Commit graph

7 commits

Author SHA1 Message Date
Gilles Peskine 4699fa47d2 Move mbedtls_mpi_random to the bignum module
Since mbedtls_mpi_random() is not specific to ECC code, move it from
the ECP module to the bignum module.

This increases the code size in builds without short Weierstrass
curves (including builds without ECC at all) that do not optimize out
unused functions.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-06-02 21:31:24 +02:00
Gilles Peskine 7967ec5d25 mbedtls_ecp_gen_privkey_sw: generalize to mbedtls_mpi_random
Rename mbedtls_ecp_gen_privkey_sw to mbedtls_mpi_random since it has
no particular connection to elliptic curves beyond the fact that its
operation is defined by the deterministic ECDSA specification. This is
a generic function that generates a random MPI between 1 inclusive and
N exclusive.

Slightly generalize the function to accept a different lower bound,
which adds a negligible amount of complexity.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-06-02 21:31:24 +02:00
Gilles Peskine 3838f28c33 mbedtls_ecp_gen_privkey_mx: rename n_bits to high_bit
For Montgomery keys, n_bits is actually the position of the highest
bit and not the number of bits, which would be 1 more (fence vs
posts). Rename the variable accordingly to lessen the confusion.

No semantic change.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-06-02 21:31:24 +02:00
Gilles Peskine de33213f23 mbedtls_ecp_gen_privkey: create subfunctions for each curve type
Put the Montgomery and short Weierstrass implementations of
mbedtls_ecp_gen_privkey into their own function which can be tested
independently, but will not be part of the public ABI/API.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-06-02 21:31:24 +02:00
Gilles Peskine 392d1010dc Clarify some comments
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-04-09 15:46:51 +02:00
Gilles Peskine 618be2ec41 Add unit tests for fix_negative
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-04-04 01:10:41 +02:00
Gilles Peskine 80ba850e27 Create a header file for ECP internal functions
This header file will contain declarations of functions that are not
part of the public ABI/API, and must not be called from other modules,
but can be called from unit tests.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-04-04 01:10:41 +02:00