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| author | Werner Koch <[email protected]> | 2014-09-11 15:06:16 +0000 |
|---|---|---|
| committer | Werner Koch <[email protected]> | 2014-09-11 15:06:22 +0000 |
| commit | cd53cdbc3774fb193bdebcdc5d7019ddebc16dbc (patch) | |
| tree | ff7a3058a181f54dfb6aa534237e7800b47ee280 | |
| parent | mpi: Suppress set-but-unused-variables warnings. (diff) | |
| download | gnupg-cd53cdbc3774fb193bdebcdc5d7019ddebc16dbc.tar.gz gnupg-cd53cdbc3774fb193bdebcdc5d7019ddebc16dbc.zip | |
mpi: Improve mpi_invm to detect bad input.
* mpi/mpi-inv.c (mpi_invm): Return 0 for bad input.
--
Without this patch the function may enter an endless loop. This is a
backport from libgcrypt.
GnuPG-bug-id: 1713
| -rw-r--r-- | mpi/mpi-inv.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/mpi/mpi-inv.c b/mpi/mpi-inv.c index b76263047..361c57ea4 100644 --- a/mpi/mpi-inv.c +++ b/mpi/mpi-inv.c @@ -165,6 +165,11 @@ mpi_invm( MPI x, MPI a, MPI n ) int sign; int odd ; + if (!mpi_cmp_ui (a, 0)) + return 0; /* Inverse does not exists. */ + if (!mpi_cmp_ui (n, 1)) + return 0; /* Inverse does not exists. */ + u = mpi_copy(a); v = mpi_copy(n); |