(void *dst, const void *src, size_t size) +static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size) { + if (!dst || size > end - dst) + return NULL; memcpy(dst, src, size); return dst + size; } @@ -28,12 +26,12 @@ static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size) return src + size; } -static inline int dh_data_size(const struct dh *p) +static inline unsigned int dh_data_size(const struct dh *p) { return p->key_size + p->p_size + p->g_size; } -int crypto_dh_key_len(const struct dh *p) +unsigned int crypto_dh_key_len(const struct dh *p) { return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p); } @@ -42,30 +40,30 @@ EXPORT_SYMBOL_GPL(crypto_dh_key_len); int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params) { u8 *ptr = buf; + u8 * const end = ptr + len; struct kpp_secret secret = { .type = CRYPTO_KPP_SECRET_TYPE_DH, .len = len }; - if (unlikely(!buf)) + if (unlikely(!len)) return -EINVAL; - if (len != crypto_dh_key_len(params)) + ptr = dh_pack_data(ptr, end, &secret, sizeof(secret)); + ptr = dh_pack_data(ptr, end, ¶ms->key_size, + sizeof(params->key_size)); + ptr = dh_pack_data(ptr, end, ¶ms->p_size, sizeof(params->p_size)); + ptr = dh_pack_data(ptr, end, ¶ms->g_size, sizeof(params->g_size)); + ptr = dh_pack_data(ptr, end, params->key, params->key_size); + ptr = dh_pack_data(ptr, end, params->p, params->p_size); + ptr = dh_pack_data(ptr, end, params->g, params->g_size); + if (ptr != end) return -EINVAL; - - ptr = dh_pack_data(ptr, &secret, sizeof(secret)); - ptr = dh_pack_data(ptr, ¶ms->key_size, sizeof(params->key_size)); - ptr = dh_pack_data(ptr, ¶ms->p_size, sizeof(params->p_size)); - ptr = dh_pack_data(ptr, ¶ms->g_size, sizeof(params->g_size)); - ptr = dh_pack_data(ptr, params->key, params->key_size); - ptr = dh_pack_data(ptr, params->p, params->p_size); - dh_pack_data(ptr, params->g, params->g_size); - return 0; } EXPORT_SYMBOL_GPL(crypto_dh_encode_key); -int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) +int __crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) { const u8 *ptr = buf; struct kpp_secret secret; @@ -92,4 +90,31 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) return 0; } + +int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) +{ + int err; + + err = __crypto_dh_decode_key(buf, len, params); + if (err) + return err; + + /* + * Don't permit the buffer for 'key' or 'g' to be larger than 'p', since + * some drivers assume otherwise. + */ + if (params->key_size > params->p_size || + params->g_size > params->p_size) + return -EINVAL; + + /* + * Don't permit 'p' to be 0. It's not a prime number, and it's subject + * to corner cases such as 'mod 0' being undefined or + * crypto_kpp_maxsize() returning 0. + */ + if (memchr_inv(params->p, 0, params->p_size) == NULL) + return -EINVAL; + + return 0; +} EXPORT_SYMBOL_GPL(crypto_dh_decode_key); |