diff options
Diffstat (limited to 'lib/crypto/c_src/rsa.c')
-rw-r--r-- | lib/crypto/c_src/rsa.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/lib/crypto/c_src/rsa.c b/lib/crypto/c_src/rsa.c new file mode 100644 index 0000000000..2b71b5adde --- /dev/null +++ b/lib/crypto/c_src/rsa.c @@ -0,0 +1,175 @@ +#include "rsa.h" +#include "bn.h" + +static ERL_NIF_TERM rsa_generate_key(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]); +static ERL_NIF_TERM put_rsa_private_key(ErlNifEnv* env, const RSA *rsa); +static int check_erlang_interrupt(int maj, int min, BN_GENCB *ctxt); + +int get_rsa_private_key(ErlNifEnv* env, ERL_NIF_TERM key, RSA *rsa) +{ + /* key=[E,N,D]|[E,N,D,P1,P2,E1,E2,C] */ + ERL_NIF_TERM head, tail; + BIGNUM *e, *n, *d; + BIGNUM *p, *q; + BIGNUM *dmp1, *dmq1, *iqmp; + + if (!enif_get_list_cell(env, key, &head, &tail) + || !get_bn_from_bin(env, head, &e) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &n) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &d)) { + return 0; + } + (void) RSA_set0_key(rsa, n, e, d); + if (enif_is_empty_list(env, tail)) { + return 1; + } + if (!enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &p) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &q) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &dmp1) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &dmq1) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &iqmp) + || !enif_is_empty_list(env, tail)) { + return 0; + } + (void) RSA_set0_factors(rsa, p, q); + (void) RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp); + return 1; +} + +int get_rsa_public_key(ErlNifEnv* env, ERL_NIF_TERM key, RSA *rsa) +{ + /* key=[E,N] */ + ERL_NIF_TERM head, tail; + BIGNUM *e, *n; + + if (!enif_get_list_cell(env, key, &head, &tail) + || !get_bn_from_bin(env, head, &e) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &n) + || !enif_is_empty_list(env, tail)) { + return 0; + } + + (void) RSA_set0_key(rsa, n, e, NULL); + return 1; +} + +/* Creates a term which can be parsed by get_rsa_private_key(). This is a list of plain integer binaries (not mpints). */ +static ERL_NIF_TERM put_rsa_private_key(ErlNifEnv* env, const RSA *rsa) +{ + ERL_NIF_TERM result[8]; + const BIGNUM *n, *e, *d, *p, *q, *dmp1, *dmq1, *iqmp; + + /* Return at least [E,N,D] */ + n = NULL; e = NULL; d = NULL; + RSA_get0_key(rsa, &n, &e, &d); + + result[0] = bin_from_bn(env, e); // Exponent E + result[1] = bin_from_bn(env, n); // Modulus N = p*q + result[2] = bin_from_bn(env, d); // Exponent D + + /* Check whether the optional additional parameters are available */ + p = NULL; q = NULL; + RSA_get0_factors(rsa, &p, &q); + dmp1 = NULL; dmq1 = NULL; iqmp = NULL; + RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp); + + if (p && q && dmp1 && dmq1 && iqmp) { + result[3] = bin_from_bn(env, p); // Factor p + result[4] = bin_from_bn(env, q); // Factor q + result[5] = bin_from_bn(env, dmp1); // D mod (p-1) + result[6] = bin_from_bn(env, dmq1); // D mod (q-1) + result[7] = bin_from_bn(env, iqmp); // (1/q) mod p + + return enif_make_list_from_array(env, result, 8); + } else { + return enif_make_list_from_array(env, result, 3); + } +} + +static int check_erlang_interrupt(int maj, int min, BN_GENCB *ctxt) +{ + ErlNifEnv *env = BN_GENCB_get_arg(ctxt); + + if (!enif_is_current_process_alive(env)) { + return 0; + } else { + return 1; + } +} + +static ERL_NIF_TERM rsa_generate_key(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{/* (ModulusSize, PublicExponent) */ + int modulus_bits; + BIGNUM *pub_exp, *three; + RSA *rsa; + int success; + ERL_NIF_TERM result; + BN_GENCB *intr_cb; +#ifndef HAVE_OPAQUE_BN_GENCB + BN_GENCB intr_cb_buf; +#endif + + if (!enif_get_int(env, argv[0], &modulus_bits) || modulus_bits < 256) { + return enif_make_badarg(env); + } + + if (!get_bn_from_bin(env, argv[1], &pub_exp)) { + return enif_make_badarg(env); + } + + /* Make sure the public exponent is large enough (at least 3). + * Without this, RSA_generate_key_ex() can run forever. */ + three = BN_new(); + BN_set_word(three, 3); + success = BN_cmp(pub_exp, three); + BN_free(three); + if (success < 0) { + BN_free(pub_exp); + return enif_make_badarg(env); + } + + /* For large keys, prime generation can take many seconds. Set up + * the callback which we use to test whether the process has been + * interrupted. */ +#ifdef HAVE_OPAQUE_BN_GENCB + intr_cb = BN_GENCB_new(); +#else + intr_cb = &intr_cb_buf; +#endif + BN_GENCB_set(intr_cb, check_erlang_interrupt, env); + + rsa = RSA_new(); + success = RSA_generate_key_ex(rsa, modulus_bits, pub_exp, intr_cb); + BN_free(pub_exp); + +#ifdef HAVE_OPAQUE_BN_GENCB + BN_GENCB_free(intr_cb); +#endif + + if (!success) { + RSA_free(rsa); + return atom_error; + } + + result = put_rsa_private_key(env, rsa); + RSA_free(rsa); + + return result; +} + +ERL_NIF_TERM rsa_generate_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{ + /* RSA key generation can take a long time (>1 sec for a large + * modulus), so schedule it as a CPU-bound operation. */ + return enif_schedule_nif(env, "rsa_generate_key", + ERL_NIF_DIRTY_JOB_CPU_BOUND, + rsa_generate_key, argc, argv); +} |