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author | Salvatore Benedetto <salvatore.benedetto@intel.com> | 2016-06-22 18:49:15 +0200 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2016-06-23 12:29:57 +0200 |
commit | 3c4b23901a0c766879dff680cd6bdab47bcdbbd2 (patch) | |
tree | 3bcc903dce759f69193f4b9fa638f1383d7323d3 /crypto/ecdh_helper.c | |
parent | crypto: dh - Add DH software implementation (diff) | |
download | linux-3c4b23901a0c766879dff680cd6bdab47bcdbbd2.tar.xz linux-3c4b23901a0c766879dff680cd6bdab47bcdbbd2.zip |
crypto: ecdh - Add ECDH software support
* Implement ECDH under kpp API
* Provide ECC software support for curve P-192 and
P-256.
* Add kpp test for ECDH with data generated by OpenSSL
Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/ecdh_helper.c')
-rw-r--r-- | crypto/ecdh_helper.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/crypto/ecdh_helper.c b/crypto/ecdh_helper.c new file mode 100644 index 000000000000..3cd8a2414e60 --- /dev/null +++ b/crypto/ecdh_helper.c @@ -0,0 +1,86 @@ +/* + * 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 Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/err.h> +#include <linux/string.h> +#include <crypto/ecdh.h> +#include <crypto/kpp.h> + +#define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 2 * sizeof(short)) + +static inline u8 *ecdh_pack_data(void *dst, const void *src, size_t sz) +{ + memcpy(dst, src, sz); + return dst + sz; +} + +static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz) +{ + memcpy(dst, src, sz); + return src + sz; +} + +int crypto_ecdh_key_len(const struct ecdh *params) +{ + return ECDH_KPP_SECRET_MIN_SIZE + params->key_size; +} +EXPORT_SYMBOL_GPL(crypto_ecdh_key_len); + +int crypto_ecdh_encode_key(char *buf, unsigned int len, + const struct ecdh *params) +{ + u8 *ptr = buf; + struct kpp_secret secret = { + .type = CRYPTO_KPP_SECRET_TYPE_ECDH, + .len = len + }; + + if (unlikely(!buf)) + return -EINVAL; + + if (len != crypto_ecdh_key_len(params)) + return -EINVAL; + + ptr = ecdh_pack_data(ptr, &secret, sizeof(secret)); + ptr = ecdh_pack_data(ptr, ¶ms->curve_id, sizeof(params->curve_id)); + ptr = ecdh_pack_data(ptr, ¶ms->key_size, sizeof(params->key_size)); + ecdh_pack_data(ptr, params->key, params->key_size); + + return 0; +} +EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key); + +int crypto_ecdh_decode_key(const char *buf, unsigned int len, + struct ecdh *params) +{ + const u8 *ptr = buf; + struct kpp_secret secret; + + if (unlikely(!buf || len < ECDH_KPP_SECRET_MIN_SIZE)) + return -EINVAL; + + ptr = ecdh_unpack_data(&secret, ptr, sizeof(secret)); + if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH) + return -EINVAL; + + ptr = ecdh_unpack_data(¶ms->curve_id, ptr, sizeof(params->curve_id)); + ptr = ecdh_unpack_data(¶ms->key_size, ptr, sizeof(params->key_size)); + if (secret.len != crypto_ecdh_key_len(params)) + return -EINVAL; + + /* Don't allocate memory. Set pointer to data + * within the given buffer + */ + params->key = (void *)ptr; + + return 0; +} +EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key); |