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Diffstat (limited to 'secure/lib/libcrypto/man/BIO_f_md.3')
-rw-r--r-- | secure/lib/libcrypto/man/BIO_f_md.3 | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/BIO_f_md.3 b/secure/lib/libcrypto/man/BIO_f_md.3 new file mode 100644 index 0000000..5605e18 --- /dev/null +++ b/secure/lib/libcrypto/man/BIO_f_md.3 @@ -0,0 +1,272 @@ +.\" 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 "BIO_f_md 3" +.TH BIO_f_md 3 "2005-02-24" "0.9.7d" "OpenSSL" +.SH "NAME" +BIO_f_md, BIO_set_md, BIO_get_md, BIO_get_md_ctx \- message digest BIO filter +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 2 +\& #include <openssl/bio.h> +\& #include <openssl/evp.h> +.Ve +.PP +.Vb 4 +\& BIO_METHOD * BIO_f_md(void); +\& int BIO_set_md(BIO *b,EVP_MD *md); +\& int BIO_get_md(BIO *b,EVP_MD **mdp); +\& int BIO_get_md_ctx(BIO *b,EVP_MD_CTX **mdcp); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +\&\fIBIO_f_md()\fR returns the message digest \s-1BIO\s0 method. This is a filter +\&\s-1BIO\s0 that digests any data passed through it, it is a \s-1BIO\s0 wrapper +for the digest routines \fIEVP_DigestInit()\fR, \fIEVP_DigestUpdate()\fR +and \fIEVP_DigestFinal()\fR. +.PP +Any data written or read through a digest \s-1BIO\s0 using \fIBIO_read()\fR and +\&\fIBIO_write()\fR is digested. +.PP +\&\fIBIO_gets()\fR, if its \fBsize\fR parameter is large enough finishes the +digest calculation and returns the digest value. \fIBIO_puts()\fR is +not supported. +.PP +\&\fIBIO_reset()\fR reinitialises a digest \s-1BIO\s0. +.PP +\&\fIBIO_set_md()\fR sets the message digest of \s-1BIO\s0 \fBb\fR to \fBmd\fR: this +must be called to initialize a digest \s-1BIO\s0 before any data is +passed through it. It is a \fIBIO_ctrl()\fR macro. +.PP +\&\fIBIO_get_md()\fR places the a pointer to the digest BIOs digest method +in \fBmdp\fR, it is a \fIBIO_ctrl()\fR macro. +.PP +\&\fIBIO_get_md_ctx()\fR returns the digest BIOs context into \fBmdcp\fR. +.SH "NOTES" +.IX Header "NOTES" +The context returned by \fIBIO_get_md_ctx()\fR can be used in calls +to \fIEVP_DigestFinal()\fR and also the signature routines \fIEVP_SignFinal()\fR +and \fIEVP_VerifyFinal()\fR. +.PP +The context returned by \fIBIO_get_md_ctx()\fR is an internal context +structure. Changes made to this context will affect the digest +\&\s-1BIO\s0 itself and the context pointer will become invalid when the digest +\&\s-1BIO\s0 is freed. +.PP +After the digest has been retrieved from a digest \s-1BIO\s0 it must be +reinitialized by calling \fIBIO_reset()\fR, or \fIBIO_set_md()\fR before any more +data is passed through it. +.PP +If an application needs to call \fIBIO_gets()\fR or \fIBIO_puts()\fR through +a chain containing digest BIOs then this can be done by prepending +a buffering \s-1BIO\s0. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fIBIO_f_md()\fR returns the digest \s-1BIO\s0 method. +.PP +\&\fIBIO_set_md()\fR, \fIBIO_get_md()\fR and \fIBIO_md_ctx()\fR return 1 for success and +0 for failure. +.SH "EXAMPLES" +.IX Header "EXAMPLES" +The following example creates a \s-1BIO\s0 chain containing an \s-1SHA1\s0 and \s-1MD5\s0 +digest \s-1BIO\s0 and passes the string \*(L"Hello World\*(R" through it. Error +checking has been omitted for clarity. +.PP +.Vb 14 +\& BIO *bio, *mdtmp; +\& char message[] = "Hello World"; +\& bio = BIO_new(BIO_s_null()); +\& mdtmp = BIO_new(BIO_f_md()); +\& BIO_set_md(mdtmp, EVP_sha1()); +\& /* For BIO_push() we want to append the sink BIO and keep a note of +\& * the start of the chain. +\& */ +\& bio = BIO_push(mdtmp, bio); +\& mdtmp = BIO_new(BIO_f_md()); +\& BIO_set_md(mdtmp, EVP_md5()); +\& bio = BIO_push(mdtmp, bio); +\& /* Note: mdtmp can now be discarded */ +\& BIO_write(bio, message, strlen(message)); +.Ve +.PP +The next example digests data by reading through a chain instead: +.PP +.Vb 14 +\& BIO *bio, *mdtmp; +\& char buf[1024]; +\& int rdlen; +\& bio = BIO_new_file(file, "rb"); +\& mdtmp = BIO_new(BIO_f_md()); +\& BIO_set_md(mdtmp, EVP_sha1()); +\& bio = BIO_push(mdtmp, bio); +\& mdtmp = BIO_new(BIO_f_md()); +\& BIO_set_md(mdtmp, EVP_md5()); +\& bio = BIO_push(mdtmp, bio); +\& do { +\& rdlen = BIO_read(bio, buf, sizeof(buf)); +\& /* Might want to do something with the data here */ +\& } while(rdlen > 0); +.Ve +.PP +This next example retrieves the message digests from a \s-1BIO\s0 chain and +outputs them. This could be used with the examples above. +.PP +.Vb 16 +\& BIO *mdtmp; +\& unsigned char mdbuf[EVP_MAX_MD_SIZE]; +\& int mdlen; +\& int i; +\& mdtmp = bio; /* Assume bio has previously been set up */ +\& do { +\& EVP_MD *md; +\& mdtmp = BIO_find_type(mdtmp, BIO_TYPE_MD); +\& if(!mdtmp) break; +\& BIO_get_md(mdtmp, &md); +\& printf("%s digest", OBJ_nid2sn(EVP_MD_type(md))); +\& mdlen = BIO_gets(mdtmp, mdbuf, EVP_MAX_MD_SIZE); +\& for(i = 0; i < mdlen; i++) printf(":%02X", mdbuf[i]); +\& printf("\en"); +\& mdtmp = BIO_next(mdtmp); +\& } while(mdtmp); +.Ve +.PP +.Vb 1 +\& BIO_free_all(bio); +.Ve +.SH "BUGS" +.IX Header "BUGS" +The lack of support for \fIBIO_puts()\fR and the non standard behaviour of +\&\fIBIO_gets()\fR could be regarded as anomalous. It could be argued that \fIBIO_gets()\fR +and \fIBIO_puts()\fR should be passed to the next \s-1BIO\s0 in the chain and digest +the data passed through and that digests should be retrieved using a +separate \fIBIO_ctrl()\fR call. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\s-1TBA\s0 |