filters.c

/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors:                                                             |
   | Wez Furlong (wez@thebrainroom.com)                                   |
   | Sara Golemon (pollita@php.net)                                       |
   | Moriyoshi Koizumi (moriyoshi@php.net)                                |
   | Marcus Boerger (helly@php.net)                                       |
   +----------------------------------------------------------------------+
*/

#include "php.h"
#include "php_globals.h"
#include "ext/standard/basic_functions.h"
#include "ext/standard/file.h"
#include "ext/standard/php_string.h"
#include "zend_smart_str.h"

/* {{{ rot13 stream filter implementation */
static const char rot13_from[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
static const char rot13_to[] = "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM";

static php_stream_filter_status_t strfilter_rot13_filter(
	php_stream *stream,
	php_stream_filter *thisfilter,
	php_stream_bucket_brigade *buckets_in,
	php_stream_bucket_brigade *buckets_out,
	size_t *bytes_consumed,
	int flags
	)
{
	php_stream_bucket *bucket;
	size_t consumed = 0;

	while (buckets_in->head) {
		bucket = php_stream_bucket_make_writeable(buckets_in->head);

		php_strtr(bucket->buf, bucket->buflen, rot13_from, rot13_to, 52);
		consumed += bucket->buflen;

		php_stream_bucket_append(buckets_out, bucket);
	}

	if (bytes_consumed) {
		*bytes_consumed = consumed;
	}

	return PSFS_PASS_ON;
}

static const php_stream_filter_ops strfilter_rot13_ops = {
	strfilter_rot13_filter,
	NULL,
	"string.rot13"
};

static php_stream_filter *strfilter_rot13_create(const char *filtername, zval *filterparams, uint8_t persistent)
{
	return php_stream_filter_alloc(&strfilter_rot13_ops, NULL, persistent);
}

static const php_stream_filter_factory strfilter_rot13_factory = {
	strfilter_rot13_create
};
/* }}} */

/* {{{ string.toupper / string.tolower stream filter implementation */
static const char lowercase[] = "abcdefghijklmnopqrstuvwxyz";
static const char uppercase[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

static php_stream_filter_status_t strfilter_toupper_filter(
	php_stream *stream,
	php_stream_filter *thisfilter,
	php_stream_bucket_brigade *buckets_in,
	php_stream_bucket_brigade *buckets_out,
	size_t *bytes_consumed,
	int flags
	)
{
	php_stream_bucket *bucket;
	size_t consumed = 0;

	while (buckets_in->head) {
		bucket = php_stream_bucket_make_writeable(buckets_in->head);

		php_strtr(bucket->buf, bucket->buflen, lowercase, uppercase, 26);
		consumed += bucket->buflen;

		php_stream_bucket_append(buckets_out, bucket);
	}

	if (bytes_consumed) {
		*bytes_consumed = consumed;
	}

	return PSFS_PASS_ON;
}

static php_stream_filter_status_t strfilter_tolower_filter(
	php_stream *stream,
	php_stream_filter *thisfilter,
	php_stream_bucket_brigade *buckets_in,
	php_stream_bucket_brigade *buckets_out,
	size_t *bytes_consumed,
	int flags
	)
{
	php_stream_bucket *bucket;
	size_t consumed = 0;

	while (buckets_in->head) {
		bucket = php_stream_bucket_make_writeable(buckets_in->head);

		php_strtr(bucket->buf, bucket->buflen, uppercase, lowercase, 26);
		consumed += bucket->buflen;

		php_stream_bucket_append(buckets_out, bucket);
	}

	if (bytes_consumed) {
		*bytes_consumed = consumed;
	}

	return PSFS_PASS_ON;
}

static const php_stream_filter_ops strfilter_toupper_ops = {
	strfilter_toupper_filter,
	NULL,
	"string.toupper"
};

static const php_stream_filter_ops strfilter_tolower_ops = {
	strfilter_tolower_filter,
	NULL,
	"string.tolower"
};

static php_stream_filter *strfilter_toupper_create(const char *filtername, zval *filterparams, uint8_t persistent)
{
	return php_stream_filter_alloc(&strfilter_toupper_ops, NULL, persistent);
}

static php_stream_filter *strfilter_tolower_create(const char *filtername, zval *filterparams, uint8_t persistent)
{
	return php_stream_filter_alloc(&strfilter_tolower_ops, NULL, persistent);
}

static const php_stream_filter_factory strfilter_toupper_factory = {
	strfilter_toupper_create
};

static const php_stream_filter_factory strfilter_tolower_factory = {
	strfilter_tolower_create
};
/* }}} */

