NeoMutt  2022-04-29-247-gc6aae8
Teaching an old dog new tricks
DOXYGEN
pgppacket.c
Go to the documentation of this file.
1
29#include "config.h"
30#include <stdbool.h>
31#include <stdio.h>
32#include <stdlib.h>
33#include "mutt/lib.h"
34#include "pgppacket.h"
35
36#define CHUNK_SIZE 1024
37
38static unsigned char *pbuf = NULL;
39static size_t plen = 0;
40
51static int read_material(size_t material, size_t *used, FILE *fp)
52{
53 if (*used + material >= plen)
54 {
55 size_t nplen = *used + material + CHUNK_SIZE;
56
57 unsigned char *p = realloc(pbuf, nplen);
58 if (!p)
59 {
60 perror("realloc");
61 return -1;
62 }
63 plen = nplen;
64 pbuf = p;
65 }
66
67 if (fread(pbuf + *used, 1, material, fp) < material)
68 {
69 perror("fread");
70 return -1;
71 }
72
73 *used += material;
74 return 0;
75}
76
85unsigned char *pgp_read_packet(FILE *fp, size_t *len)
86{
87 size_t used = 0;
88 LOFF_T startpos;
89 unsigned char ctb;
90 unsigned char b;
91 size_t material;
92
93 startpos = ftello(fp);
94 if (startpos < 0)
95 return NULL;
96
97 if (plen == 0)
98 {
101 }
102
103 if (fread(&ctb, 1, 1, fp) < 1)
104 {
105 if (!feof(fp))
106 perror("fread");
107 goto bail;
108 }
109
110 if (!(ctb & 0x80))
111 {
112 goto bail;
113 }
114
115 if (ctb & 0x40) /* handle PGP 5.0 packets. */
116 {
117 bool partial = false;
118 pbuf[0] = ctb;
119 used++;
120
121 do
122 {
123 if (fread(&b, 1, 1, fp) < 1)
124 {
125 perror("fread");
126 goto bail;
127 }
128
129 if (b < 192)
130 {
131 material = b;
132 partial = false;
133 }
134 else if (b <= 223)
135 {
136 material = (b - 192) * 256;
137 if (fread(&b, 1, 1, fp) < 1)
138 {
139 perror("fread");
140 goto bail;
141 }
142 material += b + 192;
143 partial = false;
144 }
145 else if (b < 255)
146 {
147 material = 1 << (b & 0x1f);
148 partial = true;
149 }
150 else
151 /* b == 255 */
152 {
153 unsigned char buf[4];
154 if (fread(buf, 4, 1, fp) < 1)
155 {
156 perror("fread");
157 goto bail;
158 }
159 material = (size_t) buf[0] << 24;
160 material |= buf[1] << 16;
161 material |= buf[2] << 8;
162 material |= buf[3];
163 partial = false;
164 }
165
166 if (read_material(material, &used, fp) == -1)
167 goto bail;
168
169 } while (partial);
170 }
171 else
172 /* Old-Style PGP */
173 {
174 int bytes = 0;
175 pbuf[0] = 0x80 | ((ctb >> 2) & 0x0f);
176 used++;
177
178 switch (ctb & 0x03)
179 {
180 case 0:
181 {
182 if (fread(&b, 1, 1, fp) < 1)
183 {
184 perror("fread");
185 goto bail;
186 }
187
188 material = b;
189 break;
190 }
191
192 case 1:
193 bytes = 2;
194 /* fallthrough */
195
196 case 2:
197 {
198 if (!bytes)
199 bytes = 4;
200
201 material = 0;
202
203 for (int i = 0; i < bytes; i++)
204 {
205 if (fread(&b, 1, 1, fp) < 1)
206 {
207 perror("fread");
208 goto bail;
209 }
210
211 material = (material << 8) + b;
212 }
213 break;
214 }
215
216 default:
217 goto bail;
218 }
219
220 if (read_material(material, &used, fp) == -1)
221 goto bail;
222 }
223
224 if (len)
225 *len = used;
226
227 return pbuf;
228
229bail:
230
231 (void) mutt_file_seek(fp, startpos, SEEK_SET);
232 return NULL;
233}
234
241{
242 plen = 0;
243 FREE(&pbuf);
244}
bool mutt_file_seek(FILE *fp, LOFF_T offset, int whence)
Wrapper for fseeko with error handling.
Definition: file.c:690
void * mutt_mem_malloc(size_t size)
Allocate memory on the heap.
Definition: memory.c:90
#define FREE(x)
Definition: memory.h:43
Convenience wrapper for the library headers.
static unsigned char * pbuf
Cached PGP data packet.
Definition: pgppacket.c:38
void pgp_release_packet(void)
Free the cached PGP packet.
Definition: pgppacket.c:240
static int read_material(size_t material, size_t *used, FILE *fp)
Read PGP data into a buffer.
Definition: pgppacket.c:51
#define CHUNK_SIZE
Amount of data to read at once.
Definition: pgppacket.c:36
unsigned char * pgp_read_packet(FILE *fp, size_t *len)
Read a PGP packet from a file.
Definition: pgppacket.c:85
static size_t plen
Length of cached packet.
Definition: pgppacket.c:39
Parse PGP data packets.