int ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, u_int compat) { u_char *sig = NULL; size_t slen = 0, len; unsigned long long smlen; int r, ret; struct sshbuf *b = NULL; if (lenp != NULL) *lenp = 0; if (sigp != NULL) *sigp = NULL; if (key == NULL || sshkey_type_plain(key->type) != KEY_ED25519 || key->ed25519_sk == NULL || datalen >= INT_MAX - crypto_sign_ed25519_BYTES) return SSH_ERR_INVALID_ARGUMENT; smlen = slen = datalen + crypto_sign_ed25519_BYTES; if ((sig = malloc(slen)) == NULL) return SSH_ERR_ALLOC_FAIL; if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen, key->ed25519_sk)) != 0 || smlen <= datalen) { r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */ goto out; } /* encode signature */ if ((b = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_put_cstring(b, "ssh-ed25519")) != 0 || (r = sshbuf_put_string(b, sig, smlen - datalen)) != 0) goto out; len = sshbuf_len(b); if (sigp != NULL) { if ((*sigp = malloc(len)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*sigp, sshbuf_ptr(b), len); } if (lenp != NULL) *lenp = len; /* success */ r = 0; out: sshbuf_free(b); if (sig != NULL) { explicit_bzero(sig, slen); free(sig); } return r; }
int ssh_rsa_complete_crt_parameters(struct sshkey *key, const BIGNUM *iqmp) { const BIGNUM *rsa_p, *rsa_q, *rsa_d; BIGNUM *aux = NULL, *d_consttime = NULL; BIGNUM *rsa_dmq1 = NULL, *rsa_dmp1 = NULL, *rsa_iqmp = NULL; BN_CTX *ctx = NULL; int r; if (key == NULL || key->rsa == NULL || sshkey_type_plain(key->type) != KEY_RSA) return SSH_ERR_INVALID_ARGUMENT; RSA_get0_key(key->rsa, NULL, NULL, &rsa_d); RSA_get0_factors(key->rsa, &rsa_p, &rsa_q); if ((ctx = BN_CTX_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((aux = BN_new()) == NULL || (rsa_dmq1 = BN_new()) == NULL || (rsa_dmp1 = BN_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((d_consttime = BN_dup(rsa_d)) == NULL || (rsa_iqmp = BN_dup(iqmp)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } BN_set_flags(aux, BN_FLG_CONSTTIME); BN_set_flags(d_consttime, BN_FLG_CONSTTIME); if ((BN_sub(aux, rsa_q, BN_value_one()) == 0) || (BN_mod(rsa_dmq1, d_consttime, aux, ctx) == 0) || (BN_sub(aux, rsa_p, BN_value_one()) == 0) || (BN_mod(rsa_dmp1, d_consttime, aux, ctx) == 0)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (!RSA_set0_crt_params(key->rsa, rsa_dmp1, rsa_dmq1, rsa_iqmp)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_dmp1 = rsa_dmq1 = rsa_iqmp = NULL; /* transferred */ /* success */ r = 0; out: BN_clear_free(aux); BN_clear_free(d_consttime); BN_clear_free(rsa_dmp1); BN_clear_free(rsa_dmq1); BN_clear_free(rsa_iqmp); BN_CTX_free(ctx); return r; }
int sshkey_xmss_enable_maxsign(struct sshkey *k, u_int32_t maxsign) { struct ssh_xmss_state *state = k->xmss_state; if (sshkey_type_plain(k->type) != KEY_XMSS) return SSH_ERR_INVALID_ARGUMENT; if (maxsign == 0) return 0; if (state->idx + maxsign < state->idx) return SSH_ERR_INVALID_ARGUMENT; state->maxidx = state->idx + maxsign; return 0; }
u_int32_t sshkey_xmss_signatures_left(const struct sshkey *k) { struct ssh_xmss_state *state = k->xmss_state; u_int32_t idx; if (sshkey_type_plain(k->type) == KEY_XMSS && state && state->maxidx) { idx = k->xmss_sk ? PEEK_U32(k->xmss_sk) : state->idx; if (idx < state->maxidx) return state->maxidx - idx; } return 0; }
