60bf8890df5360148df921f26d8dc4d667dd5926 ecmult: fix definition of STRAUSS_SCRATCH_OBJECTS (Jonas Nick)
Pull request description:
This bug was introduced in 7506e064d791e529d2e57bb52c156deb33b897ef by adding
an allocation but not updating the constant.
ACKs for top commit:
robot-dreams:
ACK 60bf8890df5360148df921f26d8dc4d667dd5926
real-or-random:
ACK 60bf8890df5360148df921f26d8dc4d667dd5926
Tree-SHA512: d7782fe9bf09fea8cf22304ab13679223a48f4d8b09081e662ea162a68c4e35f6b5820fbe4c6030fabad02a48dfdd02eb9eef22262c1dbbf02955bb92b75aef8
This header contains a static array that replaces the ecmult_context pre_g and pre_g_128 tables.
The gen_ecmult_static_pre_g program generates this header file.
29a299e373d5f0e326be74c514c7c70ddf50cce1 Run the undefined behaviour sanitizer on Travis (Fabien)
7506e064d791e529d2e57bb52c156deb33b897ef Prevent arithmetic on NULL pointer if the scratch space is too small (Fabien)
Pull request description:
ACKs for top commit:
sipa:
ACK 29a299e373d5f0e326be74c514c7c70ddf50cce1. Reviewed the code changes and verified that building with these sanitizer flags catches the existing error, as well as a signed integer overflow if introduced.
real-or-random:
ACK 29a299e373d5f0e326be74c514c7c70ddf50cce1 code inspection
jonasnick:
utACK 29a299e373d5f0e326be74c514c7c70ddf50cce1
Tree-SHA512: 4d788f12f3d7b48018e884910adb9b530a05d88f504de83dadeab8a22d75da83c05a1518f7317de5f536c4dd243ea7b347b1eaddb2ca1d804c663e41b85db69d
If the scratch space is too small when calling
`secp256k1_ecmult_strauss_batch()`, the `state.pre_a` allocation will
fail and the pointer will be `NULL`. This causes `state.pre_a_lam` to be
computed from the `NULL` pointer.
It is also possible that the first allocation to fail is for `state.ps`,
which will cause the failure to occur when in
`secp256k1_ecmult_strauss_wnaf()`.
The issue has been detected by UBSAN using Clang 10:
```
CC=clang \
CFLAGS="-fsanitize=undefined -fno-omit-frame-pointer" \
LDFLAGS="-fsanitize=undefined -fno-omit-frame-pointer" \
../configure
UBSAN_OPTIONS=print_stacktrace=1:halt_on_error=1 make check
```
9ab96f7 Use trivial algorithm in ecmult_multi if scratch space is small (Jonas Nick)
Pull request description:
`ecmult_multi` already selects the trivial algorithm if the scratch space is NULL. With this PR the trivial algorithm is also selected if the scratch space is too small to use pippenger or strauss instead of returning 0. That makes it more easier to avoid consensus relevant inconsistencies just because scratch space construction was messed up.
ACKs for commit 9ab96f:
real-or-random:
utACK 9ab96f7
Tree-SHA512: aa451adf8880af15cf167a59cb07fc411edc43f26c8eb0873bdae2774382ba182e2a1c54487912f8f2999cb0402d554b9d293e2fb9483234471348a1f43c6653
This makes WINDOW_G a configurable value in the range of [2..24].
The upper limit of 24 is a defensive choice. The code is probably
correct for values up to 27 but those larger values yield in huge
tables (>= 256MiB), which are i) unlikely to be really beneficial
in practice and ii) increasingly difficult to test.
9bd89c8 Optimize secp256k1_fe_normalize_weak calls. Move secp256k1_fe_normalize_weak calls out of ECMULT_TABLE_GET_GE and ECMULT_TABLE_GET_GE_STORAGE and into secp256k1_ge_globalz_set_table_gej instead. (Russell O'Connor)
Pull request description:
Move secp256k1_fe_normalize_weak calls out of ECMULT_TABLE_GET_GE and ECMULT_TABLE_GET_GE_STORAGE and into secp256k1_ge_globalz_set_table_gej instead.
Tree-SHA512: 7bbb1aca8e37a268a26d7061bd1f390db129e697792f1d5ddd10ea34927616edc26ef118b500c3e5e14d1d463196033ef64e4d34b765380325c24835458b7a9b
ec0a7b3 Don't touch leading zeros in wnaf_fixed. (Jonas Nick)
9e36d1b Fix bug in wnaf_fixed where the wnaf array is not completely zeroed when given a 0 scalar. (Jonas Nick)
96f68a0 Don't invert scalar in wnaf_fixed when it is even because a caller might intentionally give a scalar with many leading zeros. (Jonas Nick)
6dbb007 Increase sparsity of pippenger fixed window naf representation (Jonas Nick)
Pull request description:
Fixes#506
Tree-SHA512: 49a237a7d09c0c376ba4e6b1f522b9aff2517e420dfef9df810fd5ba920e0b98be8fe3f730b32e41b4aef475bc4cf3b13220024bd8d6f40c2744e6f392ff97a8