/* {{{ base64 / quoted_printable stream filter implementation */

typedef enum _php_conv_err_t {
	PHP_CONV_ERR_SUCCESS = SUCCESS,
	PHP_CONV_ERR_UNKNOWN,
	PHP_CONV_ERR_TOO_BIG,
	PHP_CONV_ERR_INVALID_SEQ,
	PHP_CONV_ERR_UNEXPECTED_EOS,
	PHP_CONV_ERR_EXISTS,
	PHP_CONV_ERR_MORE,
	PHP_CONV_ERR_ALLOC,
	PHP_CONV_ERR_NOT_FOUND
} php_conv_err_t;

typedef struct _php_conv php_conv;

typedef php_conv_err_t (*php_conv_convert_func)(php_conv *, const char **, size_t *, char **, size_t *);
typedef void (*php_conv_dtor_func)(php_conv *);

struct _php_conv {
	php_conv_convert_func convert_op;
	php_conv_dtor_func dtor;
};

#define php_conv_convert(a, b, c, d, e) ((php_conv *)(a))->convert_op((php_conv *)(a), (b), (c), (d), (e))
#define php_conv_dtor(a) ((php_conv *)a)->dtor((a))

/* {{{ php_conv_base64_encode */
typedef struct _php_conv_base64_encode {
	php_conv _super;

	const char *lbchars;
	size_t lbchars_len;
	size_t erem_len;
	unsigned int line_ccnt;
	unsigned int line_len;
	int lbchars_dup;
	int persistent;
	unsigned char erem[3];
} php_conv_base64_encode;

static php_conv_err_t php_conv_base64_encode_convert(php_conv_base64_encode *inst, const char **in_p, size_t *in_left, char **out_p, size_t *out_left);
static void php_conv_base64_encode_dtor(php_conv_base64_encode *inst);

static const unsigned char b64_tbl_enc[256] = {
	'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
	'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
	'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
	'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/',
	'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
	'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
	'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
	'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/',
	'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
	'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
	'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
	'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/',
	'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
	'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
	'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
	'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'
};

static php_conv_err_t php_conv_base64_encode_ctor(php_conv_base64_encode *inst, unsigned int line_len, const char *lbchars, size_t lbchars_len, int lbchars_dup, int persistent)
{
	inst->_super.convert_op = (php_conv_convert_func) php_conv_base64_encode_convert;
	inst->_super.dtor = (php_conv_dtor_func) php_conv_base64_encode_dtor;
	inst->erem_len = 0;
	inst->line_ccnt = line_len;
	inst->line_len = line_len;
	if (lbchars != NULL) {
		inst->lbchars = (lbchars_dup ? pestrdup(lbchars, persistent) : lbchars);
		inst->lbchars_len = lbchars_len;
	} else {
		inst->lbchars = NULL;
	}
	inst->lbchars_dup = lbchars_dup;
	inst->persistent = persistent;
	return PHP_CONV_ERR_SUCCESS;
}

static void php_conv_base64_encode_dtor(php_conv_base64_encode *inst)
{
	assert(inst != NULL);
	if (inst->lbchars_dup && inst->lbchars != NULL) {
		pefree((void *)inst->lbchars, inst->persistent);
	}
}

static php_conv_err_t php_conv_base64_encode_flush(php_conv_base64_encode *inst, const char **in_pp, size_t *in_left_p, char **out_pp, size_t *out_left_p)
{
	volatile php_conv_err_t err = PHP_CONV_ERR_SUCCESS;
	register unsigned char *pd;
	register size_t ocnt;
	unsigned int line_ccnt;

	pd = (unsigned char *)(*out_pp);
	ocnt = *out_left_p;
	line_ccnt = inst->line_ccnt;

