diff options
Diffstat (limited to 'secure/lib/libcrypto/man/EVP_BytesToKey.3')
-rw-r--r-- | secure/lib/libcrypto/man/EVP_BytesToKey.3 | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/EVP_BytesToKey.3 b/secure/lib/libcrypto/man/EVP_BytesToKey.3 new file mode 100644 index 0000000..cef6b36 --- /dev/null +++ b/secure/lib/libcrypto/man/EVP_BytesToKey.3 @@ -0,0 +1,194 @@ +.\" 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 "EVP_BytesToKey 3" +.TH EVP_BytesToKey 3 "2005-02-24" "0.9.7d" "OpenSSL" +.SH "NAME" +EVP_BytesToKey \- password based encryption routine +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +.Ve +.PP +.Vb 4 +\& int EVP_BytesToKey(const EVP_CIPHER *type,const EVP_MD *md, +\& const unsigned char *salt, +\& const unsigned char *data, int datal, int count, +\& unsigned char *key,unsigned char *iv); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +\&\fIEVP_BytesToKey()\fR derives a key and \s-1IV\s0 from various parameters. \fBtype\fR is +the cipher to derive the key and \s-1IV\s0 for. \fBmd\fR is the message digest to use. +The \fBsalt\fR paramter is used as a salt in the derivation: it should point to +an 8 byte buffer or \s-1NULL\s0 if no salt is used. \fBdata\fR is a buffer containing +\&\fBdatal\fR bytes which is used to derive the keying data. \fBcount\fR is the +iteration count to use. The derived key and \s-1IV\s0 will be written to \fBkey\fR +and \fBiv\fR respectively. +.SH "NOTES" +.IX Header "NOTES" +A typical application of this function is to derive keying material for an +encryption algorithm from a password in the \fBdata\fR parameter. +.PP +Increasing the \fBcount\fR parameter slows down the algorithm which makes it +harder for an attacker to peform a brute force attack using a large number +of candidate passwords. +.PP +If the total key and \s-1IV\s0 length is less than the digest length and +\&\fB\s-1MD5\s0\fR is used then the derivation algorithm is compatible with PKCS#5 v1.5 +otherwise a non standard extension is used to derive the extra data. +.PP +Newer applications should use more standard algorithms such as PKCS#5 +v2.0 for key derivation. +.SH "KEY DERIVATION ALGORITHM" +.IX Header "KEY DERIVATION ALGORITHM" +The key and \s-1IV\s0 is derived by concatenating D_1, D_2, etc until +enough data is available for the key and \s-1IV\s0. D_i is defined as: +.PP +.Vb 1 +\& D_i = HASH^count(D_(i-1) || data || salt) +.Ve +.PP +where || denotes concatentaion, D_0 is empty, \s-1HASH\s0 is the digest +algorithm in use, HASH^1(data) is simply \s-1HASH\s0(data), HASH^2(data) +is \s-1HASH\s0(\s-1HASH\s0(data)) and so on. +.PP +The initial bytes are used for the key and the subsequent bytes for +the \s-1IV\s0. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fIEVP_BytesToKey()\fR returns the size of the derived key in bytes. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fIevp\fR\|(3), \fIrand\fR\|(3), +\&\fIEVP_EncryptInit\fR\|(3), +.SH "HISTORY" +.IX Header "HISTORY" |