/src/ghostpdl/base/sa85d.c

Source (jump to first uncovered line)
/* Copyright (C) 2001-2023 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, for further information.
*/


/* ASCII85Decode filter */
#include "std.h"
#include "strimpl.h"
#include "sa85d.h"
#include "scanchar.h"

/* ------ ASCII85Decode ------ */

private_st_A85D_state();

/* Initialize the state */
static int
s_A85D_init(stream_state * st)
{
    stream_A85D_state *const ss = (stream_A85D_state *) st;

    s_A85D_init_inline(ss);
    return 0;
}

/* Process a buffer */
static int a85d_finish(int, ulong, stream_cursor_write *);
static int
s_A85D_process(stream_state * st, stream_cursor_read * pr,
               stream_cursor_write * pw, bool last)
{
    stream_A85D_state *const ss = (stream_A85D_state *) st;
    register const byte *p = pr->ptr;
    register byte *q = pw->ptr;
    /* stop processing early unless the target is empty (last == true)  */
    /* to make sure we consume the EOD marker correctly. The EOD marker */
    /* might be as many as 6 characters after the last valid data char  */
    /* D <cr> <lf> '~' <cr> <lf> '>' where 'D' is a data character.     */
    const byte *rlimit = pr->limit - (last ? 0 : 7); /* max EOD len + 1 */
    const byte *r = max(p, rlimit);
    byte *wlimit = pw->limit;
    int ccount = ss->odd;
    ulong word = ss->word;
    int status = 0;

    /* scan to make sure that an EOD isn't fully contained in the */
    /* last part of the buffer (between rlimit and pr->limit).    */
    while (r < pr->limit) {
        if (*++r == '~')
            while (r < pr->limit)
                if (*++r == '>') {
                    /* we have both characters of a complete EOD. */
                    rlimit = pr->limit; /* go ahead and process everything */
                    r = rlimit;   /* break out of the while loops */
                    break;
                }
    }
    while (p < rlimit) {
        int ch = *++p;
        uint ccode = ch - '!';

        if (ccode < 85) { /* catches ch < '!' as well */
            if (ccount == 4) {
                /*
                 * We've completed a 32-bit group.  Make sure we have
                 * room for it in the output.
                 */
                if (wlimit - q < 4) {
                    p--;
                    status = 1;
                    break;
                }
                /* Check for overflow condition, throw ioerror if so */
                if (word >= 0x03030303 && ccode > 0) {
                    status = ERRC;
                    break;
                }
                word = word * 85 + ccode;
                q[1] = (byte) (word >> 24);
                q[2] = (byte) (word >> 16);
                q[3] = (byte) ((uint) word >> 8);
                q[4] = (byte) word;
                q += 4;
                word = 0;
                ccount = 0;
            } else {
                word = word * 85 + ccode;
                ++ccount;
            }
        } else if (ch == 'z' && ccount == 0) {
            if (wlimit - q < 4) {
                p--;
                status = 1;
                break;
            }
            q[1] = q[2] = q[3] = q[4] = 0,
                q += 4;
        } else if (scan_char_decoder[ch] == ctype_space)
            DO_NOTHING;
        else if (ch == '~') {
            int i = 1;

            rlimit = pr->limit;   /* Here we use the real "limit" */
            /* Handle odd bytes. */
            if (p == rlimit) {
                if (!last)
                  p--;
                else if (ss->pdf_rules)
                  goto finish;
                else
                    status = ERRC;
                break;
            }
            if ((int)(wlimit - q) < ccount - 1) {
                status = 1;
                p--;
                break;
            }

            /* According to PLRM 3rd, if the A85 filter encounters '~',
             * the next character must be '>'.
             * And any other characters should raise an ioerror.
             * But Adobe Acrobat allows CR/LF between ~ and >.
             * So we allow CR/LF between them. */
            /* PDF further relaxes the requirements and accepts bare '~'.
             */
            while ((p + i <= rlimit) && (p[i] == 13 || p[i] == 10))
                i++;
            if (p + i <= rlimit && p[i] != '>') {
                if (ss->pdf_rules) {
                    if (p[i] == 13 || p[i] == 10) {
                        if (!last)
                            break;
                    } else {
                        p--;
                    }
                } else {
                    if (p + i == rlimit) {
                        if (last)
                            status = ERRC;
                        else
                            p--; /* we'll see the '~' after filling the buffer */
                    }
                    break;
                }
            }
          finish:
            if (p + i <= rlimit)
                p += i;    /* advance to the '>' */
            else
                p = rlimit; /* Can happen if the '>' is missing */
            pw->ptr = q;
            status = a85d_finish(ccount, word, pw);
            q = pw->ptr;
            break;
        } else {   /* syntax error or exception */
            status = ERRC;
            break;
        }
    }
    pw->ptr = q;
    if (status == 0 && last) {
        if ((int)(wlimit - q) < ccount - 1)
            status = 1;
        else if (ss->require_eod)
            status = ERRC;
        else
            status = a85d_finish(ccount, word, pw);
    }
    pr->ptr = p;
    ss->odd = ccount;
    ss->word = word;
    return status;
}
/* Handle the end of input data. */
static int
a85d_finish(int ccount, ulong word, stream_cursor_write * pw)
{
    /* Assume there is enough room in the output buffer! */
    byte *q = pw->ptr;
    int status = EOFC;

