RMD160(3) BSD Library Functions Manual RMD160(3)
RMD160Init, RMD160Update, RMD160Final, RMD160Transform, RMD160End, RMD160File, RMD160Data -- calculate the ``RIPEMD-160'' message digest
RMD160Update(RMD160_CTX *context, const u_char *data, u_int nbytes);
RMD160Final(u_char digest, RMD160_CTX *context);
RMD160Transform(uint32_t state, const uint32_t block);
RMD160End(RMD160_CTX *context, char *buf);
RMD160File(char *filename, char *buf);
RMD160Data(u_char *data, size_t len, char *buf);
The RMD160 functions implement the 160-bit RIPE message digest hash algorithm (RMD-160). RMD-160 is used to generate a condensed representa-
tion of a message called a message digest. The algorithm takes a message less than 2^64 bits as input and produces a 160-bit digest suitable
for use as a digital signature.
The RMD160 functions are considered to be more secure than the md4(3) and md5(3) functions and at least as secure as the sha1(3) function.
All share a similar interface.
The RMD160Init() function initializes a RMD160_CTX context for use with RMD160Update(), and RMD160Final(). The RMD160Update() function adds
data of length nbytes to the RMD160_CTX specified by context. RMD160Final() is called when all data has been added via RMD160Update() and
stores a message digest in the digest parameter. When a null pointer is passed to RMD160Final() as first argument only the final padding
will be applied and the current context can still be used with RMD160Update().
The RMD160Transform() function is used by RMD160Update() to hash 512-bit blocks and forms the core of the algorithm. Most programs should
use the interface provided by RMD160Init(), RMD160Update() and RMD160Final() instead of calling RMD160Transform() directly.
The RMD160End() function is a front end for RMD160Final() which converts the digest into an ASCII representation of the 160 bit digest in
The RMD160File() function calculates the digest for a file and returns the result via RMD160End(). If RMD160File() is unable to open the
file a NULL pointer is returned.
The RMD160Data() function calculates the digest of an arbitrary string and returns the result via RMD160End().
For each of the RMD160End(), RMD160File(), and RMD160Data() functions the buf parameter should either be a string of at least 41 characters
in size or a NULL pointer. In the latter case, space will be dynamically allocated via malloc(3) and should be freed using free(3) when it
is no longer needed.
The follow code fragment will calculate the digest for the string "abc" which is ``0x8eb208f7e05d987a9b044a8e98c6b087f15a0bfc''.
buf = "abc";
n = strlen(buf);
RMD160Update(&rmd, (u_char *)buf, n);
/* Print the digest as one long hex value */
for (n = 0; n < 20; n++)
Alternately, the helper functions could be used in the following way:
char *buf = "abc";
", RMD160Data(buf, strlen(buf), output));
rmd160(1), md4(3), md5(3), sha1(3)
H. Dobbertin, A. Bosselaers, B. Preneel, RIPEMD-160, a strengthened version of RIPEMD.
Information technology - Security techniques - Hash-functions - Part 3: Dedicated hash-functions, ISO/IEC 10118-3.
H. Dobbertin, A. Bosselaers, B. Preneel, "The RIPEMD-160 cryptographic hash function", Dr. Dobb's Journal, Vol. 22, No. 1, pp. 24-28, January
The RMD-160 functions appeared in OpenBSD 2.1.
This implementation of RMD-160 was written by Antoon Bosselaers.
The RMD160End(), RMD160File(), and RMD160Data() helper functions are derived from code written by Poul-Henning Kamp.
If a message digest is to be copied to a multi-byte type (ie: an array of five 32-bit integers) it will be necessary to perform byte swapping
on little endian machines such as the i386, alpha, and VAX.
July 16, 1997 BSD