	switch (inst->erem_len) {
		case 0:
			/* do nothing */
			break;

		case 1:
			if (line_ccnt < 4 && inst->lbchars != NULL) {
				if (ocnt < inst->lbchars_len) {
					return PHP_CONV_ERR_TOO_BIG;
				}
				memcpy(pd, inst->lbchars, inst->lbchars_len);
				pd += inst->lbchars_len;
				ocnt -= inst->lbchars_len;
				line_ccnt = inst->line_len;
			}
			if (ocnt < 4) {
				err = PHP_CONV_ERR_TOO_BIG;
				goto out;
			}
			*(pd++) = b64_tbl_enc[(inst->erem[0] >> 2)];
			*(pd++) = b64_tbl_enc[(unsigned char)(inst->erem[0] << 4)];
			*(pd++) = '=';
			*(pd++) = '=';
			inst->erem_len = 0;
			ocnt -= 4;
			line_ccnt -= 4;
			break;

		case 2:
			if (line_ccnt < 4 && inst->lbchars != NULL) {
				if (ocnt < inst->lbchars_len) {
					return PHP_CONV_ERR_TOO_BIG;
				}
				memcpy(pd, inst->lbchars, inst->lbchars_len);
				pd += inst->lbchars_len;
				ocnt -= inst->lbchars_len;
				line_ccnt = inst->line_len;
			}
			if (ocnt < 4) {
				err = PHP_CONV_ERR_TOO_BIG;
				goto out;
			}
			*(pd++) = b64_tbl_enc[(inst->erem[0] >> 2)];
			*(pd++) = b64_tbl_enc[(unsigned char)(inst->erem[0] << 4) | (inst->erem[1] >> 4)];
			*(pd++) = b64_tbl_enc[(unsigned char)(inst->erem[1] << 2)];
			*(pd++) = '=';
			inst->erem_len = 0;
			ocnt -=4;
			line_ccnt -= 4;
			break;

		default:
			/* should not happen... */
			err = PHP_CONV_ERR_UNKNOWN;
			break;
	}
out:
	*out_pp = (char *)pd;
	*out_left_p = ocnt;
	inst->line_ccnt = line_ccnt;
	return err;
}

static php_conv_err_t php_conv_base64_encode_convert(php_conv_base64_encode *inst, const char **in_pp, size_t *in_left_p, char **out_pp, size_t *out_left_p)
{
	volatile php_conv_err_t err = PHP_CONV_ERR_SUCCESS;
	register size_t ocnt, icnt;
	register unsigned char *ps, *pd;
	register unsigned int line_ccnt;

	if (in_pp == NULL || in_left_p == NULL) {
		return php_conv_base64_encode_flush(inst, in_pp, in_left_p, out_pp, out_left_p);
	}

	pd = (unsigned char *)(*out_pp);
	ocnt = *out_left_p;
	ps = (unsigned char *)(*in_pp);
	icnt = *in_left_p;
	line_ccnt = inst->line_ccnt;

	/* consume the remainder first */
	switch (inst->erem_len) {
		case 1:
			if (icnt >= 2) {
				if (line_ccnt < 4 && inst->lbchars != NULL) {
					if (ocnt < inst->lbchars_len) {
						return PHP_CONV_ERR_TOO_BIG;
					}
					memcpy(pd, inst->lbchars, inst->lbchars_len);
					pd += inst->lbchars_len;
					ocnt -= inst->lbchars_len;
					line_ccnt = inst->line_len;
				}
				if (ocnt < 4) {
					err = PHP_CONV_ERR_TOO_BIG;
					goto out;
				}
				*(pd++) = b64_tbl_enc[(inst->erem[0] >> 2)];
				*(pd++) = b64_tbl_enc[(unsigned char)(inst->erem[0] << 4) | (ps[0] >> 4)];
				*(pd++) = b64_tbl_enc[(unsigned char)(ps[0] << 2) | (ps[1] >> 6)];
				*(pd++) = b64_tbl_enc[ps[1]];
				ocnt -= 4;
				ps += 2;
				icnt -= 2;
				inst->erem_len = 0;
				line_ccnt -= 4;
			}
			break;

