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') 78ASCII string which represents the 160 bits in hexadecimal. 79.Pp 80The 81.Fn RIPEMD160_File 82function calculates the digest of a file, and uses 83.Fn RIPEMD160_End 84to return the result. 85If the file cannot be opened, a null pointer is returned. 86The 87.Fn RIPEMD160_FileChunk 88function is similar to 89.Fn RIPEMD160_File , 90but it only calculates the digest over a byte-range of the file specified, 91starting at 92.Fa offset 93and spanning 94.Fa length 95bytes. 96If the 97.Fa length 98parameter is specified as 0, or more than the length of the remaining part 99of the file, 100.Fn RIPEMD160_FileChunk 101calculates the digest from 102.Fa offset 103to the end of file. 104The 105.Fn RIPEMD160_Data 106function calculates the digest of a chunk of data in memory, and uses 107.Fn RIPEMD160_End 108to return the result. 109.Pp 110When using 111.Fn RIPEMD160_End , 112.Fn RIPEMD160_File , 113or 114.Fn RIPEMD160_Data , 115the 116.Fa buf 117argument can be a null pointer, in which case the returned string 118is allocated with 119.Xr malloc 3 120and subsequently must be explicitly deallocated using 121.Xr free 3 122after use. 123If the 124.Fa buf 125argument is non-null it must point to at least 41 characters of buffer space. 126.Sh ERRORS 127The 128.Fn RIPEMD160_End 129function called with a null buf argument may fail and return NULL if: 130.Bl -tag -width Er 131.It Bq Er ENOMEM 132Insufficient storage space is available. 133.El 134.Pp 135The 136.Fn RIPEMD160_File 137and 138.Fn RIPEMD160_FileChunk 139may return NULL when underlying 140.Xr open 2 , 141.Xr fstat 2 , 142.Xr lseek 2 , 143or 144.Xr RIPEMD160_End 3 145fail. 146.Sh SEE ALSO 147.Xr md4 3 , 148.Xr md5 3 , 149.Xr sha 3 , 150.Xr sha256 3 , 151.Xr sha512 3 , 152.Xr skein 3 153.Sh HISTORY 154These functions appeared in 155.Fx 4.0 . 156.Sh AUTHORS 157The core hash routines were implemented by Eric Young based on the 158published RIPEMD160 specification. 159.Sh BUGS 160No method is known to exist which finds two files having the same hash value, 161nor to find a file with a specific hash value. 162There is on the other hand no guarantee that such a method does not exist. 163