Class: OpenSSL::HMAC

Inherits:
Object
  • Object
show all
Defined in:
ossl_hmac.c

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#new(key, digest) ⇒ Object

Returns an instance of OpenSSL::HMAC set with the key and digest algorithm to be used. The instance represents the initial state of the message authentication code before any data has been processed. To process data with it, use the instance method #update with your data as an argument.

Example

key = ‘key’ digest = OpenSSL::Digest.new(‘sha1’) instance = OpenSSL::HMAC.new(key, digest) #=> f42bb0eeb018ebbd4597ae7213711ec60760843f instance.class #=> OpenSSL::HMAC

A note about comparisons

Two instances won’t be equal when they’re compared, even if they have the same value. Use #to_s or #hexdigest to return the authentication code that the instance represents. For example:

other_instance = OpenSSL::HMAC.new(‘key’, OpenSSL::Digest.new(‘sha1’)) #=> f42bb0eeb018ebbd4597ae7213711ec60760843f instance #=> f42bb0eeb018ebbd4597ae7213711ec60760843f instance == other_instance #=> false instance.to_s == other_instance.to_s #=> true



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# File 'ossl_hmac.c', line 103

static VALUE
ossl_hmac_initialize(VALUE self, VALUE key, VALUE digest)
{
    HMAC_CTX *ctx;

    StringValue(key);
    GetHMAC(self, ctx);
    HMAC_Init(ctx, RSTRING_PTR(key), RSTRING_LENINT(key),
		 GetDigestPtr(digest));

    return self;
}

Class Method Details

.digest(digest, key, data) ⇒ aString

Returns the authentication code as a binary string. The digest parameter must be an instance of OpenSSL::Digest.

Example

key = ‘key’ data = ‘The quick brown fox jumps over the lazy dog’ digest = OpenSSL::Digest.new(‘sha1’)

hmac = OpenSSL::HMAC.digest(digest, key, data) #=> “xDE|x9Bx85xB8xB7x8AxA6xBCx8Az6xF7nx90px1Cx9DxB4xD9”

Returns:

  • (aString) 


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# File 'ossl_hmac.c', line 281

static VALUE
ossl_hmac_s_digest(VALUE klass, VALUE digest, VALUE key, VALUE data)
{
    unsigned char *buf;
    unsigned int buf_len;

    StringValue(key);
    StringValue(data);
    buf = HMAC(GetDigestPtr(digest), RSTRING_PTR(key), RSTRING_LENINT(key),
	       (unsigned char *)RSTRING_PTR(data), RSTRING_LEN(data), NULL, &buf_len);

    return rb_str_new((const char *)buf, buf_len);
}

.hexdigest(digest, key, data) ⇒ aString

Returns the authentication code as a hex-encoded string. The digest parameter must be an instance of OpenSSL::Digest.

Example

key = ‘key’ data = ‘The quick brown fox jumps over the lazy dog’ digest = OpenSSL::Digest.new(‘sha1’)

hmac = OpenSSL::HMAC.hexdigest(digest, key, data) #=> “de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9”

Returns:

  • (aString) 


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# File 'ossl_hmac.c', line 312

static VALUE
ossl_hmac_s_hexdigest(VALUE klass, VALUE digest, VALUE key, VALUE data)
{
    unsigned char *buf;
    char *hexbuf;
    unsigned int buf_len;
    VALUE hexdigest;

    StringValue(key);
    StringValue(data);

    buf = HMAC(GetDigestPtr(digest), RSTRING_PTR(key), RSTRING_LENINT(key),
	       (unsigned char *)RSTRING_PTR(data), RSTRING_LEN(data), NULL, &buf_len);
    if (string2hex(buf, buf_len, &hexbuf, NULL) != 2 * (int)buf_len) {
	ossl_raise(eHMACError, "Cannot convert buf to hexbuf");
    }
    hexdigest = ossl_buf2str(hexbuf, 2 * buf_len);

    return hexdigest;
}

Instance Method Details

#digest ⇒ String

Returns the authentication code an instance represents as a binary string.

Example

instance = OpenSSL::HMAC.new(‘key’, OpenSSL::Digest.new(‘sha1’)) #=> f42bb0eeb018ebbd4597ae7213711ec60760843f instance.digest #=> “xF4+xB0xEExB0x18xEBxBDEx97xAErx13qx1ExC6a‘x84?”

Returns:

  • (String) 


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# File 'ossl_hmac.c', line 190

static VALUE
ossl_hmac_digest(VALUE self)
{
    HMAC_CTX *ctx;
    unsigned char *buf;
    unsigned int buf_len;
    VALUE digest;

    GetHMAC(self, ctx);
    hmac_final(ctx, &buf, &buf_len);
    digest = ossl_buf2str((char *)buf, buf_len);

    return digest;
}

#hexdigest ⇒ String Also known as: inspect, to_s

Returns the authentication code an instance represents as a hex-encoded string.

Returns:

  • (String) 


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# File 'ossl_hmac.c', line 213

static VALUE
ossl_hmac_hexdigest(VALUE self)
{
    HMAC_CTX *ctx;
    unsigned char *buf;
    char *hexbuf;
    unsigned int buf_len;
    VALUE hexdigest;

    GetHMAC(self, ctx);
    hmac_final(ctx, &buf, &buf_len);
    if (string2hex(buf, buf_len, &hexbuf, NULL) != 2 * (int)buf_len) {
	OPENSSL_free(buf);
	ossl_raise(eHMACError, "Memory alloc error");
    }
    OPENSSL_free(buf);
    hexdigest = ossl_buf2str(hexbuf, 2 * buf_len);

    return hexdigest;
}

#reset ⇒ self

Returns self as it was when it was first initialized, with all processed data cleared from it.

Example

data = “The quick brown fox jumps over the lazy dog” instance = OpenSSL::HMAC.new(‘key’, OpenSSL::Digest.new(‘sha1’)) #=> f42bb0eeb018ebbd4597ae7213711ec60760843f

instance.update(data) #=> de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9 instance.reset #=> f42bb0eeb018ebbd4597ae7213711ec60760843f

Returns:

  • (self) 


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# File 'ossl_hmac.c', line 253

static VALUE
ossl_hmac_reset(VALUE self)
{
    HMAC_CTX *ctx;

    GetHMAC(self, ctx);
    HMAC_Init(ctx, NULL, 0, NULL);

    return self;
}

#update(string) ⇒ self Also known as: <<

Returns self updated with the message to be authenticated. Can be called repeatedly with chunks of the message.

Example

first_chunk = ‘The quick brown fox jumps ’ second_chunk = ‘over the lazy dog’

instance.update(first_chunk) #=> 5b9a8038a65d571076d97fe783989e52278a492a instance.update(second_chunk) #=> de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9

Returns:

  • (self) 


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# File 'ossl_hmac.c', line 149

static VALUE
ossl_hmac_update(VALUE self, VALUE data)
{
    HMAC_CTX *ctx;

    StringValue(data);
    GetHMAC(self, ctx);
    HMAC_Update(ctx, (unsigned char *)RSTRING_PTR(data), RSTRING_LEN(data));

    return self;
}