[U-Boot] [PATCH 2/4] SECURE BOOT: separate functions for reading keys
Ruchika Gupta
ruchika.gupta at nxp.com
Fri Jan 15 08:07:31 CET 2016
> -----Original Message-----
> From: Aneesh Bansal
> Sent: Tuesday, December 08, 2015 2:14 PM
> To: u-boot at lists.denx.de
> Cc: Yusong Sun <yorksun at freescale.com>; Ruchika Gupta
> <ruchika.gupta at freescale.com>; Prabhakar Kushwaha
> <prabhakar at freescale.com>; Aneesh Bansal
> <aneesh.bansal at freescale.com>; Saksham Jain <saksham at freescale.com>
> Subject: [PATCH 2/4] SECURE BOOT: separate functions for reading keys
>
> Separate functions are created for reading and checking the sanity of Public
> keys:
> - read_validate_single_key
> - read_validate_ie_tbl
> - read_validate_srk_table
>
> Signed-off-by: Saksham Jain <saksham at freescale.com>
> Signed-off-by: Aneesh Bansal <aneesh.bansal at freescale.com>
> ---
> board/freescale/common/fsl_validate.c | 169 +++++++++++++++++++---------
> ------
> 1 file changed, 96 insertions(+), 73 deletions(-)
>
> diff --git a/board/freescale/common/fsl_validate.c
> b/board/freescale/common/fsl_validate.c
> index 282ce53..ef7a5ae 100644
> --- a/board/freescale/common/fsl_validate.c
> +++ b/board/freescale/common/fsl_validate.c
> @@ -24,6 +24,10 @@
> #define SHA256_NIBBLES (256/4)
> #define NUM_HEX_CHARS (sizeof(ulong) * 2)
>
> +#define CHECK_KEY_LEN(key_len) (((key_len) == 2 * KEY_SIZE_BYTES /
> 4) || \
> + ((key_len) == 2 * KEY_SIZE_BYTES / 2) || \
> + ((key_len) == 2 * KEY_SIZE_BYTES))
> +
> /* This array contains DER value for SHA-256 */ static const u8
> hash_identifier[] = { 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60,
> 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00,
> @@ -179,20 +183,97 @@ static u32 is_key_revoked(u32 keynum, u32
> rev_flag)
> return 0;
> }
>
> -/* It validates srk_table key lengths.*/ -static u32 validate_srk_tbl(struct
> srk_table *tbl, u32 num_entries)
> +/* It read validates srk_table key lengths.*/ static u32
> +read_validate_srk_tbl(struct fsl_secboot_img_priv *img)
> {
> int i = 0;
> - for (i = 0; i < num_entries; i++) {
> - if (!((tbl[i].key_len == 2 * KEY_SIZE_BYTES/4) ||
> - (tbl[i].key_len == 2 * KEY_SIZE_BYTES/2) ||
> - (tbl[i].key_len == 2 * KEY_SIZE_BYTES)))
> + u32 ret, key_num, key_revoc_flag, size;
> + struct fsl_secboot_img_hdr *hdr = &img->hdr;
> + void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
> +
> + if ((hdr->len_kr.num_srk == 0) ||
> + (hdr->len_kr.num_srk > MAX_KEY_ENTRIES))
> + return
> ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY;
> +
> + key_num = hdr->len_kr.srk_sel;
> + if (key_num == 0 || key_num > hdr->len_kr.num_srk)
> + return ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM;
> +
> + /* Get revoc key from sfp */
> + key_revoc_flag = get_key_revoc();
> + ret = is_key_revoked(key_num, key_revoc_flag);
> + if (ret)
> + return ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED;
> +
> + size = hdr->len_kr.num_srk * sizeof(struct srk_table);
> +
> + memcpy(&img->srk_tbl, esbc + hdr->srk_tbl_off, size);
> +
> + for (i = 0; i < hdr->len_kr.num_srk; i++) {
> + if (!CHECK_KEY_LEN(img->srk_tbl[i].key_len))
> return
> ERROR_ESBC_CLIENT_HEADER_INV_SRK_ENTRY_KEYLEN;
> }
> +
> + img->key_len = img->srk_tbl[key_num - 1].key_len;
> +
> + memcpy(&img->img_key, &(img->srk_tbl[key_num - 1].pkey),
> + img->key_len);
> +
> return 0;
> }
> #endif
>
> +static u32 read_validate_single_key(struct fsl_secboot_img_priv *img) {
> + struct fsl_secboot_img_hdr *hdr = &img->hdr;
> + void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
> +
> + /* check key length */
> + if (!CHECK_KEY_LEN(hdr->key_len))
> + return ERROR_ESBC_CLIENT_HEADER_KEY_LEN;
> +
> + memcpy(&img->img_key, esbc + hdr->pkey, hdr->key_len);
> +
> + img->key_len = hdr->key_len;
> +
> + return 0;
> +}
> +
> +#if defined(CONFIG_FSL_ISBC_KEY_EXT)
> +static u32 read_validate_ie_tbl(struct fsl_secboot_img_priv *img) {
> + struct fsl_secboot_img_hdr *hdr = &img->hdr;
> + u32 ie_key_len, ie_revoc_flag, ie_num;
> + struct ie_key_info *ie_info;
> +
> + if (get_ie_info_addr(&img->ie_addr))
> + return ERROR_IE_TABLE_NOT_FOUND;
> + ie_info = (struct ie_key_info *)(uintptr_t)img->ie_addr;