int ssh_ed25519_verify(const struct sshkey *key, const u_char *signature, size_t signaturelen, const u_char *data, size_t datalen, u_int compat) { struct sshbuf *b = NULL; char *ktype = NULL; const u_char *sigblob; u_char *sm = NULL, *m = NULL; size_t len; unsigned long long smlen = 0, mlen = 0; int r, ret; if (key == NULL || sshkey_type_plain(key->type) != KEY_ED25519 || key->ed25519_pk == NULL || datalen >= INT_MAX - crypto_sign_ed25519_BYTES) return SSH_ERR_INVALID_ARGUMENT; if ((b = sshbuf_from(signature, signaturelen)) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 || (r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0) goto out; if (strcmp("ssh-ed25519", ktype) != 0) { r = SSH_ERR_KEY_TYPE_MISMATCH; goto out; } if (sshbuf_len(b) != 0) { r = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } if (len > crypto_sign_ed25519_BYTES) { r = SSH_ERR_INVALID_FORMAT; goto out; } if (datalen >= SIZE_MAX - len) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } smlen = len + datalen; mlen = smlen; if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(sm, sigblob, len); memcpy(sm+len, data, datalen); if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen, key->ed25519_pk)) != 0) { debug2("%s: crypto_sign_ed25519_open failed: %d", __func__, ret); } if (ret != 0 || mlen != datalen) { r = SSH_ERR_SIGNATURE_INVALID; goto out; } /* XXX compare 'm' and 'data' ? */ /* success */ r = 0; out: if (sm != NULL) { explicit_bzero(sm, smlen); free(sm); } if (m != NULL) { explicit_bzero(m, smlen); /* NB mlen may be invalid if r != 0 */ free(m); } sshbuf_free(b); free(ktype); return r; }
int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, u_int compat) { DSA_SIG *sig = NULL; u_char digest[SSH_DIGEST_MAX_LENGTH], sigblob[SIGBLOB_LEN]; size_t rlen, slen, len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1); struct sshbuf *b = NULL; int ret = SSH_ERR_INVALID_ARGUMENT; if (lenp != NULL) *lenp = 0; if (sigp != NULL) *sigp = NULL; if (key == NULL || key->dsa == NULL || sshkey_type_plain(key->type) != KEY_DSA) return SSH_ERR_INVALID_ARGUMENT; if (dlen == 0) return SSH_ERR_INTERNAL_ERROR; if ((ret = ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen, digest, sizeof(digest))) != 0) goto out; if ((sig = DSA_do_sign(digest, dlen, key->dsa)) == NULL) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rlen = BN_num_bytes(sig->r); slen = BN_num_bytes(sig->s); if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) { ret = SSH_ERR_INTERNAL_ERROR; goto out; } explicit_bzero(sigblob, SIGBLOB_LEN); BN_bn2bin(sig->r, sigblob + SIGBLOB_LEN - INTBLOB_LEN - rlen); BN_bn2bin(sig->s, sigblob + SIGBLOB_LEN - slen); if (compat & SSH_BUG_SIGBLOB) { if (sigp != NULL) { if ((*sigp = malloc(SIGBLOB_LEN)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*sigp, sigblob, SIGBLOB_LEN); } if (lenp != NULL) *lenp = SIGBLOB_LEN; ret = 0; } else { /* ietf-drafts */ if ((b = sshbuf_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if ((ret = sshbuf_put_cstring(b, "ssh-dss")) != 0 || (ret = sshbuf_put_string(b, sigblob, SIGBLOB_LEN)) != 0) goto out; len = sshbuf_len(b); if (sigp != NULL) { if ((*sigp = malloc(len)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*sigp, sshbuf_ptr(b), len); } if (lenp != NULL) *lenp = len; ret = 0; } out: explicit_bzero(digest, sizeof(digest)); if (sig != NULL) DSA_SIG_free(sig); sshbuf_free(b); return ret; }
int ssh_dss_verify(const struct sshkey *key, const u_char *signature, size_t signaturelen, const u_char *data, size_t datalen, u_int compat) { DSA_SIG *sig = NULL; u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob = NULL; size_t len, dlen = ssh_digest_bytes(SSH_DIGEST_SHA1); int ret = SSH_ERR_INTERNAL_ERROR; struct sshbuf *b = NULL; char *ktype = NULL; if (key == NULL || key->dsa == NULL || sshkey_type_plain(key->type) != KEY_DSA) return SSH_ERR_INVALID_ARGUMENT; if (dlen == 0) return SSH_ERR_INTERNAL_ERROR; /* fetch signature */ if (compat & SSH_BUG_SIGBLOB) { if ((sigblob = malloc(signaturelen)) == NULL) return SSH_ERR_ALLOC_FAIL; memcpy(sigblob, signature, signaturelen); len = signaturelen; } else { /* ietf-drafts */ if ((b = sshbuf_from(signature, signaturelen)) == NULL) return SSH_ERR_ALLOC_FAIL; if (sshbuf_get_cstring(b, &ktype, NULL) != 0 || sshbuf_get_string(b, &sigblob, &len) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (strcmp("ssh-dss", ktype) != 0) { ret = SSH_ERR_KEY_TYPE_MISMATCH; goto out; } if (sshbuf_len(b) != 0) { ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } } if (len != SIGBLOB_LEN) { ret = SSH_ERR_INVALID_FORMAT; goto out; } /* parse signature */ if ((sig = DSA_SIG_new()) == NULL || (sig->r = BN_new()) == NULL || (sig->s = BN_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if ((BN_bin2bn(sigblob, INTBLOB_LEN, sig->r) == NULL) || (BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s) == NULL)) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } /* sha1 the data */ if ((ret = ssh_digest_memory(SSH_DIGEST_SHA1, data, datalen, digest, sizeof(digest))) != 0) goto out; switch (DSA_do_verify(digest, dlen, sig, key->dsa)) { case 1: ret = 0; break; case 0: ret = SSH_ERR_SIGNATURE_INVALID; goto out; default: ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } out: explicit_bzero(digest, sizeof(digest)); if (sig != NULL) DSA_SIG_free(sig); sshbuf_free(b); free(ktype); if (sigblob != NULL) { explicit_bzero(sigblob, len); free(sigblob); } return ret; }
/* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ int ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, const char *alg_ident) { u_char digest[SSH_DIGEST_MAX_LENGTH], *sig = NULL; size_t slen; u_int dlen, len; int nid, hash_alg, ret = SSH_ERR_INTERNAL_ERROR; struct sshbuf *b = NULL; if (lenp != NULL) *lenp = 0; if (sigp != NULL) *sigp = NULL; if (alg_ident == NULL || strlen(alg_ident) == 0 || strncmp(alg_ident, "ssh-rsa-cert", strlen("ssh-rsa-cert")) == 0) hash_alg = SSH_DIGEST_SHA1; else hash_alg = rsa_hash_alg_from_ident(alg_ident); if (key == NULL || key->rsa == NULL || hash_alg == -1 || sshkey_type_plain(key->type) != KEY_RSA || BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) return SSH_ERR_INVALID_ARGUMENT; slen = RSA_size(key->rsa); if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM) return SSH_ERR_INVALID_ARGUMENT; /* hash the data */ nid = rsa_hash_alg_nid(hash_alg); if ((dlen = ssh_digest_bytes(hash_alg)) == 0) return SSH_ERR_INTERNAL_ERROR; if ((ret = ssh_digest_memory(hash_alg, data, datalen, digest, sizeof(digest))) != 0) goto out; if ((sig = malloc(slen)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (RSA_sign(nid, digest, dlen, sig, &len, key->rsa) != 1) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (len < slen) { size_t diff = slen - len; memmove(sig + diff, sig, len); explicit_bzero(sig, diff); } else if (len > slen) { ret = SSH_ERR_INTERNAL_ERROR; goto out; } /* encode signature */ if ((b = sshbuf_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if ((ret = sshbuf_put_cstring(b, rsa_hash_alg_ident(hash_alg))) != 0 || (ret = sshbuf_put_string(b, sig, slen)) != 0) goto out; len = sshbuf_len(b); if (sigp != NULL) { if ((*sigp = malloc(len)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*sigp, sshbuf_ptr(b), len); } if (lenp != NULL) *lenp = len; ret = 0; out: explicit_bzero(digest, sizeof(digest)); if (sig != NULL) { explicit_bzero(sig, slen); free(sig); } sshbuf_free(b); return ret; }
