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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
commitb5896ba9f6047e7031e2bdee0622d543e11a6734 (patch)
treefd7b460593a2fee1be579bec5697e6d887ea3421 /src/global/mime_state.c
parentInitial commit. (diff)
downloadpostfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.tar.xz
postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.zip
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/global/mime_state.c')
-rw-r--r--src/global/mime_state.c1300
1 files changed, 1300 insertions, 0 deletions
diff --git a/src/global/mime_state.c b/src/global/mime_state.c
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+/*++
+/* NAME
+/* mime_state 3
+/* SUMMARY
+/* MIME parser state machine
+/* SYNOPSIS
+/* #include <mime_state.h>
+/*
+/* MIME_STATE *mime_state_alloc(flags, head_out, head_end,
+/* body_out, body_end,
+/* err_print, context)
+/* int flags;
+/* void (*head_out)(void *ptr, int header_class,
+/* const HEADER_OPTS *header_info,
+/* VSTRING *buf, off_t offset);
+/* void (*head_end)(void *ptr);
+/* void (*body_out)(void *ptr, int rec_type,
+/* const char *buf, ssize_t len,
+/* off_t offset);
+/* void (*body_end)(void *ptr);
+/* void (*err_print)(void *ptr, int err_flag, const char *text)
+/* void *context;
+/*
+/* int mime_state_update(state, rec_type, buf, len)
+/* MIME_STATE *state;
+/* int rec_type;
+/* const char *buf;
+/* ssize_t len;
+/*
+/* MIME_STATE *mime_state_free(state)
+/* MIME_STATE *state;
+/*
+/* const char *mime_state_error(error_code)
+/* int error_code;
+/*
+/* typedef struct {
+/* .in +4
+/* const int code; /* internal error code */
+/* const char *dsn; /* RFC 3463 */
+/* const char *text; /* descriptive text */
+/* .in -4
+/* } MIME_STATE_DETAIL;
+/*
+/* const MIME_STATE_DETAIL *mime_state_detail(error_code)
+/* int error_code;
+/* DESCRIPTION
+/* This module implements a one-pass MIME processor with optional
+/* 8-bit to quoted-printable conversion.
+/*
+/* In order to fend off denial of service attacks, message headers
+/* are truncated at or above var_header_limit bytes, message boundary
+/* strings are truncated at var_mime_bound_len bytes, and the multipart
+/* nesting level is limited to var_mime_maxdepth levels.
+/*
+/* mime_state_alloc() creates a MIME state machine. The machine
+/* is delivered in its initial state, expecting content type
+/* text/plain, 7-bit data.
+/*
+/* mime_state_update() updates the MIME state machine according
+/* to the input record type and the record content.
+/* The result value is the bit-wise OR of zero or more of the following:
+/* .IP MIME_ERR_TRUNC_HEADER
+/* A message header was longer than var_header_limit bytes.
+/* .IP MIME_ERR_NESTING
+/* The MIME structure was nested more than var_mime_maxdepth levels.
+/* .IP MIME_ERR_8BIT_IN_HEADER
+/* A message header contains 8-bit data. This is always illegal.
+/* .IP MIME_ERR_8BIT_IN_7BIT_BODY
+/* A MIME header specifies (or defaults to) 7-bit content, but the
+/* corresponding message body or body parts contain 8-bit content.
+/* .IP MIME_ERR_ENCODING_DOMAIN
+/* An entity of type "message" or "multipart" specifies the wrong
+/* content transfer encoding domain, or specifies a transformation
+/* (quoted-printable, base64) instead of a domain (7bit, 8bit,
+/* or binary).
+/* .PP
+/* mime_state_free() releases storage for a MIME state machine,
+/* and conveniently returns a null pointer.
+/*
+/* mime_state_error() returns a string representation for the
+/* specified error code. When multiple errors are specified it
+/* reports what it deems the most serious one.
+/*
+/* mime_state_detail() returns a table entry with error
+/* information for the specified error code. When multiple
+/* errors are specified it reports what it deems the most
+/* serious one.
+/*
+/* Arguments:
+/* .IP body_out
+/* The output routine for body lines. It receives unmodified input
+/* records, or the result of 8-bit -> 7-bit conversion.
+/* .IP body_end
+/* A null pointer, or a pointer to a routine that is called after
+/* the last input record is processed.
+/* .IP buf
+/* Buffer with the content of a logical or physical message record.
+/* .IP context
+/* Caller context that is passed on to the head_out and body_out
+/* routines.
+/* .IP enc_type
+/* The content encoding: MIME_ENC_7BIT or MIME_ENC_8BIT.
+/* .IP err_print
+/* Null pointer, or pointer to a function that is called with
+/* arguments: the application context, the error type, and the
+/* offending input. Only one instance per error type is reported.
+/* .IP flags
+/* Special processing options. Specify the bit-wise OR of zero or
+/* more of the following:
+/* .RS
+/* .IP MIME_OPT_DISABLE_MIME
+/* Pay no attention to Content-* message headers, and switch to
+/* message body state at the end of the primary message headers.
+/* .IP MIME_OPT_REPORT_TRUNC_HEADER
+/* Report errors that set the MIME_ERR_TRUNC_HEADER error flag
+/* (see above).
+/* .IP MIME_OPT_REPORT_8BIT_IN_HEADER
+/* Report errors that set the MIME_ERR_8BIT_IN_HEADER error
+/* flag (see above). This rarely stops legitimate mail.
+/* .IP MIME_OPT_REPORT_8BIT_IN_7BIT_BODY
+/* Report errors that set the MIME_ERR_8BIT_IN_7BIT_BODY error
+/* flag (see above). This currently breaks Majordomo mail that is
+/* forwarded for approval, because Majordomo does not propagate
+/* MIME type information from the enclosed message to the message
+/* headers of the request for approval.
+/* .IP MIME_OPT_REPORT_ENCODING_DOMAIN
+/* Report errors that set the MIME_ERR_ENCODING_DOMAIN error
+/* flag (see above).
+/* .IP MIME_OPT_REPORT_NESTING
+/* Report errors that set the MIME_ERR_NESTING error flag
+/* (see above).
+/* .IP MIME_OPT_DOWNGRADE
+/* Transform content that claims to be 8-bit into quoted-printable.
+/* Where appropriate, update Content-Transfer-Encoding: message
+/* headers.
+/* .RE
+/* .sp
+/* For convenience, MIME_OPT_NONE requests no special processing.
+/* .IP header_class
+/* Specifies where a message header is located.
+/* .RS
+/* .IP MIME_HDR_PRIMARY
+/* In the primary message header section.
