One Hat Cyber Team

Edit File: SHA256_Init.3ssl

.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35)
.\"
.\" Standard preamble:
.\" ========================================================================
.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.  \*(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-
.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" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
.    if \nF \{\
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{\
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\"
.\" 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 "sha 3"
.TH sha 3 "2019-12-20" "1.0.2u" "OpenSSL"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
SHA1, SHA1_Init, SHA1_Update, SHA1_Final, SHA224, SHA224_Init, SHA224_Update,
SHA224_Final, SHA256, SHA256_Init, SHA256_Update, SHA256_Final, SHA384,
SHA384_Init, SHA384_Update, SHA384_Final, SHA512, SHA512_Init, SHA512_Update,
SHA512_Final \- Secure Hash Algorithm
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\& #include <openssl/sha.h>
\&
\& int SHA1_Init(SHA_CTX *c);
\& int SHA1_Update(SHA_CTX *c, const void *data, size_t len);
\& int SHA1_Final(unsigned char *md, SHA_CTX *c);
\& unsigned char *SHA1(const unsigned char *d, size_t n,
\&      unsigned char *md);
\&
\& int SHA224_Init(SHA256_CTX *c);
\& int SHA224_Update(SHA256_CTX *c, const void *data, size_t len);
\& int SHA224_Final(unsigned char *md, SHA256_CTX *c);
\& unsigned char *SHA224(const unsigned char *d, size_t n,
\&      unsigned char *md);
\&
\& int SHA256_Init(SHA256_CTX *c);
\& int SHA256_Update(SHA256_CTX *c, const void *data, size_t len);
\& int SHA256_Final(unsigned char *md, SHA256_CTX *c);
\& unsigned char *SHA256(const unsigned char *d, size_t n,
\&      unsigned char *md);
\&
\& int SHA384_Init(SHA512_CTX *c);
\& int SHA384_Update(SHA512_CTX *c, const void *data, size_t len);
\& int SHA384_Final(unsigned char *md, SHA512_CTX *c);
\& unsigned char *SHA384(const unsigned char *d, size_t n,
\&      unsigned char *md);
\&
\& int SHA512_Init(SHA512_CTX *c);
\& int SHA512_Update(SHA512_CTX *c, const void *data, size_t len);
\& int SHA512_Final(unsigned char *md, SHA512_CTX *c);
\& unsigned char *SHA512(const unsigned char *d, size_t n,
\&      unsigned char *md);
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Applications should use the higher level functions
\&\fBEVP_DigestInit\fR\|(3) etc. instead of calling the hash
functions directly.
.PP
\&\s-1SHA\-1\s0 (Secure Hash Algorithm) is a cryptographic hash function with a
160 bit output.
.PP
\&\s-1\fBSHA1\s0()\fR computes the \s-1SHA\-1\s0 message digest of the \fBn\fR
bytes at \fBd\fR and places it in \fBmd\fR (which must have space for
\&\s-1SHA_DIGEST_LENGTH\s0 == 20 bytes of output). If \fBmd\fR is \s-1NULL,\s0 the digest
is placed in a static array. Note: setting \fBmd\fR to \s-1NULL\s0 is \fBnot thread safe\fR.
.PP
The following functions may be used if the message is not completely
stored in memory:
.PP
\&\fBSHA1_Init()\fR initializes a \fB\s-1SHA_CTX\s0\fR structure.
.PP
\&\fBSHA1_Update()\fR can be called repeatedly with chunks of the message to
be hashed (\fBlen\fR bytes at \fBdata\fR).
.PP
\&\fBSHA1_Final()\fR places the message digest in \fBmd\fR, which must have space
for \s-1SHA_DIGEST_LENGTH\s0 == 20 bytes of output, and erases the \fB\s-1SHA_CTX\s0\fR.
.PP
The \s-1SHA224, SHA256, SHA384\s0 and \s-1SHA512\s0 families of functions operate in the
same way as for the \s-1SHA1\s0 functions. Note that \s-1SHA224\s0 and \s-1SHA256\s0 use a
\&\fB\s-1SHA256_CTX\s0\fR object instead of \fB\s-1SHA_CTX\s0\fR. \s-1SHA384\s0 and \s-1SHA512\s0 use \fB\s-1SHA512_CTX\s0\fR.
The buffer \fBmd\fR must have space for the output from the \s-1SHA\s0 variant being used
(defined by \s-1SHA224_DIGEST_LENGTH, SHA256_DIGEST_LENGTH, SHA384_DIGEST_LENGTH\s0 and
\&\s-1SHA512_DIGEST_LENGTH\s0). Also note that, as for the \s-1\fBSHA1\s0()\fR function above, the
\&\s-1\fBSHA224\s0()\fR, \s-1\fBSHA256\s0()\fR, \s-1\fBSHA384\s0()\fR and \s-1\fBSHA512\s0()\fR functions are not thread safe if
\&\fBmd\fR is \s-1NULL.\s0
.PP
The predecessor of \s-1SHA\-1, SHA,\s0 is also implemented, but it should be
used only when backward compatibility is required.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\s-1\fBSHA1\s0()\fR, \s-1\fBSHA224\s0()\fR, \s-1\fBSHA256\s0()\fR, \s-1\fBSHA384\s0()\fR and \s-1\fBSHA512\s0()\fR return a pointer to the hash
value.
.PP
\&\fBSHA1_Init()\fR, \fBSHA1_Update()\fR and \fBSHA1_Final()\fR and equivalent \s-1SHA224, SHA256,
SHA384\s0 and \s-1SHA512\s0 functions return 1 for success, 0 otherwise.
.SH "CONFORMING TO"
.IX Header "CONFORMING TO"
\&\s-1US\s0 Federal Information Processing Standard \s-1FIPS PUB 180\-4\s0 (Secure Hash
Standard),
\&\s-1ANSI X9.30\s0
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\fBripemd\fR\|(3), \fBhmac\fR\|(3), \fBEVP_DigestInit\fR\|(3)
.SH "HISTORY"
.IX Header "HISTORY"
\&\s-1\fBSHA1\s0()\fR, \fBSHA1_Init()\fR, \fBSHA1_Update()\fR and \fBSHA1_Final()\fR are available in all
versions of SSLeay and OpenSSL.