diff options
| -rw-r--r-- | include/libssh/libssh.h | 6 | ||||
| -rw-r--r-- | include/libssh/priv.h | 8 | ||||
| -rw-r--r-- | libssh/auth.c | 396 | ||||
| -rw-r--r-- | libssh/keyfiles.c | 130 |
4 files changed, 304 insertions, 236 deletions
diff --git a/include/libssh/libssh.h b/include/libssh/libssh.h index ad3b8b1..d2e6219 100644 --- a/include/libssh/libssh.h +++ b/include/libssh/libssh.h @@ -82,6 +82,7 @@ typedef struct channel_struct CHANNEL; typedef struct agent_struct AGENT; typedef struct ssh_session SSH_SESSION; typedef struct ssh_kbdint SSH_KBDINT; +struct keys_struct; /* integer values */ typedef uint32_t u32; @@ -255,8 +256,9 @@ PUBLIC_KEY *publickey_from_privatekey(PRIVATE_KEY *prv); void privatekey_free(PRIVATE_KEY *prv); STRING *publickey_from_file(SSH_SESSION *session, const char *filename, int *type); -STRING *publickey_from_next_file(SSH_SESSION *session, const char **pub_keys_path, - const char **keys_path, char **privkeyfile, int *type, int *count); +STRING *publickey_from_next_file(SSH_SESSION *session, + struct keys_struct *keytab, size_t keytab_size, + char **privkeyfile, int *type, unsigned int *count); int ssh_is_server_known(SSH_SESSION *session); int ssh_write_knownhost(SSH_SESSION *session); diff --git a/include/libssh/priv.h b/include/libssh/priv.h index c54edef..62f78ba 100644 --- a/include/libssh/priv.h +++ b/include/libssh/priv.h @@ -299,6 +299,11 @@ struct agent_struct { unsigned int count; }; +struct keys_struct { + const char *private; + const char *public; +}; + struct ssh_session { struct error_struct error; struct socket *socket; @@ -719,6 +724,9 @@ int match_hostname(const char *host, const char *pattern, unsigned int len); /** Zero a structure given a pointer to the structure */ #define ZERO_STRUCTP(x) do { if ((x) != NULL) memset((char *)(x), 0, sizeof(*(x))); } while(0) +/** Get the size of an array */ +#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0])) + #ifdef HAVE_LIBGCRYPT /* gcrypt_missing.c */ int my_gcry_dec2bn(bignum *bn, const char *data); diff --git a/libssh/auth.c b/libssh/auth.c index 99c2d05..dc063ef 100644 --- a/libssh/auth.c +++ b/libssh/auth.c @@ -687,224 +687,242 @@ error: return rc; } -static const char *keys_path[] = { - NULL, - "%s/.ssh/identity", - "%s/.ssh/id_dsa", - "%s/.ssh/id_rsa", - NULL -}; - -static const char *pub_keys_path[] = { - NULL, - "%s/.ssh/identity.pub", - "%s/.ssh/id_dsa.pub", - "%s/.ssh/id_rsa.pub", - NULL +static struct keys_struct keytab[] = { + { + .private = "%s/.ssh/identity", + .public = "%s/.ssh/identity.pub" + }, + { + .private = "%s/.ssh/id_dsa", + .public = "%s/.ssh/id_dsa.pub", + }, + { + .private = "%s/.ssh/id_rsa", + .public = "%s/.ssh/id_rsa.pub", + }, + { + .private = NULL, + .public = NULL + } }; /* this function initialy was in the client */ /* but the fools are the ones who never change mind */ -/** it may fail, for instance it doesn't ask for a password and uses a default - * asker for passphrases (in case the private key is encrypted) - * \brief Tries to automaticaly authenticate with public key and "none" - * \param session ssh session - * \param passphrase use this passphrase to unlock the privatekey. Use - * NULL if you don't want to use a passphrase or the - * user should be asked. - * \returns SSH_AUTH_ERROR : a serious error happened\n - * SSH_AUTH_DENIED : Authentication failed : use another method\n - * SSH_AUTH_PARTIAL : You've been partially authenticated, you still have to use another method\n - * SSH_AUTH_SUCCESS : Authentication success - * \see ssh_userauth_kbdint() - * \see ssh_userauth_password() - * \see ssh_options_set_identity() +/** + * @brief Tries to automaticaly authenticate with public key and "none" + * + * It may fail, for instance it doesn't ask for a password and uses a default + * asker for passphrases (in case the private key is encrypted). + * + * @param session The ssh session to authenticate with. + * + * @param passphrase Use this passphrase to unlock the privatekey. Use NULL + * if you don't want to use a passphrase or the user + * should be asked. + * + * @returns SSH_AUTH_ERROR: A serious error happened\n + * SSH_AUTH_DENIED: Authentication failed: use another method\n + * SSH_AUTH_PARTIAL: You've been partially authenticated, you still + * have to use another method\n + * SSH_AUTH_SUCCESS: Authentication success + * + * @see ssh_userauth_kbdint() + * @see ssh_userauth_password() + * @see ssh_options_set_identity() */ - int ssh_userauth_autopubkey(SSH_SESSION *session, const char *passphrase) { - int count=1; /* bypass identity */ - int type=0; - int err; - STRING *pubkey; - struct public_key_struct *publickey; - char *privkeyfile=NULL; - PRIVATE_KEY *privkey; - char *id = NULL; + struct public_key_struct *publickey; + STRING *pubkey; + PRIVATE_KEY *privkey; + char *privkeyfile = NULL; + char *id = NULL; + size_t size; + unsigned int count = 0; + int type = 0; + int rc; - enter_function(); + enter_function(); - // always testing none - err=ssh_userauth_none(session,NULL); - if(err==SSH_AUTH_ERROR || err==SSH_AUTH_SUCCESS){ - leave_function(); - return err; - } + /* Always test none authentication */ + rc = ssh_userauth_none(session, NULL); + if (rc == SSH_AUTH_ERROR || rc == SSH_AUTH_SUCCESS) { + leave_function(); + return rc; + } - /* try ssh-agent keys first */ + /* Try authentication with ssh-agent first */ #ifndef _WIN32 - if (agent_is_running(session)) { - ssh_log(session, SSH_LOG_RARE, - "Trying to authenticate with SSH agent keys"); - - for (publickey = agent_get_first_ident(session, &privkeyfile); - publickey != NULL; - publickey = agent_get_next_ident(session, &privkeyfile)) { - - ssh_log(session, SSH_LOG_RARE, "Trying identity %s", privkeyfile); - - pubkey = publickey_to_string(publickey); - if (pubkey) { - err = ssh_userauth_offer_pubkey(session, NULL, publickey->type, pubkey); - string_free(pubkey); - if (err == SSH_AUTH_ERROR) { - SAFE_FREE(id); - SAFE_FREE(privkeyfile); - publickey_free(publickey); - leave_function(); + if (agent_is_running(session)) { + ssh_log(session, SSH_LOG_RARE, + "Trying to authenticate with SSH agent keys"); - return err; - } else if (err != SSH_AUTH_SUCCESS) { - ssh_log(session, SSH_LOG_PACKET, "Public key refused by server\n"); - SAFE_FREE(id); - SAFE_FREE(privkeyfile); - publickey_free(publickey); - continue; - } - ssh_log(session, SSH_LOG_RARE, "Public key accepted"); - /* pubkey accepted by server ! */ - err = ssh_userauth_agent_pubkey(session, NULL, publickey); - if (err == SSH_AUTH_ERROR) { - SAFE_FREE(id); - SAFE_FREE(privkeyfile); - publickey_free(publickey); - leave_function(); + for (publickey = agent_get_first_ident(session, &privkeyfile); + publickey != NULL; + publickey = agent_get_next_ident(session, &privkeyfile)) { - return err; - } else if (err != SSH_AUTH_SUCCESS) { - ssh_log(session, SSH_LOG_RARE, - "Server accepted public key but refused the signature\n" - "It might be a bug of libssh\n"); - SAFE_FREE(id); - SAFE_FREE(privkeyfile); - publickey_free(publickey); - continue; - } - /* auth success */ - ssh_log(session, SSH_LOG_RARE, "Authentication using %s success\n", - privkeyfile); + ssh_log(session, SSH_LOG_RARE, "Trying identity %s", privkeyfile); + + pubkey = publickey_to_string(publickey); + if (pubkey) { + rc = ssh_userauth_offer_pubkey(session, NULL, publickey->type, pubkey); + string_free(pubkey); + if (rc == SSH_AUTH_ERROR) { SAFE_FREE(id); SAFE_FREE(privkeyfile); publickey_free(publickey); + leave_function(); + return rc; + } else if (rc != SSH_AUTH_SUCCESS) { + ssh_log(session, SSH_LOG_PACKET, "Public key refused by server\n"); + SAFE_FREE(id); + SAFE_FREE(privkeyfile); + publickey_free(publickey); + continue; + } + ssh_log(session, SSH_LOG_RARE, "Public key accepted"); + /* pubkey accepted by server ! */ + rc = ssh_userauth_agent_pubkey(session, NULL, publickey); + if (rc == SSH_AUTH_ERROR) { + SAFE_FREE(id); + SAFE_FREE(privkeyfile); + publickey_free(publickey); leave_function(); - return SSH_AUTH_SUCCESS; - } /* if pubkey */ + return rc; + } else if (rc != SSH_AUTH_SUCCESS) { + ssh_log(session, SSH_LOG_RARE, + "Server accepted public key but refused the signature\n" + "It might be a bug of libssh\n"); + SAFE_FREE(id); + SAFE_FREE(privkeyfile); + publickey_free(publickey); + continue; + } + /* auth success */ + ssh_log(session, SSH_LOG_RARE, "Authentication using %s success\n", + privkeyfile); SAFE_FREE(id); SAFE_FREE(privkeyfile); publickey_free(publickey); - } /* for each privkey */ - } /* if agent is running */ + + leave_function(); + + return SSH_AUTH_SUCCESS; + } /* if pubkey */ + SAFE_FREE(id); + SAFE_FREE(privkeyfile); + publickey_free(publickey); + } /* for each privkey */ + } /* if agent is running */ #endif - if(session->options->identity){ - ssh_log(session, SSH_LOG_RARE, - "Trying identity file %s\n", session->options->identity); - keys_path[0]=session->options->identity; - /* let's hope alloca exists */ - id=malloc(strlen(session->options->identity)+1 + 4); - if (id == NULL) { - keys_path[0] = NULL; - leave_function(); - return SSH_AUTH_ERROR; - } - sprintf(id,"%s.pub",session->options->identity); - pub_keys_path[0]=id; - count =0; + size = ARRAY_SIZE(keytab); + if (session->options->identity) { + ssh_log(session, SSH_LOG_RARE, + "Trying identity file %s\n", session->options->identity); + + id = malloc(strlen(session->options->identity) + 1 + 4); + if (id == NULL) { + leave_function(); + return SSH_AUTH_ERROR; } - while((pubkey=publickey_from_next_file(session,pub_keys_path,keys_path, &privkeyfile,&type,&count))){ - err=ssh_userauth_offer_pubkey(session,NULL,type,pubkey); - if(err==SSH_AUTH_ERROR){ - if(id){ - pub_keys_path[0]=NULL; - keys_path[0]=NULL; - free(id); - } - free(pubkey); - free(privkeyfile); - leave_function(); - return err; - } else - if(err != SSH_AUTH_SUCCESS){ - ssh_log(session, SSH_LOG_RARE, "Public key refused by server\n"); - free(pubkey); - pubkey=NULL; - free(privkeyfile); - privkeyfile=NULL; - continue; - } - /* pubkey accepted by server ! */ - privkey=privatekey_from_file(session,privkeyfile,type,passphrase); - if(!privkey){ - ssh_log(session, SSH_LOG_FUNCTIONS, - "Reading private key %s failed (bad passphrase ?)\n", - privkeyfile); - free(pubkey); - pubkey=NULL; - free(privkeyfile); - privkeyfile=NULL; - continue; /* continue the loop with other pubkey */ - } - err=ssh_userauth_pubkey(session,NULL,pubkey,privkey); - if(err==SSH_AUTH_ERROR){ - if(id){ - pub_keys_path[0]=NULL; - keys_path[0]=NULL; - free(id); - } - free(pubkey); - free(privkeyfile); - privatekey_free(privkey); - leave_function(); - return err; - } else - if(err != SSH_AUTH_SUCCESS){ - ssh_log(session, SSH_LOG_FUNCTIONS, - "Weird : server accepted our public key but refused the signature\n" - "it might be a bug of libssh\n"); - free(pubkey); - pubkey=NULL; - free(privkeyfile); - privkeyfile=NULL; - privatekey_free(privkey); - continue; - } - /* auth success */ - ssh_log(session, SSH_LOG_RARE, - "Authentication using %s success\n", privkeyfile); - free(pubkey); + sprintf(id, "%s.pub", session->options->identity); + + keytab[size - 1].private = session->options->identity; + keytab[size - 1].public = id; + } + + while ((pubkey = publickey_from_next_file(session, keytab, size, + &privkeyfile, &type, &count))) { + rc = ssh_userauth_offer_pubkey(session, NULL, type, pubkey); + if (rc == SSH_AUTH_ERROR){ + if (id != NULL) { + keytab[size - 1].private = NULL; + keytab[size - 1].public = NULL; + SAFE_FREE(id); + } + string_free(pubkey); + SAFE_FREE(privkeyfile); + leave_function(); + return rc; + } else { + if (rc != SSH_AUTH_SUCCESS){ + ssh_log(session, SSH_LOG_RARE, "Public key refused by server"); + string_free(pubkey); + pubkey = NULL; + SAFE_FREE(privkeyfile); + privkeyfile = NULL; + continue; + } + } + + /* Public key accepted by server! */ + privkey = privatekey_from_file(session, privkeyfile, type, passphrase); + if (privkey == NULL) { + ssh_log(session, SSH_LOG_FUNCTIONS, + "Reading private key %s failed (bad passphrase ?)", + privkeyfile); + string_free(pubkey); + pubkey = NULL; + SAFE_FREE(privkeyfile); + privkeyfile = NULL; + continue; /* continue the loop with other pubkey */ + } + + rc = ssh_userauth_pubkey(session, NULL, pubkey, privkey); + if (rc == SSH_AUTH_ERROR) { + if (id != NULL) { + keytab[size - 1].private = NULL; + keytab[size - 1].public = NULL; + SAFE_FREE(id); + } + string_free(pubkey); + SAFE_FREE(privkeyfile); + privatekey_free(privkey); + leave_function(); + return rc; + } else { + if (rc != SSH_AUTH_SUCCESS){ + ssh_log(session, SSH_LOG_FUNCTIONS, + "The server accepted the public key but refused the signature"); + string_free(pubkey); + pubkey = NULL; + SAFE_FREE(privkeyfile); + privkeyfile = NULL; privatekey_free(privkey); - free(privkeyfile); - if(id){ - pub_keys_path[0]=NULL; - keys_path[0]=NULL; - free(id); - } - leave_function(); - return SSH_AUTH_SUCCESS; + continue; + } } - /* at this point, pubkey is NULL and so is privkeyfile */ - ssh_log(session, SSH_LOG_FUNCTIONS, - "Tried every public key, none matched\n"); - ssh_set_error(session,SSH_NO_ERROR,"no public key matched"); - if(id){ - pub_keys_path[0]=NULL; - keys_path[0]=NULL; - free(id); + + /* auth success */ + ssh_log(session, SSH_LOG_RARE, + "Successfully authenticated using %s", privkeyfile); + string_free(pubkey); + privatekey_free(privkey); + SAFE_FREE(privkeyfile); + if (id != NULL) { + keytab[size - 1].private = NULL; + keytab[size - 1].public = NULL; + SAFE_FREE(id); } + leave_function(); - return SSH_AUTH_DENIED; + return SSH_AUTH_SUCCESS; + } + /* at this point, pubkey is NULL and so is privkeyfile */ + ssh_log(session, SSH_LOG_FUNCTIONS, + "Tried every public key, none matched"); + ssh_set_error(session,SSH_NO_ERROR,"No public key matched"); + if (id) { + keytab[size - 1].private = NULL; + keytab[size - 1].public = NULL; + SAFE_FREE(id); + } + + leave_function(); + return SSH_AUTH_DENIED; } static struct ssh_kbdint *kbdint_new() { diff --git a/libssh/keyfiles.c b/libssh/keyfiles.c index cc627d8..b6f84da 100644 --- a/libssh/keyfiles.c +++ b/libssh/keyfiles.c @@ -920,52 +920,92 @@ STRING *publickey_from_file(SSH_SESSION *session, const char *filename, } -/* why recursing ? i'll explain. on top, publickey_from_next_file will be executed until NULL returned */ -/* we can't return null if one of the possible keys is wrong. we must test them before getting over */ -STRING *publickey_from_next_file(SSH_SESSION *session, const char **pub_keys_path, - const char **keys_path, char **privkeyfile, int *type, int *count) { - static char *home=NULL; - char public[256]; - char private[256]; - const char *priv; - const char *pub; - STRING *pubkey; - if(!home) - home=ssh_get_user_home_dir(); - if(home==NULL) { - ssh_set_error(session,SSH_FATAL,"User home dir impossible to guess"); - return NULL; - } - ssh_set_error(session,SSH_REQUEST_DENIED,"no