diff options
Diffstat (limited to 'secure/lib/libcrypto/man/EVP_EncodeInit.3')
| -rw-r--r-- | secure/lib/libcrypto/man/EVP_EncodeInit.3 | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/EVP_EncodeInit.3 b/secure/lib/libcrypto/man/EVP_EncodeInit.3 new file mode 100644 index 0000000..d664100 --- /dev/null +++ b/secure/lib/libcrypto/man/EVP_EncodeInit.3 @@ -0,0 +1,260 @@ +.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.30) +.\" +.\" 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 turned on, 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 "EVP_EncodeInit 3" +.TH EVP_EncodeInit 3 "2016-05-03" "1.0.1t" "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" +EVP_EncodeInit, EVP_EncodeUpdate, EVP_EncodeFinal, EVP_EncodeBlock, +EVP_DecodeInit, EVP_DecodeUpdate, EVP_DecodeFinal, EVP_DecodeBlock \- EVP base 64 +encode/decode routines +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +\& +\& void EVP_EncodeInit(EVP_ENCODE_CTX *ctx); +\& void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, +\& const unsigned char *in, int inl); +\& void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl); +\& int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int n); +\& +\& void EVP_DecodeInit(EVP_ENCODE_CTX *ctx); +\& int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl, +\& const unsigned char *in, int inl); +\& int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned +\& char *out, int *outl); +\& int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +The \s-1EVP\s0 encode routines provide a high level interface to base 64 encoding and +decoding. Base 64 encoding converts binary data into a printable form that uses +the characters A\-Z, a\-z, 0\-9, \*(L"+\*(R" and \*(L"/\*(R" to represent the data. For every 3 +bytes of binary data provided 4 bytes of base 64 encoded data will be produced +plus some occasional newlines (see below). If the input data length is not a +multiple of 3 then the output data will be padded at the end using the \*(L"=\*(R" +character. +.PP +Encoding of binary data is performed in blocks of 48 input bytes (or less for +the final block). For each 48 byte input block encoded 64 bytes of base 64 data +is output plus an additional newline character (i.e. 65 bytes in total). The +final block (which may be less than 48 bytes) will output 4 bytes for every 3 +bytes of input. If the data length is not divisible by 3 then a full 4 bytes is +still output for the final 1 or 2 bytes of input. Similarly a newline character +will also be output. +.PP +\&\fIEVP_EncodeInit()\fR initialises \fBctx\fR for the start of a new encoding operation. +.PP +\&\fIEVP_EncodeUpdate()\fR encode \fBinl\fR bytes of data found in the buffer pointed to by +\&\fBin\fR. The output is stored in the buffer \fBout\fR and the number of bytes output +is stored in \fB*outl\fR. It is the caller's responsibility to ensure that the +buffer at \fBout\fR is sufficiently large to accommodate the output data. Only full +blocks of data (48 bytes) will be immediately processed and output by this +function. Any remainder is held in the \fBctx\fR object and will be processed by a +subsequent call to \fIEVP_EncodeUpdate()\fR or \fIEVP_EncodeFinal()\fR. To calculate the +required size of the output buffer add together the value of \fBinl\fR with the +amount of unprocessed data held in \fBctx\fR and divide the result by 48 (ignore +any remainder). This gives the number of blocks of data that will be processed. +Ensure the output buffer contains 65 bytes of storage for each block, plus an +additional byte for a \s-1NUL\s0 terminator. \fIEVP_EncodeUpdate()\fR may be called +repeatedly to process large amounts of input data. In the event of an error +\&\fIEVP_EncodeUpdate()\fR will set \fB*outl\fR to 0. +.PP +\&\fIEVP_EncodeFinal()\fR must be called at the end of an encoding operation. It will +process any partial block of data remaining in the \fBctx\fR object. The output +data will be stored in \fBout\fR and the length of the data written will be stored +in \fB*outl\fR. It is the caller's responsibility to ensure that \fBout\fR is +sufficiently large to accommodate the output data which will never be more than +65 bytes plus an additional \s-1NUL\s0 terminator (i.e. 66 bytes in total). +.PP +\&\fIEVP_EncodeBlock()\fR encodes a full block of input data in \fBf\fR and of length +\&\fBdlen\fR and stores it in \fBt\fR. For every 3 bytes of input provided 4 bytes of +output data will be produced. If \fBdlen\fR is not divisible by 3 then the block is +encoded as a final block of data and the output is padded such that it is always +divisible by 4. Additionally a \s-1NUL\s0 terminator character will be added. For +example if 16 bytes of input data is provided then 24 bytes of encoded data is +created plus 1 byte for a \s-1NUL\s0 terminator (i.e. 25 bytes in total). The length of +the data generated \fIwithout\fR the \s-1NUL\s0 terminator is returned from the function. +.PP +\&\fIEVP_DecodeInit()\fR initialises \fBctx\fR for the start of a new decoding operation. +.PP +\&\fIEVP_DecodeUpdate()\fR decodes \fBinl\fR characters of data found in the buffer pointed +to by \fBin\fR. The output is stored in the buffer \fBout\fR and the number of bytes +output is stored in \fB*outl\fR. It is the caller's responsibility to ensure that +the buffer at \fBout\fR is sufficiently large to accommodate the output data. This +function will attempt to decode as much data as possible in 4 byte chunks. Any +whitespace, newline or carriage return characters are ignored. Any partial chunk +of unprocessed data (1, 2 or 3 bytes) that remains at the end will be held in +the \fBctx\fR object and processed by a subsequent call to \fIEVP_DecodeUpdate()\fR. If +any illegal base 64 characters are encountered or if the base 64 padding +character \*(L"=\*(R" is encountered in the middle of the data then the function returns +\&\-1 to indicate an error. A return value of 0 or 1 indicates successful +processing of the data. A return value of 0 additionally indicates that the last +input data characters processed included the base 64 padding character \*(L"=\*(R" and +therefore no more non-padding character data is expected to be processed. For +every 4 valid base 64 bytes processed (ignoring whitespace, carriage returns and +line feeds), 3 bytes of binary output data will be produced (or less at the end +of the data where the padding character \*(L"=\*(R" has been used). +.PP +\&\fIEVP_DecodeFinal()\fR must be called at the end of a decoding operation. If there +is any unprocessed data still in \fBctx\fR then the input data must not have been +a multiple of 4 and therefore an error has occurred. The function will return \-1 +in this case. Otherwise the function returns 1 on success. +.PP +\&\fIEVP_DecodeBlock()\fR will decode the block of \fBn\fR characters of base 64 data +contained in \fBf\fR and store the result in \fBt\fR. Any leading whitespace will be +trimmed as will any trailing whitespace, newlines, carriage returns or \s-1EOF\s0 +characters. After such trimming the length of the data in \fBf\fR must be divisbile +by 4. For every 4 input bytes exactly 3 output bytes will be produced. The +output will be padded with 0 bits if necessary to ensure that the output is +always 3 bytes for every 4 input bytes. This function will return the length of +the data decoded or \-1 on error. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fIEVP_EncodeBlock()\fR returns the number of bytes encoded excluding the \s-1NUL\s0 +terminator. +.PP +\&\fIEVP_DecodeUpdate()\fR returns \-1 on error and 0 or 1 on success. If 0 is returned +then no more non-padding base 64 characters are expected. +.PP +\&\fIEVP_DecodeFinal()\fR returns \-1 on error or 1 on success. +.PP +\&\fIEVP_DecodeBlock()\fR returns the length of the data decoded or \-1 on error. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fIevp\fR\|(3) |
