aboutsummaryrefslogtreecommitdiffstats
path: root/libhashsum_init_blake_hasher.3
diff options
context:
space:
mode:
authorMattias Andrée <maandree@kth.se>2024-08-30 17:20:30 +0200
committerMattias Andrée <maandree@kth.se>2024-08-30 17:20:30 +0200
commit87437d71b36518dac5086f8cc92480935e4cf60b (patch)
tree8cabd9b8871320216d371aa7c0e8774fd06d91f4 /libhashsum_init_blake_hasher.3
parentm + add support for z parameter for keccak (diff)
downloadlibhashsum-87437d71b36518dac5086f8cc92480935e4cf60b.tar.gz
libhashsum-87437d71b36518dac5086f8cc92480935e4cf60b.tar.bz2
libhashsum-87437d71b36518dac5086f8cc92480935e4cf60b.tar.xz
m + add man pages
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat (limited to 'libhashsum_init_blake_hasher.3')
-rw-r--r--libhashsum_init_blake_hasher.3295
1 files changed, 295 insertions, 0 deletions
diff --git a/libhashsum_init_blake_hasher.3 b/libhashsum_init_blake_hasher.3
new file mode 100644
index 0000000..f6f77bb
--- /dev/null
+++ b/libhashsum_init_blake_hasher.3
@@ -0,0 +1,295 @@
+.TH LIBHASHSUM_INIT_BLAKE_HASHER 3 libhashsum
+.SH NAME
+libhashsum_init_blake_hasher - initialise state for BLAKE hashing
+
+.SH SYNOPSIS
+.nf
+#include <libhashsum.h>
+
+\fBstruct libhashsum_hasher\fP {
+ enum libhashsum_algorithm \fIalgorithm\fP;
+ const char *\fIalgorithm_string\fP;
+ size_t \fIinput_block_size\fP;
+ size_t \fIhash_size\fP;
+ unsigned char *\fIhash_output\fP;
+ unsigned char \fIsupports_non_whole_bytes\fP;
+ size_t (*\fIprocess\fP)(struct libhashsum_hasher *\fPthis\fP, const void *\fPdata\fP, size_t \fPbytes\fP);
+ int (*\fIfinalise_const\fP)(struct libhashsum_hasher *\fPthis\fP, const void *\fPdata\fP, size_t \fPbytes\fP, unsigned \fPextra_bits\fP);
+ int (*\fIfinalise\fP)(struct libhashsum_hasher *\fPthis\fP, void *\fPdata\fP, size_t \fPbytes\fP, unsigned \fPextra_bits\fP, size_t \fPsize\fP);
+ void (*\fIdestroy\fP)(struct libhashsum_hasher *\fPthis\fP);
+ union libhashsum_state { /* definition omitted */ } \fIstate\fP;
+};
+
+int \fBlibhashsum_init_blake_hasher\fP(struct libhashsum_hasher *\fIhasher\fP, size_t \fIhashbits\fP, const void *\fIsalt\fP, size_t \fIsaltbytes\fP);
+.fi
+.PP
+Link with
+.I -lhashsum
+.IR "-lblake" .
+
+.SH DESCRIPTION
+The
+.B libhashsum_init_blake_hasher
+function initialises
+.I *hasher
+for hashing using the cryptographic hash function BLAKE
+(a version of BLAKE), and stores hash function information
+and hashing functions for BLAKE in
+.IR *hasher .
+.PP
+.I hashbits
+shall be the hash size in bits, which shall be either
+224, 256, 384, or 512.
+.PP
+.I salt
+shall be
+.I NULL
+or a buffer that shall be used as a salt
+.RI ( NULL
+is equivalent to all zeroes).
+.PP
+.I saltbytes
+shall be the number bytes in
+.IR salt ,
+which must be 16 if
+.I hashbits
+is 224 or 256, and 32 if
+.I hashbits
+is 384 or 512; however
+.I saltbytes
+is ignored if
+.I salt
+is
+.IR NULL .
+.PP
+.I hasher->algorithm
+will be set to either
+.I LIBHASHSUM_BLAKE224
+(if
+.I hashbits
+is 224),
+.I LIBHASHSUM_BLAKE256
+(if
+.I hashbits
+is 256),
+.I LIBHASHSUM_BLAKE384
+(if
+.I hashbits
+is 384), or
+.I LIBHASHSUM_BLAKE512
+if
+.I hashbits
+is 512).
+.PP
+.I hasher->algorithm_string
+will be set to
+.RB \(dq BLAKE \fIhashbits\fP\(dq
+or (if
+.I salt
+is neither
+.I NULL
+nor all zeroes)
+.RB \(dq BLAKE \fIhashbits\fP[salt= \fIlowercase_hexadecimal(salt)\fP ] \(dq,
+in which case
+.I hasher->algorithm_string
+will point to a buffer in
+.IR hasher->state .
+.PP
+.I hasher->input_block_size
+will be set to the block size BLAKE uses, in bytes.
+.PP
+.I hasher->hash_size
+will be set to the hash size, in bytes
+.RI ( hashbits/8 ).
+.PP
+.I hasher->hash_output
+will be set to
+.IR NULL .
