/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: 2025-08-28 07:06

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	605	{
31	605	stream_A85D_state const ss = (stream_A85D_state ) st;
32
33	605	s_A85D_init_inline(ss);
34	605	return 0;
35	605	}
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	649k	{
43	649k	stream_A85D_state const ss = (stream_A85D_state ) st;
44	649k	register const byte *p = pr->ptr;
45	649k	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	649k	const byte rlimit = pr->limit - (last ? 0 : 7); / max EOD len + 1 */
51	649k	const byte *r = max(p, rlimit);
52	649k	byte *wlimit = pw->limit;
53	649k	int ccount = ss->odd;
54	649k	ulong word = ss->word;
55	649k	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	1.46M	while (r < pr->limit) {
60	817k	if (*++r == '~')
61	4.34M	while (r < pr->limit)
62	3.71M	if (*++r == '>') {
63		/* we have both characters of a complete EOD. */
64	600	rlimit = pr->limit; /* go ahead and process everything */
65	600	r = rlimit; /* break out of the while loops */
66	600	break;
67	600	}
68	817k	}
69	7.00M	while (p < rlimit) {
70	6.99M	int ch = *++p;
71	6.99M	uint ccode = ch - '!';
72
73	6.99M	if (ccode < 85) { /* catches ch < '!' as well */
74	6.32M	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	1.26M	if (wlimit - q < 4) {
80	1.40k	p--;
81	1.40k	status = 1;
82	1.40k	break;
83	1.40k	}
84		/* Check for overflow condition, throw ioerror if so */
85	1.26M	if (word >= 0x03030303 && ccode > 0) {
86	185	status = ERRC;
87	185	break;
88	185	}
89	1.26M	word = word * 85 + ccode;
90	1.26M	q[1] = (byte) (word >> 24);
91	1.26M	q[2] = (byte) (word >> 16);
92	1.26M	q[3] = (byte) ((uint) word >> 8);
93	1.26M	q[4] = (byte) word;
94	1.26M	q += 4;
95	1.26M	word = 0;
96	1.26M	ccount = 0;
97	5.06M	} else {
98	5.06M	word = word * 85 + ccode;
99	5.06M	++ccount;
100	5.06M	}
101	6.32M	} else if (ch == 'z' && ccount == 0) {
102	535	if (wlimit - q < 4) {
103	0	p--;
104	0	status = 1;
105	0	break;
106	0	}
107	535	q[1] = q[2] = q[3] = q[4] = 0,
108	535	q += 4;
109	671k	} else if (scan_char_decoder[ch] == ctype_space)
110	671k	DO_NOTHING;
111	642k	else if (ch == '~') {
112	641k	int i = 1;
113
114	641k	rlimit = pr->limit; /* Here we use the real "limit" */
115		/* Handle odd bytes. */
116	641k	if (p == rlimit) {
117	21	if (!last)
118	0	p--;
119	21	else if (ss->pdf_rules)
120	0	goto finish;
121	21	else
122	21	status = ERRC;
123	21	break;
124	21	}
125	641k	if ((int)(wlimit - q) < ccount - 1) {
126	131	status = 1;
127	131	p--;
128	131	break;
129	131	}
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	644k	while ((p + i <= rlimit) && (p[i] == 13 \|\| p[i] == 10))
139	2.92k	i++;
140	641k	if (p + i <= rlimit && p[i] != '>') {
141	641k	if (ss->pdf_rules) {
142	1	if (p[i] == 13 \|\| p[i] == 10) {
143	0	if (!last)
144	0	break;
145	1	} else {
146	1	p--;
147	1	}
148	641k	} else {
149	641k	if (p + i == rlimit) {
150	23	if (last)
151	23	status = ERRC;
152	0	else
153	0	p--; /* we'll see the '~' after filling the buffer */
154	23	}
155	641k	break;
156	641k	}
157	641k	}
158	197	finish:
159	197	if (p + i <= rlimit)
160	148	p += i; /* advance to the '>' */
161	49	else
162	49	p = rlimit; /* Can happen if the '>' is missing */
163	197	pw->ptr = q;
164	197	status = a85d_finish(ccount, word, pw);
165	197	q = pw->ptr;
166	197	break;
167	641k	} else { /* syntax error or exception */
168	499	status = ERRC;
169	499	break;
170	499	}
171	6.99M	}
172	649k	pw->ptr = q;
173	649k	if (status == 0 && last) {
174	649	if ((int)(wlimit - q) < ccount - 1)
175	0	status = 1;
176	649	else if (ss->require_eod)
177	642	status = ERRC;
178	7	else
179	7	status = a85d_finish(ccount, word, pw);
180	649	}
181	649k	pr->ptr = p;
182	649k	ss->odd = ccount;
183	649k	ss->word = word;
184	649k	return status;
185	649k	}
186		/* Handle the end of input data. */
187		static int
188		a85d_finish(int ccount, ulong word, stream_cursor_write * pw)
189	204	{
190		/* Assume there is enough room in the output buffer! */
191	204	byte *q = pw->ptr;
192	204	int status = EOFC;
193
194	204	switch (ccount) {
195	46	case 0:
196	46	break;
197	26	case 1: /* syntax error */
198	26	status = ERRC;
199	26	break;
200	50	case 2: /* 1 odd byte */
201	50	word = word * (85L * 85 * 85) + 85L * 85 * 85 - 1L;
202	50	goto o1;
203	48	case 3: /* 2 odd bytes */
204	48	word = word * (85L * 85) + 85L * 85L - 1L;
205	48	goto o2;
206	34	case 4: /* 3 odd bytes */
207	34	word = word * 85L + 84L;
208	34	q[3] = (byte) (word >> 8);
209	82	o2: q[2] = (byte) (word >> 16);
210	132	o1: q[1] = (byte) (word >> 24);
211	132	q += ccount - 1;
212	132	pw->ptr = q;
213	204	}
214	204	return status;
215	204	}
216
217		/* Stream template */
218		const stream_template s_A85D_template = {
219		&st_A85D_state, s_A85D_init, s_A85D_process, 2, 4
220		};