method

syssign

v2_5_5 - Show latest stable - Class: OpenSSL::PKey::DSA

syssign(p1)

public

Computes and returns the DSA signature of string, where string is expected to be an already-computed message digest of the original input data. The signature is issued using the private key of this DSA instance.

Parameters

string is a message digest of the original input data to be signed.

Example

dsa = OpenSSL::PKey::DSA.new(2048)
doc = "Sign me"
digest = OpenSSL::Digest::SHA1.digest(doc)
sig = dsa.syssign(digest)

static VALUE
ossl_dsa_sign(VALUE self, VALUE data)
{
    DSA *dsa;
    const BIGNUM *dsa_q;
    unsigned int buf_len;
    VALUE str;

    GetDSA(self, dsa);
    DSA_get0_pqg(dsa, NULL, &dsa_q, NULL);
    if (!dsa_q)
        ossl_raise(eDSAError, "incomplete DSA");
    if (!DSA_PRIVATE(self, dsa))
        ossl_raise(eDSAError, "Private DSA key needed!");
    StringValue(data);
    str = rb_str_new(0, DSA_size(dsa));
    if (!DSA_sign(0, (unsigned char *)RSTRING_PTR(data), RSTRING_LENINT(data),
                  (unsigned char *)RSTRING_PTR(str),
                  &buf_len, dsa)) { /* type is ignored (0) */
        ossl_raise(eDSAError, NULL);
    }
    rb_str_set_len(str, buf_len);

    return str;
}

syssign

Parameters

Example

Related methods