diff options
| -rw-r--r-- | crypto/Kconfig | 5 | ||||
| -rw-r--r-- | crypto/Makefile | 1 | ||||
| -rw-r--r-- | crypto/curve25519-generic.c | 90 |
3 files changed, 96 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index 64cc4a93b51c..fab259d9d056 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -264,6 +264,11 @@ config CRYPTO_ECRDSA standard algorithms (called GOST algorithms). Only signature verification is implemented. +config CRYPTO_CURVE25519 + tristate "Curve25519 algorithm" + select CRYPTO_KPP + select CRYPTO_LIB_CURVE25519_GENERIC + comment "Authenticated Encryption with Associated Data" config CRYPTO_CCM diff --git a/crypto/Makefile b/crypto/Makefile index 9995527c4be7..d627ec4e0522 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -168,6 +168,7 @@ obj-$(CONFIG_CRYPTO_ZSTD) += zstd.o obj-$(CONFIG_CRYPTO_OFB) += ofb.o obj-$(CONFIG_CRYPTO_ECC) += ecc.o obj-$(CONFIG_CRYPTO_ESSIV) += essiv.o +obj-$(CONFIG_CRYPTO_CURVE25519) += curve25519-generic.o ecdh_generic-y += ecdh.o ecdh_generic-y += ecdh_helper.o diff --git a/crypto/curve25519-generic.c b/crypto/curve25519-generic.c new file mode 100644 index 000000000000..bd88fd571393 --- /dev/null +++ b/crypto/curve25519-generic.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#include <crypto/curve25519.h> +#include <crypto/internal/kpp.h> +#include <crypto/kpp.h> +#include <linux/module.h> +#include <linux/scatterlist.h> + +static int curve25519_set_secret(struct crypto_kpp *tfm, const void *buf, + unsigned int len) +{ + u8 *secret = kpp_tfm_ctx(tfm); + + if (!len) + curve25519_generate_secret(secret); + else if (len == CURVE25519_KEY_SIZE && + crypto_memneq(buf, curve25519_null_point, CURVE25519_KEY_SIZE)) + memcpy(secret, buf, CURVE25519_KEY_SIZE); + else + return -EINVAL; + return 0; +} + +static int curve25519_compute_value(struct kpp_request *req) +{ + struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); + const u8 *secret = kpp_tfm_ctx(tfm); + u8 public_key[CURVE25519_KEY_SIZE]; + u8 buf[CURVE25519_KEY_SIZE]; + int copied, nbytes; + u8 const *bp; + + if (req->src) { + copied = sg_copy_to_buffer(req->src, + sg_nents_for_len(req->src, + CURVE25519_KEY_SIZE), + public_key, CURVE25519_KEY_SIZE); + if (copied != CURVE25519_KEY_SIZE) + return -EINVAL; + bp = public_key; + } else { + bp = curve25519_base_point; + } + + curve25519_generic(buf, secret, bp); + + /* might want less than we've got */ + nbytes = min_t(size_t, CURVE25519_KEY_SIZE, req->dst_len); + copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst, + nbytes), + buf, nbytes); + if (copied != nbytes) + return -EINVAL; + return 0; +} + +static unsigned int curve25519_max_size(struct crypto_kpp *tfm) +{ + return CURVE25519_KEY_SIZE; +} + +static struct kpp_alg curve25519_alg = { + .base.cra_name = "curve25519", + .base.cra_driver_name = "curve25519-generic", + .base.cra_priority = 100, + .base.cra_module = THIS_MODULE, + .base.cra_ctxsize = CURVE25519_KEY_SIZE, + + .set_secret = curve25519_set_secret, + .generate_public_key = curve25519_compute_value, + .compute_shared_secret = curve25519_compute_value, + .max_size = curve25519_max_size, +}; + +static int curve25519_init(void) +{ + return crypto_register_kpp(&curve25519_alg); +} + +static void curve25519_exit(void) +{ + crypto_unregister_kpp(&curve25519_alg); +} + +subsys_initcall(curve25519_init); +module_exit(curve25519_exit); + +MODULE_ALIAS_CRYPTO("curve25519"); +MODULE_ALIAS_CRYPTO("curve25519-generic"); +MODULE_LICENSE("GPL"); |