+++ /dev/null
-/*
-
- silcssh.c
-
- Author: Pekka Riikonen <priikone@silcnet.org>
-
- Copyright (C) 2007 Pekka Riikonen
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; version 2 of the License.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
-*/
-
-#include "silc.h"
-
-/************************* Static utility functions *************************/
-
-/* Key fields destructor */
-
-static void silc_ssh_field_dest(void *key, void *context, void *user_context)
-{
- silc_free(key);
- silc_free(context);
-}
-
-/* Parse header line from key. Doesn't return the line termination
- characters. */
-
-SilcBool silc_ssh_parse_line(SilcBuffer key, SilcBuffer line,
- SilcBool cont)
-{
- char *tmp;
- int i, data_len;
- SilcBool valid = cont;
-
- data_len = silc_buffer_len(key);
- tmp = silc_buffer_data(key);
- for (i = 0; i < data_len; i++) {
- /* All header lines must have ':' character */
- if (!cont && tmp[i] == ':')
- valid = TRUE;
-
- if ((data_len - i >= 1 && tmp[i] == '\r') ||
- (data_len - i >= 1 && tmp[i] == '\n')) {
-
- if (!valid)
- return FALSE;
-
- if (line)
- silc_buffer_set(line, tmp, i);
-
- if (data_len - i >= 2 && tmp[i] == '\r' && tmp[i + 1] == '\n')
- silc_buffer_pull(key, i + 2);
- else
- silc_buffer_pull(key, i + 1);
-
- return TRUE;
- }
- }
-
- return FALSE;
-}
-
-/* Allocate fields hash table */
-
-SilcHashTable silc_ssh_allocate_fields(void)
-{
- return silc_hash_table_alloc(NULL, 0, silc_hash_string_case, NULL,
- silc_hash_string_case_compare, NULL,
- silc_ssh_field_dest, NULL, TRUE);
-}
-
-/* Parse key headers and return them into a hash table */
-
-SilcHashTable silc_ssh_parse_headers(SilcBuffer key)
-{
- SilcHashTable fields;
- unsigned char *field, *value;
- SilcBufferStruct line, v;
- SilcBool quoted = FALSE;
-
- SILC_LOG_DEBUG(("Parsing SSH key headers"));
-
- fields = silc_ssh_allocate_fields();
- if (!fields)
- return NULL;
-
- /* Parse the fields */
- while (silc_buffer_len(key) > 0) {
- if (!silc_ssh_parse_line(key, &line, FALSE))
- break;
-
- /* Get field */
-
- field = strchr(silc_buffer_data(&line), ':');
- if (!field)
- goto err;
- if (field - silc_buffer_data(&line) > 64)
- goto err;
- field = silc_memdup(silc_buffer_data(&line),
- field - silc_buffer_data(&line));
- if (!field)
- goto err;
-
- /* Skip ':' and following whitespace */
- if (!silc_buffer_pull(&line, strlen(field) + 2))
- goto err;
-
- /* Get value */
-
- memset(&v, 0, sizeof(v));
- silc_buffer_format(&v,
- SILC_STR_DATA(silc_buffer_data(&line),
- silc_buffer_len(&line)),
- SILC_STR_END);
-
- /* Handle quoted Comment lines by removing the quotation */
- if (*silc_buffer_data(&v) == '"' && !strcmp(field, "Comment"))
- quoted = TRUE;
-
- /* Handle wrapping value lines */
- while (silc_buffer_len(&v) > 0) {
- if (*silc_buffer_data(&v) == '\\') {
- if (!silc_ssh_parse_line(key, &line, TRUE))
- goto err;
- silc_buffer_format(&v,
- SILC_STR_DATA(silc_buffer_data(&line),
- silc_buffer_len(&line)),
- SILC_STR_END);
- continue;
- }
- silc_buffer_pull(&v, 1);
- }
- silc_buffer_start(&v);
-
- if (silc_buffer_len(&v) > 1024)
- goto err;
-
- if (quoted) {
- /* If the last character is quotation also, remove the quotation */
- if (*(silc_buffer_data(&v) + silc_buffer_len(&v) - 1) == '"') {
- silc_buffer_pull(&v, 1);
- silc_buffer_push_tail(&v, 1);
- }
- }
-
- value = silc_memdup(silc_buffer_data(&v), silc_buffer_len(&v));