+/* .IP MIME_HDR_MULTIPART
+/* In the header section after a multipart boundary string.
+/* .IP MIME_HDR_NESTED
+/* At the start of a nested (e.g., message/rfc822) message.
+/* .RE
+/* .sp
+/* For convenience, the macros MIME_HDR_FIRST and MIME_HDR_LAST
+/* specify the range of MIME_HDR_MUMBLE macros.
+/* .sp
+/* To find out if something is a MIME header at the beginning
+/* of an RFC 822 message or an attached message, look at the
+/* header_info argument.
+/* .IP header_info
+/* Null pointer or information about the message header, see
+/* header_opts(3).
+/* .IP head_out
+/* The output routine that is invoked for outputting a message header.
+/* A multi-line header is passed as one chunk of text with embedded
+/* newlines.
+/* It is the responsibility of the output routine to break the text
+/* at embedded newlines, and to break up long text between newlines
+/* into multiple output records.
+/* Note: an output routine is explicitly allowed to modify the text.
+/* .IP head_end
+/* A null pointer, or a pointer to a routine that is called after
+/* the last message header in the first header block is processed.
+/* .IP len
+/* Length of non-VSTRING input buffer.
+/* .IP offset
+/* The offset in bytes from the start of the current block of message
+/* headers or body lines. Line boundaries are counted as one byte.
+/* .IP rec_type
+/* The input record type as defined in rec_type(3h). State is
+/* updated for text records (REC_TYPE_NORM or REC_TYPE_CONT).
+/* Some input records are stored internally in order to reconstruct
+/* multi-line input. Upon receipt of any non-text record type, all
+/* stored input is flushed and the state is set to "body".
+/* .IP state
+/* MIME parser state created with mime_state_alloc().
+/* BUGS
+/* NOTE: when the end of headers is reached, mime_state_update()
+/* may execute up to three call-backs before returning to the
+/* caller: head_out(), head_end(), and body_out() or body_end().
+/* As long as call-backs return no result, it is up to the
+/* call-back routines to check if a previous call-back experienced
+/* an error.
+/*
+/* Different mail user agents treat malformed message boundary
+/* strings in different ways. The Postfix MIME processor cannot
+/* be bug-compatible with everything.
+/*
+/* This module will not glue together multipart boundary strings that
+/* span multiple input records.
+/*
+/* This module will not glue together RFC 2231 formatted (boundary)
+/* parameter values. RFC 2231 claims compatibility with existing
+/* MIME processors. Splitting boundary strings is not backwards
+/* compatible.
+/*
+/* The "8-bit data inside 7-bit body" test is myopic. It is not aware
+/* of any enclosing (message or multipart) encoding information.
+/*
+/* If the input ends in data other than a hard line break, this module
+/* will add a hard line break of its own. No line break is added to
+/* empty input.
+/*
+/* This code recognizes the obsolete form "headername :" but will
+/* normalize it to the canonical form "headername:". Leaving the
+/* obsolete form alone would cause too much trouble with existing code
+/* that expects only the normalized form.
+/* SEE ALSO
+/* msg(3) diagnostics interface
+/* header_opts(3) header information lookup
+/* RFC 822 (ARPA Internet Text Messages)
+/* RFC 2045 (MIME: Format of internet message bodies)
+/* RFC 2046 (MIME: Media types)
+/* DIAGNOSTICS
+/* Fatal errors: memory allocation problem.
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* HISTORY
+/* .ad
+/* .fi
+/* This code was implemented from scratch after reading the RFC
+/* documents. This was a relatively straightforward effort with
+/* few if any surprises. Victor Duchovni of Morgan Stanley shared
+/* his experiences with ambiguities in real-life MIME implementations.
+/* Liviu Daia of the Romanian Academy shared his insights in some
+/* of the darker corners.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <stdarg.h>
+#include <ctype.h>
+#include <string.h>
+
+#ifdef STRCASECMP_IN_STRINGS_H
+#include <strings.h>
+#endif
+
+/* Utility library. */
+
+#include <mymalloc.h>
+#include <msg.h>
+#include <vstring.h>
+
+/* Global library. */
+
+#include <rec_type.h>
+#include <is_header.h>
+#include <header_opts.h>
+#include <mail_params.h>
+#include <header_token.h>
+#include <lex_822.h>
+#include <mime_state.h>
+
+/* Application-specific. */
+
+ /*
+ * Mime parser stack element for multipart content.
+ */
+typedef struct MIME_STACK {
+ int def_ctype; /* default content type */
+ int def_stype; /* default content subtype */
+ char *boundary; /* boundary string */
+ ssize_t bound_len; /* boundary length */
+ struct MIME_STACK *next; /* linkage */
+} MIME_STACK;
+
+ /*
+ * Mime parser state.
+ */
+#define MIME_MAX_TOKEN 3 /* tokens per attribute */
+
+struct MIME_STATE {
+
+ /*
+ * Volatile members.
+ */
+ int curr_state; /* header/body state */
+ int curr_ctype; /* last or default content type */
+ int curr_stype; /* last or default content subtype */
+ int curr_encoding; /* last or default content encoding */
+ int curr_domain; /* last or default encoding unit */
+ VSTRING *output_buffer; /* headers, quoted-printable body */
+ int prev_rec_type; /* previous input record type */
+ int nesting_level; /* safety */
+ MIME_STACK *stack; /* for composite types */
+ HEADER_TOKEN token[MIME_MAX_TOKEN]; /* header token array */
+ VSTRING *token_buffer; /* header parser scratch buffer */
+ int err_flags; /* processing errors */
+ off_t head_offset; /* offset in header block */
+ off_t body_offset; /* offset in body block */
+
+ /*
+ * Static members.
+ */
+ int static_flags; /* static processing options */
+ MIME_STATE_HEAD_OUT head_out; /* header output routine */
+ MIME_STATE_ANY_END head_end; /* end of primary header routine */
+ MIME_STATE_BODY_OUT body_out; /* body output routine */
+ MIME_STATE_ANY_END body_end; /* end of body output routine */
+ MIME_STATE_ERR_PRINT err_print; /* error report */
+ void *app_context; /* application context */
+};
+
+ /*
+ * Content types and subtypes that we care about, either because we have to,
+ * or because we want to filter out broken MIME messages.
+ */
+#define MIME_CTYPE_OTHER 0
+#define MIME_CTYPE_TEXT 1
+#define MIME_CTYPE_MESSAGE 2
+#define MIME_CTYPE_MULTIPART 3
+
+#define MIME_STYPE_OTHER 0
+#define MIME_STYPE_PLAIN 1
+#define MIME_STYPE_RFC822 2
+#define MIME_STYPE_PARTIAL 3
+#define MIME_STYPE_EXTERN_BODY 4
+#define MIME_STYPE_GLOBAL 5
+
+ /*
+ * MIME parser states. We steal from the public interface.
