mdc2 3 2007-03-06 0.9.9-dev OpenSSL

NAME

MDC2, MDC2_Init, MDC2_Update, MDC2_Final - MDC2 hash function

LIBRARY

libcrypto, -lcrypto

SYNOPSIS


 #include 


 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.

_M_D_C_2_(_) computes the MDC2 message digest of the nn bytes at dd and places it in mmdd (which must have space for MDC2_DIGEST_LENGTH == 16 bytes of output). If mmdd 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:

_M_D_C_2___I_n_i_t_(_) initializes a MMDDCC22__CCTTXX structure.

_M_D_C_2___U_p_d_a_t_e_(_) can be called repeatedly with chunks of the message to be hashed (lleenn bytes at ddaattaa).

_M_D_C_2___F_i_n_a_l_(_) places the message digest in mmdd, which must have space for MDC2_DIGEST_LENGTH == 16 bytes of output, and erases the MMDDCC22__CCTTXX.

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

RETURN VALUES

_M_D_C_2_(_) returns a pointer to the hash value.

_M_D_C_2___I_n_i_t_(_), _M_D_C_2___U_p_d_a_t_e_(_) and _M_D_C_2___F_i_n_a_l_(_) return 1 for success, 0 otherwise.

CONFORMING TO

ISO/IEC 10118-2, with DES

SEE ALSO

_o_p_e_n_s_s_l___s_h_a(3), _E_V_P___D_i_g_e_s_t_I_n_i_t(3)

HISTORY

_M_D_C_2_(_), _M_D_C_2___I_n_i_t_(_), _M_D_C_2___U_p_d_a_t_e_(_) and _M_D_C_2___F_i_n_a_l_(_) are available since SSLeay 0.8.