Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1300 insertions, 0 deletions

diff --git a/src/global/mime_state.c b/src/global/mime_state.c
new file mode 100644
index 0000000..e1b6a65
--- /dev/null
+++ b/src/global/mime_state.c
@@ -0,0 +1,1300 @@
+/*++
+/* 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