bson_md5_t man page

typedef struct {
   uint32_t count[2]; /* message length in bits, lsw first */
   uint32_t abcd[4];  /* digest buffer */
   uint8_t buf[64];   /* accumulate block */
} bson_md5_t;

bson_md5_t encapsulates an implementation of the MD5 algorithm. This is used in OID generation for the MD5(hostname) bytes. It is also used by some libraries such as the MongoDB C driver.

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