		case 2:
			if (icnt >= 1) {
				if (inst->line_ccnt < 4 && inst->lbchars != NULL) {
					if (ocnt < inst->lbchars_len) {
						return PHP_CONV_ERR_TOO_BIG;
					}
					memcpy(pd, inst->lbchars, inst->lbchars_len);
					pd += inst->lbchars_len;
					ocnt -= inst->lbchars_len;
					line_ccnt = inst->line_len;
				}
				if (ocnt < 4) {
					err = PHP_CONV_ERR_TOO_BIG;
					goto out;
				}
				*(pd++) = b64_tbl_enc[(inst->erem[0] >> 2)];
				*(pd++) = b64_tbl_enc[(unsigned char)(inst->erem[0] << 4) | (inst->erem[1] >> 4)];
				*(pd++) = b64_tbl_enc[(unsigned char)(inst->erem[1] << 2) | (ps[0] >> 6)];
				*(pd++) = b64_tbl_enc[ps[0]];
				ocnt -= 4;
				ps += 1;
				icnt -= 1;
				inst->erem_len = 0;
				line_ccnt -= 4;
			}
			break;
	}

	while (icnt >= 3) {
		if (line_ccnt < 4 && inst->lbchars != NULL) {
			if (ocnt < inst->lbchars_len) {
				err = PHP_CONV_ERR_TOO_BIG;
				goto out;
			}
			memcpy(pd, inst->lbchars, inst->lbchars_len);
			pd += inst->lbchars_len;
			ocnt -= inst->lbchars_len;
			line_ccnt = inst->line_len;
		}
		if (ocnt < 4) {
			err = PHP_CONV_ERR_TOO_BIG;
			goto out;
		}
		*(pd++) = b64_tbl_enc[ps[0] >> 2];
		*(pd++) = b64_tbl_enc[(unsigned char)(ps[0] << 4) | (ps[1] >> 4)];
		*(pd++) = b64_tbl_enc[(unsigned char)(ps[1] << 2) | (ps[2] >> 6)];
		*(pd++) = b64_tbl_enc[ps[2]];

		ps += 3;
		icnt -=3;
		ocnt -= 4;
		line_ccnt -= 4;
	}
	for (;icnt > 0; icnt--) {
		inst->erem[inst->erem_len++] = *(ps++);
	}

out:
	*in_pp = (const char *)ps;
	*in_left_p = icnt;
	*out_pp = (char *)pd;
	*out_left_p = ocnt;
	inst->line_ccnt = line_ccnt;

	return err;
}

/* }}} */

/* {{{ php_conv_base64_decode */
typedef struct _php_conv_base64_decode {
	php_conv _super;

	unsigned int urem;
	unsigned int urem_nbits;
	unsigned int ustat;
	int eos;
} php_conv_base64_decode;

static php_conv_err_t php_conv_base64_decode_convert(php_conv_base64_decode *inst, const char **in_p, size_t *in_left, char **out_p, size_t *out_left);
static void php_conv_base64_decode_dtor(php_conv_base64_decode *inst);

static unsigned int b64_tbl_dec[256] = {
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64,128, 64, 64,
	64,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
	64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
};

static int php_conv_base64_decode_ctor(php_conv_base64_decode *inst)
{
	inst->_super.convert_op = (php_conv_convert_func) php_conv_base64_decode_convert;
	inst->_super.dtor = (php_conv_dtor_func) php_conv_base64_decode_dtor;

	inst->urem = 0;
	inst->urem_nbits = 0;
	inst->ustat = 0;
	inst->eos = 0;
	return SUCCESS;
}

static void php_conv_base64_decode_dtor(php_conv_base64_decode *inst)
{
	/* do nothing */
}

