aboutsummaryrefslogtreecommitdiffstats
path: root/libkeccak_rawshakesum_fd.3
diff options
context:
space:
mode:
authorMattias Andrée <maandree@kth.se>2019-02-11 16:22:00 +0100
committerMattias Andrée <maandree@kth.se>2019-02-11 16:22:00 +0100
commit5ff4c5af715d098852d124de116d354ee10f4ea4 (patch)
tree5789ad5798f2dbf21d9406a2942e48b222f773ae /libkeccak_rawshakesum_fd.3
parentRemove old file (diff)
downloadlibkeccak-5ff4c5af715d098852d124de116d354ee10f4ea4.tar.gz
libkeccak-5ff4c5af715d098852d124de116d354ee10f4ea4.tar.bz2
libkeccak-5ff4c5af715d098852d124de116d354ee10f4ea4.tar.xz
Split most .c files into one per function and flatten file hierarchy
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat (limited to 'libkeccak_rawshakesum_fd.3')
-rw-r--r--libkeccak_rawshakesum_fd.3108
1 files changed, 108 insertions, 0 deletions
diff --git a/libkeccak_rawshakesum_fd.3 b/libkeccak_rawshakesum_fd.3
new file mode 100644
index 0000000..8fad150
--- /dev/null
+++ b/libkeccak_rawshakesum_fd.3
@@ -0,0 +1,108 @@
+.TH LIBKECCAK_RAWSHAKESUM_FD 3 LIBKECCAK
+.SH NAME
+libkeccak_rawshakesum_fd - Calculate a RawSHAKE hashsum of a file
+.SH SYNOPSIS
+.nf
+#include <libkeccak.h>
+
+int libkeccak_rawshakesum_fd(int \fIfd\fP, libkeccak_state_t *\fIstate\fP, long int \fIsemicapacity\fP, long int \fIoutput\fP, void *\fIhashsum\fP);
+.fi
+.PP
+Link with
+.IR -lkeccak .
+.SH DESCRIPTION
+The
+.BR libkeccak_rawshakesum_fd ()
+function calculates a RawSHAKE hashsum of a file, whose
+file desriptor is specified by
+.I fd
+(and should be at the beginning of the file.) The hash
+algorithm is tuned by the
+.I semicapacity
+and
+.I output
+parameters; they specify the half of the capacity and
+the output size, respectively, in bits.
+.PP
+The hash is stored in binary form to
+.IR hashsum .
+.I hashsum
+should have an allocation size of at least
+.RI ((( output
++ 7) / 8) * sizeof(char)).
+.PP
+.I *state
+should not be initialised.
+.BR libkeccak_rawshakesum_fd ()
+initialises
+.I *state
+itself. Therefore there would be a memory leak if
+.I *state
+is already initialised.
+.SH RETURN VALUES
+The
+.BR libkeccak_rawshakesum_fd ()
+function returns 0 upon successful completion.
+On error, -1 is returned and
+.I errno
+is set to describe the error.
+.SH ERRORS
+The
+.BR libkeccak_rawshakesum_fd ()
+function may fail for any reason, except those resulting in
+.I errno
+being set to
+.BR EINTR ,
+specified for the functions
+.BR read (2),
+.BR malloc (3),
+and
+.BR realloc (3).
+.SH NOTES
+Be aware,
+.BR libkeccak_rawshakesum_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_rawshakesum_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_rawshakesum_fd ()
+does not stop if interrupted
+.RB ( read (2)
+returns
+.BR EINTR .)
+.PP
+.BR libkeccak_rawshakesum_fd ()
+assumes all information is non-sensitive, and will
+therefore not perform any secure erasure of information.
+.PP
+.BR libkeccak_rawshakesum_fd ()
+does not validate the tuning of the algorithm.
+.SH EXAMPLE
+This example calculates the RawSHAKE256(, 512) hash of the input
+from stdin, and prints the hash, in hexadecimal form, to stdout.
+.LP
+.nf
+libkeccak_state_t state;
+if (libkeccak_rawshakesum_fd(STDIN_FILENO, &state, 256, 512, binhash) < 0)
+ goto fail;
+libkeccak_behex_lower(hexhash, binhash, sizeof(binhash));
+printf(\(dq%s\en\(dq, hexhash);
+libkeccak_state_destroy(&state);
+.fi
+.SH SEE ALSO
+.BR libkeccak_behex_lower (3),
+.BR libkeccak_behex_upper (3),
+.BR libkeccak_generalised_sum_fd (3),
+.BR libkeccak_keccaksum_fd (3),
+.BR libkeccak_sha3sum_fd (3),
+.BR libkeccak_shakesum_fd (3),
+.BR libkeccak_spec_rawshake (3),
+.BR libkeccak_spec_check (3),
+.BR libkeccak_generalised_spec_initialise (3),
+.BR libkeccak_state_initialise (3)