> + if (ie_info->num_keys == 0 || ie_info->num_keys > 32)
> + return
> ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY;
> +
> + ie_num = hdr->ie_key_sel;
> + if (ie_num == 0 || ie_num > ie_info->num_keys)
> + return
> ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM;
> +
> + ie_revoc_flag = ie_info->key_revok;
> + if ((u32)(1 << (ie_num - 1)) & ie_revoc_flag)
> + return ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED;
> +
> + ie_key_len = ie_info->ie_key_tbl[ie_num - 1].key_len;
> +
> + if (!CHECK_KEY_LEN(ie_key_len))
> + return
> ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN;
> +
> + memcpy(&img->img_key, &(ie_info->ie_key_tbl[ie_num - 1].pkey),
> + ie_key_len);
> +
> + img->key_len = ie_key_len;
> + return 0;
> +}
> +#endif
> +
> +
> /* This function return length of public key.*/ static inline u32
> get_key_len(struct fsl_secboot_img_priv *img) { @@ -541,13 +622,9 @@
> static int read_validate_esbc_client_header(struct fsl_secboot_img_priv
> *img)
> struct fsl_secboot_img_hdr *hdr = &img->hdr;
> void *esbc = (u8 *)(uintptr_t)img->ehdrloc;
> u8 *k, *s;
> + u32 ret = 0;
> +
> #ifdef CONFIG_KEY_REVOCATION
> - u32 ret;
> - u32 key_num, key_revoc_flag, size;
> -#endif
> -#if defined(CONFIG_FSL_ISBC_KEY_EXT)
> - struct ie_key_info *ie_info;
> - u32 ie_num, ie_revoc_flag, ie_key_len;
> #endif
> int key_found = 0;
>
> @@ -568,80 +645,26 @@ static int read_validate_esbc_client_header(struct
> fsl_secboot_img_priv *img)
> /* Key checking*/
> #ifdef CONFIG_KEY_REVOCATION
> if (check_srk(img)) {
> - if ((hdr->len_kr.num_srk == 0) ||
> - (hdr->len_kr.num_srk > MAX_KEY_ENTRIES))
> - return
> ERROR_ESBC_CLIENT_HEADER_INVALID_SRK_NUM_ENTRY;
> -
> - key_num = hdr->len_kr.srk_sel;
> - if (key_num == 0 || key_num > hdr->len_kr.num_srk)
> - return
> ERROR_ESBC_CLIENT_HEADER_INVALID_KEY_NUM;
> -
> - /* Get revoc key from sfp */
> - key_revoc_flag = get_key_revoc();
> - ret = is_key_revoked(key_num, key_revoc_flag);
> - if (ret)
> - return ERROR_ESBC_CLIENT_HEADER_KEY_REVOKED;
> -
> - size = hdr->len_kr.num_srk * sizeof(struct srk_table);
> -
> - memcpy(&img->srk_tbl, esbc + hdr->srk_tbl_off, size);
> -
> - ret = validate_srk_tbl(img->srk_tbl, hdr->len_kr.num_srk);
> -
> + ret = read_validate_srk_tbl(img);
> if (ret != 0)
> return ret;
> -
> - img->key_len = img->srk_tbl[key_num - 1].key_len;
> -
> - memcpy(&img->img_key, &(img->srk_tbl[key_num - 1].pkey),
> - img->key_len);
> -
> key_found = 1;
> }
> #endif
>
> #if defined(CONFIG_FSL_ISBC_KEY_EXT)
> if (!key_found && check_ie(img)) {
> - if (get_ie_info_addr(&img->ie_addr))
> - return ERROR_IE_TABLE_NOT_FOUND;
> - ie_info = (struct ie_key_info *)(uintptr_t)img->ie_addr;
> - if (ie_info->num_keys == 0 || ie_info->num_keys > 32)
> - return
> ERROR_ESBC_CLIENT_HEADER_INVALID_IE_NUM_ENTRY;
> -
> - ie_num = hdr->ie_key_sel;
> - if (ie_num == 0 || ie_num > ie_info->num_keys)
> - return
> ERROR_ESBC_CLIENT_HEADER_INVALID_IE_KEY_NUM;
> -
> - ie_revoc_flag = ie_info->key_revok;
> - if ((u32)(1 << (ie_num - 1)) & ie_revoc_flag)
> - return
> ERROR_ESBC_CLIENT_HEADER_IE_KEY_REVOKED;
> -
> - ie_key_len = ie_info->ie_key_tbl[ie_num - 1].key_len;
> -
> - if (!((ie_key_len == 2 * KEY_SIZE_BYTES / 4) ||
> - (ie_key_len == 2 * KEY_SIZE_BYTES / 2) ||
> - (ie_key_len == 2 * KEY_SIZE_BYTES)))
> - return
> ERROR_ESBC_CLIENT_HEADER_INV_IE_ENTRY_KEYLEN;
> -
> - memcpy(&img->img_key, &(ie_info->ie_key_tbl[ie_num -
> 1].pkey),
> - ie_key_len);
> -
> - img->key_len = ie_key_len;
> + ret = read_validate_ie_tbl(img);
> + if (ret != 0)
> + return ret;
> key_found = 1;
> }
> #endif
>
> if (key_found == 0) {
> - /* check key length */
> - if (!((hdr->key_len == 2 * KEY_SIZE_BYTES / 4) ||
> - (hdr->key_len == 2 * KEY_SIZE_BYTES / 2) ||
> - (hdr->key_len == 2 * KEY_SIZE_BYTES)))
> - return ERROR_ESBC_CLIENT_HEADER_KEY_LEN;
> -
> - memcpy(&img->img_key, esbc + hdr->pkey, hdr->key_len);
> -
> - img->key_len = hdr->key_len;
> -
> + ret = read_validate_single_key(img);
> + if (ret != 0)
> + return ret;
> key_found = 1;
> }
>
> --
> 1.8.1.4
Acked-by: Ruchika Gupta <ruchika.gupta at nxp.com>
More information about the U-Boot
mailing list