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Diffstat (limited to 'doc/man/libkeccak_generalised_sum_fd.3')
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diff --git a/doc/man/libkeccak_generalised_sum_fd.3 b/doc/man/libkeccak_generalised_sum_fd.3 new file mode 100644 index 0000000..2518cc0 --- /dev/null +++ b/doc/man/libkeccak_generalised_sum_fd.3 @@ -0,0 +1,105 @@ +.TH LIBKECCAK_GENERALISED_SUM_FD 3 LIBKECCAK-%VERSION% +.SH NAME +libkeccak_generalised_sum_fd - Calculate the hash of a file +.SH SYNOPSIS +.LP +.nf +#include <libkeccak.h> +.P +int libkeccak_generalised_sum_fd(int \fIfd\fP, libkeccak_state_t *\fIstate\fP, + const libkeccak_spec_t *\fIspec\fP, + const char *\fIsuffix\fP, char *\fIhashsum\fP); +.fi +.P +Link with \fI-lkeccak\fP. +.SH DESCRIPTION +The +.BR libkeccak_generalised_sum_fd () +calculates the hash of a file, whose file desriptor is specified +by \fIfd\fP (and should be at the beginning of the file.) The +hash algorithm is specified by \fI*spec\fP and \fIsuffix\fP, +where \fI*spec\fP is the tuning of the algorithm and \fIsuffix\fP +is the bits append to the message (or \fINULL\fP if none.) +.PP +The hash is stored in binary form to \fIhashsum\fP. \fIhashsum\fP +should have an allocation size of at least +(((\fIspec->output\fP + 7) / 8) * sizeof(char)). +.PP +\fI*state\fP should not be allocated. +.BR libkeccak_generalised_sum_fd () +initialises \fI*state\fP itself. Therefore there would be a +memory leak if \fI*state\fP is already initialised. +.SH RETURN VALUES +The +.BR libkeccak_generalised_sum_fd () +function return 0 upon successful completion. +On error, -1 is returned and \fIerrno\fP is set to describe +the error. +.SH ERRORS +The +.BR libkeccak_generalised_sum_fd () +function may fail for any reason, except those resulting +in \fIerrno\fP being set to \fBEINTR\fP, specified for the +functions +.BR read (2), +.BR malloc (3), +and +.BR realloc (3). +.SH NOTES +Be aware, +.BR libkeccak_generalised_sum_fd () +hashes the file until the end has been reached. For pipes +and sockets and this means until the file has been closed. +But for character devices, this usually means never. +Attempting to hash files in /dev is therefore usually a +bad idea. +.BR libkeccak_generalised_sum_fd () +does not check for the file length or file type before +hashing as this could limit what you can do, and make +the library more complex. +.PP +.BR libkeccak_generalised_sum_fd () +does not stop if interrupted (\fBread\fP(2) returns +\fBEINTR\fP.) +.PP +.BR libkeccak_generalised_sum_fd () +assumes all information is non-sensitive, and will +therefore not perform any secure erasure of information. +.SH EXAMPLES +This example calculates the Keccak[b = 1024, c = 576, n = 256] +hash of the input from stdin, and prints the hash, in hexadecimal +form, to stdout. +.LP +.nf +libkeccak_state_t state; +libkeccak_spec_t spec; +char binhash[256 / 8]; +char hexhash[256 / 8 * 2 + 1]; + +spec.bitrate = 1024; +spec.capacity = 576; +spec.output = 256; + +if (libkeccak_generalised_sum_fd(STDIN_FILNO, &state, &spec, NULL, binhash) < 0) + goto fail; +libkeccak_behex_lower(hexhash, binhash, sizeof(binhash)); +printf("%s\\n", hexhash); +.fi +.SH SEE ALSO +.BR libkeccak_behex_lower (3), +.BR libkeccak_behex_upper (3), +.BR libkeccak_keccaksum_fd (3), +.BR libkeccak_sha3sum_fd (3), +.BR libkeccak_rawshakesum_fd (3), +.BR libkeccak_shakesum_fd (3), +.BR libkeccak_spec_sha3 (3), +.BR libkeccak_spec_shake (3), +.BR libkeccak_spec_rawshake (3), +.BR libkeccak_spec_check (3), +.BR libkeccak_generalised_spec_initialise (3) +.SH AUTHORS +Principal author, Mattias Andrée. See the LICENSE file for the full +list of authors. +.SH BUGS +Please report bugs to https://github.com/maandree/bus/issues or to +maandree@member.fsf.org |