md4(3ext) - osol9

1md4(3EXT)                 Extended Library Functions                 md4(3EXT)
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NAME

6       md4, MD4Init, MD4Update, MD4Final - MD4 digest functions
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SYNOPSIS

9       cc [ flag ... ] file ... -lmd [ library ... ]
10       #include <md4.h>
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12       void MD4Init(MD4_CTX *context);
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15       void MD4Update(MD4_CTX *context, unsigned char *input,
16            unsigned int inlen);
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19       void MD4Final(unsigned char *output, MD4_CTX *context);
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DESCRIPTION

23       The MD4 functions implement the MD4 message-digest algorithm. The algo‐
24       rithm takes as input a message of arbitrary length and produces a "fin‐
25       gerprint"  or  "message digest" as output. The MD4 message-digest algo‐
26       rithm is intended for digital signature  applications  in  which  large
27       files are "compressed" in a secure manner before being encrypted with a
28       private (secret) key under a public-key cryptosystem such as RSA.
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30   MD4Init(), MD4Update(), MD4Final()
31       The MD4Init(), MD4Update(),  and  MD4Final()  functions  allow  an  MD4
32       digest to be computed over multiple message blocks. Between blocks, the
33       state of the MD4 computation is held in an MD4 context structure  allo‐
34       cated by the caller. A complete digest computation consists of calls to
35       MD4 functions in the following order: one call  to  MD4Init(),  one  or
36       more calls to MD4Update(), and one call to MD4Final().
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39       The MD4Init() function initializes the MD4 context structure pointed to
40       by context.
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43       The MD4Update() function computes a partial MD4 digest  on  the  inlen-
44       byte  message  block  pointed  to by input, and updates the MD4 context
45       structure pointed to by context accordingly.
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48       The MD4Final() function generates the final MD4 digest, using  the  MD4
49       context  structure  pointed to by context. The MD4 digest is written to
50       output. After a call to MD4Final(), the state of the context  structure
51       is  undefined. It must be reinitialized with MD4Init() before it can be
52       used again.
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RETURN VALUES

55       These functions do not return a value.
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SECURITY

58       The MD4 digest algorithm is not currently considered  cryptographically
59       secure.  It  is included in libmd(3LIB) for use by legacy protocols and
60       systems only. It should not be used by new systems or protocols.
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EXAMPLES

63       Example 1 Authenticate a message found in multiple buffers
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66       The following is a sample function that  must  authenticate  a  message
67       that  is  found  in  multiple buffers. The calling function provides an
68       authentication buffer that will contain the result of the MD4 digest.
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71         #include <sys/types.h>
72         #include <sys/uio.h>
73         #include <md4.h>
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75         int
76         AuthenticateMsg(unsigned char *auth_buffer, struct iovec
77                         *messageIov, unsigned int num_buffers)
78         {
79             MD4_CTX ctx;
80             unsigned int i;
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82             MD4Init(&ctx);
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84             for(i=0; i<num_buffers; i++)
85             {
86                  MD4Update(&ctx, messageIov->iov_base,
87                            messageIov->iov_len);
88                  messageIov += sizeof(struct iovec);
89             }
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91             MD4Final(auth_buffer, &ctx);
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93             return 0;
94         }
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ATTRIBUTES

98       See attributes(5) for descriptions of the following attributes:
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103       ┌─────────────────────────────┬─────────────────────────────┐
104       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
105       ├─────────────────────────────┼─────────────────────────────┤
106       │Interface Stability          │Committed                    │
107       ├─────────────────────────────┼─────────────────────────────┤
108       │MT-Level                     │MT-Safe                      │
109       └─────────────────────────────┴─────────────────────────────┘
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