diff options
| author | Billy Brumley <bbrumley@gmail.com> | 2019-02-02 10:53:29 +0200 |
|---|---|---|
| committer | Nicola Tuveri <nic.tuv@gmail.com> | 2019-02-20 19:54:19 +0200 |
| commit | 48e82c8e22f8ac16ad0666d99172f6dbaf33953a (patch) | |
| tree | 7d86658594b9a9800f1eefae0a926bf403c5db3c /crypto/err | |
| parent | 70fa3aa108320d15536228656b120d3e08de0e40 (diff) | |
SCA hardening for mod. field inversion in EC_GROUP
This commit adds a dedicated function in `EC_METHOD` to access a modular
field inversion implementation suitable for the specifics of the
implemented curve, featuring SCA countermeasures.
The new pointer is defined as:
`int (*field_inv)(const EC_GROUP*, BIGNUM *r, const BIGNUM *a, BN_CTX*)`
and computes the multiplicative inverse of `a` in the underlying field,
storing the result in `r`.
Three implementations are included, each including specific SCA
countermeasures:
- `ec_GFp_simple_field_inv()`, featuring SCA hardening through
blinding.
- `ec_GFp_mont_field_inv()`, featuring SCA hardening through Fermat's
Little Theorem (FLT) inversion.
- `ec_GF2m_simple_field_inv()`, that uses `BN_GF2m_mod_inv()` which
already features SCA hardening through blinding.
From a security point of view, this also helps addressing a leakage
previously affecting conversions from projective to affine coordinates.
This commit also adds a new error reason code (i.e.,
`EC_R_CANNOT_INVERT`) to improve consistency between the three
implementations as all of them could fail for the same reason but
through different code paths resulting in inconsistent error stack
states.
Co-authored-by: Nicola Tuveri <nic.tuv@gmail.com>
(cherry picked from commit e0033efc30b0f00476bba8f0fa5512be5dc8a3f1)
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/8262)
Diffstat (limited to 'crypto/err')
| -rw-r--r-- | crypto/err/openssl.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt index 3864bf9202..6b5f7dbef6 100644 --- a/crypto/err/openssl.txt +++ b/crypto/err/openssl.txt @@ -519,6 +519,7 @@ EC_F_ECX_PUB_ENCODE:268:ecx_pub_encode EC_F_EC_ASN1_GROUP2CURVE:153:ec_asn1_group2curve EC_F_EC_ASN1_GROUP2FIELDID:154:ec_asn1_group2fieldid EC_F_EC_GF2M_MONTGOMERY_POINT_MULTIPLY:208:ec_GF2m_montgomery_point_multiply +EC_F_EC_GF2M_SIMPLE_FIELD_INV:296:ec_GF2m_simple_field_inv EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT:159:\ ec_GF2m_simple_group_check_discriminant EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE:195:ec_GF2m_simple_group_set_curve @@ -535,6 +536,7 @@ EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES:164:\ ec_GF2m_simple_set_compressed_coordinates EC_F_EC_GFP_MONT_FIELD_DECODE:133:ec_GFp_mont_field_decode EC_F_EC_GFP_MONT_FIELD_ENCODE:134:ec_GFp_mont_field_encode +EC_F_EC_GFP_MONT_FIELD_INV:297:ec_GFp_mont_field_inv EC_F_EC_GFP_MONT_FIELD_MUL:131:ec_GFp_mont_field_mul EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE:209:ec_GFp_mont_field_set_to_one EC_F_EC_GFP_MONT_FIELD_SQR:132:ec_GFp_mont_field_sqr @@ -555,6 +557,7 @@ EC_F_EC_GFP_NIST_FIELD_MUL:200:ec_GFp_nist_field_mul EC_F_EC_GFP_NIST_FIELD_SQR:201:ec_GFp_nist_field_sqr EC_F_EC_GFP_NIST_GROUP_SET_CURVE:202:ec_GFp_nist_group_set_curve EC_F_EC_GFP_SIMPLE_BLIND_COORDINATES:287:ec_GFp_simple_blind_coordinates +EC_F_EC_GFP_SIMPLE_FIELD_INV:298:ec_GFp_simple_field_inv EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT:165:\ ec_GFp_simple_group_check_discriminant EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE:166:ec_GFp_simple_group_set_curve @@ -2116,6 +2119,7 @@ EC_R_ASN1_ERROR:115:asn1 error EC_R_BAD_SIGNATURE:156:bad signature EC_R_BIGNUM_OUT_OF_RANGE:144:bignum out of range EC_R_BUFFER_TOO_SMALL:100:buffer too small +EC_R_CANNOT_INVERT:165:cannot invert EC_R_COORDINATES_OUT_OF_RANGE:146:coordinates out of range EC_R_CURVE_DOES_NOT_SUPPORT_ECDH:160:curve does not support ecdh EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING:159:curve does not support signing |