    switch (ccount) {
        case 0:
            break;
        case 1:   /* syntax error */
            status = ERRC;
            break;
        case 2:   /* 1 odd byte */
            word = word * (85L * 85 * 85) + 85L * 85 * 85 - 1L;
            goto o1;
        case 3:   /* 2 odd bytes */
            word = word * (85L * 85) + 85L * 85L - 1L;
            goto o2;
        case 4:   /* 3 odd bytes */
            word = word * 85L + 84L;
            q[3] = (byte) (word >> 8);
o2:     q[2] = (byte) (word >> 16);
o1:     q[1] = (byte) (word >> 24);
            q += ccount - 1;
            pw->ptr = q;
    }
    return status;
}

/* Stream template */
const stream_template s_A85D_template = {
    &st_A85D_state, s_A85D_init, s_A85D_process, 2, 4
};

Coverage Report

Created: 2025-06-24 07:01

Line	Count	Source (jump to first uncovered line)
1		/* Copyright (C) 2001-2023 Artifex Software, Inc.
2		All Rights Reserved.
3
4		This software is provided AS-IS with no warranty, either express or
5		implied.
6
7		This software is distributed under license and may not be copied,
8		modified or distributed except as expressly authorized under the terms
9		of the license contained in the file LICENSE in this distribution.
10
11		Refer to licensing information at http://www.artifex.com or contact
12		Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
13		CA 94129, USA, for further information.
14		*/
15
16
17		/* ASCII85Decode filter */
18		#include "std.h"
19		#include "strimpl.h"
20		#include "sa85d.h"
21		#include "scanchar.h"
22
23		/* ------ ASCII85Decode ------ */
24
25		private_st_A85D_state();
26
27		/* Initialize the state */
28		static int
29		s_A85D_init(stream_state * st)
30	519	{
31	519	stream_A85D_state const ss = (stream_A85D_state ) st;
32
33	519	s_A85D_init_inline(ss);
34	519	return 0;
35	519	}
36
37		/* Process a buffer */
38		static int a85d_finish(int, ulong, stream_cursor_write *);
39		static int
40		s_A85D_process(stream_state * st, stream_cursor_read * pr,
41		stream_cursor_write * pw, bool last)
42	574k	{
43	574k	stream_A85D_state const ss = (stream_A85D_state ) st;
44	574k	register const byte *p = pr->ptr;
45	574k	register byte *q = pw->ptr;
46		/* stop processing early unless the target is empty (last == true) */
47		/* to make sure we consume the EOD marker correctly. The EOD marker */
48		/* might be as many as 6 characters after the last valid data char */
49		/* D <cr> <lf> '~' <cr> <lf> '>' where 'D' is a data character. */
50	574k	const byte rlimit = pr->limit - (last ? 0 : 7); / max EOD len + 1 */
51	574k	const byte *r = max(p, rlimit);
52	574k	byte *wlimit = pw->limit;
53	574k	int ccount = ss->odd;
54	574k	ulong word = ss->word;
55	574k	int status = 0;
56
57		/* scan to make sure that an EOD isn't fully contained in the */
58		/* last part of the buffer (between rlimit and pr->limit). */
59	1.31M	while (r < pr->limit) {
60	743k	if (*++r == '~')
61	3.82M	while (r < pr->limit)
62	3.26M	if (*++r == '>') {
63		/* we have both characters of a complete EOD. */
64	586	rlimit = pr->limit; /* go ahead and process everything */
65	586	r = rlimit; /* break out of the while loops */
66	586	break;
67	586	}
68	743k	}
69	6.71M	while (p < rlimit) {
70	6.70M	int ch = *++p;
71	6.70M	uint ccode = ch - '!';
72
73	6.70M	if (ccode < 85) { /* catches ch < '!' as well */
74	6.10M	if (ccount == 4) {
75		/*
76		* We've completed a 32-bit group. Make sure we have
77		* room for it in the output.
78		*/
79	1.22M	if (wlimit - q < 4) {
80	1.39k	p--;
81	1.39k	status = 1;
82	1.39k	break;
83	1.39k	}
84		/* Check for overflow condition, throw ioerror if so */