+ */
+#define MIME_STATE_PRIMARY MIME_HDR_PRIMARY /* primary headers */
+#define MIME_STATE_MULTIPART MIME_HDR_MULTIPART /* after --boundary */
+#define MIME_STATE_NESTED MIME_HDR_NESTED /* message/rfc822 */
+#define MIME_STATE_BODY (MIME_HDR_NESTED + 1)
+
+#define SET_MIME_STATE(ptr, state, ctype, stype, encoding, domain) do { \
+ (ptr)->curr_state = (state); \
+ (ptr)->curr_ctype = (ctype); \
+ (ptr)->curr_stype = (stype); \
+ (ptr)->curr_encoding = (encoding); \
+ (ptr)->curr_domain = (domain); \
+ if ((state) == MIME_STATE_BODY) \
+ (ptr)->body_offset = 0; \
+ else \
+ (ptr)->head_offset = 0; \
+ } while (0)
+
+#define SET_CURR_STATE(ptr, state) do { \
+ (ptr)->curr_state = (state); \
+ if ((state) == MIME_STATE_BODY) \
+ (ptr)->body_offset = 0; \
+ else \
+ (ptr)->head_offset = 0; \
+ } while (0)
+
+ /*
+ * MIME encodings and domains. We intentionally use the same codes for
+ * encodings and domains, so that we can easily find out whether a content
+ * transfer encoding header specifies a domain or whether it specifies
+ * domain+encoding, which is illegal for multipart/any and message/any.
+ */
+typedef struct MIME_ENCODING {
+ const char *name; /* external representation */
+ int encoding; /* internal representation */
+ int domain; /* subset of encoding */
+} MIME_ENCODING;
+
+#define MIME_ENC_QP 1 /* encoding + domain */
+#define MIME_ENC_BASE64 2 /* encoding + domain */
+ /* These are defined in mime_state.h as part of the external interface. */
+#ifndef MIME_ENC_7BIT
+#define MIME_ENC_7BIT 7 /* domain only */
+#define MIME_ENC_8BIT 8 /* domain only */
+#define MIME_ENC_BINARY 9 /* domain only */
+#endif
+
+static const MIME_ENCODING mime_encoding_map[] = { /* RFC 2045 */
+ "7bit", MIME_ENC_7BIT, MIME_ENC_7BIT, /* domain */
+ "8bit", MIME_ENC_8BIT, MIME_ENC_8BIT, /* domain */
+ "binary", MIME_ENC_BINARY, MIME_ENC_BINARY, /* domain */
+ "base64", MIME_ENC_BASE64, MIME_ENC_7BIT, /* encoding */
+ "quoted-printable", MIME_ENC_QP, MIME_ENC_7BIT, /* encoding */
+ 0,
+};
+
+ /*
+ * Silly Little Macros.
+ */
+#define STR(x) vstring_str(x)
+#define LEN(x) VSTRING_LEN(x)
+#define END(x) vstring_end(x)
+#define CU_CHAR_PTR(x) ((const unsigned char *) (x))
+
+#define REPORT_ERROR_LEN(state, err_type, text, len) do { \
+ if ((state->err_flags & err_type) == 0) { \
+ if (state->err_print != 0) \
+ state->err_print(state->app_context, err_type, text, len); \
+ state->err_flags |= err_type; \
+ } \
+ } while (0)
+
+#define REPORT_ERROR(state, err_type, text) do { \
+ const char *_text = text; \
+ ssize_t _len = strlen(text); \
+ REPORT_ERROR_LEN(state, err_type, _text, _len); \
+ } while (0)
+
+#define REPORT_ERROR_BUF(state, err_type, buf) \
+ REPORT_ERROR_LEN(state, err_type, STR(buf), LEN(buf))
+
+
+ /*
+ * Outputs and state changes are interleaved, so we must maintain separate
+ * offsets for header and body segments.
+ */
+#define HEAD_OUT(ptr, info, len) do { \
+ if ((ptr)->head_out) { \
+ (ptr)->head_out((ptr)->app_context, (ptr)->curr_state, \
+ (info), (ptr)->output_buffer, (ptr)->head_offset); \
+ (ptr)->head_offset += (len) + 1; \
+ } \
+ } while(0)
+
+#define BODY_OUT(ptr, rec_type, text, len) do { \
+ if ((ptr)->body_out) { \
+ (ptr)->body_out((ptr)->app_context, (rec_type), \
+ (text), (len), (ptr)->body_offset); \
+ (ptr)->body_offset += (len) + 1; \
+ } \
+ } while(0)
+
+/* mime_state_push - push boundary onto stack */
+
+static void mime_state_push(MIME_STATE *state, int def_ctype, int def_stype,
+ const char *boundary)
+{
+ MIME_STACK *stack;
+
+ /*
+ * RFC 2046 mandates that a boundary string be up to 70 characters long.
+ * Some MTAs, including Postfix, include the fully-qualified MTA name
+ * which can be longer, so we are willing to handle boundary strings that
+ * exceed the RFC specification. We allow for message headers of up to
+ * var_header_limit characters. In order to avoid denial of service, we
+ * have to impose a configurable limit on the amount of text that we are
+ * willing to store as a boundary string. Despite this truncation way we
+ * will still correctly detect all intermediate boundaries and all the
+ * message headers that follow those boundaries.