#define bmask(a) (0xffff >> (16 - a))
static php_conv_err_t php_conv_base64_decode_convert(php_conv_base64_decode *inst, const char **in_pp, size_t *in_left_p, char **out_pp, size_t *out_left_p)
{
	php_conv_err_t err;

	unsigned int urem, urem_nbits;
	unsigned int pack, pack_bcnt;
	unsigned char *ps, *pd;
	size_t icnt, ocnt;
	unsigned int ustat;

	static const unsigned int nbitsof_pack = 8;

	if (in_pp == NULL || in_left_p == NULL) {
		if (inst->eos || inst->urem_nbits == 0) {
			return PHP_CONV_ERR_SUCCESS;
		}
		return PHP_CONV_ERR_UNEXPECTED_EOS;
	}

	err = PHP_CONV_ERR_SUCCESS;

	ps = (unsigned char *)*in_pp;
	pd = (unsigned char *)*out_pp;
	icnt = *in_left_p;
	ocnt = *out_left_p;

	urem = inst->urem;
	urem_nbits = inst->urem_nbits;
	ustat = inst->ustat;

	pack = 0;
	pack_bcnt = nbitsof_pack;

	for (;;) {
		if (pack_bcnt >= urem_nbits) {
			pack_bcnt -= urem_nbits;
			pack |= (urem << pack_bcnt);
			urem_nbits = 0;
		} else {
			urem_nbits -= pack_bcnt;
			pack |= (urem >> urem_nbits);
			urem &= bmask(urem_nbits);
			pack_bcnt = 0;
		}
		if (pack_bcnt > 0) {
			unsigned int i;

			if (icnt < 1) {
				break;
			}

			i = b64_tbl_dec[(unsigned int)*(ps++)];
			icnt--;
			ustat |= i & 0x80;

			if (!(i & 0xc0)) {
				if (ustat) {
					err = PHP_CONV_ERR_INVALID_SEQ;
					break;
				}
				if (6 <= pack_bcnt) {
					pack_bcnt -= 6;
					pack |= (i << pack_bcnt);
					urem = 0;
				} else {
					urem_nbits = 6 - pack_bcnt;
					pack |= (i >> urem_nbits);
					urem = i & bmask(urem_nbits);
					pack_bcnt = 0;
				}
			} else if (ustat) {
				if (pack_bcnt == 8 || pack_bcnt == 2) {
					err = PHP_CONV_ERR_INVALID_SEQ;
					break;
				}
				inst->eos = 1;
			}
		}
		if ((pack_bcnt | ustat) == 0) {
			if (ocnt < 1) {
				err = PHP_CONV_ERR_TOO_BIG;
				break;
			}
			*(pd++) = pack;
			ocnt--;
			pack = 0;
			pack_bcnt = nbitsof_pack;
		}
	}

	if (urem_nbits >= pack_bcnt) {
		urem |= (pack << (urem_nbits - pack_bcnt));
		urem_nbits += (nbitsof_pack - pack_bcnt);
	} else {
		urem |= (pack >> (pack_bcnt - urem_nbits));
		urem_nbits += (nbitsof_pack - pack_bcnt);
	}

	inst->urem = urem;
	inst->urem_nbits = urem_nbits;
	inst->ustat = ustat;

	*in_pp = (const char *)ps;
	*in_left_p = icnt;
	*out_pp = (char *)pd;
	*out_left_p = ocnt;

	return err;
}
#undef bmask
/* }}} */

/* {{{ php_conv_qprint_encode */
typedef struct _php_conv_qprint_encode {
	php_conv _super;

	const char *lbchars;
	size_t lbchars_len;
	int opts;
	unsigned int line_ccnt;
	unsigned int line_len;
	int lbchars_dup;
	int persistent;
	unsigned int lb_ptr;
	unsigned int lb_cnt;
} php_conv_qprint_encode;

#define PHP_CONV_QPRINT_OPT_BINARY             0x00000001
#define PHP_CONV_QPRINT_OPT_FORCE_ENCODE_FIRST 0x00000002

static void php_conv_qprint_encode_dtor(php_conv_qprint_encode *inst);
static php_conv_err_t php_conv_qprint_encode_convert(php_conv_qprint_encode *inst, const char **in_pp, size_t *in_left_p, char **out_pp, size_t *out_left_p);

static void php_conv_qprint_encode_dtor(php_conv_qprint_encode *inst)
{
	assert(inst != NULL);
	if (inst->lbchars_dup && inst->lbchars != NULL) {
		pefree((void *)inst->lbchars, inst->persistent);
	}
}

