diff options
author | Werner Koch <wk@gnupg.org> | 2018-06-05 14:29:53 +0200 |
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committer | Werner Koch <wk@gnupg.org> | 2018-06-05 14:29:53 +0200 |
commit | 6606ae44e0de1069b29dd4215ee9748280940e1b (patch) | |
tree | f9e87594b36d7f1c1bc339ce15a4b763e9688b7c /mpi | |
parent | 61dbb7c08ab11c10060e193b52e3e1d2ec6dd062 (diff) | |
download | libgcrypt-6606ae44e0de1069b29dd4215ee9748280940e1b.tar.gz |
mpi: New internal function _gcry_mpi_cmpabs.
* mpi/mpi-cmp.c (_gcry_mpi_cmp): Factor out to ...
(do_mpi_cmp): New. Add arg absmode.
(_gcry_mpi_cmpabs): New.
* src/gcrypt-int.h (mpi_cmpabs): New macro.
Signed-off-by: Werner Koch <wk@gnupg.org>
Diffstat (limited to 'mpi')
-rw-r--r-- | mpi/mpi-cmp.c | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/mpi/mpi-cmp.c b/mpi/mpi-cmp.c index 838a7c92..66e09612 100644 --- a/mpi/mpi-cmp.c +++ b/mpi/mpi-cmp.c @@ -54,15 +54,19 @@ _gcry_mpi_cmp_ui (gcry_mpi_t u, unsigned long v) } -int -_gcry_mpi_cmp (gcry_mpi_t u, gcry_mpi_t v) +/* Helper for _gcry_mpi_cmp and _gcry_mpi_cmpabs. */ +static int +do_mpi_cmp (gcry_mpi_t u, gcry_mpi_t v, int absmode) { mpi_size_t usize; mpi_size_t vsize; + int usign; + int vsign; int cmp; if (mpi_is_opaque (u) || mpi_is_opaque (v)) { + /* We have no signan and thus ABSMODE has no efeect here. */ if (mpi_is_opaque (u) && !mpi_is_opaque (v)) return -1; if (!mpi_is_opaque (u) && mpi_is_opaque (v)) @@ -82,26 +86,42 @@ _gcry_mpi_cmp (gcry_mpi_t u, gcry_mpi_t v) usize = u->nlimbs; vsize = v->nlimbs; + usign = absmode? 0 : u->sign; + vsign = absmode? 0 : v->sign; /* Compare sign bits. */ - if (!u->sign && v->sign) + if (!usign && vsign) return 1; - if (u->sign && !v->sign) + if (usign && !vsign) return -1; /* U and V are either both positive or both negative. */ - if (usize != vsize && !u->sign && !v->sign) + if (usize != vsize && !usign && !vsign) return usize - vsize; - if (usize != vsize && u->sign && v->sign) + if (usize != vsize && usign && vsign) return vsize + usize; if (!usize ) return 0; if (!(cmp = _gcry_mpih_cmp (u->d, v->d, usize))) return 0; - if ((cmp < 0?1:0) == (u->sign?1:0)) + if ((cmp < 0?1:0) == (usign?1:0)) return 1; } return -1; } + + +int +_gcry_mpi_cmp (gcry_mpi_t u, gcry_mpi_t v) +{ + return do_mpi_cmp (u, v, 0); +} + +/* Compare only the absolute values. */ +int +_gcry_mpi_cmpabs (gcry_mpi_t u, gcry_mpi_t v) +{ + return do_mpi_cmp (u, v, 1); +} |