+ */
+ state->nesting_level += 1;
+ stack = (MIME_STACK *) mymalloc(sizeof(*stack));
+ stack->def_ctype = def_ctype;
+ stack->def_stype = def_stype;
+ if ((stack->bound_len = strlen(boundary)) > var_mime_bound_len)
+ stack->bound_len = var_mime_bound_len;
+ stack->boundary = mystrndup(boundary, stack->bound_len);
+ stack->next = state->stack;
+ state->stack = stack;
+ if (msg_verbose)
+ msg_info("PUSH boundary %s", stack->boundary);
+}
+
+/* mime_state_pop - pop boundary from stack */
+
+static void mime_state_pop(MIME_STATE *state)
+{
+ MIME_STACK *stack;
+
+ if ((stack = state->stack) == 0)
+ msg_panic("mime_state_pop: there is no stack");
+ if (msg_verbose)
+ msg_info("POP boundary %s", stack->boundary);
+ state->nesting_level -= 1;
+ state->stack = stack->next;
+ myfree(stack->boundary);
+ myfree((void *) stack);
+}
+
+/* mime_state_alloc - create MIME state machine */
+
+MIME_STATE *mime_state_alloc(int flags,
+ MIME_STATE_HEAD_OUT head_out,
+ MIME_STATE_ANY_END head_end,
+ MIME_STATE_BODY_OUT body_out,
+ MIME_STATE_ANY_END body_end,
+ MIME_STATE_ERR_PRINT err_print,
+ void *context)
+{
+ MIME_STATE *state;
+
+ state = (MIME_STATE *) mymalloc(sizeof(*state));
+
+ /* Volatile members. */
+ state->err_flags = 0;
+ state->body_offset = 0; /* XXX */
+ SET_MIME_STATE(state, MIME_STATE_PRIMARY,
+ MIME_CTYPE_TEXT, MIME_STYPE_PLAIN,
+ MIME_ENC_7BIT, MIME_ENC_7BIT);
+ state->output_buffer = vstring_alloc(100);
+ state->prev_rec_type = 0;
+ state->stack = 0;
+ state->token_buffer = vstring_alloc(1);
+ state->nesting_level = -1; /* BC Fix 20170512 */
+
+ /* Static members. */
+ state->static_flags = flags;
+ state->head_out = head_out;
+ state->head_end = head_end;
+ state->body_out = body_out;
+ state->body_end = body_end;
+ state->err_print = err_print;
+ state->app_context = context;
+ return (state);
+}
+
+/* mime_state_free - destroy MIME state machine */
+
+MIME_STATE *mime_state_free(MIME_STATE *state)
+{
+ vstring_free(state->output_buffer);
+ while (state->stack)
+ mime_state_pop(state);
+ if (state->token_buffer)
+ vstring_free(state->token_buffer);
+ myfree((void *) state);
+ return (0);
+}
+
+/* mime_state_content_type - process content-type header */
+
+static void mime_state_content_type(MIME_STATE *state,
+ const HEADER_OPTS *header_info)
+{
+ const char *cp;
+ ssize_t tok_count;
+ int def_ctype;
+ int def_stype;
+
+#define TOKEN_MATCH(tok, text) \
+ ((tok).type == HEADER_TOK_TOKEN && strcasecmp((tok).u.value, (text)) == 0)
+
+#define RFC2045_TSPECIALS "()<>@,;:\\\"/[]?="
+
+#define PARSE_CONTENT_TYPE_HEADER(state, ptr) \
+ header_token(state->token, MIME_MAX_TOKEN, \
+ state->token_buffer, ptr, RFC2045_TSPECIALS, ';')
+
+ cp = STR(state->output_buffer) + strlen(header_info->name) + 1;
+ if ((tok_count = PARSE_CONTENT_TYPE_HEADER(state, &cp)) > 0) {
+
+ /*
+ * text/whatever. Right now we don't really care if it is plain or
+ * not, but we may want to recognize subtypes later, and then this
+ * code can serve as an example.
+ */
+ if (TOKEN_MATCH(state->token[0], "text")) {
+ state->curr_ctype = MIME_CTYPE_TEXT;
+ if (tok_count >= 3
+ && state->token[1].type == '/'
+ && TOKEN_MATCH(state->token[2], "plain"))
+ state->curr_stype = MIME_STYPE_PLAIN;
+ else
+ state->curr_stype = MIME_STYPE_OTHER;
+ return;
+ }
+
+ /*
+ * message/whatever body parts start with another block of message
+ * headers that we may want to look at. The partial and external-body
+ * subtypes cannot be subjected to 8-bit -> 7-bit conversion, so we
+ * must properly recognize them.
+ */
+ if (TOKEN_MATCH(state->token[0], "message")) {
+ state->curr_ctype = MIME_CTYPE_MESSAGE;
+ state->curr_stype = MIME_STYPE_OTHER;
+ if (tok_count >= 3
+ && state->token[1].type == '/') {
+ if (TOKEN_MATCH(state->token[2], "rfc822"))
+ state->curr_stype = MIME_STYPE_RFC822;
+ else if (TOKEN_MATCH(state->token[2], "partial"))
+ state->curr_stype = MIME_STYPE_PARTIAL;
+ else if (TOKEN_MATCH(state->token[2], "external-body"))
+ state->curr_stype = MIME_STYPE_EXTERN_BODY;
+ else if (TOKEN_MATCH(state->token[2], "global"))
+ state->curr_stype = MIME_STYPE_GLOBAL;
+ }
+ return;
+ }
+
+ /*
+ * multipart/digest has default content type message/rfc822,
+ * multipart/whatever has default content type text/plain.
+ */
+ if (TOKEN_MATCH(state->token[0], "multipart")) {
+ state->curr_ctype = MIME_CTYPE_MULTIPART;
+ if (tok_count >= 3
+ && state->token[1].type == '/'
+ && TOKEN_MATCH(state->token[2], "digest")) {
+ def_ctype = MIME_CTYPE_MESSAGE;
+ def_stype = MIME_STYPE_RFC822;
+ } else {
+ def_ctype = MIME_CTYPE_TEXT;
+ def_stype = MIME_STYPE_PLAIN;
+ }
+
+ /*
+ * Yes, this is supposed to capture multiple boundary strings,
+ * which are illegal and which could be used to hide content in
+ * an implementation dependent manner. The code below allows us
+ * to find embedded message headers as long as the sender uses
+ * only one of these same-level boundary strings.
+ *
+ * Yes, this is supposed to ignore the boundary value type.
+ */
+ while ((tok_count = PARSE_CONTENT_TYPE_HEADER(state, &cp)) >= 0) {
+ if (tok_count >= 3
+ && TOKEN_MATCH(state->token[0], "boundary")
+ && state->token[1].type == '=') {
+ if (state->nesting_level > var_mime_maxdepth) {
+ if (state->static_flags & MIME_OPT_REPORT_NESTING)
+ REPORT_ERROR_BUF(state, MIME_ERR_NESTING,
+ state->output_buffer);
+ } else {
+ mime_state_push(state, def_ctype, def_stype,
+ state->token[2].u.value);
+ }
+ }
+ }
+ }
+ return;
+ }
+
+ /*
+ * other/whatever.
+ */
+ else {
+ state->curr_ctype = MIME_CTYPE_OTHER;
+ return;
+ }
+}
+
+/* mime_state_content_encoding - process content-transfer-encoding header */
+
+static void mime_state_content_encoding(MIME_STATE *state,
+ const HEADER_OPTS *header_info)
+{
+ const char *cp;
+ const MIME_ENCODING *cmp;
+
+#define PARSE_CONTENT_ENCODING_HEADER(state, ptr) \
+ header_token(state->token, 1, state->token_buffer, ptr, (char *) 0, 0)
+
+ /*
+ * Do content-transfer-encoding header. Never set the encoding domain to
+ * something other than 7bit, 8bit or binary, even if we don't recognize
+ * the input.
