class OpenSSL::HMAC

Public Class Methods

digest(digest, key, data) → aString click to toggle source

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|\x9B\x85\xB8\xB7\x8A\xA6\xBC\x8Az6\xF7\n\x90p\x1C\x9D\xB4\xD9"
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 click to toggle source

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"
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;
}
new(key, digest) → hmac click to toggle source

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
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;
}

Public Instance Methods

<<(p1)
Alias for: update
digest → string click to toggle source

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+\xB0\xEE\xB0\x18\xEB\xBDE\x97\xAEr\x13q\x1E\xC6\a`\x84?"
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 click to toggle source

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

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;
}
Also aliased as: inspect, to_s
inspect()
Alias for: hexdigest
reset → self click to toggle source

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

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

    return self;
}
to_s()
Alias for: hexdigest
update(string) → self click to toggle source

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
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;
}
Also aliased as: <<