clean up in-comment Sage code (refer to secp256k1_params.sage, update to Python3)

Some of the C source files contain contain in-comment Sage code
calculating secp256k1 parameters that are already defined in the file
secp256k1_params.sage.  Replace that by a corresponding load instruction
and access the necessary variables. In ecdsa_impl.h, update the comment
to use a one-line shell command calling sage to get the values.

The remaining code (test `test_add_neg_y_diff_x` in tests.c) is updated
to work with a current version based on Python3 (Sage 9.0+, see
https://wiki.sagemath.org/Python3-Switch).

The latter can be seen as a small follow-up to PR #849 (commit
13c88efed0).
This commit is contained in:
Sebastian Falbesoner
2023-06-11 16:38:12 +02:00
parent 60556c9f49
commit 600c5adcd5
2 changed files with 9 additions and 29 deletions

View File

@@ -16,17 +16,8 @@
#include "ecdsa.h"
/** Group order for secp256k1 defined as 'n' in "Standards for Efficient Cryptography" (SEC2) 2.7.1
* sage: for t in xrange(1023, -1, -1):
* .. p = 2**256 - 2**32 - t
* .. if p.is_prime():
* .. print '%x'%p
* .. break
* 'fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f'
* sage: a = 0
* sage: b = 7
* sage: F = FiniteField (p)
* sage: '%x' % (EllipticCurve ([F (a), F (b)]).order())
* 'fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141'
* $ sage -c 'load("secp256k1_params.sage"); print(hex(N))'
* 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
*/
static const secp256k1_fe secp256k1_ecdsa_const_order_as_fe = SECP256K1_FE_CONST(
0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFEUL,
@@ -35,12 +26,8 @@ static const secp256k1_fe secp256k1_ecdsa_const_order_as_fe = SECP256K1_FE_CONST
/** Difference between field and order, values 'p' and 'n' values defined in
* "Standards for Efficient Cryptography" (SEC2) 2.7.1.
* sage: p = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F
* sage: a = 0
* sage: b = 7
* sage: F = FiniteField (p)
* sage: '%x' % (p - EllipticCurve ([F (a), F (b)]).order())
* '14551231950b75fc4402da1722fc9baee'
* $ sage -c 'load("secp256k1_params.sage"); print(hex(P-N))'
* 0x14551231950b75fc4402da1722fc9baee
*/
static const secp256k1_fe secp256k1_ecdsa_const_p_minus_order = SECP256K1_FE_CONST(
0, 0, 0, 1, 0x45512319UL, 0x50B75FC4UL, 0x402DA172UL, 0x2FC9BAEEUL