+ */
+ cp = STR(state->output_buffer) + strlen(header_info->name) + 1;
+ if (PARSE_CONTENT_ENCODING_HEADER(state, &cp) > 0
+ && state->token[0].type == HEADER_TOK_TOKEN) {
+ for (cmp = mime_encoding_map; cmp->name != 0; cmp++) {
+ if (strcasecmp(state->token[0].u.value, cmp->name) == 0) {
+ state->curr_encoding = cmp->encoding;
+ state->curr_domain = cmp->domain;
+ break;
+ }
+ }
+ }
+}
+
+/* mime_state_enc_name - encoding to printable form */
+
+static const char *mime_state_enc_name(int encoding)
+{
+ const MIME_ENCODING *cmp;
+
+ for (cmp = mime_encoding_map; cmp->name != 0; cmp++)
+ if (encoding == cmp->encoding)
+ return (cmp->name);
+ return ("unknown");
+}
+
+/* mime_state_downgrade - convert 8-bit data to quoted-printable */
+
+static void mime_state_downgrade(MIME_STATE *state, int rec_type,
+ const char *text, ssize_t len)
+{
+ static char hexchars[] = "0123456789ABCDEF";
+ const unsigned char *cp;
+ int ch;
+
+#define QP_ENCODE(buffer, ch) { \
+ VSTRING_ADDCH(buffer, '='); \
+ VSTRING_ADDCH(buffer, hexchars[(ch >> 4) & 0xff]); \
+ VSTRING_ADDCH(buffer, hexchars[ch & 0xf]); \
+ }
+
+ /*
+ * Insert a soft line break when the output reaches a critical length
+ * before we reach a hard line break.
+ */
+ for (cp = CU_CHAR_PTR(text); cp < CU_CHAR_PTR(text + len); cp++) {
+ /* Critical length before hard line break. */
+ if (LEN(state->output_buffer) > 72) {
+ VSTRING_ADDCH(state->output_buffer, '=');
+ VSTRING_TERMINATE(state->output_buffer);
+ BODY_OUT(state, REC_TYPE_NORM,
+ STR(state->output_buffer),
+ LEN(state->output_buffer));
+ VSTRING_RESET(state->output_buffer);
+ }
+ /* Append the next character. */
+ ch = *cp;
+ if ((ch < 32 && ch != '\t') || ch == '=' || ch > 126) {
+ QP_ENCODE(state->output_buffer, ch);
+ } else {
+ VSTRING_ADDCH(state->output_buffer, ch);
+ }
+ }
+
+ /*
+ * Flush output after a hard line break (i.e. the end of a REC_TYPE_NORM
+ * record). Fix trailing whitespace as per the RFC: in the worst case,
+ * the output length will grow from 73 characters to 75 characters.
+ */
+ if (rec_type == REC_TYPE_NORM) {
+ if (LEN(state->output_buffer) > 0
+ && ((ch = END(state->output_buffer)[-1]) == ' ' || ch == '\t')) {
+ vstring_truncate(state->output_buffer,
+ LEN(state->output_buffer) - 1);
+ QP_ENCODE(state->output_buffer, ch);
+ }
+ VSTRING_TERMINATE(state->output_buffer);
+ BODY_OUT(state, REC_TYPE_NORM,
+ STR(state->output_buffer),
+ LEN(state->output_buffer));
+ VSTRING_RESET(state->output_buffer);
+ }
+}
+
+/* mime_state_update - update MIME state machine */
+
+int mime_state_update(MIME_STATE *state, int rec_type,
+ const char *text, ssize_t len)
+{
+ int input_is_text = (rec_type == REC_TYPE_NORM
+ || rec_type == REC_TYPE_CONT);
+ MIME_STACK *sp;
+ const HEADER_OPTS *header_info;
+ const unsigned char *cp;
+
+#define SAVE_PREV_REC_TYPE_AND_RETURN_ERR_FLAGS(state, rec_type) do { \
+ state->prev_rec_type = rec_type; \
+ return (state->err_flags); \
+ } while (0)
+
+ /*
+ * Be sure to flush any partial output line that might still be buffered
+ * up before taking any other "end of input" actions.
+ */
+ if (!input_is_text && state->prev_rec_type == REC_TYPE_CONT)
+ mime_state_update(state, REC_TYPE_NORM, "", 0);
+
+ /*
+ * This message state machine is kept simple for the sake of robustness.
+ * Standards evolve over time, and we want to be able to correctly
+ * process messages that are not yet defined. This state machine knows
+ * about headers and bodies, understands that multipart/whatever has
+ * multiple body parts with a header and body, and that message/whatever
+ * has message headers at the start of a body part.
+ */
+ switch (state->curr_state) {
+
+ /*
+ * First, deal with header information that we have accumulated from
+ * previous input records. Discard text that does not fit in a header
+ * buffer. Our limit is quite generous; Sendmail will refuse mail
+ * with only 32kbyte in all the message headers combined.
+ */
+ case MIME_STATE_PRIMARY:
+ case MIME_STATE_MULTIPART:
+ case MIME_STATE_NESTED:
+ if (LEN(state->output_buffer) > 0) {
+ if (input_is_text) {
+ if (state->prev_rec_type == REC_TYPE_CONT) {
+ if (LEN(state->output_buffer) < var_header_limit) {
+ vstring_strncat(state->output_buffer, text, len);
+ } else {
+ if (state->static_flags & MIME_OPT_REPORT_TRUNC_HEADER)
+ REPORT_ERROR_BUF(state, MIME_ERR_TRUNC_HEADER,
+ state->output_buffer);
+ }
+ SAVE_PREV_REC_TYPE_AND_RETURN_ERR_FLAGS(state, rec_type);
+ }
+ if (IS_SPACE_TAB(*text)) {
+ if (LEN(state->output_buffer) < var_header_limit) {
+ vstring_strcat(state->output_buffer, "\n");
+ vstring_strncat(state->output_buffer, text, len);
+ } else {
+ if (state->static_flags & MIME_OPT_REPORT_TRUNC_HEADER)
+ REPORT_ERROR_BUF(state, MIME_ERR_TRUNC_HEADER,
+ state->output_buffer);
+ }
+ SAVE_PREV_REC_TYPE_AND_RETURN_ERR_FLAGS(state, rec_type);
+ }
+ }
+
+ /*
+ * The input is (the beginning of) another message header, or is
+ * not a message header, or is not even a text record. With no
+ * more input to append to this saved header, do output
+ * processing and reset the saved header buffer. Hold on to the
+ * content transfer encoding header if we have to do a 8->7
+ * transformation, because the proper information depends on the
+ * content type header: message and multipart require a domain,
+ * leaf entities have either a transformation or a domain.
