diff options
Diffstat (limited to 'external_libs/python/pyzmq-14.7.0/bundled/libsodium/src/libsodium/crypto_sign/ed25519/ref10/fe_isnegative.c')
-rw-r--r-- | external_libs/python/pyzmq-14.7.0/bundled/libsodium/src/libsodium/crypto_sign/ed25519/ref10/fe_isnegative.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/external_libs/python/pyzmq-14.7.0/bundled/libsodium/src/libsodium/crypto_sign/ed25519/ref10/fe_isnegative.c b/external_libs/python/pyzmq-14.7.0/bundled/libsodium/src/libsodium/crypto_sign/ed25519/ref10/fe_isnegative.c new file mode 100644 index 00000000..3b2c8b8d --- /dev/null +++ b/external_libs/python/pyzmq-14.7.0/bundled/libsodium/src/libsodium/crypto_sign/ed25519/ref10/fe_isnegative.c @@ -0,0 +1,16 @@ +#include "fe.h" + +/* +return 1 if f is in {1,3,5,...,q-2} +return 0 if f is in {0,2,4,...,q-1} + +Preconditions: + |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc. +*/ + +int fe_isnegative(const fe f) +{ + unsigned char s[32]; + fe_tobytes(s,f); + return s[0] & 1; +} |