---
name: "ripemd"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/RIPEMD160_Data"
---

# ripemd(3)

calculate the RIPEMD160 message digest

Part of [RIPEMD160\_Data(3)](/RIPEMD160_Data/3.md).

## NAME

**RIPEMD160\_Init**, **RIPEMD160\_Update**, **RIPEMD160\_Final**, **RIPEMD160\_End**, **RIPEMD160\_Fd**, **RIPEMD160\_FdChunk**, **RIPEMD160\_File**, **RIPEMD160\_FileChunk**, **RIPEMD160\_Data** – calculate the RIPEMD160 message digest

## LIBRARY

library “libmd”

## SYNOPSIS

**#include \<sys/types.h\>**

**#include \<ripemd.h\>**

*void*\

**RIPEMD160\_Init**(*RIPEMD160\_CTX \*context*);

*void*\

**RIPEMD160\_Update**(*RIPEMD160\_CTX \*context*, *const unsigned char \*data*, *unsigned int len*);

*void*\

**RIPEMD160\_Final**(*unsigned char digest\[20\]*, *RIPEMD160\_CTX \*context*);

*char \**\

**RIPEMD160\_End**(*RIPEMD160\_CTX \*context*, *char \*buf*);

*char \**\

**RIPEMD160\_Fd**(*int fd*, *char \*buf*);

*char \**\

**RIPEMD160\_FdChunk**(*int fd*, *char \*buf*, *off\_t offset*, *off\_t length*);

*char \**\

**RIPEMD160\_File**(*const char \*filename*, *char \*buf*);

*char \**\

**RIPEMD160\_FileChunk**(*const char \*filename*, *char \*buf*, *off\_t offset*, *off\_t length*);

*char \**\

**RIPEMD160\_Data**(*const unsigned char \*data*, *unsigned int len*, *char \*buf*);

## DESCRIPTION

The RIPEMD160\_ functions calculate a 160-bit cryptographic checksum (digest) for any number of input bytes. A cryptographic checksum is a one-way hash function; that is, it is computationally impractical to find the input corresponding to a particular output. This net result is a “fingerprint” of the input-data, which does not disclose the actual input.

The **RIPEMD160\_Init**(), **RIPEMD160\_Update**(), and **RIPEMD160\_Final**() functions are the core functions. Allocate an *RIPEMD160\_CTX*, initialize it with **RIPEMD160\_Init**(), run over the data with **RIPEMD160\_Update**(), and finally extract the result using **RIPEMD160\_Final**(), which will also erase the *RIPEMD160\_CTX*.

The **RIPEMD160\_End**() function is a wrapper for **RIPEMD160\_Final**() which converts the return value to a 41-character (including the terminating '\\0') ASCII string which represents the 160 bits in hexadecimal.

The **RIPEMD160\_File**() function calculates the digest of a file, and uses **RIPEMD160\_End**() to return the result. If the file cannot be opened, a null pointer is returned. The **RIPEMD160\_FileChunk**() function is similar to **RIPEMD160\_File**(), but it only calculates the digest over a byte-range of the file specified, starting at *offset* and spanning *length* bytes. If the *length* parameter is specified as 0, or more than the length of the remaining part of the file, **RIPEMD160\_FileChunk**() calculates the digest from *offset* to the end of file. The **RIPEMD160\_Data**() function calculates the digest of a chunk of data in memory, and uses **RIPEMD160\_End**() to return the result.

The **RIPEMD160\_Fd**() and **RIPEMD160\_FdChunk**() functions are identical to their **RIPEMD160\_File**() and **RIPEMD160\_FileChunk**() counterparts, with the exception that the first argument is an *fd* instead of a *filename*.

When using **RIPEMD160\_End**(), **RIPEMD160\_File**(), or **RIPEMD160\_Data**(), the *buf* argument can be a null pointer, in which case the returned string is allocated with [malloc(3)](/malloc/3.md) and subsequently must be explicitly deallocated using [free(3)](/free/3.md) after use. If the *buf* argument is non-null it must point to at least 41 characters of buffer space.

## ERRORS

The **RIPEMD160\_End**() function called with a null buf argument may fail and return NULL if:

- \[ENOMEM\]

  Insufficient storage space is available.

The **RIPEMD160\_File**() and **RIPEMD160\_FileChunk**() may return NULL when underlying [open(2)](/open/2.md), [fstat(2)](/fstat/2.md), [lseek(2)](/lseek/2.md), or [RIPEMD160\_End(3)](/RIPEMD160_End/3.md) fail.

## SEE ALSO

[md4(3)](/md4/3.md), [md5(3)](/md5/3.md), [sha(3)](/sha/3.md), [sha256(3)](/sha256/3.md), [sha512(3)](/sha512/3.md), [skein(3)](/skein/3.md)

## HISTORY

These functions appeared in FreeBSD 4.0.

## AUTHORS

The core hash routines were implemented by Eric Young based on the published RIPEMD160 specification.

## BUGS

No method is known to exist which finds two files having the same hash value, nor to find a file with a specific hash value. There is on the other hand no guarantee that such a method does not exist.