+ */
+ if (LEN(state->output_buffer) > 0) {
+ header_info = header_opts_find(STR(state->output_buffer));
+ if (!(state->static_flags & MIME_OPT_DISABLE_MIME)
+ && header_info != 0) {
+ if (header_info->type == HDR_CONTENT_TYPE)
+ mime_state_content_type(state, header_info);
+ if (header_info->type == HDR_CONTENT_TRANSFER_ENCODING)
+ mime_state_content_encoding(state, header_info);
+ }
+ if ((state->static_flags & MIME_OPT_REPORT_8BIT_IN_HEADER) != 0
+ && (state->err_flags & MIME_ERR_8BIT_IN_HEADER) == 0) {
+ for (cp = CU_CHAR_PTR(STR(state->output_buffer));
+ cp < CU_CHAR_PTR(END(state->output_buffer)); cp++)
+ if (*cp & 0200) {
+ REPORT_ERROR_BUF(state, MIME_ERR_8BIT_IN_HEADER,
+ state->output_buffer);
+ break;
+ }
+ }
+ /* Output routine is explicitly allowed to change the data. */
+ if (header_info == 0
+ || header_info->type != HDR_CONTENT_TRANSFER_ENCODING
+ || (state->static_flags & MIME_OPT_DOWNGRADE) == 0
+ || state->curr_domain == MIME_ENC_7BIT)
+ HEAD_OUT(state, header_info, len);
+ state->prev_rec_type = 0;
+ VSTRING_RESET(state->output_buffer);
+ }
+ }
+
+ /*
+ * With past header information moved out of the way, proceed with a
+ * clean slate.
+ */
+ if (input_is_text) {
+ ssize_t header_len;
+
+ /*
+ * See if this input is (the beginning of) a message header.
+ *
+ * Normalize obsolete "name space colon" syntax to "name colon".
+ * Things would be too confusing otherwise.
+ *
+ * Don't assume that the input is null terminated.
+ */
+ if ((header_len = is_header_buf(text, len)) > 0) {
+ vstring_strncpy(state->output_buffer, text, header_len);
+ for (text += header_len, len -= header_len;
+ len > 0 && IS_SPACE_TAB(*text);
+ text++, len--)
+ /* void */ ;
+ vstring_strncat(state->output_buffer, text, len);
+ SAVE_PREV_REC_TYPE_AND_RETURN_ERR_FLAGS(state, rec_type);
+ }
+ }
+
+ /*
+ * This input terminates a block of message headers. When converting
+ * 8-bit to 7-bit mail, this is the right place to emit the correct
+ * content-transfer-encoding header. With message or multipart we
+ * specify 7bit, with leaf entities we specify quoted-printable.
+ *
+ * We're not going to convert non-text data into base 64. If they send
+ * arbitrary binary data as 8-bit text, then the data is already
+ * broken beyond recovery, because the Postfix SMTP server sanitizes
+ * record boundaries, treating broken record boundaries as CRLF.
+ *
+ * Clear the output buffer, we will need it for storage of the
+ * conversion result.
+ */
+ if ((state->static_flags & MIME_OPT_DOWNGRADE)
+ && state->curr_domain != MIME_ENC_7BIT) {
+ if ((state->curr_ctype == MIME_CTYPE_MESSAGE
+ && state->curr_stype != MIME_STYPE_GLOBAL)
+ || state->curr_ctype == MIME_CTYPE_MULTIPART)
+ cp = CU_CHAR_PTR("7bit");
+ else
+ cp = CU_CHAR_PTR("quoted-printable");
+ vstring_sprintf(state->output_buffer,
+ "Content-Transfer-Encoding: %s", cp);
+ HEAD_OUT(state, (HEADER_OPTS *) 0, len);
+ VSTRING_RESET(state->output_buffer);
+ }
+
+ /*
+ * This input terminates a block of message headers. Call the
+ * optional header end routine at the end of the first header block.
+ */
+ if (state->curr_state == MIME_STATE_PRIMARY && state->head_end)
+ state->head_end(state->app_context);
+
+ /*
+ * This is the right place to check if the sender specified an
+ * appropriate identity encoding (7bit, 8bit, binary) for multipart
+ * and for message.
+ */
+ if (state->static_flags & MIME_OPT_REPORT_ENCODING_DOMAIN) {
+ if (state->curr_ctype == MIME_CTYPE_MESSAGE) {
+ if (state->curr_stype == MIME_STYPE_PARTIAL
+ || state->curr_stype == MIME_STYPE_EXTERN_BODY) {
+ if (state->curr_domain != MIME_ENC_7BIT)
+ REPORT_ERROR(state, MIME_ERR_ENCODING_DOMAIN,
+ mime_state_enc_name(state->curr_encoding));
+ }
+ /* EAI: message/global allows non-identity encoding. */
+ else if (state->curr_stype == MIME_STYPE_RFC822) {
+ if (state->curr_encoding != state->curr_domain)
+ REPORT_ERROR(state, MIME_ERR_ENCODING_DOMAIN,
+ mime_state_enc_name(state->curr_encoding));
+ }
+ } else if (state->curr_ctype == MIME_CTYPE_MULTIPART) {
+ if (state->curr_encoding != state->curr_domain)
+ REPORT_ERROR(state, MIME_ERR_ENCODING_DOMAIN,
+ mime_state_enc_name(state->curr_encoding));
+ }
+ }
+
+ /*
+ * Find out if the next body starts with its own message headers. In
+ * aggressive mode, examine headers of partial and external-body
+ * messages. Otherwise, treat such headers as part of the "body". Set
+ * the proper encoding information for the multipart prolog.
+ *
+ * XXX We parse headers inside message/* content even when the encoding
+ * is invalid (encoding != domain). With base64 we won't recognize
+ * any headers, and with quoted-printable we won't recognize MIME
+ * boundary strings, but the MIME processor will still resynchronize
+ * when it runs into the higher-level boundary string at the end of
+ * the message/* content. Although we will treat some headers as body
+ * text, we will still do a better job than if we were treating the
+ * entire message/* content as body text.
+ *
+ * XXX This changes state to MIME_STATE_NESTED and then outputs a body
+ * line, so that the body offset is not properly reset.
+ *
+ * Don't assume that the input is null terminated.
