/* * Parse the public, unencrypted portion of a RSA1 key. */ int sshkey_parse_public_rsa1(struct sshbuf *blob, struct sshkey **keyp, char **commentp) { int r; struct sshkey *pub = NULL; struct sshbuf *copy = NULL; *keyp = NULL; if (commentp != NULL) *commentp = NULL; /* Check that it is at least big enough to contain the ID string. */ if (sshbuf_len(blob) < sizeof(authfile_id_string)) return SSH_ERR_INVALID_FORMAT; /* * Make sure it begins with the id string. Consume the id string * from the buffer. */ if (memcmp(sshbuf_ptr(blob), authfile_id_string, sizeof(authfile_id_string)) != 0) return SSH_ERR_INVALID_FORMAT; /* Make a working copy of the keyblob and skip past the magic */ if ((copy = sshbuf_fromb(blob)) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshbuf_consume(copy, sizeof(authfile_id_string))) != 0) goto out; /* Skip cipher type, reserved data and key bits. */ if ((r = sshbuf_get_u8(copy, NULL)) != 0 || /* cipher type */ (r = sshbuf_get_u32(copy, NULL)) != 0 || /* reserved */ (r = sshbuf_get_u32(copy, NULL)) != 0) /* key bits */ goto out; /* Read the public key from the buffer. */ if ((pub = sshkey_new(KEY_RSA1)) == NULL || (r = sshbuf_get_bignum1(copy, pub->rsa->n)) != 0 || (r = sshbuf_get_bignum1(copy, pub->rsa->e)) != 0) goto out; /* Finally, the comment */ if ((r = sshbuf_get_string(copy, (u_char**)commentp, NULL)) != 0) goto out; /* The encrypted private part is not parsed by this function. */ r = 0; *keyp = pub; pub = NULL; out: if (copy != NULL) sshbuf_free(copy); if (pub != NULL) sshkey_free(pub); return r; }
/* parse buffer and return algorithm proposal */ int kex_buf2prop(struct sshbuf *raw, int *first_kex_follows, char ***propp) { struct sshbuf *b = NULL; u_char v; u_int i; char **proposal = NULL; int r; *propp = NULL; if ((proposal = calloc(PROPOSAL_MAX, sizeof(char *))) == NULL) return SSH_ERR_ALLOC_FAIL; if ((b = sshbuf_fromb(raw)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_consume(b, KEX_COOKIE_LEN)) != 0) /* skip cookie */ goto out; /* extract kex init proposal strings */ for (i = 0; i < PROPOSAL_MAX; i++) { if ((r = sshbuf_get_cstring(b, &(proposal[i]), NULL)) != 0) goto out; debug2("%s: %s", proposal_names[i], proposal[i]); } /* first kex follows / reserved */ if ((r = sshbuf_get_u8(b, &v)) != 0 || /* first_kex_follows */ (r = sshbuf_get_u32(b, &i)) != 0) /* reserved */ goto out; if (first_kex_follows != NULL) *first_kex_follows = v; debug2("first_kex_follows %d ", v); debug2("reserved %u ", i); r = 0; *propp = proposal; out: if (r != 0 && proposal != NULL) kex_prop_free(proposal); sshbuf_free(b); return r; }
static int parse_option_list(struct sshbuf *oblob, struct passwd *pw, u_int which, int crit, int *cert_no_port_forwarding_flag, int *cert_no_agent_forwarding_flag, int *cert_no_x11_forwarding_flag, int *cert_no_pty_flag, int *cert_no_user_rc, char **cert_forced_command, int *cert_source_address_done) { struct ssh *ssh = active_state; /* XXX */ char *command, *allowed; const char *remote_ip; char *name = NULL; struct sshbuf *c = NULL, *data = NULL; int r, ret = -1, result, found; if ((c = sshbuf_fromb(oblob)) == NULL) { error("%s: sshbuf_fromb failed", __func__); goto out; } while (sshbuf_len(c) > 0) { sshbuf_free(data); data = NULL; if ((r = sshbuf_get_cstring(c, &name, NULL)) != 0 || (r = sshbuf_froms(c, &data)) != 0) { error("Unable to parse certificate options: %s", ssh_err(r)); goto out; } debug3("found certificate option \"%.100s\" len %zu", name, sshbuf_len(data)); found = 0; if ((which & OPTIONS_EXTENSIONS) != 0) { if (strcmp(name, "permit-X11-forwarding") == 0) { *cert_no_x11_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-agent-forwarding") == 0) { *cert_no_agent_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-port-forwarding") == 0) { *cert_no_port_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-pty") == 0) { *cert_no_pty_flag = 0; found = 1; } else if (strcmp(name, "permit-user-rc") == 0) { *cert_no_user_rc = 0; found = 1; } } if (!found && (which & OPTIONS_CRITICAL) != 0) { if (strcmp(name, "force-command") == 0) { if ((r = sshbuf_get_cstring(data, &command, NULL)) != 0) { error("Unable to parse \"%s\" " "section: %s", name, ssh_err(r)); goto out; } if (*cert_forced_command != NULL) { error("Certificate has multiple " "force-command options"); free(command); goto out; } *cert_forced_command = command; found = 1; } if (strcmp(name, "source-address") == 0) { if ((r = sshbuf_get_cstring(data, &allowed, NULL)) != 0) { error("Unable to parse \"%s\" " "section: %s", name, ssh_err(r)); goto out; } if ((*cert_source_address_done)++) { error("Certificate has multiple " "source-address options"); free(allowed); goto out; } remote_ip = ssh_remote_ipaddr(ssh); result = addr_match_cidr_list(remote_ip, allowed); free(allowed); switch (result) { case 1: /* accepted */ break; case 0: /* no match */ logit("Authentication tried for %.100s " "with valid certificate but not " "from a permitted host " "(ip=%.200s).", pw->pw_name, remote_ip); auth_debug_add("Your address '%.200s' " "is not permitted to use this " "certificate for login.", remote_ip); goto out; case -1: default: error("Certificate source-address " "contents invalid"); goto out; } found = 1; } } if (!found) { if (crit) { error("Certificate critical option \"%s\" " "is not supported", name); goto out; } else { logit("Certificate extension \"%s\" " "is not supported", name); } } else if (sshbuf_len(data) != 0) { error("Certificate option \"%s\" corrupt " "(extra data)", name); goto out; } free(name); name = NULL; } /* successfully parsed all options */ ret = 0; out: if (ret != 0 && cert_forced_command != NULL && *cert_forced_command != NULL) { free(*cert_forced_command); *cert_forced_command = NULL; } free(name); sshbuf_free(data); sshbuf_free(c); return ret; }
static int sshkey_parse_private_rsa1(struct sshbuf *blob, const char *passphrase, struct sshkey **keyp, char **commentp) { int r; u_int16_t check1, check2; u_int8_t cipher_type; struct sshbuf *decrypted = NULL, *copy = NULL; u_char *cp; char *comment = NULL; struct sshcipher_ctx ciphercontext; const struct sshcipher *cipher; struct sshkey *prv = NULL; *keyp = NULL; if (commentp != NULL) *commentp = NULL; /* Check that it is at least big enough to contain the ID string. */ if (sshbuf_len(blob) < sizeof(authfile_id_string)) return SSH_ERR_INVALID_FORMAT; /* * Make sure it begins with the id string. Consume the id string * from the buffer. */ if (memcmp(sshbuf_ptr(blob), authfile_id_string, sizeof(authfile_id_string)) != 0) return SSH_ERR_INVALID_FORMAT; if ((prv = sshkey_new_private(KEY_RSA1)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((copy = sshbuf_fromb(blob)) == NULL || (decrypted = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_consume(copy, sizeof(authfile_id_string))) != 0) goto out; /* Read cipher type. */ if ((r = sshbuf_get_u8(copy, &cipher_type)) != 0 || (r = sshbuf_get_u32(copy, NULL)) != 0) /* reserved */ goto out; /* Read the public key and comment from the buffer. */ if ((r = sshbuf_get_u32(copy, NULL)) != 0 || /* key bits */ (r = sshbuf_get_bignum1(copy, prv->rsa->n)) != 0 || (r = sshbuf_get_bignum1(copy, prv->rsa->e)) != 0 || (r = sshbuf_get_cstring(copy, &comment, NULL)) != 0) goto out; /* Check that it is a supported cipher. */ cipher = cipher_by_number(cipher_type); if (cipher == NULL) { r = SSH_ERR_KEY_UNKNOWN_CIPHER; goto out; } /* Initialize space for decrypted data. */ if ((r = sshbuf_reserve(decrypted, sshbuf_len(copy), &cp)) != 0) goto out; /* Rest of the buffer is encrypted. Decrypt it using the passphrase. */ if ((r = cipher_set_key_string(&ciphercontext, cipher, passphrase, CIPHER_DECRYPT)) != 0) goto out; if ((r = cipher_crypt(&ciphercontext, cp, sshbuf_ptr(copy), sshbuf_len(copy), 0, 0)) != 0) { cipher_cleanup(&ciphercontext); goto out; } if ((r = cipher_cleanup(&ciphercontext)) != 0) goto out; if ((r = sshbuf_get_u16(decrypted, &check1)) != 0 || (r = sshbuf_get_u16(decrypted, &check2)) != 0) goto out; if (check1 != check2) { r = SSH_ERR_KEY_WRONG_PASSPHRASE; goto out; } /* Read the rest of the private key. */ if ((r = sshbuf_get_bignum1(decrypted, prv->rsa->d)) != 0 || (r = sshbuf_get_bignum1(decrypted, prv->rsa->iqmp)) != 0 || (r = sshbuf_get_bignum1(decrypted, prv->rsa->q)) != 0 || (r = sshbuf_get_bignum1(decrypted, prv->rsa->p)) != 0) goto out; /* calculate p-1 and q-1 */ if ((r = rsa_generate_additional_parameters(prv->rsa)) != 0) goto out; /* enable blinding */ if (RSA_blinding_on(prv->rsa, NULL) != 1) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } r = 0; *keyp = prv; prv = NULL; if (commentp != NULL) { *commentp = comment; comment = NULL; } out: bzero(&ciphercontext, sizeof(ciphercontext)); if (comment != NULL) free(comment); if (prv != NULL) sshkey_free(prv); if (copy != NULL) sshbuf_free(copy); if (decrypted != NULL) sshbuf_free(decrypted); return r; }
static int cert_option_list(struct sshauthopt *opts, struct sshbuf *oblob, u_int which, int crit) { char *command, *allowed; char *name = NULL; struct sshbuf *c = NULL, *data = NULL; int r, ret = -1, found; if ((c = sshbuf_fromb(oblob)) == NULL) { error("%s: sshbuf_fromb failed", __func__); goto out; } while (sshbuf_len(c) > 0) { sshbuf_free(data); data = NULL; if ((r = sshbuf_get_cstring(c, &name, NULL)) != 0 || (r = sshbuf_froms(c, &data)) != 0) { error("Unable to parse certificate options: %s", ssh_err(r)); goto out; } debug3("found certificate option \"%.100s\" len %zu", name, sshbuf_len(data)); found = 0; if ((which & OPTIONS_EXTENSIONS) != 0) { if (strcmp(name, "permit-X11-forwarding") == 0) { opts->permit_x11_forwarding_flag = 1; found = 1; } else if (strcmp(name, "permit-agent-forwarding") == 0) { opts->permit_agent_forwarding_flag = 1; found = 1; } else if (strcmp(name, "permit-port-forwarding") == 0) { opts->permit_port_forwarding_flag = 1; found = 1; } else if (strcmp(name, "permit-pty") == 0) { opts->permit_pty_flag = 1; found = 1; } else if (strcmp(name, "permit-user-rc") == 0) { opts->permit_user_rc = 1; found = 1; } } if (!found && (which & OPTIONS_CRITICAL) != 0) { if (strcmp(name, "force-command") == 0) { if ((r = sshbuf_get_cstring(data, &command, NULL)) != 0) { error("Unable to parse \"%s\" " "section: %s", name, ssh_err(r)); goto out; } if (opts->force_command != NULL) { error("Certificate has multiple " "force-command options"); free(command); goto out; } opts->force_command = command; found = 1; } if (strcmp(name, "source-address") == 0) { if ((r = sshbuf_get_cstring(data, &allowed, NULL)) != 0) { error("Unable to parse \"%s\" " "section: %s", name, ssh_err(r)); goto out; } if (opts->required_from_host_cert != NULL) { error("Certificate has multiple " "source-address options"); free(allowed); goto out; } /* Check syntax */ if (addr_match_cidr_list(NULL, allowed) == -1) { error("Certificate source-address " "contents invalid"); goto out; } opts->required_from_host_cert = allowed; found = 1; } } if (!found) { if (crit) { error("Certificate critical option \"%s\" " "is not supported", name); goto out; } else { logit("Certificate extension \"%s\" " "is not supported", name); } } else if (sshbuf_len(data) != 0) { error("Certificate option \"%s\" corrupt " "(extra data)", name); goto out; } free(name); name = NULL; } /* successfully parsed all options */ ret = 0; out: free(name); sshbuf_free(data); sshbuf_free(c); return ret; }
int sshkey_xmss_decrypt_state(const struct sshkey *k, struct sshbuf *encoded, struct sshbuf **retp) { struct ssh_xmss_state *state = k->xmss_state; struct sshbuf *copy = NULL, *decrypted = NULL; struct sshcipher_ctx *ciphercontext = NULL; const struct sshcipher *cipher = NULL; u_char *key, *iv = NULL, *dp; size_t keylen, ivlen, authlen, aadlen; u_int blocksize, encrypted_len, index; int r = SSH_ERR_INTERNAL_ERROR; if (retp != NULL) *retp = NULL; if (state == NULL || state->enc_keyiv == NULL || state->enc_ciphername == NULL) return SSH_ERR_INTERNAL_ERROR; if ((cipher = cipher_by_name(state->enc_ciphername)) == NULL) { r = SSH_ERR_INVALID_FORMAT; goto out; } blocksize = cipher_blocksize(cipher); keylen = cipher_keylen(cipher); ivlen = cipher_ivlen(cipher); authlen = cipher_authlen(cipher); if (state->enc_keyiv_len != keylen + ivlen) { r = SSH_ERR_INTERNAL_ERROR; goto out; } key = state->enc_keyiv; if ((copy = sshbuf_fromb(encoded)) == NULL || (decrypted = sshbuf_new()) == NULL || (iv = malloc(ivlen)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } /* check magic */ if (sshbuf_len(encoded) < sizeof(XMSS_MAGIC) || memcmp(sshbuf_ptr(encoded), XMSS_MAGIC, sizeof(XMSS_MAGIC))) { r = SSH_ERR_INVALID_FORMAT; goto out; } /* parse public portion */ if ((r = sshbuf_consume(encoded, sizeof(XMSS_MAGIC))) != 0 || (r = sshbuf_get_u32(encoded, &index)) != 0 || (r = sshbuf_get_u32(encoded, &encrypted_len)) != 0) goto out; /* check size of encrypted key blob */ if (encrypted_len < blocksize || (encrypted_len % blocksize) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } /* check that an appropriate amount of auth data is present */ if (sshbuf_len(encoded) < encrypted_len + authlen) { r = SSH_ERR_INVALID_FORMAT; goto out; } aadlen = sshbuf_len(copy) - sshbuf_len(encoded); /* replace first 4 bytes of IV with index to ensure uniqueness */ memcpy(iv, key + keylen, ivlen); POKE_U32(iv, index); /* decrypt private state of key */ if ((r = sshbuf_reserve(decrypted, aadlen + encrypted_len, &dp)) != 0 || (r = cipher_init(&ciphercontext, cipher, key, keylen, iv, ivlen, 0)) != 0 || (r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(copy), encrypted_len, aadlen, authlen)) != 0) goto out; /* there should be no trailing data */ if ((r = sshbuf_consume(encoded, encrypted_len + authlen)) != 0) goto out; if (sshbuf_len(encoded) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } /* remove AAD */ if ((r = sshbuf_consume(decrypted, aadlen)) != 0) goto out; /* XXX encrypted includes unchecked padding */ /* success */ r = 0; if (retp != NULL) { *retp = decrypted; decrypted = NULL; } out: cipher_free(ciphercontext); sshbuf_free(copy); sshbuf_free(decrypted); free(iv); return r; }