#define NEXT_CHAR(ps, icnt, lb_ptr, lb_cnt, lbchars) \
	((lb_ptr) < (lb_cnt) ? (lbchars)[(lb_ptr)] : *(ps))

#define CONSUME_CHAR(ps, icnt, lb_ptr, lb_cnt) \
	if ((lb_ptr) < (lb_cnt)) { \
		(lb_ptr)++; \
	} else { \
		(lb_cnt) = (lb_ptr) = 0; \
		--(icnt); \
		(ps)++; \
	}

static php_conv_err_t php_conv_qprint_encode_convert(php_conv_qprint_encode *inst, const char **in_pp, size_t *in_left_p, char **out_pp, size_t *out_left_p)
{
	php_conv_err_t err = PHP_CONV_ERR_SUCCESS;
	unsigned char *ps, *pd;
	size_t icnt, ocnt;
	unsigned int c;
	unsigned int line_ccnt;
	unsigned int lb_ptr;
	unsigned int lb_cnt;
	unsigned int trail_ws;
	int opts;
	static const char qp_digits[] = "0123456789ABCDEF";

	line_ccnt = inst->line_ccnt;
	opts = inst->opts;
	lb_ptr = inst->lb_ptr;
	lb_cnt = inst->lb_cnt;

	if (in_pp == NULL || in_left_p == NULL) {
		return PHP_CONV_ERR_SUCCESS;
	}

	ps = (unsigned char *)(*in_pp);
	icnt = *in_left_p;
	pd = (unsigned char *)(*out_pp);
	ocnt = *out_left_p;
	trail_ws = 0;

	for (;;) {
		if (!(opts & PHP_CONV_QPRINT_OPT_BINARY) && inst->lbchars != NULL && inst->lbchars_len > 0) {
			/* look ahead for the line break chars to make a right decision
			 * how to consume incoming characters */

			if (icnt > 0 && *ps == inst->lbchars[lb_cnt]) {
				lb_cnt++;

				if (lb_cnt >= inst->lbchars_len) {
					unsigned int i;

					if (ocnt < lb_cnt) {
						lb_cnt--;
						err = PHP_CONV_ERR_TOO_BIG;
						break;
					}

					for (i = 0; i < lb_cnt; i++) {
						*(pd++) = inst->lbchars[i];
						ocnt--;
					}
					line_ccnt = inst->line_len;
					lb_ptr = lb_cnt = 0;
				}
				ps++, icnt--;
				continue;
			}
		}

		if (lb_ptr >= lb_cnt && icnt == 0) {
			break;
		}

		c = NEXT_CHAR(ps, icnt, lb_ptr, lb_cnt, inst->lbchars);

		if (!(opts & PHP_CONV_QPRINT_OPT_BINARY) &&
			(trail_ws == 0) &&
			(c == '\t' || c == ' ')) {
			if (line_ccnt < 2 && inst->lbchars != NULL) {
				if (ocnt < inst->lbchars_len + 1) {
					err = PHP_CONV_ERR_TOO_BIG;
					break;
				}

				*(pd++) = '=';
				ocnt--;
				line_ccnt--;

				memcpy(pd, inst->lbchars, inst->lbchars_len);
				pd += inst->lbchars_len;
				ocnt -= inst->lbchars_len;
				line_ccnt = inst->line_len;
			} else {
				if (ocnt < 1) {
					err = PHP_CONV_ERR_TOO_BIG;
					break;
				}

				/* Check to see if this is EOL whitespace. */
				if (inst->lbchars != NULL) {
					unsigned char *ps2;
					unsigned int lb_cnt2;
					size_t j;

					lb_cnt2 = 0;
					ps2 = ps;
					trail_ws = 1;

					for (j = icnt - 1; j > 0; j--, ps2++) {
						if (*ps2 == inst->lbchars[lb_cnt2]) {
							lb_cnt2++;
							if (lb_cnt2 >= inst->lbchars_len) {
								/* Found trailing ws. Reset to top of main
								 * for loop to allow for code to do necessary
								 * wrapping/encoding. */
								break;
							}
						} else if (lb_cnt2 != 0 || (*ps2 != '\t' && *ps2 != ' ')) {
							/* At least one non-EOL character following, so
							 * don't need to encode ws. */
							trail_ws = 0;
							break;
						} else {
							trail_ws++;
						}
					}
				}

