Class

This abstract class provides a common interface to message digest implementation classes written in C.

Write a Digest subclass in C

Digest::Base provides a common interface to message digest classes written in C. These classes must provide a struct of type rb_digest_metadata_t:

typedef int (*rb_digest_hash_init_func_t)(void *);
typedef void (*rb_digest_hash_update_func_t)(void *, unsigned char *, size_t);
typedef int (*rb_digest_hash_finish_func_t)(void *, unsigned char *);

typedef struct {
  int api_version;
  size_t digest_len;
  size_t block_len;
  size_t ctx_size;
  rb_digest_hash_init_func_t init_func;
  rb_digest_hash_update_func_t update_func;
  rb_digest_hash_finish_func_t finish_func;
} rb_digest_metadata_t;

This structure must be set as an instance variable named metadata (without the +@+ in front of the name). By example:

 static const rb_digest_metadata_t sha1 = {
    RUBY_DIGEST_API_VERSION,
    SHA1_DIGEST_LENGTH,
    SHA1_BLOCK_LENGTH,
    sizeof(SHA1_CTX),
    (rb_digest_hash_init_func_t)SHA1_Init,
    (rb_digest_hash_update_func_t)SHA1_Update,
    (rb_digest_hash_finish_func_t)SHA1_Finish,
};

rb_ivar_set(cDigest_SHA1, rb_intern("metadata"),
            rb_digest_make_metadata(&sha1));
Instance Methods

Return the block length of the digest in bytes.

Return the length of the hash value in bytes.

Reset the digest to its initial state and return self.

Update the digest using given string and return self.