diff options
Diffstat (limited to 'common/image-cipher.c')
| -rw-r--r-- | common/image-cipher.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/common/image-cipher.c b/common/image-cipher.c new file mode 100644 index 0000000000..cee3b03ee5 --- /dev/null +++ b/common/image-cipher.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2019, Softathome + */ + +#ifdef USE_HOSTCC +#include "mkimage.h" +#include <time.h> +#else +#include <common.h> +#include <malloc.h> +DECLARE_GLOBAL_DATA_PTR; +#endif /* !USE_HOSTCC*/ +#include <image.h> +#include <uboot_aes.h> +#include <u-boot/aes.h> + +struct cipher_algo cipher_algos[] = { + { + .name = "aes128", + .key_len = AES128_KEY_LENGTH, + .iv_len = AES_BLOCK_LENGTH, +#if IMAGE_ENABLE_ENCRYPT + .calculate_type = EVP_aes_128_cbc, +#endif + .encrypt = image_aes_encrypt, + .decrypt = image_aes_decrypt, + .add_cipher_data = image_aes_add_cipher_data + }, + { + .name = "aes192", + .key_len = AES192_KEY_LENGTH, + .iv_len = AES_BLOCK_LENGTH, +#if IMAGE_ENABLE_ENCRYPT + .calculate_type = EVP_aes_192_cbc, +#endif + .encrypt = image_aes_encrypt, + .decrypt = image_aes_decrypt, + .add_cipher_data = image_aes_add_cipher_data + }, + { + .name = "aes256", + .key_len = AES256_KEY_LENGTH, + .iv_len = AES_BLOCK_LENGTH, +#if IMAGE_ENABLE_ENCRYPT + .calculate_type = EVP_aes_256_cbc, +#endif + .encrypt = image_aes_encrypt, + .decrypt = image_aes_decrypt, + .add_cipher_data = image_aes_add_cipher_data + } +}; + +struct cipher_algo *image_get_cipher_algo(const char *full_name) +{ + int i; + const char *name; + + for (i = 0; i < ARRAY_SIZE(cipher_algos); i++) { + name = cipher_algos[i].name; + if (!strncmp(name, full_name, strlen(name))) + return &cipher_algos[i]; + } + + return NULL; +} + +static int fit_image_setup_decrypt(struct image_cipher_info *info, + const void *fit, int image_noffset, + int cipher_noffset) +{ + const void *fdt = gd_fdt_blob(); + const char *node_name; + char node_path[128]; + int noffset; + char *algo_name; + int ret; + + node_name = fit_get_name(fit, image_noffset, NULL); + if (!node_name) { + printf("Can't get node name\n"); + return -1; + } + + if (fit_image_cipher_get_algo(fit, cipher_noffset, &algo_name)) { + printf("Can't get algo name for cipher '%s' in image '%s'\n", + node_name, node_name); + return -1; + } + + info->keyname = fdt_getprop(fit, cipher_noffset, "key-name-hint", NULL); + if (!info->keyname) { + printf("Can't get key name\n"); + return -1; + } + + info->ivname = fdt_getprop(fit, cipher_noffset, "iv-name-hint", NULL); + if (!info->ivname) { + printf("Can't get IV name\n"); + return -1; + } + + info->fit = fit; + info->node_noffset = image_noffset; + info->name = algo_name; + info->cipher = image_get_cipher_algo(algo_name); + if (!info->cipher) { + printf("Can't get cipher\n"); + return -1; + } + + ret = fit_image_get_data_size_unciphered(fit, image_noffset, + &info->size_unciphered); + if (ret) { + printf("Can't get size of unciphered data\n"); + return -1; + } + + /* + * Search the cipher node in the u-boot fdt + * the path should be: /cipher/key-<algo>-<key>-<iv> + */ + snprintf(node_path, sizeof(node_path), "/%s/key-%s-%s-%s", + FIT_CIPHER_NODENAME, algo_name, info->keyname, info->ivname); + + noffset = fdt_path_offset(fdt, node_path); + if (noffset < 0) { + printf("Can't found cipher node offset\n"); + return -1; + } + + /* read key */ + info->key = fdt_getprop(fdt, noffset, "key", NULL); + if (!info->key) { + printf("Can't get key in cipher node '%s'\n", node_path); + return -1; + } + + /* read iv */ + info->iv = fdt_getprop(fdt, noffset, "iv", NULL); + if (!info->iv) { + printf("Can't get IV in cipher node '%s'\n", node_path); + return -1; + } + + return 0; +} + +int fit_image_decrypt_data(const void *fit, + int image_noffset, int cipher_noffset, + const void *data_ciphered, size_t size_ciphered, + void **data_unciphered, size_t *size_unciphered) +{ + struct image_cipher_info info; + int ret; + + ret = fit_image_setup_decrypt(&info, fit, image_noffset, + cipher_noffset); + if (ret < 0) + goto out; + + ret = info.cipher->decrypt(&info, data_ciphered, size_ciphered, + data_unciphered, size_unciphered); + + out: + return ret; +} |