/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: 2025-06-10 06:58

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	47	{
31	47	stream_A85D_state const ss = (stream_A85D_state ) st;
32
33	47	s_A85D_init_inline(ss);
34	47	return 0;
35	47	}
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	185k	{
43	185k	stream_A85D_state const ss = (stream_A85D_state ) st;
44	185k	register const byte *p = pr->ptr;
45	185k	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	185k	const byte rlimit = pr->limit - (last ? 0 : 7); / max EOD len + 1 */
51	185k	const byte *r = max(p, rlimit);
52	185k	byte *wlimit = pw->limit;
53	185k	int ccount = ss->odd;
54	185k	ulong word = ss->word;
55	185k	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	417k	while (r < pr->limit) {
60	231k	if (*++r == '~')
61	1.24M	while (r < pr->limit)
62	1.06M	if (*++r == '>') {
63		/* we have both characters of a complete EOD. */
64	34	rlimit = pr->limit; /* go ahead and process everything */
65	34	r = rlimit; /* break out of the while loops */
66	34	break;
67	34	}
68	231k	}
69	643k	while (p < rlimit) {
70	643k	int ch = *++p;
71	643k	uint ccode = ch - '!';
72
73	643k	if (ccode < 85) { /* catches ch < '!' as well */
74	457k	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	91.4k	if (wlimit - q < 4) {
80	117	p--;
81	117	status = 1;
82	117	break;
83	117	}
84		/* Check for overflow condition, throw ioerror if so */
85	91.3k	if (word >= 0x03030303 && ccode > 0) {
86	15	status = ERRC;
87	15	break;
88	15	}
89	91.3k	word = word * 85 + ccode;
90	91.3k	q[1] = (byte) (word >> 24);
91	91.3k	q[2] = (byte) (word >> 16);
92	91.3k	q[3] = (byte) ((uint) word >> 8);
93	91.3k	q[4] = (byte) word;
94	91.3k	q += 4;
95	91.3k	word = 0;
96	91.3k	ccount = 0;
97	365k	} else {
98	365k	word = word * 85 + ccode;
99	365k	++ccount;
100	365k	}
101	457k	} else if (ch == 'z' && ccount == 0) {
102	90	if (wlimit - q < 4) {
103	0	p--;
104	0	status = 1;
105	0	break;
106	0	}
107	90	q[1] = q[2] = q[3] = q[4] = 0,
108	90	q += 4;
109	185k	} else if (scan_char_decoder[ch] == ctype_space)
110	185k	DO_NOTHING;
111	185k	else if (ch == '~') {
112	185k	int i = 1;
113
114	185k	rlimit = pr->limit; /* Here we use the real "limit" */
115		/* Handle odd bytes. */
116	185k	if (p == rlimit) {
117	1	if (!last)
118	0	p--;
119	1	else if (ss->pdf_rules)
120	0	goto finish;
121	1	else
122	1	status = ERRC;
123	1	break;
124	1	}
125	185k	if ((int)(wlimit - q) < ccount - 1) {
126	26	status = 1;
127	26	p--;
128	26	break;
129	26	}
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	185k	while ((p + i <= rlimit) && (p[i] == 13 \|\| p[i] == 10))
139	228	i++;
140	185k	if (p + i <= rlimit && p[i] != '>') {
141	185k	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	185k	} else {
149	185k	if (p + i == rlimit) {
150	1	if (last)
151	1	status = ERRC;
152	0	else
153	0	p--; /* we'll see the '~' after filling the buffer */
154	1	}
155	185k	break;
156	185k	}
157	185k	}
158	7	finish:
159	7	if (p + i <= rlimit)
160	7	p += i; /* advance to the '>' */
161	0	else
162	0	p = rlimit; /* Can happen if the '>' is missing */
163	7	pw->ptr = q;
164	7	status = a85d_finish(ccount, word, pw);
165	7	q = pw->ptr;
166	7	break;
167	185k	} else { /* syntax error or exception */
168	51	status = ERRC;
169	51	break;
170	51	}
171	643k	}
172	185k	pw->ptr = q;
173	185k	if (status == 0 && last) {
174	50	if ((int)(wlimit - q) < ccount - 1)
175	0	status = 1;
176	50	else if (ss->require_eod)
177	49	status = ERRC;
178	1	else
179	1	status = a85d_finish(ccount, word, pw);
180	50	}
181	185k	pr->ptr = p;
182	185k	ss->odd = ccount;
183	185k	ss->word = word;
184	185k	return status;
185	185k	}
186		/* Handle the end of input data. */
187		static int
188		a85d_finish(int ccount, ulong word, stream_cursor_write * pw)
189	8	{
190		/* Assume there is enough room in the output buffer! */
191	8	byte *q = pw->ptr;
192	8	int status = EOFC;
193
194	8	switch (ccount) {
195	1	case 0:
196	1	break;
197	0	case 1: /* syntax error */
198	0	status = ERRC;
199	0	break;
200	3	case 2: /* 1 odd byte */
201	3	word = word * (85L * 85 * 85) + 85L * 85 * 85 - 1L;
202	3	goto o1;
203	3	case 3: /* 2 odd bytes */
204	3	word = word * (85L * 85) + 85L * 85L - 1L;
205	3	goto o2;
206	1	case 4: /* 3 odd bytes */
207	1	word = word * 85L + 84L;
208	1	q[3] = (byte) (word >> 8);
209	4	o2: q[2] = (byte) (word >> 16);
210	7	o1: q[1] = (byte) (word >> 24);
211	7	q += ccount - 1;
212	7	pw->ptr = q;
213	8	}
214	8	return status;
215	8	}
216
217		/* Stream template */
218		const stream_template s_A85D_template = {
219		&st_A85D_state, s_A85D_init, s_A85D_process, 2, 4
220		};