/src/ghostpdl/base/sa85d.c

Source (jump to first uncovered line)
/* Copyright (C) 2001-2022 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.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, 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: 2022-10-31 07:00

Line	Count	Source (jump to first uncovered line)
1		/* Copyright (C) 2001-2022 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., 1305 Grant Avenue - Suite 200, Novato,
13		CA 94945, U.S.A., +1(415)492-9861, 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	225	{
31	225	stream_A85D_state const ss = (stream_A85D_state ) st;
32
33	225	s_A85D_init_inline(ss);
34	225	return 0;
35	225	}
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	113k	{
43	113k	stream_A85D_state const ss = (stream_A85D_state ) st;
44	113k	register const byte *p = pr->ptr;
45	113k	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	113k	const byte rlimit = pr->limit - (last ? 0 : 7); / max EOD len + 1 */
51	113k	const byte *r = max(p, rlimit);
52	113k	byte *wlimit = pw->limit;
53	113k	int ccount = ss->odd;
54	113k	ulong word = ss->word;
55	113k	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	287k	while (r < pr->limit) {
60	173k	if (*++r == '~')
61	721k	while (r < pr->limit)
62	614k	if (*++r == '>') {
63		/* we have both characters of a complete EOD. */
64	16	rlimit = pr->limit; /* go ahead and process everything */
65	16	r = rlimit; /* break out of the while loops */
66	16	break;
67	16	}
68	173k	}
69	2.45M	while (p < rlimit) {
70	2.45M	int ch = *++p;
71	2.45M	uint ccode = ch - '!';
72
73	2.45M	if (ccode < 85) { /* catches ch < '!' as well */
74	2.28M	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	457k	if (wlimit - q < 4) {
80	561	p--;
81	561	status = 1;
82	561	break;
83	561	}
84		/* Check for overflow condition, throw ioerror if so */
85	456k	if (word >= 0x03030303 && ccode > 0) {
86	85	status = ERRC;
87	85	break;
88	85	}
89	456k	word = word * 85 + ccode;
90	456k	q[1] = (byte) (word >> 24);
91	456k	q[2] = (byte) (word >> 16);
92	456k	q[3] = (byte) ((uint) word >> 8);
93	456k	q[4] = (byte) word;
94	456k	q += 4;
95	456k	word = 0;
96	456k	ccount = 0;
97	1.82M	} else {
98	1.82M	word = word * 85 + ccode;
99	1.82M	++ccount;
100	1.82M	}
101	2.28M	} else if (ch == 'z' && ccount == 0) {
102	258	if (wlimit - q < 4) {
103	0	p--;
104	0	status = 1;
105	0	break;
106	0	}
107	258	q[1] = q[2] = q[3] = q[4] = 0,
108	258	q += 4;
109	168k	} else if (scan_char_decoder[ch] == ctype_space)
110	168k	DO_NOTHING;
111	110k	else if (ch == '~') {
112	110k	int i = 1;
113
114	110k	rlimit = pr->limit; /* Here we use the real "limit" */
115		/* Handle odd bytes. */
116	110k	if (p == rlimit) {
117	15	if (!last)
118	0	p--;
119	15	else if (ss->pdf_rules)
120	0	goto finish;
121	15	else
122	15	status = ERRC;
123	15	break;
124	15	}
125	110k	if ((int)(wlimit - q) < ccount - 1) {
126	15	status = 1;
127	15	p--;
128	15	break;
129	15	}
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	110k	while ((p + i <= rlimit) && (p[i] == 13 \|\| p[i] == 10))
139	502	i++;
140	110k	if (p + i <= rlimit && p[i] != '>') {
141	110k	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	110k	} else {
149	110k	if (p + i == rlimit) {
150	9	if (last)
151	9	status = ERRC;
152	0	else
153	0	p--; /* we'll see the '~' after filling the buffer */
154	9	}
155	110k	break;
156	110k	}
157	110k	}
158	48	finish:
159	48	if (p + i <= rlimit)
160	24	p += i; /* advance to the '>' */
161	24	else
162	24	p = rlimit; /* Can happen if the '>' is missing */
163	48	pw->ptr = q;
164	48	status = a85d_finish(ccount, word, pw);
165	48	q = pw->ptr;
166	48	break;
167	110k	} else { /* syntax error or exception */
168	275	status = ERRC;
169	275	break;
170	275	}
171	2.45M	}
172	113k	pw->ptr = q;
173	113k	if (status == 0 && last) {
174	341	if ((int)(wlimit - q) < ccount - 1)
175	1	status = 1;
176	340	else if (ss->require_eod)
177	340	status = ERRC;
178	0	else
179	0	status = a85d_finish(ccount, word, pw);
180	341	}
181	113k	pr->ptr = p;
182	113k	ss->odd = ccount;
183	113k	ss->word = word;
184	113k	return status;
185	113k	}
186		/* Handle the end of input data. */
187		static int
188		a85d_finish(int ccount, ulong word, stream_cursor_write * pw)
189	48	{
190		/* Assume there is enough room in the output buffer! */
191	48	byte *q = pw->ptr;
192	48	int status = EOFC;
193
194	48	switch (ccount) {
195	11	case 0:
196	11	break;
197	9	case 1: /* syntax error */
198	9	status = ERRC;
199	9	break;
200	18	case 2: /* 1 odd byte */
201	18	word = word * (85L * 85 * 85) + 85L * 85 * 85 - 1L;
202	18	goto o1;
203	6	case 3: /* 2 odd bytes */
204	6	word = word * (85L * 85) + 85L * 85L - 1L;
205	6	goto o2;
206	4	case 4: /* 3 odd bytes */
207	4	word = word * 85L + 84L;
208	4	q[3] = (byte) (word >> 8);
209	10	o2: q[2] = (byte) (word >> 16);
210	28	o1: q[1] = (byte) (word >> 24);
211	28	q += ccount - 1;
212	28	pw->ptr = q;
213	48	}
214	48	return status;
215	48	}
216
217		/* Stream template */
218		const stream_template s_A85D_template = {
219		&st_A85D_state, s_A85D_init, s_A85D_process, 2, 4
220		};