NAME

       MDC2, MDC2_Init, MDC2_Update, MDC2_Final - MDC2 hash function

SYNOPSIS

        #include <openssl/mdc2.h>

        unsigned char *MDC2(const unsigned char *d, unsigned long n,
                         unsigned char *md);

        int MDC2_Init(MDC2_CTX *c);
        int MDC2_Update(MDC2_CTX *c, const unsigned char *data,
                         unsigned long len);
        int MDC2_Final(unsigned char *md, MDC2_CTX *c);

DESCRIPTION

       MDC2 is a method to construct hash functions with 128 bit output from block ciphers.
       These functions are an implementation of MDC2 with DES.

       MDC2() computes the MDC2 message digest of the n bytes at d and places it in md (which
       must have space for MDC2_DIGEST_LENGTH == 16 bytes of output). If md is NULL, the digest
       is placed in a static array.

       The following functions may be used if the message is not completely stored in memory:

       MDC2_Init() initializes a MDC2_CTX structure.

       MDC2_Update() can be called repeatedly with chunks of the message to be hashed (len bytes
       at data).

       MDC2_Final() places the message digest in md, which must have space for MDC2_DIGEST_LENGTH
       == 16 bytes of output, and erases the MDC2_CTX.

       Applications should use the higher level functions EVP_DigestInit(3) etc. instead of
       calling the hash functions directly.

RETURN VALUES

       MDC2() returns a pointer to the hash value.

       MDC2_Init(), MDC2_Update() and MDC2_Final() return 1 for success, 0 otherwise.

CONFORMING TO

       ISO/IEC 10118-2, with DES

SEE ALSO

       sha(3), EVP_DigestInit(3)

HISTORY

       MDC2(), MDC2_Init(), MDC2_Update() and MDC2_Final() are available since SSLeay 0.8.