DSA_do_sign 3 2003-07-24 0.9.9-dev OpenSSL

NAME

DSA_do_sign, DSA_do_verify - raw DSA signature operations

LIBRARY

libcrypto, -lcrypto

SYNOPSIS


 #include 


 DSA_SIG *DSA_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);


 int DSA_do_verify(const unsigned char *dgst, int dgst_len,
             DSA_SIG *sig, DSA *dsa);

DESCRIPTION

_D_S_A___d_o___s_i_g_n_(_) computes a digital signature on the lleenn byte message digest ddggsstt using the private key ddssaa and returns it in a newly allocated DDSSAA__SSIIGG structure.

_D_S_A___s_i_g_n___s_e_t_u_p(3) may be used to precompute part of the signing operation in case signature generation is time-critical.

_D_S_A___d_o___v_e_r_i_f_y_(_) verifies that the signature ssiigg matches a given message digest ddggsstt of size lleenn. ddssaa is the signer's public key.

RETURN VALUES

_D_S_A___d_o___s_i_g_n_(_) returns the signature, NULL on error. _D_S_A___d_o___v_e_r_i_f_y_(_) returns 1 for a valid signature, 0 for an incorrect signature and -1 on error. The error codes can be obtained by _E_R_R___g_e_t___e_r_r_o_r(3).

SEE ALSO

_o_p_e_n_s_s_l___d_s_a(3), _E_R_R___g_e_t___e_r_r_o_r(3), _o_p_e_n_s_s_l___r_a_n_d(3), _D_S_A___S_I_G___n_e_w(3), _D_S_A___s_i_g_n(3)

HISTORY

_D_S_A___d_o___s_i_g_n_(_) and _D_S_A___d_o___v_e_r_i_f_y_(_) were added in OpenSSL 0.9.3.