Hi,
The problem comes certainly from the line calling SHA_Update : you are
always hashing DATA_SIZE_IN_BYTES byte of data but the command line
tool hashes only the exact length of the file. You should replace
DATA_SIZE_IN_BYTES with strlen(data) .
Cheers,
Mounir IDRASSI
IDRIX
http://www.idrix.net
k b a écrit :
Hi,
here's what i'm doing, i comparing the sha1 hash generated with the
command line tool
#>openssl sha1 -out digest.txt -binary smallplaintxt
against the one created by my c program.
i load both the hash using hexedit to see if they are the same but to
my surprise they differ.
here's what i'm doing in my c file.
#define DATA_SIZE_IN_BYTES 5
int main (int argc, char *argv[])
{
SHA_CTX shaCTX;
static unsigned char hash[SHA_DIGEST_LENGTH];
char * generateHashFile = argv[1];
if (!SHA_Init(&shaCTX)) {
return -1;
}
char *data = (char *) readPlainText();
printf("length %d, %s\n", strlen(data), data);
SHA_Update(&shaCTX, data, (sizeof(char) * DATA_SIZE_IN_BYTES));
SHA_Final(hash, &shaCTX);
OPENSSL_cleanse(&shaCTX, sizeof(shaCTX));
FILE *fp;
printf("writing hash to %s\n", generateHashFile);
fp = fopen(generateHashFile, "wb");
if (ferror(fp) != 0) {
return -1;
}
int i = 0;
for (i = 0; i < SHA_DIGEST_LENGTH; i++) {
putc(hash[i], fp);
}
fclose(fp);
return 0;
}
char * readPlainText()
{
char *plainTxt = malloc(sizeof(char) * DATA_SIZE_IN_BYTES);
if (plainTxt == NULL ) printf("malloc failed\n");
memset(plainTxt, 0x00, sizeof(char) * DATA_SIZE_IN_BYTES);
FILE *fp ;
int ch = -1;
fp = fopen("smallplaintxt", "rb");
if (fp == NULL || (ferror(fp) != 0))
{
printf("unable to read plain text file \n");
exit(-1);
}
char * ptr = plainTxt;
while ( (ch = getc(fp)) != EOF )
{
printf("%c\n", (char) ch);
*ptr++ = (char) ch;
}
fclose(fp);
return plainTxt;
}
any insight would be appreciated.
KB
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______________________________________________________________________
OpenSSL Project http://www.openssl.org
Development Mailing List openssl-dev@openssl.org
Automated List Manager [EMAIL PROTECTED]
