1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/objects.h>
#include <openssl/comp.h>
static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in,
unsigned int ilen);
static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in,
unsigned int ilen);
static COMP_METHOD rle_method = {
NID_rle_compression,
LN_rle_compression,
NULL,
NULL,
rle_compress_block,
rle_expand_block,
NULL,
NULL,
};
COMP_METHOD *COMP_rle(void)
{
return (&rle_method);
}
static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in,
unsigned int ilen)
{
if (ilen == 0)
return 0;
if (olen <= ilen)
return -1;
*(out++) = 0;
memcpy(out, in, ilen);
return (ilen + 1);
}
static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
unsigned int olen, unsigned char *in,
unsigned int ilen)
{
int i;
if (ilen == 0)
return 0;
if (olen < (ilen - 1))
return -1;
i = *(in++);
if (i != 0)
return -1;
memcpy(out, in, ilen - 1);
return (ilen - 1);
}
|