1.\" 2.\" ---------------------------------------------------------------------------- 3.\" "THE BEER-WARE LICENSE" (Revision 42): 4.\" <phk@FreeBSD.org> wrote this file. As long as you retain this notice you 5.\" can do whatever you want with this stuff. If we meet some day, and you think 6.\" this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7.\" ---------------------------------------------------------------------------- 8.\" 9.\" From: Id: mdX.3,v 1.14 1999/02/11 20:31:49 wollman Exp 10.\" $FreeBSD$ 11.\" 12.Dd July 20, 2018 13.Dt RIPEMD 3 14.Os 15.Sh NAME 16.Nm RIPEMD160_Init , 17.Nm RIPEMD160_Update , 18.Nm RIPEMD160_Final , 19.Nm RIPEMD160_End , 20.Nm RIPEMD160_File , 21.Nm RIPEMD160_FileChunk , 22.Nm RIPEMD160_Data 23.Nd calculate the RIPEMD160 message digest 24.Sh LIBRARY 25.Lb libmd 26.Sh SYNOPSIS 27.In sys/types.h 28.In ripemd.h 29.Ft void 30.Fn RIPEMD160_Init "RIPEMD160_CTX *context" 31.Ft void 32.Fn RIPEMD160_Update "RIPEMD160_CTX *context" "const unsigned char *data" "unsigned int len" 33.Ft void 34.Fn RIPEMD160_Final "unsigned char digest[20]" "RIPEMD160_CTX *context" 35.Ft "char *" 36.Fn RIPEMD160_End "RIPEMD160_CTX *context" "char *buf" 37.Ft "char *" 38.Fn RIPEMD160_File "const char *filename" "char *buf" 39.Ft "char *" 40.Fn RIPEMD160_FileChunk "const char *filename" "char *buf" "off_t offset" "off_t length" 41.Ft "char *" 42.Fn RIPEMD160_Data "const unsigned char *data" "unsigned int len" "char *buf" 43.Sh DESCRIPTION 44The 45.Li RIPEMD160_ 46functions calculate a 160-bit cryptographic checksum (digest) 47for any number of input bytes. 48A cryptographic checksum is a one-way 49hash function; that is, it is computationally impractical to find 50the input corresponding to a particular output. 51This net result is a 52.Dq fingerprint 53of the input-data, which does not disclose the actual input. 54.Pp 55The 56.Fn RIPEMD160_Init , 57.Fn RIPEMD160_Update , 58and 59.Fn RIPEMD160_Final 60functions are the core functions. 61Allocate an 62.Vt RIPEMD160_CTX , 63initialize it with 64.Fn RIPEMD160_Init , 65run over the data with 66.Fn RIPEMD160_Update , 67and finally extract the result using 68.Fn RIPEMD160_Final , 69which will also erase the 70.Vt RIPEMD160_CTX . 71.Pp 72The 73.Fn RIPEMD160_End 74function is a wrapper for 75.Fn RIPEMD160_Final 76which converts the return value to a 41-character 77(including the terminating '\e0') 78.Tn ASCII 79string which represents the 160 bits in hexadecimal. 80.Pp 81The 82.Fn RIPEMD160_File 83function calculates the digest of a file, and uses 84.Fn RIPEMD160_End 85to return the result. 86If the file cannot be opened, a null pointer is returned. 87The 88.Fn RIPEMD160_FileChunk 89function is similar to 90.Fn RIPEMD160_File , 91but it only calculates the digest over a byte-range of the file specified, 92starting at 93.Fa offset 94and spanning 95.Fa length 96bytes. 97If the 98.Fa length 99parameter is specified as 0, or more than the length of the remaining part 100of the file, 101.Fn RIPEMD160_FileChunk 102calculates the digest from 103.Fa offset 104to the end of file. 105The 106.Fn RIPEMD160_Data 107function calculates the digest of a chunk of data in memory, and uses 108.Fn RIPEMD160_End 109to return the result. 110.Pp 111When using 112.Fn RIPEMD160_End , 113.Fn RIPEMD160_File , 114or 115.Fn RIPEMD160_Data , 116the 117.Fa buf 118argument can be a null pointer, in which case the returned string 119is allocated with 120.Xr malloc 3 121and subsequently must be explicitly deallocated using 122.Xr free 3 123after use. 124If the 125.Fa buf 126argument is non-null it must point to at least 41 characters of buffer space. 127.Sh ERRORS 128The 129.Fn RIPEMD160_End 130function called with a null buf argument may fail and return NULL if: 131.Bl -tag -width Er 132.It Bq Er ENOMEM 133Insufficient storage space is available. 134.El 135.Pp 136The 137.Fn RIPEMD160_File 138and 139.Fn RIPEMD160_FileChunk 140may return NULL when underlying 141.Xr open 2 , 142.Xr fstat 2 , 143.Xr lseek 2 , 144or 145.Xr RIPEMD160_End 2 146fail. 147.Sh SEE ALSO 148.Xr md4 3 , 149.Xr md5 3 , 150.Xr sha 3 , 151.Xr sha256 3 , 152.Xr sha512 3 , 153.Xr skein 3 154.Sh HISTORY 155These functions appeared in 156.Fx 4.0 . 157.Sh AUTHORS 158The core hash routines were implemented by Eric Young based on the 159published 160.Tn RIPEMD160 161specification. 162.Sh BUGS 163No method is known to exist which finds two files having the same hash value, 164nor to find a file with a specific hash value. 165There is on the other hand no guarantee that such a method does not exist. 166