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Diffstat (limited to 'libtommath/bn_mp_grow.c')
-rw-r--r-- | libtommath/bn_mp_grow.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/libtommath/bn_mp_grow.c b/libtommath/bn_mp_grow.c new file mode 100644 index 0000000..b6987df --- /dev/null +++ b/libtommath/bn_mp_grow.c @@ -0,0 +1,57 @@ +#include <tommath.h> +#ifdef BN_MP_GROW_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* grow as required */ +int mp_grow (mp_int * a, int size) +{ + int i; + mp_digit *tmp; + + /* if the alloc size is smaller alloc more ram */ + if (a->alloc < size) { + /* ensure there are always at least MP_PREC digits extra on top */ + size += (MP_PREC * 2) - (size % MP_PREC); + + /* reallocate the array a->dp + * + * We store the return in a temporary variable + * in case the operation failed we don't want + * to overwrite the dp member of a. + */ + tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * size); + if (tmp == NULL) { + /* reallocation failed but "a" is still valid [can be freed] */ + return MP_MEM; + } + + /* reallocation succeeded so set a->dp */ + a->dp = tmp; + + /* zero excess digits */ + i = a->alloc; + a->alloc = size; + for (; i < a->alloc; i++) { + a->dp[i] = 0; + } + } + return MP_OKAY; +} +#endif + +/* $Source: /root/tcl/repos-to-convert/tcl/libtommath/bn_mp_grow.c,v $ */ +/* $Revision: 1.1.1.1.2.1 $ */ +/* $Date: 2005/09/26 20:16:53 $ */ |