frost/secp256k1-zkp
3
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Make secp256k1_scalar_get_bits support 32-bit reads

Browse Source 
The old code would trigger UB when count=32.
This commit is contained in:
Pieter Wuille
2021-12-28 18:13:04 -05:00
parent 5005abee60
commit e03dcc44b5
4 changed files with 15 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/scalar.h
View File

@@ -22,10 +22,10 @@
/** Clear a scalar to prevent the leak of sensitive data. */
static void secp256k1_scalar_clear(secp256k1_scalar *r);
/** Access bits from a scalar. All requested bits must belong to the same 32-bit limb. */
/** Access bits (1 < count <= 32) from a scalar. All requested bits must belong to the same 32-bit limb. */
static uint32_t secp256k1_scalar_get_bits_limb32(const secp256k1_scalar *a, unsigned int offset, unsigned int count);
/** Access bits from a scalar. Not constant time in offset and count. */
/** Access bits (1 < count <= 32) from a scalar. offset + count must be < 256. Not constant time in offset and count. */
static uint32_t secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count);
/** Set a scalar from a big endian byte array. The scalar will be reduced modulo group order `n`.