diff options
Diffstat (limited to 'tools/env/fw_env.c')
| -rw-r--r-- | tools/env/fw_env.c | 129 |
1 files changed, 127 insertions, 2 deletions
diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c index f5cd521491..30d5b037f0 100644 --- a/tools/env/fw_env.c +++ b/tools/env/fw_env.c @@ -31,6 +31,10 @@ #include "fw_env.h" +#include <aes.h> + +#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) + #define WHITESPACE(c) ((c == '\t') || (c == ' ')) #define min(x, y) ({ \ @@ -98,6 +102,11 @@ static struct environment environment = { .flag_scheme = FLAG_NONE, }; +/* Is AES encryption used? */ +static int aes_flag; +static uint8_t aes_key[AES_KEY_LENGTH] = { 0 }; +static int env_aes_cbc_crypt(char *data, const int enc); + static int HaveRedundEnv = 0; static unsigned char active_flag = 1; @@ -120,6 +129,10 @@ static inline ulong getenvsize (void) if (HaveRedundEnv) rc -= sizeof (char); + + if (aes_flag) + rc &= ~(AES_KEY_LENGTH - 1); + return rc; } @@ -191,6 +204,36 @@ char *fw_getdefenv(char *name) return NULL; } +static int parse_aes_key(char *key) +{ + char tmp[5] = { '0', 'x', 0, 0, 0 }; + unsigned long ul; + int i; + + if (strnlen(key, 64) != 32) { + fprintf(stderr, + "## Error: '-a' option requires 16-byte AES key\n"); + return -1; + } + + for (i = 0; i < 16; i++) { + tmp[2] = key[0]; + tmp[3] = key[1]; + errno = 0; + ul = strtoul(tmp, NULL, 16); + if (errno) { + fprintf(stderr, + "## Error: '-a' option requires valid AES key\n"); + return -1; + } + aes_key[i] = ul & 0xff; + key += 2; + } + aes_flag = 1; + + return 0; +} + /* * Print the current definition of one, or more, or all * environment variables @@ -201,6 +244,19 @@ int fw_printenv (int argc, char *argv[]) int i, n_flag; int rc = 0; + if (argc >= 2 && strcmp(argv[1], "-a") == 0) { + if (argc < 3) { + fprintf(stderr, + "## Error: '-a' option requires AES key\n"); + return -1; + } + rc = parse_aes_key(argv[2]); + if (rc) + return rc; + argv += 2; + argc -= 2; + } + if (fw_env_open()) return -1; @@ -266,6 +322,16 @@ int fw_printenv (int argc, char *argv[]) int fw_env_close(void) { + int ret; + if (aes_flag) { + ret = env_aes_cbc_crypt(environment.data, 1); + if (ret) { + fprintf(stderr, + "Error: can't encrypt env for flash\n"); + return ret; + } + } + /* * Update CRC */ @@ -413,7 +479,7 @@ int fw_env_write(char *name, char *value) */ int fw_setenv(int argc, char *argv[]) { - int i; + int i, rc; size_t len; char *name; char *value = NULL; @@ -423,6 +489,24 @@ int fw_setenv(int argc, char *argv[]) return -1; } + if (strcmp(argv[1], "-a") == 0) { + if (argc < 3) { + fprintf(stderr, + "## Error: '-a' option requires AES key\n"); + return -1; + } + rc = parse_aes_key(argv[2]); + if (rc) + return rc; + argv += 2; + argc -= 2; + } + + if (argc < 2) { + errno = EINVAL; + return -1; + } + if (fw_env_open()) { fprintf(stderr, "Error: environment not initialized\n"); return -1; @@ -900,6 +984,28 @@ static int flash_flag_obsolete (int dev, int fd, off_t offset) return rc; } +/* Encrypt or decrypt the environment before writing or reading it. */ +static int env_aes_cbc_crypt(char *payload, const int enc) +{ + uint8_t *data = (uint8_t *)payload; + const int len = getenvsize(); + uint8_t key_exp[AES_EXPAND_KEY_LENGTH]; + uint32_t aes_blocks; + + /* First we expand the key. */ + aes_expand_key(aes_key, key_exp); + + /* Calculate the number of AES blocks to encrypt. */ + aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH); + + if (enc) + aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks); + else + aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks); + + return 0; +} + static int flash_write (int fd_current, int fd_target, int dev_target) { int rc; @@ -923,6 +1029,7 @@ static int flash_write (int fd_current, int fd_target, int dev_target) fprintf(stderr, "Writing new environment at 0x%lx on %s\n", DEVOFFSET (dev_target), DEVNAME (dev_target)); #endif + rc = flash_write_buf(dev_target, fd_target, environment.image, CUR_ENVSIZE, DEVOFFSET(dev_target), DEVTYPE(dev_target)); @@ -981,8 +1088,10 @@ static int flash_read (int fd) rc = flash_read_buf(dev_current, fd, environment.image, CUR_ENVSIZE, DEVOFFSET (dev_current), mtdinfo.type); + if (rc != CUR_ENVSIZE) + return -1; - return (rc != CUR_ENVSIZE) ? -1 : 0; + return 0; } static int flash_io (int mode) @@ -1075,6 +1184,8 @@ int fw_env_open(void) unsigned char flag1; void *addr1; + int ret; + struct env_image_single *single; struct env_image_redundant *redundant; @@ -1109,6 +1220,13 @@ int fw_env_open(void) return -1; crc0 = crc32 (0, (uint8_t *) environment.data, ENV_SIZE); + + if (aes_flag) { + ret = env_aes_cbc_crypt(environment.data, 0); + if (ret) + return ret; + } + crc0_ok = (crc0 == *environment.crc); if (!HaveRedundEnv) { if (!crc0_ok) { @@ -1159,6 +1277,13 @@ int fw_env_open(void) } crc1 = crc32 (0, (uint8_t *) redundant->data, ENV_SIZE); + + if (aes_flag) { + ret = env_aes_cbc_crypt(redundant->data, 0); + if (ret) + return ret; + } + crc1_ok = (crc1 == redundant->crc); flag1 = redundant->flags; |