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| author | Andrew Duda <aduda@meraki.com> | 2016-11-08 18:53:40 +0000 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2016-11-21 14:07:30 -0500 |
| commit | da29f2991d75fc8aa3289407a0e686a4a22f8c9e (patch) | |
| tree | 3c972878a859196e72be31fe6da6d0ae5047d38b /common | |
| parent | 5300a4f9336291fb713fcfaf9ea6e51b71824800 (diff) | |
| download | u-boot-imx-da29f2991d75fc8aa3289407a0e686a4a22f8c9e.zip u-boot-imx-da29f2991d75fc8aa3289407a0e686a4a22f8c9e.tar.gz u-boot-imx-da29f2991d75fc8aa3289407a0e686a4a22f8c9e.tar.bz2 | |
rsa: Verify RSA padding programatically
Padding verification was done against static SHA/RSA pair arrays which
take up a lot of static memory, are mostly 0xff, and cannot be reused
for additional SHA/RSA pairings. The padding can be easily computed
according to PKCS#1v2.1 as:
EM = 0x00 || 0x01 || PS || 0x00 || T
where PS is (emLen - tLen - 3) octets of 0xff and T is DER encoding
of the hash.
Store DER prefix in checksum_algo and create rsa_verify_padding
function to handle verification of a message for any SHA/RSA pairing.
Signed-off-by: Andrew Duda <aduda@meraki.com>
Signed-off-by: aduda <aduda@meraki.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'common')
| -rw-r--r-- | common/image-sig.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/common/image-sig.c b/common/image-sig.c index 28f7a20..008d2c5 100644 --- a/common/image-sig.c +++ b/common/image-sig.c @@ -34,32 +34,35 @@ struct checksum_algo checksum_algos[] = { { "sha1", SHA1_SUM_LEN, + SHA1_DER_LEN, + sha1_der_prefix, RSA2048_BYTES, #if IMAGE_ENABLE_SIGN EVP_sha1, #endif hash_calculate, - padding_sha1_rsa2048, }, { "sha256", SHA256_SUM_LEN, + SHA256_DER_LEN, + sha256_der_prefix, RSA2048_BYTES, #if IMAGE_ENABLE_SIGN EVP_sha256, #endif hash_calculate, - padding_sha256_rsa2048, }, { "sha256", SHA256_SUM_LEN, + SHA256_DER_LEN, + sha256_der_prefix, RSA4096_BYTES, #if IMAGE_ENABLE_SIGN EVP_sha256, #endif hash_calculate, - padding_sha256_rsa4096, } }; |