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"),
Data_Wrap_Struct(0, 0, 0, (void *)&sha1));
Instance Methods
ext/digest/digest.c
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static VALUE
rb_digest_base_block_length(VALUE self)
{
rb_digest_metadata_t *algo;
algo = get_digest_obj_metadata(self);
return SIZET2NUM(algo->block_len);
}
Return the block length of the digest in bytes.
ext/digest/digest.c
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static VALUE
rb_digest_base_digest_length(VALUE self)
{
rb_digest_metadata_t *algo;
algo = get_digest_obj_metadata(self);
return SIZET2NUM(algo->digest_len);
}
Return the length of the hash value in bytes.
ext/digest/digest.c
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static VALUE
rb_digest_base_reset(VALUE self)
{
rb_digest_metadata_t *algo;
void *pctx;
algo = get_digest_obj_metadata(self);
TypedData_Get_Struct(self, void, &digest_type, pctx);
algo_init(algo, pctx);
return self;
}
Reset the digest to its initial state and return self.
ext/digest/digest.c
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static VALUE
rb_digest_base_update(VALUE self, VALUE str)
{
rb_digest_metadata_t *algo;
void *pctx;
algo = get_digest_obj_metadata(self);
TypedData_Get_Struct(self, void, &digest_type, pctx);
StringValue(str);
algo->update_func(pctx, (unsigned char *)RSTRING_PTR(str), RSTRING_LEN(str));
RB_GC_GUARD(str);
return self;
}
Update the digest using given string and return self.