				if (trail_ws == 0) {
					*(pd++) = c;
					ocnt--;
					line_ccnt--;
					CONSUME_CHAR(ps, icnt, lb_ptr, lb_cnt);
				}
			}
		} else if ((!(opts & PHP_CONV_QPRINT_OPT_FORCE_ENCODE_FIRST) || line_ccnt < inst->line_len) && ((c >= 33 && c <= 60) || (c >= 62 && c <= 126))) {
			if (line_ccnt < 2 && inst->lbchars != NULL) {
				if (ocnt < inst->lbchars_len + 1) {
					err = PHP_CONV_ERR_TOO_BIG;
					break;
				}
				*(pd++) = '=';
				ocnt--;
				line_ccnt--;

				memcpy(pd, inst->lbchars, inst->lbchars_len);
				pd += inst->lbchars_len;
				ocnt -= inst->lbchars_len;
				line_ccnt = inst->line_len;
			}
			if (ocnt < 1) {
				err = PHP_CONV_ERR_TOO_BIG;
				break;
			}
			*(pd++) = c;
			ocnt--;
			line_ccnt--;
			CONSUME_CHAR(ps, icnt, lb_ptr, lb_cnt);
		} else {
			if (line_ccnt < 4 && inst->lbchars != NULL) {
				if (ocnt < inst->lbchars_len + 1) {
					err = PHP_CONV_ERR_TOO_BIG;
					break;
				}
				*(pd++) = '=';
				ocnt--;
				line_ccnt--;

				memcpy(pd, inst->lbchars, inst->lbchars_len);
				pd += inst->lbchars_len;
				ocnt -= inst->lbchars_len;
				line_ccnt = inst->line_len;
			}
			if (ocnt < 3) {
				err = PHP_CONV_ERR_TOO_BIG;
				break;
			}
			*(pd++) = '=';
			*(pd++) = qp_digits[(c >> 4)];
			*(pd++) = qp_digits[(c & 0x0f)];
			ocnt -= 3;
			line_ccnt -= 3;
			if (trail_ws > 0) {
				trail_ws--;
			}
			CONSUME_CHAR(ps, icnt, lb_ptr, lb_cnt);
		}
	}

	*in_pp = (const char *)ps;
	*in_left_p = icnt;
	*out_pp = (char *)pd;
	*out_left_p = ocnt;
	inst->line_ccnt = line_ccnt;
	inst->lb_ptr = lb_ptr;
	inst->lb_cnt = lb_cnt;
	return err;
}
#undef NEXT_CHAR
#undef CONSUME_CHAR

static php_conv_err_t php_conv_qprint_encode_ctor(php_conv_qprint_encode *inst, unsigned int line_len, const char *lbchars, size_t lbchars_len, int lbchars_dup, int opts, int persistent)
{
	if (line_len < 4 && lbchars != NULL) {
		return PHP_CONV_ERR_TOO_BIG;
	}
	inst->_super.convert_op = (php_conv_convert_func) php_conv_qprint_encode_convert;
	inst->_super.dtor = (php_conv_dtor_func) php_conv_qprint_encode_dtor;
	inst->line_ccnt = line_len;
	inst->line_len = line_len;
	if (lbchars != NULL) {
		inst->lbchars = (lbchars_dup ? pestrdup(lbchars, persistent) : lbchars);
		inst->lbchars_len = lbchars_len;
	} else {
		inst->lbchars = NULL;
	}
	inst->lbchars_dup = lbchars_dup;
	inst->persistent = persistent;
	inst->opts = opts;
	inst->lb_cnt = inst->lb_ptr = 0;
	return PHP_CONV_ERR_SUCCESS;
}
/* }}} */