public key matched"); - if((pub=pub_keys_path[*count])==NULL) - return NULL; - if((priv=keys_path[*count])==NULL) - return NULL; - ++*count; - /* are them readable ? */ - snprintf(public,256,pub,home); - ssh_log(session,SSH_LOG_PACKET,"Trying to open public key %s",public); - if(!ssh_file_readaccess_ok(public)){ - ssh_log(session,SSH_LOG_PACKET,"Failed"); - return publickey_from_next_file(session,pub_keys_path,keys_path,privkeyfile,type,count); - } - snprintf(private,256,priv,home); - ssh_log(session,SSH_LOG_PACKET,"Trying to open private key %s",private); - if(!ssh_file_readaccess_ok(private)){ - ssh_log(session,SSH_LOG_PACKET,"Failed"); - return publickey_from_next_file(session,pub_keys_path,keys_path,privkeyfile,type,count); - } - ssh_log(session,SSH_LOG_PACKET,"Success reading public and private key"); - /* ok, we are sure both the priv8 and public key files are readable : we return the public one as a string, - and the private filename in arguments */ - pubkey=publickey_from_file(session,public,type); - if(!pubkey){ - ssh_log(session,SSH_LOG_PACKET,"Wasn't able to open public key file %s : %s",public,ssh_get_error(session)); - return publickey_from_next_file(session,pub_keys_path,keys_path,privkeyfile,type,count); +/* + * Why a recursive function? + * + * publickey_from_next_file() will be executed until NULL is returned + * We can't return NULL if one of the possible keys is wrong. We want to + * test them before getting over + */ +STRING *publickey_from_next_file(SSH_SESSION *session, + struct keys_struct *keytab, size_t keytab_size, + char **privkeyfile, int *type, + unsigned int *count) { + static char *home = NULL; + + char public[256] = {0}; + char private[256] = {0}; + const char *priv; + const char *pub; + char *new; + STRING *pubkey; + + if (home == NULL) { + home = ssh_get_user_home_dir(); + if (home == NULL) { + ssh_set_error(session,SSH_FATAL,"User home dir impossible to guess"); + return NULL; } - *privkeyfile=realloc(*privkeyfile,strlen(private)+1); - strcpy(*privkeyfile,private); - return pubkey; + } + + if (*count >= keytab_size) { + return NULL; + } + + pub = keytab[*count].public; + if (pub == NULL) { + return NULL; + } + priv = keytab[*count].private; + if (priv == NULL) { + return NULL; + } + + (*count)++; + + /* are them readable ? */ + snprintf(public, sizeof(public), pub, home); + ssh_log(session, SSH_LOG_PACKET, "Trying to open public key %s", public); + if (!ssh_file_readaccess_ok(public)) { + ssh_log(session, SSH_LOG_PACKET, "Failed"); + return publickey_from_next_file(session, keytab, keytab_size, + privkeyfile, type, count); + } + + snprintf(private, sizeof(private), priv, home); + ssh_log(session, SSH_LOG_PACKET, "Trying to open private key %s", private); + if (!ssh_file_readaccess_ok(private)) { + ssh_log(session, SSH_LOG_PACKET, "Failed"); + return publickey_from_next_file(session, keytab, keytab_size, + privkeyfile, type, count); + } + + ssh_log(session, SSH_LOG_PACKET, "Success reading public and private key"); + + /* + * We are sure both the private and public key file is readable. We return + * the public as a string, and the private filename as an argument + */ + pubkey = publickey_from_file(session, public, type); + if (pubkey == NULL) { + ssh_log(session, SSH_LOG_PACKET, + "Wasn't able to open public key file %s: %s", + public, + ssh_get_error(session)); + return publickey_from_next_file(session, keytab, keytab_size, + privkeyfile, type, count); + } + + new = realloc(*privkeyfile, strlen(private) + 1); + if (new == NULL) { + string_free(pubkey); + return NULL; + } + + strcpy(new, private); + *privkeyfile = new; + + return pubkey; } static int alldigits(const char *s) { |