openssl/doc/md2.doc
1998-12-21 10:52:47 +00:00

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The MD2 library.
MD2 is a message digest algorithm that can be used to condense an arbitrary
length message down to a 16 byte hash. The functions all need to be passed
a MD2_CTX which is used to hold the MD2 context during multiple MD2_Update()
function calls. The normal method of use for this library is as follows
MD2_Init(...);
MD2_Update(...);
...
MD2_Update(...);
MD2_Final(...);
This library requires the inclusion of 'md2.h'.
The main negative about MD2 is that it is slow, especially when compared
to MD5.
The functions are as follows:
void MD2_Init(
MD2_CTX *c);
This function needs to be called to initiate a MD2_CTX structure for
use.
void MD2_Update(
MD2_CTX *c;
unsigned char *data;
unsigned long len);
This updates the message digest context being generated with 'len'
bytes from the 'data' pointer. The number of bytes can be any
length.
void MD2_Final(
unsigned char *md;
MD2_CTX *c;
This function is called when a message digest of the data digested
with MD2_Update() is wanted. The message digest is put in the 'md'
array and is MD2_DIGEST_LENGTH (16) bytes long.
unsigned char *MD2(
unsigned long n;
unsigned char *d;
unsigned char *md;
This function performs a MD2_Init(), followed by a MD2_Update()
followed by a MD2_Final() (using a local MD2_CTX).
The resulting digest is put into 'md' if it is not NULL.
Regardless of the value of 'md', the message
digest is returned from the function. If 'md' was NULL, the message
digest returned is being stored in a static structure.