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md5(3)                                             OpenSSL                                            md5(3)



NAME
       MD2, MD4, MD5, MD2_Init, MD2_Update, MD2_Final, MD4_Init, MD4_Update, MD4_Final, MD5_Init,
       MD5_Update, MD5_Final - MD2, MD4, and MD5 hash functions

SYNOPSIS
        #include <openssl/md2.h>

        unsigned char *MD2(const unsigned char *d, unsigned long n,
                         unsigned char *md);

        void MD2_Init(MD2_CTX *c);
        void MD2_Update(MD2_CTX *c, const unsigned char *data,
                         unsigned long len);
        void MD2_Final(unsigned char *md, MD2_CTX *c);


        #include <openssl/md4.h>

        unsigned char *MD4(const unsigned char *d, unsigned long n,
                         unsigned char *md);

        void MD4_Init(MD4_CTX *c);
        void MD4_Update(MD4_CTX *c, const void *data,
                         unsigned long len);
        void MD4_Final(unsigned char *md, MD4_CTX *c);


        #include <openssl/md5.h>

        unsigned char *MD5(const unsigned char *d, unsigned long n,
                         unsigned char *md);

        void MD5_Init(MD5_CTX *c);
        void MD5_Update(MD5_CTX *c, const void *data,
                         unsigned long len);
        void MD5_Final(unsigned char *md, MD5_CTX *c);

DESCRIPTION
       MD2, MD4, and MD5 are cryptographic hash functions with a 128 bit output.

       MD2(), MD4(), and MD5() compute the MD2, MD4, and MD5 message digest of the n bytes at d and place it
       in md (which must have space for MD2_DIGEST_LENGTH == MD4_DIGEST_LENGTH == MD5_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:

       MD2_Init() initializes a MD2_CTX structure.

       MD2_Update() can be called repeatedly with chunks of the message to be hashed (len bytes at data).

       MD2_Final() places the message digest in md, which must have space for MD2_DIGEST_LENGTH == 16 bytes
       of output, and erases the MD2_CTX.

       MD4_Init(), MD4_Update(), MD4_Final(), MD5_Init(), MD5_Update(), and MD5_Final() are analogous using
       an MD4_CTX and MD5_CTX structure.

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

NOTE
       MD2, MD4, and MD5 are recommended only for compatibility with existing applications. In new
       applications, SHA-1 or RIPEMD-160 should be preferred.

RETURN VALUES
       MD2(), MD4(), and MD5() return pointers to the hash value.

       MD2_Init(), MD2_Update(), MD2_Final(), MD4_Init(), MD4_Update(), MD4_Final(), MD5_Init(),
       MD5_Update(), and MD5_Final() do not return values.

CONFORMING TO
       RFC 1319, RFC 1320, RFC 1321

SEE ALSO
       sha(3), ripemd(3), EVP_DigestInit(3)

HISTORY
       MD2(), MD2_Init(), MD2_Update() MD2_Final(), MD5(), MD5_Init(), MD5_Update() and MD5_Final() are
       available in all versions of SSLeay and OpenSSL.

       MD4(), MD4_Init(), and MD4_Update() are available in OpenSSL 0.9.6 and above.



0.9.7l                                           2000-08-14                                           md5(3)