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Diffstat (limited to 'openssl/doc/crypto/BN_set_bit.pod')
-rw-r--r-- | openssl/doc/crypto/BN_set_bit.pod | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/openssl/doc/crypto/BN_set_bit.pod b/openssl/doc/crypto/BN_set_bit.pod new file mode 100644 index 000000000..b7c47b9b0 --- /dev/null +++ b/openssl/doc/crypto/BN_set_bit.pod @@ -0,0 +1,66 @@ +=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 if 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<a&=~((~0)E<gt>E<gt>n)>). An error occurs if 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>). + +For the shift functions, B<r> and B<a> may be the same variable. + +=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 L<ERR_get_error(3)|ERR_get_error(3)>. + +=head1 SEE ALSO + +L<bn(3)|bn(3)>, L<BN_num_bytes(3)|BN_num_bytes(3)>, L<BN_add(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 |