diff options
author | Ulf Möller <ulf@openssl.org> | 2000-01-23 22:06:24 +0000 |
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committer | Ulf Möller <ulf@openssl.org> | 2000-01-23 22:06:24 +0000 |
commit | dd8dec69b825c9fdafc26a200961702d850496b5 (patch) | |
tree | b7d7ca7365271c822226e1ddc6a4fd68c72273ad /doc/crypto/BN_set_bit.pod | |
parent | ce052b6c3b18d4ab5f74990d82d09827a6014823 (diff) |
Document the BN library.
Diffstat (limited to 'doc/crypto/BN_set_bit.pod')
-rw-r--r-- | doc/crypto/BN_set_bit.pod | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/doc/crypto/BN_set_bit.pod b/doc/crypto/BN_set_bit.pod new file mode 100644 index 0000000000..f75d0173ea --- /dev/null +++ b/doc/crypto/BN_set_bit.pod @@ -0,0 +1,64 @@ +=pod + +=head1 NAME + +BN_set_bit, BN_clear_bit, BN_is_bit_set, BN_mask_bits, BN_lshift, +BN_lshift1, BN_rshift, BN_rshift1 - Bit operations on BIGNUMs + +=head1 SYNOPSIS + + #include <openssl/bn.h> + + int BN_set_bit(BIGNUM *a, int n); + int BN_clear_bit(BIGNUM *a, int n); + + int BN_is_bit_set(const BIGNUM *a, int n); + + int BN_mask_bits(BIGNUM *a, int n); + + int BN_lshift(BIGNUM *r, const BIGNUM *a, int n); + int BN_lshift1(BIGNUM *r, BIGNUM *a); + + int BN_rshift(BIGNUM *r, BIGNUM *a, int n); + int BN_rshift1(BIGNUM *r, BIGNUM *a); + +=head1 DESCRIPTION + +BN_set_bit() sets bit B<n> in B<a> to 1 (C<a|=(1E<lt>E<lt>n)>). The +number is expanded if necessary. + +BN_clear_bit() sets bit B<n> in B<a> to 0 (C<a&=~(1E<lt>E<lt>n)>). An +error occurs it B<a> is shorter than B<n> bits. + +BN_is_bit_set() tests if bit B<n> in B<a> is set. + +BN_mask_bits() truncates B<a> to an B<n> bit number +(C<q&=~((~0)E<gt>E<gt>n)>). An error occurs it B<a> already is +shorter than B<n> bits. + +BN_lshift() shifts B<a> left by B<n> bits and places the result in +B<r> (C<r=a*2^n>). BN_lshift1() shifts B<a> left by one and places +the result in B<r> (C<r=2*a>). + +BN_rshift() shifts B<a> right by B<n> bits and places the result in +B<r> (C<r=a/2^n>). BN_rshift1() shifts B<a> right by one and places +the result in B<r> (C<r=a/2>). + +=head1 RETURN VALUES + +BN_is_bit_set() returns 1 if the bit is set, 0 otherwise. + +All other functions return 1 for success, 0 on error. The error codes +can be obtained by ERR_get_error(3). + +=head1 SEE ALSO + +bn(3), BN_num_bytes(3), BN_add(3) + +=head1 HISTORY + +BN_set_bit(), BN_clear_bit(), BN_is_bit_set(), BN_mask_bits(), +BN_lshift(), BN_lshift1(), BN_rshift(), and BN_rshift1() are available +in all versions of SSLeay and OpenSSL. + +=cut |