/* {{{ php_conv_qprint_decode */
typedef struct _php_conv_qprint_decode {
	php_conv _super;

	const char *lbchars;
	size_t lbchars_len;
	int scan_stat;
	unsigned int next_char;
	int lbchars_dup;
	int persistent;
	unsigned int lb_ptr;
	unsigned int lb_cnt;
} php_conv_qprint_decode;

static void php_conv_qprint_decode_dtor(php_conv_qprint_decode *inst)
{
	assert(inst != NULL);
	if (inst->lbchars_dup && inst->lbchars != NULL) {
		pefree((void *)inst->lbchars, inst->persistent);
	}
}

static php_conv_err_t php_conv_qprint_decode_convert(php_conv_qprint_decode *inst, const char **in_pp, size_t *in_left_p, char **out_pp, size_t *out_left_p)
{
	php_conv_err_t err = PHP_CONV_ERR_SUCCESS;
	size_t icnt, ocnt;
	unsigned char *ps, *pd;
	unsigned int scan_stat;
	unsigned int next_char;
	unsigned int lb_ptr, lb_cnt;

	lb_ptr = inst->lb_ptr;
	lb_cnt = inst->lb_cnt;

	if (in_pp == NULL || in_left_p == NULL) {
		if (inst->scan_stat != 0) {
			return PHP_CONV_ERR_UNEXPECTED_EOS;
		}
		return PHP_CONV_ERR_SUCCESS;
	}

	ps = (unsigned char *)(*in_pp);
	icnt = *in_left_p;
	pd = (unsigned char *)(*out_pp);
	ocnt = *out_left_p;
	scan_stat = inst->scan_stat;
	next_char = inst->next_char;

	for (;;) {
		switch (scan_stat) {
			case 0: {
				if (icnt == 0) {
					goto out;
				}
				if (*ps == '=') {
					scan_stat = 1;
				} else {
					if (ocnt < 1) {
						err = PHP_CONV_ERR_TOO_BIG;
						goto out;
					}
					*(pd++) = *ps;
					ocnt--;
				}
				ps++, icnt--;
			} break;

			case 1: {
				if (icnt == 0) {
					goto out;
				}
				if (*ps == ' ' || *ps == '\t') {
					scan_stat = 4;
					ps++, icnt--;
					break;
				} else if (!inst->lbchars && lb_cnt == 0 && *ps == '\r') {
					/* auto-detect line endings, looks like network line ending \r\n (could be mac \r) */
					lb_cnt++;
					scan_stat = 5;
					ps++, icnt--;
					break;
				} else if (!inst->lbchars && lb_cnt == 0 && *ps == '\n') {
					/* auto-detect line endings, looks like unix-lineendings, not to spec, but it is seem in the wild, a lot */
					lb_cnt = lb_ptr = 0;
					scan_stat = 0;
					ps++, icnt--;
					break;
				} else if (lb_cnt < inst->lbchars_len &&
							*ps == (unsigned char)inst->lbchars[lb_cnt]) {
					lb_cnt++;
					scan_stat = 5;
					ps++, icnt--;
					break;
				}
			} ZEND_FALLTHROUGH;

			case 2: {
				if (icnt == 0) {
					goto out;
				}

				if (!isxdigit((int) *ps)) {
					err = PHP_CONV_ERR_INVALID_SEQ;
					goto out;
				}
				next_char = (next_char << 4) | (*ps >= 'A' ? *ps - 0x37 : *ps - 0x30);
				scan_stat++;
				ps++, icnt--;
				if (scan_stat != 3) {
					break;
				}
			} ZEND_FALLTHROUGH;

			case 3: {
				if (ocnt < 1) {
					err = PHP_CONV_ERR_TOO_BIG;
					goto out;
				}
				*(pd++) = next_char;
				ocnt--;
				scan_stat = 0;
			} break;

			case 4: {
				if (icnt == 0) {
					goto out;
				}
				if (lb_cnt < inst->lbchars_len &&
					*ps == (unsigned char)inst->lbchars[lb_cnt]) {
					lb_cnt++;
					scan_stat = 5;
				} else if (*ps != '\t' && *ps != ' ') {
					err = PHP_CONV_ERR_INVALID_SEQ;
					goto out;
				}
				ps++, icnt--;
			} break;

			case 5: {
				if (icnt == 0) {
					goto out;