- if (!value)
- goto err;
- silc_buffer_purge(&v);
-
- /* Add to hash table */
- SILC_LOG_DEBUG(("Header '%s' '%s'", field, value));
- silc_hash_table_add(fields, field, value);
- }
-
- return fields;
-
- err:
- SILC_LOG_ERROR(("Malformed SSH2 key headers"));
- silc_hash_table_free(fields);
- return NULL;
-}
-
-/******************************* SILC SSH API *******************************/
-
-/* Generate key pair */
-
-SilcBool silc_ssh_generate_key(const char *algorithm,
- int bits_len, SilcRng rng,
- const char *subject,
- SilcPublicKey *ret_public_key,
- SilcPrivateKey *ret_private_key)
-{
- SilcSshPublicKey pubkey;
- SilcSshPrivateKey privkey;
- const SilcPKCSAlgorithm *alg;
- const SilcPKCSObject *pkcs;
-
- SILC_LOG_DEBUG(("Generating SSH2 %s key pair with key length %d bits",
- algorithm, bits_len));
-
- if (!rng)
- return FALSE;
-
- pkcs = silc_pkcs_find_pkcs(SILC_PKCS_SSH2);
- if (!pkcs)
- return FALSE;
-
- /* Allocate SSH public key */
- pubkey = silc_calloc(1, sizeof(*pubkey));
- if (!pubkey)
- return FALSE;
-
- /* Allocate algorithm */
- alg = silc_pkcs_find_algorithm(algorithm, "ssh");
- if (!alg) {
- SILC_LOG_ERROR(("Public key algorithm %s/ssh not supported", algorithm));
- silc_free(pubkey);
- return FALSE;
- }
- pubkey->pkcs = alg;
- pubkey->type = SILC_SSH_KEY_OPENSSH;
-
- /* Allocate SSH private key */
- privkey = silc_calloc(1, sizeof(*privkey));
- if (!privkey) {
- silc_free(pubkey);
- return FALSE;
- }
- privkey->pkcs = alg;
- privkey->type = SILC_SSH_KEY_OPENSSH;
-
- /* Allocate public key */
- *ret_public_key = silc_calloc(1, sizeof(**ret_public_key));
- if (!(*ret_public_key)) {
- silc_free(pubkey);
- silc_free(privkey);
- return FALSE;
- }
- (*ret_public_key)->pkcs = (SilcPKCSObject *)pkcs;
- (*ret_public_key)->alg = alg;
- (*ret_public_key)->public_key = pubkey;
-
- /* Allocate private key */
- *ret_private_key = silc_calloc(1, sizeof(**ret_private_key));
- if (!(*ret_private_key)) {
- silc_free(pubkey);
- silc_free(privkey);
- silc_free(*ret_public_key);
- return FALSE;
- }
- (*ret_private_key)->pkcs = (SilcPKCSObject *)pkcs;
- (*ret_private_key)->alg = alg;
- (*ret_private_key)->private_key = privkey;
-
- /* Generate the algorithm key pair */
- if (!alg->generate_key(alg, bits_len, rng, &pubkey->public_key,
- &privkey->private_key)) {
- silc_free(pubkey);
- silc_free(privkey);
- silc_free(*ret_public_key);
- silc_free(*ret_private_key);
- return FALSE;
- }
-
- if (subject)
- silc_ssh_public_key_add_field(pubkey, "Subject", subject);
-
- return TRUE;
-}
-
-/* Decode SSH public key. */
-
-int silc_ssh_public_key_decode(unsigned char *key, SilcUInt32 key_len,
- SilcSshPublicKey *ret_public_key)
-{
- SilcSshPublicKey public_key;
- const SilcPKCSAlgorithm *alg;
- SilcBufferStruct keybuf;
- char *type = NULL;
-
- SILC_LOG_DEBUG(("Parse SSH2 public key"));
-
- if (!ret_public_key)
- return 0;
-
- public_key = silc_calloc(1, sizeof(*public_key));
- if (!public_key)
- return 0;
-
- silc_buffer_set(&keybuf, key, key_len);
-
- SILC_LOG_HEXDUMP(("SSH public key, len %d", key_len), key, key_len);
-
- /* Parse public key type */
- if (silc_buffer_unformat(&keybuf,
- SILC_STR_ADVANCE,
- SILC_STR_UI32_STRING_ALLOC(&type),
- SILC_STR_END) < 0) {
- SILC_LOG_ERROR(("Malformed SSH2 public key"));
- goto err;
- }
-
- SILC_LOG_DEBUG(("SSH2 public key type %s", type));
-
