bool S3fsCred::InitialCredentials()

in src/s3fs_cred.cpp [772:875]
83 lines of code
30 McCabe index (conditional complexity)

bool S3fsCred::InitialCredentials()
{
    // should be redundant
    if(S3fsCurl::IsPublicBucket()){
        return true;
    }

    // access key loading is deferred
    if(load_ramrole || IsSetExtCredLib()){
        return true;
    }

    // 1 - keys specified on the command line
    if(IsSetAccessKeys(AutoLock::NONE)){
        return true;
    }

    // 2 - was specified on the command line
    if(IsSetPasswdFile()){
        if(!ReadPasswdFile(AutoLock::NONE)){
            return false;
        }
        return true;
    }

    // 3  - environment variables
    char* OSSACCESSKEYID     = getenv("OSSACCESSKEYID") ?     getenv("OSSACCESSKEYID") :     getenv("OSS_ACCESS_KEY_ID");
    char* OSSSECRETACCESSKEY = getenv("OSSSECRETACCESSKEY") ? getenv("OSSSECRETACCESSKEY") : getenv("OSS_ACCESS_KEY_SECRET");
    char* OSSSESSIONTOKEN    = getenv("OSSSESSIONTOKEN") ?   getenv("OSSSESSIONTOKEN") :   getenv("OSS_SESSION_TOKEN");

    if(OSSACCESSKEYID != NULL || OSSSECRETACCESSKEY != NULL){
        if( (OSSACCESSKEYID == NULL && OSSSECRETACCESSKEY != NULL) ||
            (OSSACCESSKEYID != NULL && OSSSECRETACCESSKEY == NULL) ){
            S3FS_PRN_EXIT("both environment variables OSSACCESSKEYID and OSSSECRETACCESSKEY must be set together.");
            return false;
        }
        S3FS_PRN_INFO2("access key from env variables");
        if(OSSSESSIONTOKEN != NULL){
            S3FS_PRN_INFO2("session token is available");
            if(!SetAccessKeyWithSessionToken(OSSACCESSKEYID, OSSSECRETACCESSKEY, OSSSESSIONTOKEN, AutoLock::NONE)){
                 S3FS_PRN_EXIT("session token is invalid.");
                 return false;
            }
        }else{
            S3FS_PRN_INFO2("session token is not available");
            if(is_use_session_token){
                S3FS_PRN_EXIT("environment variable OSSSESSIONTOKEN is expected to be set.");
                return false;
            }
        }
        if(!SetAccessKey(OSSACCESSKEYID, OSSSECRETACCESSKEY, AutoLock::NONE)){
            S3FS_PRN_EXIT("if one access key is specified, both keys need to be specified.");
            return false;
        }
        return true;
    }

    // 3a - from the OSS_CREDENTIAL_FILE environment variable
    char* OSS_CREDENTIAL_FILE = getenv("OSS_CREDENTIAL_FILE");
    if(OSS_CREDENTIAL_FILE != NULL){
        passwd_file = OSS_CREDENTIAL_FILE;
        if(IsSetPasswdFile()){
            if(!IsReadablePasswdFile()){
                S3FS_PRN_EXIT("OSS_CREDENTIAL_FILE: \"%s\" is not readable.", passwd_file.c_str());
                return false;
            }
            if(!ReadPasswdFile(AutoLock::NONE)){
                return false;
            }
            return true;
        }
    }

    // 4 - from the default location in the users home directory
    char* HOME = getenv("HOME");
    if(HOME != NULL){
        passwd_file = HOME;
        passwd_file += "/.passwd-ossfs";
        if(IsReadablePasswdFile()){
            if(!ReadPasswdFile(AutoLock::NONE)){
                return false;
            }

            // It is possible that the user's file was there but
            // contained no key pairs i.e. commented out
            // in that case, go look in the final location
            if(IsSetAccessKeys(AutoLock::NONE)){
                return true;
            }
        }
    }

    // 5 - from the system default location
    passwd_file = DEFAULT_PASSWD_FILE;
    if(IsReadablePasswdFile()){
        if(!ReadPasswdFile(AutoLock::NONE)){
            return false;
        }
        return true;
    }

    S3FS_PRN_EXIT("could not determine how to establish security credentials.");
    return false;
}