+ */
+ if (input_is_text) {
+ if (len == 0) {
+ state->body_offset = 0; /* XXX */
+ if (state->curr_ctype == MIME_CTYPE_MESSAGE) {
+ if (state->curr_stype == MIME_STYPE_RFC822)
+ SET_MIME_STATE(state, MIME_STATE_NESTED,
+ MIME_CTYPE_TEXT, MIME_STYPE_PLAIN,
+ MIME_ENC_7BIT, MIME_ENC_7BIT);
+ else if (state->curr_stype == MIME_STYPE_GLOBAL
+ && ((state->static_flags & MIME_OPT_DOWNGRADE) == 0
+ || state->curr_domain == MIME_ENC_7BIT))
+ /* XXX EAI: inspect encoded message/global. */
+ SET_MIME_STATE(state, MIME_STATE_NESTED,
+ MIME_CTYPE_TEXT, MIME_STYPE_PLAIN,
+ MIME_ENC_7BIT, MIME_ENC_7BIT);
+ else
+ SET_CURR_STATE(state, MIME_STATE_BODY);
+ } else if (state->curr_ctype == MIME_CTYPE_MULTIPART) {
+ SET_MIME_STATE(state, MIME_STATE_BODY,
+ MIME_CTYPE_OTHER, MIME_STYPE_OTHER,
+ MIME_ENC_7BIT, MIME_ENC_7BIT);
+ } else {
+ SET_CURR_STATE(state, MIME_STATE_BODY);
+ }
+ }
+
+ /*
+ * Invalid input. Force output of one blank line and jump to the
+ * body state, leaving all other state alone.
+ *
+ * We don't break legitimate mail by inserting a blank line
+ * separator between primary headers and a non-empty body. Many
+ * MTA's don't even record the presence or absence of this
+ * separator, nor does the Milter protocol pass it on to Milter
+ * applications.
+ *
+ * XXX We don't insert a blank line separator into attachments, to
+ * avoid breaking digital signatures. Postfix shall not do a
+ * worse mail delivery job than MTAs that can't even parse MIME.
+ * We switch to body state anyway, to avoid treating body text as
+ * header text, and mis-interpreting or truncating it. The code
+ * below for initial From_ lines is for educational purposes.
+ *
+ * Sites concerned about MIME evasion can use a MIME normalizer.
+ * Postfix has a different mission.
+ */
+ else {
+ if (msg_verbose)
+ msg_info("garbage in %s header",
+ state->curr_state == MIME_STATE_MULTIPART ? "multipart" :
+ state->curr_state == MIME_STATE_PRIMARY ? "primary" :
+ state->curr_state == MIME_STATE_NESTED ? "nested" :
+ "other");
+ switch (state->curr_state) {
+ case MIME_STATE_PRIMARY:
+ BODY_OUT(state, REC_TYPE_NORM, "", 0);
+ SET_CURR_STATE(state, MIME_STATE_BODY);
+ break;
+#if 0
+ case MIME_STATE_NESTED:
+ if (state->body_offset <= 1
+ && rec_type == REC_TYPE_NORM
+ && len > 7
+ && (strncmp(text + (*text == '>'), "From ", 5) == 0
+ || strncmp(text, "=46rom ", 7) == 0))
+ break;
+ /* FALLTHROUGH */
+#endif
+ default:
+ SET_CURR_STATE(state, MIME_STATE_BODY);
+ break;
+ }
+ }
+ }
+
+ /*
+ * This input is not text. Go to body state, unconditionally.
+ */
+ else {
+ SET_CURR_STATE(state, MIME_STATE_BODY);
+ }
+ /* FALLTHROUGH */
+
+ /*
+ * Body text. Look for message boundaries, and recover from missing
+ * boundary strings. Missing boundaries can happen in aggressive mode
+ * with text/rfc822-headers or with message/partial. Ignore non-space
+ * cruft after --boundary or --boundary--, because some MUAs do, and
+ * because only perverse software would take advantage of this to
+ * escape detection. We have to ignore trailing cruft anyway, because
+ * our saved copy of the boundary string may have been truncated for
+ * safety reasons.
+ *
+ * Optionally look for 8-bit data in content that was announced as, or
+ * that defaults to, 7-bit. Unfortunately, we cannot turn this on by
+ * default. Majordomo sends requests for approval that do not
+ * propagate the MIME information from the enclosed message to the
+ * message headers of the approval request.
+ *
+ * Set the proper state information after processing a message boundary
+ * string.
+ *
+ * Don't look for boundary strings at the start of a continued record.
+ *
+ * Don't assume that the input is null terminated.
+ */
+ case MIME_STATE_BODY:
+ if (input_is_text) {
+ if ((state->static_flags & MIME_OPT_REPORT_8BIT_IN_7BIT_BODY) != 0
+ && state->curr_encoding == MIME_ENC_7BIT
+ && (state->err_flags & MIME_ERR_8BIT_IN_7BIT_BODY) == 0) {
+ for (cp = CU_CHAR_PTR(text); cp < CU_CHAR_PTR(text + len); cp++)
+ if (*cp & 0200) {
+ REPORT_ERROR_LEN(state, MIME_ERR_8BIT_IN_7BIT_BODY,
+ text, len);
+ break;
+ }
+ }
+ if (state->stack && state->prev_rec_type != REC_TYPE_CONT
+ && len > 2 && text[0] == '-' && text[1] == '-') {
+ for (sp = state->stack; sp != 0; sp = sp->next) {
+ if (len >= 2 + sp->bound_len &&
+ strncmp(text + 2, sp->boundary, sp->bound_len) == 0) {
+ while (sp != state->stack)
+ mime_state_pop(state);
+ if (len >= 4 + sp->bound_len &&
+ strncmp(text + 2 + sp->bound_len, "--", 2) == 0) {
+ mime_state_pop(state);
+ SET_MIME_STATE(state, MIME_STATE_BODY,
+ MIME_CTYPE_OTHER, MIME_STYPE_OTHER,
+ MIME_ENC_7BIT, MIME_ENC_7BIT);
+ } else {
+ SET_MIME_STATE(state, MIME_STATE_MULTIPART,
+ sp->def_ctype, sp->def_stype,
+ MIME_ENC_7BIT, MIME_ENC_7BIT);
+ }
+ break;
+ }
+ }
+ }
+ /* Put last for consistency with header output routine. */
+ if ((state->static_flags & MIME_OPT_DOWNGRADE)
+ && state->curr_domain != MIME_ENC_7BIT)
+ mime_state_downgrade(state, rec_type, text, len);
+ else
+ BODY_OUT(state, rec_type, text, len);
+ }
+
+ /*
+ * The input is not a text record. Inform the application that this
+ * is the last opportunity to send any pending output.