85	1.22M	if (word >= 0x03030303 && ccode > 0) {
86	165	status = ERRC;
87	165	break;
88	165	}
89	1.22M	word = word * 85 + ccode;
90	1.22M	q[1] = (byte) (word >> 24);
91	1.22M	q[2] = (byte) (word >> 16);
92	1.22M	q[3] = (byte) ((uint) word >> 8);
93	1.22M	q[4] = (byte) word;
94	1.22M	q += 4;
95	1.22M	word = 0;
96	1.22M	ccount = 0;
97	4.88M	} else {
98	4.88M	word = word * 85 + ccode;
99	4.88M	++ccount;
100	4.88M	}
101	6.10M	} else if (ch == 'z' && ccount == 0) {
102	313	if (wlimit - q < 4) {
103	0	p--;
104	0	status = 1;
105	0	break;
106	0	}
107	313	q[1] = q[2] = q[3] = q[4] = 0,
108	313	q += 4;
109	599k	} else if (scan_char_decoder[ch] == ctype_space)
110	599k	DO_NOTHING;
111	567k	else if (ch == '~') {
112	567k	int i = 1;
113
114	567k	rlimit = pr->limit; /* Here we use the real "limit" */
115		/* Handle odd bytes. */
116	567k	if (p == rlimit) {
117	18	if (!last)
118	0	p--;
119	18	else if (ss->pdf_rules)
120	0	goto finish;
121	18	else
122	18	status = ERRC;
123	18	break;
124	18	}
125	567k	if ((int)(wlimit - q) < ccount - 1) {
126	113	status = 1;
127	113	p--;
128	113	break;
129	113	}
130
131		/* According to PLRM 3rd, if the A85 filter encounters '~',
132		* the next character must be '>'.
133		* And any other characters should raise an ioerror.
134		* But Adobe Acrobat allows CR/LF between ~ and >.
135		* So we allow CR/LF between them. */
136		/* PDF further relaxes the requirements and accepts bare '~'.
137		*/
138	569k	while ((p + i <= rlimit) && (p[i] == 13 \|\| p[i] == 10))
139	2.56k	i++;
140	567k	if (p + i <= rlimit && p[i] != '>') {
141	567k	if (ss->pdf_rules) {
142	0	if (p[i] == 13 \|\| p[i] == 10) {
143	0	if (!last)
144	0	break;
145	0	} else {
146	0	p--;
147	0	}
148	567k	} else {
149	567k	if (p + i == rlimit) {
150	16	if (last)
151	16	status = ERRC;
152	0	else
153	0	p--; /* we'll see the '~' after filling the buffer */
154	16	}
155	567k	break;
156	567k	}
157	567k	}
158	123	finish:
159	123	if (p + i <= rlimit)
160	83	p += i; /* advance to the '>' */
161	40	else
162	40	p = rlimit; /* Can happen if the '>' is missing */
163	123	pw->ptr = q;
164	123	status = a85d_finish(ccount, word, pw);
165	123	q = pw->ptr;
166	123	break;
167	567k	} else { /* syntax error or exception */
168	469	status = ERRC;
169	469	break;
170	469	}
171	6.70M	}
172	574k	pw->ptr = q;
173	574k	if (status == 0 && last) {
174	630	if ((int)(wlimit - q) < ccount - 1)
175	0	status = 1;
176	630	else if (ss->require_eod)
177	623	status = ERRC;
178	7	else
179	7	status = a85d_finish(ccount, word, pw);
180	630	}
181	574k	pr->ptr = p;
182	574k	ss->odd = ccount;
183	574k	ss->word = word;
184	574k	return status;
185	574k	}
186		/* Handle the end of input data. */
187		static int
188		a85d_finish(int ccount, ulong word, stream_cursor_write * pw)
189	130	{
190		/* Assume there is enough room in the output buffer! */
191	130	byte *q = pw->ptr;
192	130	int status = EOFC;
193
194	130	switch (ccount) {
195	28	case 0:
196	28	break;
197	15	case 1: /* syntax error */
198	15	status = ERRC;
199	15	break;
200	43	case 2: /* 1 odd byte */
201	43	word = word * (85L * 85 * 85) + 85L * 85 * 85 - 1L;
202	43	goto o1;
203	28	case 3: /* 2 odd bytes */
204	28	word = word * (85L * 85) + 85L * 85L - 1L;
205	28	goto o2;
206	16	case 4: /* 3 odd bytes */
207	16	word = word * 85L + 84L;
208	16	q[3] = (byte) (word >> 8);
209	44	o2: q[2] = (byte) (word >> 16);
210	87	o1: q[1] = (byte) (word >> 24);
211	87	q += ccount - 1;
212	87	pw->ptr = q;
213	130	}
214	130	return status;
215	130	}
216
217		/* Stream template */
218		const stream_template s_A85D_template = {
219		&st_A85D_state, s_A85D_init, s_A85D_process, 2, 4
220		};