diff options
Diffstat (limited to 'lib/crypto/c_src/crypto.c')
| -rw-r--r-- | lib/crypto/c_src/crypto.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/lib/crypto/c_src/crypto.c b/lib/crypto/c_src/crypto.c index e77e5fb8f0..8139b331bf 100644 --- a/lib/crypto/c_src/crypto.c +++ b/lib/crypto/c_src/crypto.c @@ -304,7 +304,7 @@ static ErlNifFunc nif_funcs[] = { {"rand_bytes", 3, rand_bytes_3}, {"strong_rand_mpint_nif", 3, strong_rand_mpint_nif}, {"rand_uniform_nif", 2, rand_uniform_nif}, - {"mod_exp_nif", 3, mod_exp_nif}, + {"mod_exp_nif", 4, mod_exp_nif}, {"dss_verify", 4, dss_verify}, {"rsa_verify_nif", 4, rsa_verify_nif}, {"aes_cbc_crypt", 4, aes_cbc_crypt}, @@ -1543,16 +1543,19 @@ static ERL_NIF_TERM rand_uniform_nif(ErlNifEnv* env, int argc, const ERL_NIF_TER } static ERL_NIF_TERM mod_exp_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) -{/* (Base,Exponent,Modulo) */ +{/* (Base,Exponent,Modulo,bin_hdr) */ BIGNUM *bn_base=NULL, *bn_exponent=NULL, *bn_modulo, *bn_result; BN_CTX *bn_ctx; unsigned char* ptr; unsigned dlen; + unsigned bin_hdr; /* return type: 0=plain binary, 4: mpint */ + unsigned extra_byte; ERL_NIF_TERM ret; - if (!get_bn_from_mpint(env, argv[0], &bn_base) - || !get_bn_from_mpint(env, argv[1], &bn_exponent) - || !get_bn_from_mpint(env, argv[2], &bn_modulo)) { + if (!get_bn_from_bin(env, argv[0], &bn_base) + || !get_bn_from_bin(env, argv[1], &bn_exponent) + || !get_bn_from_bin(env, argv[2], &bn_modulo) + || !enif_get_uint(env,argv[3],&bin_hdr) || (bin_hdr & ~4)) { if (bn_base) BN_free(bn_base); if (bn_exponent) BN_free(bn_exponent); @@ -1562,9 +1565,14 @@ static ERL_NIF_TERM mod_exp_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM arg bn_ctx = BN_CTX_new(); BN_mod_exp(bn_result, bn_base, bn_exponent, bn_modulo, bn_ctx); dlen = BN_num_bytes(bn_result); - ptr = enif_make_new_binary(env, dlen+4, &ret); - put_int32(ptr, dlen); - BN_bn2bin(bn_result, ptr+4); + extra_byte = bin_hdr && BN_is_bit_set(bn_result, dlen*8-1); + ptr = enif_make_new_binary(env, bin_hdr+extra_byte+dlen, &ret); + if (bin_hdr) { + put_int32(ptr, extra_byte+dlen); + ptr[4] = 0; /* extra zeroed byte to ensure a positive mpint */ + ptr += bin_hdr + extra_byte; + } + BN_bn2bin(bn_result, ptr); BN_free(bn_result); BN_CTX_free(bn_ctx); BN_free(bn_modulo); |