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typedef enum
  {
    DIGEST_ALGO_MD5         =  1,
    DIGEST_ALGO_SHA1        =  2,
    DIGEST_ALGO_RMD160      =  3,
    /* 4, 5, 6, and 7 are reserved. */
    DIGEST_ALGO_SHA256      =  8,
    DIGEST_ALGO_SHA384      =  9,
    DIGEST_ALGO_SHA512      = 10,
    DIGEST_ALGO_SHA224      = 11
  }
digest_algo_t;

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