+.PP
+.I hasher->supports_non_whole_bytes
+will be set to 1
+to indicate that the
+.I *hasher->finalise
+and
+.I *hasher->finalise_const
+functions support non-zero values in their
+.I extra_bits
+parameter.
+.PP
+.I hasher->process
+will be set to a pointer to the function to call
+to feed, and process, data into the hash function.
+Its parameter
+.I this
+shall be set to
+.IR hasher .
+Its parameter
+.I data
+parameter shall be set to the buffer of data to
+process, and its parameter
+.I bytes
+shall set to the number of bytes to process from
+.IR data .
+.I *hasher->process
+will return the number of bytes processed, which
+will be a multiple of
+.IR hasher->input_block_size
+no greater than
+.IR bytes .
+.PP
+.I hasher->finalise_const
+will be set to a pointer to the function to call
+once the entire text being hashed has been loaded,
+and to get the hash of the text. It's parameter
+.I this
+shall be set to
+.IR hasher .
+Its parameter
+.I data
+shall be set to the beginning of any yet unprocessed
+data, and its parameter
+.I bytes
+shall be set to the number of bytes to process from
+.IR data .
+Its parameter
+.I extra_bits
+shall be set to the number of bits to process from
+the lower bits of the incomplete byte
+.IR data[bytes] .
+The
+.I *hasher->finalise_const
+function will return 0 upon successful completion,
+and set
+.I hasher->hash_output
+to a pointer to a buffer in
+.I hasher->state
+containing the binary hash of the processed data.
+Otherwise, the function will return -1, and set
+.I errno
+to indicate the error. The function will failure
+if:
+.RS
+.TP
+.B EINVAL
+.I extra_bits
+is 8 or greater.
+.RE
+.PP
+.I hasher->finalise
+will be set to the pointer to a function that
+is an alternative to
+.I *hasher->finalise_const
+that can support zero-copy provided that the
+buffer input as the argument
+.I data
+is sufficiently large. The
+.I *hasher->finalise
+function may rewrite
+.I data
+and shall is does not safe to use for multiple
+hashers (if the same text is hashed using multiple
+hashers,
+.I *hasher->finalise_const
+must be used). The
+function's parameter
+.I size
+shall be set to the size of the buffer
+.IR data .
+.I *hasher->finalise
+is otherwise identical to
+.IR *hasher->finalise_const .
+.PP
+.I hasher->destroy
+will be set to
+.IR NULL .
+.PP
+.I hasher->state
+will be initialised, it shall be treated as
+internal to the library's implementation, and
+may change between versions.
+.PP
+.I hasher
+must not be
+.IR NULL .
+
+.SH RETURN VALUE
+Upon successful completion, the
+.B libhashsum_init_blake_hasher
+function returns 0. Otherwise,
+the function returns -1 and sets
+.I errno
+to indicate the error. If -1
+is returned, the state of
+.I *hasher
+is undefined.
+
+.SH ERRORS
+The
+.B libhashsum_init_blake_hasher
+function fails if:
+.TP
+.B ENOSYS
+Support was excluded at compile time.
+.TP
+.B EINVAL
+.I hashbits
+is either 224, 256, 384, nor 384.
+.TP
+.B EINVAL
+.I hashbits
+is either 224 or 256 and
+.I salt
+is
+.RI non- NULL
+but
+.I saltbytes
+is not 16.
+.TP
+.B EINVAL
+.I hashbits
+is either 384 or 512 and
+.I salt
+is
+.RI non- NULL
+but
+.I saltbytes
+is not 32.
+
+.SH HISTORY
+libhashsum 1.0.
+
+.SH NOTES
+.I libhashsum_init_blake_hasher(hasher, 224, salt, 16)
+and
+.I libhashsum_init_blake_hasher(hasher, 256, salt, 16)
+are equivalent to
+.I libhashsum_init_blake224_hasher(hasher, salt)
+and
+.I libhashsum_init_blake256_hasher(hasher, salt)
+respectively as well as to
+.I libhashsum_init_blakes_hasher(hasher, 224, salt)
+and
+.I libhashsum_init_blakes_hasher(hasher, 256, salt)
+respectively.
+.PP
+.I libhashsum_init_blake_hasher(hasher, 384, salt, 32)
+and
+.I libhashsum_init_blake_hasher(hasher, 512, salt, 32)
+are equivalent to
+.I libhashsum_init_blake384_hasher(hasher, salt)
+and
+.I libhashsum_init_blake512_hasher(hasher, salt)
+respectively as well as to
+.I libhashsum_init_blakeb_hasher(hasher, 384, salt)
+and
+.I libhashsum_init_blakeb_hasher(hasher, 512, salt)
+respectively.
+
+.SH SEE ALSO
+.BR libhashsum (7),
+.BR libhashsum_init_blake224_hasher (3),
+.BR libhashsum_init_blake256_hasher (3),
+.BR libhashsum_init_blake384_hasher (3),
+.BR libhashsum_init_blake512_hasher (3),
+.BR libhashsum_init_blakes_hasher (3),
+.BR libhashsum_init_blakeb_hasher (3)