int ssh_rsa_verify(const struct sshkey *key, const u_char *sig, size_t siglen, const u_char *data, size_t datalen) { char *ktype = NULL; int hash_alg, ret = SSH_ERR_INTERNAL_ERROR; size_t len, diff, modlen, dlen; struct sshbuf *b = NULL; u_char digest[SSH_DIGEST_MAX_LENGTH], *osigblob, *sigblob = NULL; if (key == NULL || key->rsa == NULL || sshkey_type_plain(key->type) != KEY_RSA || BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE || sig == NULL || siglen == 0) return SSH_ERR_INVALID_ARGUMENT; if ((b = sshbuf_from(sig, siglen)) == NULL) return SSH_ERR_ALLOC_FAIL; if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if ((hash_alg = rsa_hash_alg_from_ident(ktype)) == -1) { ret = SSH_ERR_KEY_TYPE_MISMATCH; goto out; } if (sshbuf_get_string(b, &sigblob, &len) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (sshbuf_len(b) != 0) { ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } /* RSA_verify expects a signature of RSA_size */ modlen = RSA_size(key->rsa); if (len > modlen) { ret = SSH_ERR_KEY_BITS_MISMATCH; goto out; } else if (len < modlen) { diff = modlen - len; osigblob = sigblob; if ((sigblob = realloc(sigblob, modlen)) == NULL) { sigblob = osigblob; /* put it back for clear/free */ ret = SSH_ERR_ALLOC_FAIL; goto out; } memmove(sigblob + diff, sigblob, len); explicit_bzero(sigblob, diff); len = modlen; } if ((dlen = ssh_digest_bytes(hash_alg)) == 0) { ret = SSH_ERR_INTERNAL_ERROR; goto out; } if ((ret = ssh_digest_memory(hash_alg, data, datalen, digest, sizeof(digest))) != 0) goto out; ret = openssh_RSA_verify(hash_alg, digest, dlen, sigblob, len, key->rsa); out: if (sigblob != NULL) { explicit_bzero(sigblob, len); free(sigblob); } free(ktype); sshbuf_free(b); explicit_bzero(digest, sizeof(digest)); return ret; }
/* ARGSUSED */ int ssh_ecdsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, u_int compat) { ECDSA_SIG *sig = NULL; int hash_alg; u_char digest[SSH_DIGEST_MAX_LENGTH]; size_t len, dlen; struct sshbuf *b = NULL, *bb = NULL; int ret = SSH_ERR_INTERNAL_ERROR; if (lenp != NULL) *lenp = 0; if (sigp != NULL) *sigp = NULL; if (key == NULL || key->ecdsa == NULL || sshkey_type_plain(key->type) != KEY_ECDSA) return SSH_ERR_INVALID_ARGUMENT; if ((hash_alg = sshkey_ec_nid_to_hash_alg(key->ecdsa_nid)) == -1 || (dlen = ssh_digest_bytes(hash_alg)) == 0) return SSH_ERR_INTERNAL_ERROR; if ((ret = ssh_digest_memory(hash_alg, data, datalen, digest, sizeof(digest))) != 0) goto out; if ((sig = ECDSA_do_sign(digest, dlen, key->ecdsa)) == NULL) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if ((bb = sshbuf_new()) == NULL || (b = sshbuf_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if ((ret = sshbuf_put_bignum2(bb, sig->r)) != 0 || (ret = sshbuf_put_bignum2(bb, sig->s)) != 0) goto out; if ((ret = sshbuf_put_cstring(b, sshkey_ssh_name_plain(key))) != 0 || (ret = sshbuf_put_stringb(b, bb)) != 0) goto out; len = sshbuf_len(b); if (sigp != NULL) { if ((*sigp = malloc(len)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*sigp, sshbuf_ptr(b), len); } if (lenp != NULL) *lenp = len; ret = 0; out: explicit_bzero(digest, sizeof(digest)); if (b != NULL) sshbuf_free(b); if (bb != NULL) sshbuf_free(bb); if (sig != NULL) ECDSA_SIG_free(sig); return ret; }
/* ARGSUSED */ int ssh_ecdsa_verify(const struct sshkey *key, const u_char *signature, size_t signaturelen, const u_char *data, size_t datalen, u_int compat) { ECDSA_SIG *sig = NULL; int hash_alg; u_char digest[SSH_DIGEST_MAX_LENGTH]; size_t dlen; int ret = SSH_ERR_INTERNAL_ERROR; struct sshbuf *b = NULL, *sigbuf = NULL; char *ktype = NULL; if (key == NULL || key->ecdsa == NULL || sshkey_type_plain(key->type) != KEY_ECDSA) return SSH_ERR_INVALID_ARGUMENT; if ((hash_alg = sshkey_ec_nid_to_hash_alg(key->ecdsa_nid)) == -1 || (dlen = ssh_digest_bytes(hash_alg)) == 0) return SSH_ERR_INTERNAL_ERROR; /* fetch signature */ if ((b = sshbuf_from(signature, signaturelen)) == NULL) return SSH_ERR_ALLOC_FAIL; if (sshbuf_get_cstring(b, &ktype, NULL) != 0 || sshbuf_froms(b, &sigbuf) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (strcmp(sshkey_ssh_name_plain(key), ktype) != 0) { ret = SSH_ERR_KEY_TYPE_MISMATCH; goto out; } if (sshbuf_len(b) != 0) { ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } /* parse signature */ if ((sig = ECDSA_SIG_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (sshbuf_get_bignum2(sigbuf, sig->r) != 0 || sshbuf_get_bignum2(sigbuf, sig->s) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (sshbuf_len(sigbuf) != 0) { ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } if ((ret = ssh_digest_memory(hash_alg, data, datalen, digest, sizeof(digest))) != 0) goto out; switch (ECDSA_do_verify(digest, dlen, sig, key->ecdsa)) { case 1: ret = 0; break; case 0: ret = SSH_ERR_SIGNATURE_INVALID; goto out; default: ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } out: explicit_bzero(digest, sizeof(digest)); if (sigbuf != NULL) sshbuf_free(sigbuf); if (b != NULL) sshbuf_free(b); if (sig != NULL) ECDSA_SIG_free(sig); free(ktype); return ret; }
/* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ int ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, u_int compat) { int hash_alg; u_char digest[SSH_DIGEST_MAX_LENGTH], *sig = NULL; size_t slen; u_int dlen, len; int nid, ret = SSH_ERR_INTERNAL_ERROR; struct sshbuf *b = NULL; if (lenp != NULL) *lenp = 0; if (sigp != NULL) *sigp = NULL; if (key == NULL || key->rsa == NULL || sshkey_type_plain(key->type) != KEY_RSA) return SSH_ERR_INVALID_ARGUMENT; slen = RSA_size(key->rsa); if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM) return SSH_ERR_INVALID_ARGUMENT; /* hash the data */ hash_alg = SSH_DIGEST_SHA1; nid = NID_sha1; if ((dlen = ssh_digest_bytes(hash_alg)) == 0) return SSH_ERR_INTERNAL_ERROR; if ((ret = ssh_digest_memory(hash_alg, data, datalen, digest, sizeof(digest))) != 0) goto out; if ((sig = malloc(slen)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (RSA_sign(nid, digest, dlen, sig, &len, key->rsa) != 1) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (len < slen) { size_t diff = slen - len; memmove(sig + diff, sig, len); explicit_bzero(sig, diff); } else if (len > slen) { ret = SSH_ERR_INTERNAL_ERROR; goto out; } /* encode signature */ if ((b = sshbuf_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if ((ret = sshbuf_put_cstring(b, "ssh-rsa")) != 0 || (ret = sshbuf_put_string(b, sig, slen)) != 0) goto out; len = sshbuf_len(b); if (sigp != NULL) { if ((*sigp = malloc(len)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*sigp, sshbuf_ptr(b), len); } if (lenp != NULL) *lenp = len; ret = 0; out: explicit_bzero(digest, sizeof(digest)); if (sig != NULL) { explicit_bzero(sig, slen); free(sig); } if (b != NULL) sshbuf_free(b); return ret; }
static int userauth_hostbased(struct ssh *ssh) { Authctxt *authctxt = ssh->authctxt; struct sshbuf *b; struct sshkey *key = NULL; char *pkalg, *cuser, *chost; u_char *pkblob, *sig; size_t alen, blen, slen; int r, pktype, authenticated = 0; if (!authctxt->valid) { debug2("%s: disabled because of invalid user", __func__); return 0; } /* XXX use sshkey_froms() */ if ((r = sshpkt_get_cstring(ssh, &pkalg, &alen)) != 0 || (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 || (r = sshpkt_get_cstring(ssh, &chost, NULL)) != 0 || (r = sshpkt_get_cstring(ssh, &cuser, NULL)) != 0 || (r = sshpkt_get_string(ssh, &sig, &slen)) != 0) fatal("%s: packet parsing: %s", __func__, ssh_err(r)); debug("%s: cuser %s chost %s pkalg %s slen %zu", __func__, cuser, chost, pkalg, slen); #ifdef