openssl1.0/crypto/comp/c_rle.c

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2019-08-09 10:00:55 +02:00
#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);
}