/*++ /* NAME /* smtp_key 3 /* SUMMARY /* cache/table lookup key management /* SYNOPSIS /* #include "smtp.h" /* /* char *smtp_key_prefix(buffer, delim_na, iterator, context_flags) /* VSTRING *buffer; /* const char *delim_na; /* SMTP_ITERATOR *iterator; /* int context_flags; /* DESCRIPTION /* The Postfix SMTP server accesses caches and lookup tables, /* using lookup keys that contain information from various /* contexts: per-server configuration, per-request envelope, /* and results from DNS queries. /* /* These lookup keys sometimes share the same context information. /* The primary purpose of this API is to ensure that this /* shared context is used consistently, and that its use is /* made explicit (both are needed to verify that there is no /* false cache sharing). /* /* smtp_key_prefix() constructs a lookup key prefix from context /* that may be shared with other lookup keys. The user is free /* to append additional application-specific context. The result /* value is a pointer to the result text. /* /* Arguments: /* .IP buffer /* Storage for the result. /* .IP delim_na /* The field delimiter character, and the optional place holder /* character for a) information that is unavailable, b) /* information that is inapplicable, or c) that would result /* in an empty field. Key fields that contain "delim_na" /* characters will be base64-encoded. /* Do not specify "delim_na" characters that are part of the /* base64 character set. /* .IP iterator /* Information that will be selected by the specified flags. /* .IP context_flags /* Bit-wise OR of one or more of the following. /* .RS /* .IP SMTP_KEY_FLAG_SERVICE /* The global service name. This is a proxy for /* destination-independent and request-independent context. /* .IP SMTP_KEY_FLAG_SENDER /* The envelope sender address. This is a proxy for sender-dependent /* context, such as per-sender SASL authentication. /* .IP SMTP_KEY_FLAG_REQ_NEXTHOP /* The request nexthop destination. This is a proxy for /* destination-dependent, but host-independent context. /* .IP SMTP_KEY_FLAG_NEXTHOP /* The current iterator's nexthop destination (request nexthop /* or fallback nexthop, including optional [] and :port). This /* is the form that users specify in a SASL or TLS lookup /* tables. /* .IP SMTP_KEY_FLAG_HOSTNAME /* The current iterator's remote hostname. /* .IP SMTP_KEY_FLAG_ADDR /* The current iterator's remote address. /* .IP SMTP_KEY_FLAG_PORT /* The current iterator's remote port. /* .RE /* DIAGNOSTICS /* Panic: undefined flag or zero flags. Fatal: out of memory. /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /*--*/ /* * System library. */ #include <sys_defs.h> #include <netinet/in.h> /* ntohs() for Solaris or BSD */ #include <arpa/inet.h> /* ntohs() for Linux or BSD */ #include <string.h> /* * Utility library. */ #include <msg.h> #include <vstring.h> #include <base64_code.h> /* * Global library. */ #include <mail_params.h> /* * Application-specific. */ #include <smtp.h> /* * We use a configurable field terminator and optional place holder for data * that is unavailable or inapplicable. We base64-encode content that * contains these characters, and content that needs obfuscation. */ /* smtp_key_append_na - append place-holder key field */ static void smtp_key_append_na(VSTRING *buffer, const char *delim_na) { if (delim_na[1] != 0) VSTRING_ADDCH(buffer, delim_na[1]); VSTRING_ADDCH(buffer, delim_na[0]); } /* smtp_key_append_str - append string-valued key field */ static void smtp_key_append_str(VSTRING *buffer, const char *str, const char *delim_na) { if (str == 0 || str[0] == 0) { smtp_key_append_na(buffer, delim_na); } else if (str[strcspn(str, delim_na)] != 0) { base64_encode_opt(buffer, str, strlen(str), BASE64_FLAG_APPEND); VSTRING_ADDCH(buffer, delim_na[0]); } else { vstring_sprintf_append(buffer, "%s%c", str, delim_na[0]); } } /* smtp_key_append_uint - append unsigned-valued key field */ static void smtp_key_append_uint(VSTRING *buffer, unsigned num, const char *delim_na) { vstring_sprintf_append(buffer, "%u%c", num, delim_na[0]); } /* smtp_key_prefix - format common elements in lookup key */ char *smtp_key_prefix(VSTRING *buffer, const char *delim_na, SMTP_ITERATOR *iter, int flags) { static const char myname[] = "smtp_key_prefix"; SMTP_STATE *state = iter->parent; /* private member */ /* * Sanity checks. */ if (state == 0) msg_panic("%s: no parent state", myname); if (flags & ~SMTP_KEY_MASK_ALL) msg_panic("%s: unknown key flags 0x%x", myname, flags & ~SMTP_KEY_MASK_ALL); if (flags == 0) msg_panic("%s: zero flags", myname); /* * Initialize. */ VSTRING_RESET(buffer); /* * Per-service and per-request context. */ if (flags & SMTP_KEY_FLAG_SERVICE) smtp_key_append_str(buffer, state->service, delim_na); if (flags & SMTP_KEY_FLAG_SENDER) smtp_key_append_str(buffer, state->request->sender, delim_na); /* * Per-destination context, non-canonicalized form. */ if (flags & SMTP_KEY_FLAG_REQ_NEXTHOP) smtp_key_append_str(buffer, STR(iter->request_nexthop), delim_na); if (flags & SMTP_KEY_FLAG_NEXTHOP) smtp_key_append_str(buffer, STR(iter->dest), delim_na); /* * Per-host context, canonicalized form. */ if (flags & SMTP_KEY_FLAG_HOSTNAME) smtp_key_append_str(buffer, STR(iter->host), delim_na); if (flags & SMTP_KEY_FLAG_ADDR) smtp_key_append_str(buffer, STR(iter->addr), delim_na); if (flags & SMTP_KEY_FLAG_PORT) smtp_key_append_uint(buffer, ntohs(iter->port), delim_na); /* Similarly, provide unique TLS fingerprint when applicable. */ VSTRING_TERMINATE(buffer); return STR(buffer); }