DEBUG_PK debug("signature:"); sshbuf_dump_data(sig, siglen, stderr); #endif pktype = sshkey_type_from_name(pkalg); if (pktype == KEY_UNSPEC) { /* this is perfectly legal */ logit("%s: unsupported public key algorithm: %s", __func__, pkalg); goto done; } if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) { error("%s: key_from_blob: %s", __func__, ssh_err(r)); goto done; } if (key == NULL) { error("%s: cannot decode key: %s", __func__, pkalg); goto done; } if (key->type != pktype) { error("%s: type mismatch for decoded key " "(received %d, expected %d)", __func__, key->type, pktype); goto done; } if (sshkey_type_plain(key->type) == KEY_RSA && (ssh->compat & SSH_BUG_RSASIGMD5) != 0) { error("Refusing RSA key because peer uses unsafe " "signature format"); goto done; } if (match_pattern_list(sshkey_ssh_name(key), options.hostbased_key_types, 0) != 1) { logit("%s: key type %s not in HostbasedAcceptedKeyTypes", __func__, sshkey_type(key)); goto done; } if ((b = sshbuf_new()) == NULL) fatal("%s: sshbuf_new failed", __func__); /* reconstruct packet */ if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 || (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 || (r = sshbuf_put_cstring(b, authctxt->user)) != 0 || (r = sshbuf_put_cstring(b, authctxt->service)) != 0 || (r = sshbuf_put_cstring(b, "hostbased")) != 0 || (r = sshbuf_put_string(b, pkalg, alen)) != 0 || (r = sshbuf_put_string(b, pkblob, blen)) != 0 || (r = sshbuf_put_cstring(b, chost)) != 0 || (r = sshbuf_put_cstring(b, cuser)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); #ifdef DEBUG_PK sshbuf_dump(b, stderr); #endif auth2_record_info(authctxt, "client user \"%.100s\", client host \"%.100s\"", cuser, chost); /* test for allowed key and correct signature */ authenticated = 0; if (PRIVSEP(hostbased_key_allowed(authctxt->pw, cuser, chost, key)) && PRIVSEP(sshkey_verify(key, sig, slen, sshbuf_ptr(b), sshbuf_len(b), pkalg, ssh->compat)) == 0) authenticated = 1; auth2_record_key(authctxt, authenticated, key); sshbuf_free(b); done: debug2("%s: authenticated %d", __func__, authenticated); sshkey_free(key); free(pkalg); free(pkblob); free(cuser); free(chost); free(sig); return authenticated; }
int mm_answer_keyallowed(int sock, struct sshbuf *m) { struct ssh *ssh = active_state; /* XXX */ struct sshkey *key; char *cuser, *chost; u_char *blob; size_t bloblen; enum mm_keytype type = 0; int r, allowed = 0; debug3("%s entering", __func__); if ((r = sshbuf_get_u32(m, &type)) != 0 || (r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 || (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 || (r = sshbuf_get_string(m, &blob, &bloblen)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0) fatal("%s: cannot parse key: %s", __func__, ssh_err(r)); if ((compat20 && type == MM_RSAHOSTKEY) || (!compat20 && type != MM_RSAHOSTKEY)) fatal("%s: key type and protocol mismatch", __func__); if (key != NULL && authctxt->valid) { /* These should not make it past the privsep child */ if (sshkey_type_plain(key->type) == KEY_RSA && (ssh->compat & SSH_BUG_RSASIGMD5) != 0) fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__); switch (type) { case MM_USERKEY: allowed = options.pubkey_authentication && !auth2_userkey_already_used(authctxt, key) && match_pattern_list(sshkey_ssh_name(key), options.pubkey_key_types, strlen(options.pubkey_key_types), 0) == 1 && user_key_allowed(authctxt->pw, key); pubkey_auth_info(authctxt, key, NULL); auth_method = "publickey"; if (options.pubkey_authentication && allowed != 1) auth_clear_options(); break; case MM_HOSTKEY: allowed = options.hostbased_authentication && match_pattern_list(sshkey_ssh_name(key), options.hostbased_key_types, strlen(options.hostbased_key_types), 0) == 1 && hostbased_key_allowed(authctxt->pw, cuser, chost, key); pubkey_auth_info(authctxt, key, "client user \"%.100s\", client host \"%.100s\"", cuser, chost); auth_method = "hostbased"; break; #ifdef WITH_SSH1 case MM_RSAHOSTKEY: key->type = KEY_RSA1; /* XXX */ allowed = options.rhosts_rsa_authentication && auth_rhosts_rsa_key_allowed(authctxt->pw, cuser, chost, key); if (options.rhosts_rsa_authentication && allowed != 1) auth_clear_options(); auth_method = "rsa"; break; #endif default: fatal("%s: unknown key type %d", __func__, type); break; } } if (key != NULL) sshkey_free(key); /* clear temporarily storage (used by verify) */ monitor_reset_key_state(); if (allowed) { /* Save temporarily for comparison in verify */ key_blob = blob; key_bloblen = bloblen; key_blobtype = type; hostbased_cuser = cuser; hostbased_chost = chost; } else { /* Log failed attempt */ auth_log(authctxt, 0, 0, auth_method, NULL); free(blob); free(cuser); free(chost); } debug3("%s: key %p is %s", __func__, key, allowed ? "allowed" : "not allowed"); sshbuf_reset(m); if ((r = sshbuf_put_u32(m, allowed)) != 0 || (r = sshbuf_put_u32(m, forced_command != NULL)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); if (type == MM_RSAHOSTKEY) monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); return (0); }
int ssh_rsa_verify(const struct sshkey *key, const u_char *sig, size_t siglen, const u_char *data, size_t datalen, const char *alg) { const BIGNUM *rsa_n; char *sigtype = NULL; int hash_alg, want_alg, ret = SSH_ERR_INTERNAL_ERROR; size_t len = 0, diff, modlen, dlen; struct sshbuf *b = NULL; u_char digest[SSH_DIGEST_MAX_LENGTH], *osigblob, *sigblob = NULL; if (key == NULL || key->rsa == NULL || sshkey_type_plain(key->type) != KEY_RSA || sig == NULL || siglen == 0) return SSH_ERR_INVALID_ARGUMENT; RSA_get0_key(key->rsa, &rsa_n, NULL, NULL); if (BN_num_bits(rsa_n) < SSH_RSA_MINIMUM_MODULUS_SIZE) return SSH_ERR_KEY_LENGTH; if ((b = sshbuf_from(sig, siglen)) == NULL) return SSH_ERR_ALLOC_FAIL; if (sshbuf_get_cstring(b, &sigtype, NULL) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if ((hash_alg = rsa_hash_id_from_ident(sigtype)) == -1) { ret = SSH_ERR_KEY_TYPE_MISMATCH; goto out; } /* * Allow ssh-rsa-cert-v01 certs to generate SHA2 signatures for * legacy reasons, but otherwise the signature type should match. */ if (alg != NULL && strcmp(alg, "*****@*****.**") != 0) { if ((want_alg = rsa_hash_id_from_keyname(alg)) == -1) { ret = SSH_ERR_INVALID_ARGUMENT; goto out; } if (hash_alg != want_alg) { ret = SSH_ERR_SIGNATURE_INVALID; goto out; } } if (sshbuf_get_string(b, &sigblob, &len) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (sshbuf_len(b) != 0) { ret = SSH_ERR_UNEXPECTED_TRAILING_DATA; goto out; } /* RSA_verify expects a signature of RSA_size */ modlen = RSA_size(key->rsa); if (len > modlen) { ret = SSH_ERR_KEY_BITS_MISMATCH; goto out; } else if (len < modlen) { diff = modlen - len; osigblob = sigblob; if ((sigblob = realloc(sigblob, modlen)) == NULL) { sigblob = osigblob; /* put it back for clear/free */ ret = SSH_ERR_ALLOC_FAIL; goto out; } memmove(sigblob + diff, sigblob, len); explicit_bzero(sigblob, diff); len = modlen; } if ((dlen = ssh_digest_bytes(hash_alg)) == 0) { ret = SSH_ERR_INTERNAL_ERROR; goto out; } if ((ret = ssh_digest_memory(hash_alg, data, datalen, digest, sizeof(digest))) != 0) goto out; ret = openssh_RSA_verify(hash_alg, digest, dlen, sigblob, len, key->rsa); out: freezero(sigblob, len); free(sigtype); sshbuf_free(b); explicit_bzero(digest, sizeof(digest)); return ret; }