- if (!strcmp(type, "ssh-rsa")) {
- /* RSA public key */
- alg = silc_pkcs_find_algorithm("rsa", "ssh");
- if (!alg) {
- SILC_LOG_ERROR(("Unsupported SSH2 public key type '%s'", type));
- goto err;
- }
- public_key->pkcs = alg;
-
- } else if (!strcmp(type, "ssh-dss")) {
- /* DSS public key */
- alg = silc_pkcs_find_algorithm("dsa", "ssh");
- if (!alg) {
- SILC_LOG_ERROR(("Unsupported SSH2 public key type '%s'", type));
- goto err;
- }
- public_key->pkcs = alg;
-
- } else {
- SILC_LOG_ERROR(("Unsupported SSH2 public key type '%s'", type));
- goto err;
- }
-
- /* Parse the algorithm specific public key */
- if (!alg->import_public_key(alg, silc_buffer_data(&keybuf),
- silc_buffer_len(&keybuf),
- &public_key->public_key))
- goto err;
-
- silc_free(type);
-
- *ret_public_key = public_key;
-
- return key_len;
-
- err:
- silc_free(type);
- silc_free(public_key);
- return 0;
-}
-
-/* Encode SSH public key */
-
-unsigned char *silc_ssh_public_key_encode(SilcStack stack,
- SilcSshPublicKey public_key,
- SilcUInt32 *ret_key_len)
-{
- const SilcPKCSAlgorithm *alg = public_key->pkcs;
- SilcBufferStruct buf;
- unsigned char *pk = NULL, tmp[16];
- SilcUInt32 pk_len;
-
- SILC_LOG_DEBUG(("Encode SSH2 public key"));
-
- /* Get algorithm name */
- if (!strcmp(alg->name, "rsa"))
- silc_snprintf(tmp, sizeof(tmp), "ssh-rsa");
- else if (!strcmp(alg->name, "dsa"))
- silc_snprintf(tmp, sizeof(tmp), "ssh-dss");
- else
- return NULL;
-
- /* Export PKCS algorithm public key */
- if (alg->export_public_key)
- pk = alg->export_public_key(alg, stack, public_key->public_key, &pk_len);
- if (!pk) {
- SILC_LOG_ERROR(("Error exporting PKCS algorithm key"));
- return NULL;
- }
-
- /* Encode public key */
- memset(&buf, 0, sizeof(buf));
- if (silc_buffer_sformat(stack, &buf,
- SILC_STR_UI_INT(strlen(tmp)),
- SILC_STR_UI32_STRING(tmp),
- SILC_STR_UI_XNSTRING(pk, pk_len),
- SILC_STR_END) < 0) {
- silc_sfree(stack, pk);
- return NULL;
- }
-
- silc_sfree(stack, pk);
- pk = silc_buffer_steal(&buf, ret_key_len);
-
- return pk;
-}
-
-/* Free public key */
-
-void silc_ssh_public_key_free(SilcSshPublicKey public_key)
-{
- if (public_key->fields)
- silc_hash_table_free(public_key->fields);
- public_key->pkcs->public_key_free(public_key->pkcs,
- public_key->public_key);
- silc_free(public_key);
-}
-
-/* Return public key header field value */
-
-const char *silc_ssh_public_key_get_field(SilcSshPublicKey public_key,
- const char *field)
-{
- char *value;
-
- if (!field || !public_key->fields)
- return NULL;
-
- if (!silc_hash_table_find(public_key->fields, (void *)field,
- NULL, (void *)&value))
- return NULL;
-
- return (const char *)value;
-}
-
-/* Add public key header value */
-
-SilcBool silc_ssh_public_key_add_field(SilcSshPublicKey public_key,
- const char *field,
- const char *value)
-{
- if (!field || !value)
- return FALSE;
-
- if (!public_key->fields) {
- public_key->fields =
- silc_hash_table_alloc(NULL, 0, silc_hash_string_case, NULL,
- silc_hash_string_case_compare, NULL,
- silc_ssh_field_dest, NULL, TRUE);
- if (!public_key->fields)
- return FALSE;
- }
-
- return silc_hash_table_add(public_key->fields, strdup(field), strdup(value));
-}
-
-/* Set public key type */
-
-void silc_ssh_public_key_set_type(SilcSshPublicKey public_key,
- SilcSshKeyType type)
-{
- public_key->type = type;
-}
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