+ */
+ else {
+ if (state->body_end)
+ state->body_end(state->app_context);
+ }
+ SAVE_PREV_REC_TYPE_AND_RETURN_ERR_FLAGS(state, rec_type);
+
+ /*
+ * Oops. This can't happen.
+ */
+ default:
+ msg_panic("mime_state_update: unknown state: %d", state->curr_state);
+ }
+}
+
+ /*
+ * Mime error to (DSN, text) mapping. Order matters; more serious errors
+ * must precede less serious errors, because the error-to-text conversion
+ * can report only one error.
+ */
+static const MIME_STATE_DETAIL mime_err_detail[] = {
+ MIME_ERR_NESTING, "5.6.0", "MIME nesting exceeds safety limit",
+ MIME_ERR_TRUNC_HEADER, "5.6.0", "message header length exceeds safety limit",
+ MIME_ERR_8BIT_IN_HEADER, "5.6.0", "improper use of 8-bit data in message header",
+ MIME_ERR_8BIT_IN_7BIT_BODY, "5.6.0", "improper use of 8-bit data in message body",
+ MIME_ERR_ENCODING_DOMAIN, "5.6.0", "invalid message/* or multipart/* encoding domain",
+ 0,
+};
+
+/* mime_state_error - error code to string */
+
+const char *mime_state_error(int error_code)
+{
+ const MIME_STATE_DETAIL *mp;
+
+ if (error_code == 0)
+ msg_panic("mime_state_error: there is no error");
+ for (mp = mime_err_detail; mp->code; mp++)
+ if (mp->code & error_code)
+ return (mp->text);
+ msg_panic("mime_state_error: unknown error code %d", error_code);
+}
+
+/* mime_state_detail - error code to table entry with assorted data */
+
+const MIME_STATE_DETAIL *mime_state_detail(int error_code)
+{
+ const MIME_STATE_DETAIL *mp;
+
+ if (error_code == 0)
+ msg_panic("mime_state_detail: there is no error");
+ for (mp = mime_err_detail; mp->code; mp++)
+ if (mp->code & error_code)
+ return (mp);
+ msg_panic("mime_state_detail: unknown error code %d", error_code);
+}
+
+#ifdef TEST
+
+#include <stdlib.h>
+#include <stringops.h>
+#include <vstream.h>
+#include <msg_vstream.h>
+#include <rec_streamlf.h>
+
+ /*
+ * Stress test the REC_TYPE_CONT/NORM handling, but don't break header
+ * labels.
+ */
+/*#define REC_LEN 40*/
+
+#define REC_LEN 1024
+
+static void head_out(void *context, int class, const HEADER_OPTS *unused_info,
+ VSTRING *buf, off_t offset)
+{
+ VSTREAM *stream = (VSTREAM *) context;
+
+ vstream_fprintf(stream, "%s %ld\t|%s\n",
+ class == MIME_HDR_PRIMARY ? "MAIN" :
+ class == MIME_HDR_MULTIPART ? "MULT" :
+ class == MIME_HDR_NESTED ? "NEST" :
+ "ERROR", (long) offset, STR(buf));
+}
+
+static void head_end(void *context)
+{
+ VSTREAM *stream = (VSTREAM *) context;
+
+ vstream_fprintf(stream, "HEADER END\n");
+}
+
+static void body_out(void *context, int rec_type, const char *buf, ssize_t len,
+ off_t offset)
+{
+ VSTREAM *stream = (VSTREAM *) context;
+
+ vstream_fprintf(stream, "BODY %c %ld\t|", rec_type, (long) offset);
+ vstream_fwrite(stream, buf, len);
+ if (rec_type == REC_TYPE_NORM)
+ VSTREAM_PUTC('\n', stream);
+}
+
+static void body_end(void *context)
+{
+ VSTREAM *stream = (VSTREAM *) context;
+
+ vstream_fprintf(stream, "BODY END\n");
+}
+
+static void err_print(void *unused_context, int err_flag,
+ const char *text, ssize_t len)
+{
+ msg_warn("%s: %.*s", mime_state_error(err_flag),
+ len < 100 ? (int) len : 100, text);
+}
+
+int var_header_limit = 2000;
+int var_mime_maxdepth = 20;
+int var_mime_bound_len = 2000;
+char *var_drop_hdrs = DEF_DROP_HDRS;
+
+int main(int unused_argc, char **argv)
+{
+ int rec_type;
+ int last = 0;
+ VSTRING *buf;
+ MIME_STATE *state;
+ int err;
+
+ /*
+ * Initialize.
+ */
+#define MIME_OPTIONS \
+ (MIME_OPT_REPORT_8BIT_IN_7BIT_BODY \
+ | MIME_OPT_REPORT_8BIT_IN_HEADER \
+ | MIME_OPT_REPORT_ENCODING_DOMAIN \
+ | MIME_OPT_REPORT_TRUNC_HEADER \
+ | MIME_OPT_REPORT_NESTING \
+ | MIME_OPT_DOWNGRADE)
+
+ msg_vstream_init(basename(argv[0]), VSTREAM_OUT);
+ msg_verbose = 1;
+ buf = vstring_alloc(10);
+ state = mime_state_alloc(MIME_OPTIONS,
+ head_out, head_end,
+ body_out, body_end,
+ err_print,
+ (void *) VSTREAM_OUT);
+
+ /*
+ * Main loop.
+ */
+ do {
+ rec_type = rec_streamlf_get(VSTREAM_IN, buf, REC_LEN);
+ VSTRING_TERMINATE(buf);
+ err = mime_state_update(state, last = rec_type, STR(buf), LEN(buf));
+ vstream_fflush(VSTREAM_OUT);
+ } while (rec_type > 0);
+
+ /*
+ * Error reporting.
+ */
+ if (err & MIME_ERR_TRUNC_HEADER)
+ msg_warn("message header length exceeds safety limit");
+ if (err & MIME_ERR_NESTING)
+ msg_warn("MIME nesting exceeds safety limit");
+ if (err & MIME_ERR_8BIT_IN_HEADER)
+ msg_warn("improper use of 8-bit data in message header");
+ if (err & MIME_ERR_8BIT_IN_7BIT_BODY)
+ msg_warn("improper use of 8-bit data in message body");
+ if (err & MIME_ERR_ENCODING_DOMAIN)
+ msg_warn("improper message/* or multipart/* encoding domain");
+
+ /*
+ * Cleanup.
+ */
+ mime_state_free(state);
+ vstring_free(buf);
+ exit(0);
+}
+
+#endif