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Diffstat (limited to 'secure/lib/libcrypto/man/BN_num_bytes.3')
-rw-r--r-- | secure/lib/libcrypto/man/BN_num_bytes.3 | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/BN_num_bytes.3 b/secure/lib/libcrypto/man/BN_num_bytes.3 new file mode 100644 index 0000000..6fe4ec8 --- /dev/null +++ b/secure/lib/libcrypto/man/BN_num_bytes.3 @@ -0,0 +1,186 @@ +.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14 +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sh \" Subsection heading +.br +.if t .Sp +.ne 5 +.PP +\fB\\$1\fR +.PP +.. +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. | will give a +.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to +.\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' +.\" expand to `' in nroff, nothing in troff, for use with C<>. +.tr \(*W-|\(bv\*(Tr +.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' +.ie n \{\ +. ds -- \(*W- +. ds PI pi +. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch +. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch +. ds L" "" +. ds R" "" +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds -- \|\(em\| +. ds PI \(*p +. ds L" `` +. ds R" '' +'br\} +.\" +.\" If the F register is turned on, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. +.if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. nr % 0 +. rr F +.\} +.\" +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.hy 0 +.if n .na +.\" +.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). +.\" Fear. Run. Save yourself. No user-serviceable parts. +. \" fudge factors for nroff and troff +.if n \{\ +. ds #H 0 +. ds #V .8m +. ds #F .3m +. ds #[ \f1 +. ds #] \fP +.\} +.if t \{\ +. ds #H ((1u-(\\\\n(.fu%2u))*.13m) +. ds #V .6m +. ds #F 0 +. ds #[ \& +. ds #] \& +.\} +. \" simple accents for nroff and troff +.if n \{\ +. ds ' \& +. ds ` \& +. ds ^ \& +. ds , \& +. ds ~ ~ +. ds / +.\} +.if t \{\ +. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" +. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' +. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' +. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' +. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' +. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' +.\} +. \" troff and (daisy-wheel) nroff accents +.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' +.ds 8 \h'\*(#H'\(*b\h'-\*(#H' +.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] +.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' +.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' +.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] +.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] +.ds ae a\h'-(\w'a'u*4/10)'e +.ds Ae A\h'-(\w'A'u*4/10)'E +. \" corrections for vroff +.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' +.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' +. \" for low resolution devices (crt and lpr) +.if \n(.H>23 .if \n(.V>19 \ +\{\ +. ds : e +. ds 8 ss +. ds o a +. ds d- d\h'-1'\(ga +. ds D- D\h'-1'\(hy +. ds th \o'bp' +. ds Th \o'LP' +. ds ae ae +. ds Ae AE +.\} +.rm #[ #] #H #V #F C +.\" ======================================================================== +.\" +.IX Title "BN_num_bytes 3" +.TH BN_num_bytes 3 "2005-02-24" "0.9.7d" "OpenSSL" +.SH "NAME" +BN_num_bits, BN_num_bytes, BN_num_bits_word \- get BIGNUM size +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/bn.h> +.Ve +.PP +.Vb 1 +\& int BN_num_bytes(const BIGNUM *a); +.Ve +.PP +.Vb 1 +\& int BN_num_bits(const BIGNUM *a); +.Ve +.PP +.Vb 1 +\& int BN_num_bits_word(BN_ULONG w); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +\&\fIBN_num_bytes()\fR returns the size of a \fB\s-1BIGNUM\s0\fR in bytes. +.PP +\&\fIBN_num_bits_word()\fR returns the number of significant bits in a word. +If we take 0x00000432 as an example, it returns 11, not 16, not 32. +Basically, except for a zero, it returns \fIfloor(log2(w))+1\fR. +.PP +\&\fIBN_num_bits()\fR returns the number of significant bits in a \fB\s-1BIGNUM\s0\fR, +following the same principle as \fIBN_num_bits_word()\fR. +.PP +\&\fIBN_num_bytes()\fR is a macro. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +The size. +.SH "NOTES" +.IX Header "NOTES" +Some have tried using \fIBN_num_bits()\fR on individual numbers in \s-1RSA\s0 keys, +\&\s-1DH\s0 keys and \s-1DSA\s0 keys, and found that they don't always come up with +the number of bits they expected (something like 512, 1024, 2048, +\&...). This is because generating a number with some specific number +of bits doesn't always set the highest bits, thereby making the number +of \fIsignificant\fR bits a little lower. If you want to know the \*(L"key +size\*(R" of such a key, either use functions like \fIRSA_size()\fR, \fIDH_size()\fR +and \fIDSA_size()\fR, or use \fIBN_num_bytes()\fR and multiply with 8 (although +there's no real guarantee that will match the \*(L"key size\*(R", just a lot +more probability). +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fIbn\fR\|(3), \fIDH_size\fR\|(3), \fIDSA_size\fR\|(3), +\&\fIRSA_size\fR\|(3) +.SH "HISTORY" +.IX Header "HISTORY" +\&\fIBN_num_bytes()\fR, \fIBN_num_bits()\fR and \fIBN_num_bits_word()\fR are available in +all versions of SSLeay and OpenSSL. |