Online SHA1 Hash Generator

How do I copy a char* to a unsigned char* correctly in C. Following is my code

int main(int argc, char **argv){    unsigned char *digest;    digest = malloc(20 * sizeof(unsigned char));    strncpy(digest, argv[2], 20);    return 0;}

I would like to correctly copy char* array to unsigned char* array. I get the following warning using the above code

warning: pointer targets in passing argument 1 of âstrncpyâ differ in signedness 

EDIT: Adding more information, My requirement is that the caller provide a SHA digest to the main function as a string on command line and the main function internally save it in the digest. SHA digest can be best represented using a unsigned char.

Now the catch is that I can't change the signature of the main function (** char) because the main function parses other arguments which it requires as char* and not unsigned char*.

I need to find collision of "last 6-bytes of SHA-1 digest". Here is my Python code (have deleted unrelated part):

import hashlibimport osimport binasciistart_string = os.urandom(20)x0 = binascii.hexlify(start_string)hash_value = hashlib.sha1(x0)x1 = hash_value.hexdigest()while x0[28:]!=x1[28:]:  x0 = x1  x1_hash = hashlib.sha1(x0)  x1 = x1_hash.hexdigest()else:  print x0  print x1

I am using a Thinkpad T400 laptop (Intel Core 2 Duo 2.8GHz, 6 MB L2 cache, 800 MHz). How long it can find the collision? Anyway to improve the code to make it faster? (this Python)

I'd like to generate a SHA1 hash continually from a stream that is updated as data is read from the stream.

What I need, but won't work:

const crypto = require('crypto');const hash = crypto.createHash('sha256');hash.update('abc');console.log(hash.digest('hex')); // hash of abchash.update('def');console.log(hash.digest('hex')); // hash of abcdef

This won't work since once hash.digest() is called, you cannot call hash.update() again.

How can I get the hash for the string each time a chunk is added?... without loading the whole string in memory.... without writing the whole string to the hash again but instead reusing the already written chunks plus the new chunk.

All the examples from the Node.js docs requires the stream to end before the SHA1 is calculated. Once this occurs you cannot write data into the stream anymore.

https://nodejs.org/api/crypto.html#crypto_class_hash

const crypto = require('crypto');const hash = crypto.createHash('sha256');hash.on('readable', () => {  const data = hash.read();  if (data) {    console.log(data.toString('hex'));    // Prints:    //   6a2da20943931e9834fc12cfe5bb47bbd9ae43489a30726962b576f4e3993e50  }});hash.write('some data to hash');hash.end();

I would like:

const crypto = require('crypto');const hash = crypto.createHash('sha256');hash.on('readable', () => {  const data = hash.read();  if (data) {    console.log(data.toString('hex'));  }});hash.write('abc'); // generate hash of "abc"hash.write('def');hash.end(); // generate hash of "abcdef"

According to this answer you can compute sha1 in blocks.

Can SHA-1 algorithm be computed on a stream? With low memory footprint?

So you should be able to reuse the calculation from the previous chunks in the stream without having to recalculate as a whole?

The pseudo code from wikipedia shows processing in 512 bit chunks

https://en.wikipedia.org/wiki/SHA-1

Note 1: All variables are unsigned 32-bit quantities and wrap modulo 232 when calculating, except for        ml, the message length, which is a 64-bit quantity, and        hh, the message digest, which is a 160-bit quantity.Note 2: All constants in this pseudo code are in big endian.        Within each word, the most significant byte is stored in the leftmost byte positionInitialize variables:h0 = 0x67452301h1 = 0xEFCDAB89h2 = 0x98BADCFEh3 = 0x10325476h4 = 0xC3D2E1F0ml = message length in bits (always a multiple of the number of bits in a character).Pre-processing:append the bit '1' to the message e.g. by adding 0x80 if message length is a multiple of 8 bits.append 0 ≤ k < 512 bits '0', such that the resulting message length in bits   is congruent to −64 ≡ 448 (mod 512)append ml, the original message length, as a 64-bit big-endian integer. Thus, the total length is a multiple of 512 bits.Process the message in successive 512-bit chunks:break message into 512-bit chunksfor each chunk    break chunk into sixteen 32-bit big-endian words w[i], 0 ≤ i ≤ 15    Extend the sixteen 32-bit words into eighty 32-bit words:    for i from 16 to 79        w[i] = (w[i-3] xor w[i-8] xor w[i-14] xor w[i-16]) leftrotate 1    Initialize hash value for this chunk:    a = h0    b = h1    c = h2    d = h3    e = h4    Main loop:[3][54]    for i from 0 to 79        if 0 ≤ i ≤ 19 then            f = (b and c) or ((not b) and d)            k = 0x5A827999        else if 20 ≤ i ≤ 39            f = b xor c xor d            k = 0x6ED9EBA1        else if 40 ≤ i ≤ 59            f = (b and c) or (b and d) or (c and d)             k = 0x8F1BBCDC        else if 60 ≤ i ≤ 79            f = b xor c xor d            k = 0xCA62C1D6        temp = (a leftrotate 5) + f + e + k + w[i]        e = d        d = c        c = b leftrotate 30        b = a        a = temp    Add this chunk's hash to result so far:    h0 = h0 + a    h1 = h1 + b     h2 = h2 + c    h3 = h3 + d    h4 = h4 + eProduce the final hash value (big-endian) as a 160-bit number:hh = (h0 leftshift 128) or (h1 leftshift 96) or (h2 leftshift 64) or (h3 leftshift 32) or h4

Im connecting an Siemens S7-1200 series to a mysql database.I got TCP/IP working, but the handshake c.q. password isn't recognized by MySQL (acces denied for 'user'@'PLCIP using password: yes).I tried SHA1(pass), SHA1(SHA1(pass)) and SHA1(20byte salt+SHA1(SHA1(pass)) but keeping the same error.Doesn't MySQL 5.7 support this anymore or do I make a mistake over here?SHA1 result in the right hash (tested by hash calculator).Can someone help me out how to perform the right handshake?

Regards,John

i want to check my passwords with help of the sha1-hashed pw files from haveibeenpawned. And of course I want to do it locally ;-). In order to be able to compare those hashes with a sha1-hash, that i created from a password, I used two different approaches:

php:

  $pw='1234';  $pwhash = strtoupper(sha1($pw));

c:

  char pw[] = "1234";  size_t pwlen = sizeof(pw);  SHA1(pw, pwlen, pwhash);   // and convert binary to Hex-string "02X" ...

First question is: Why the hashes are different? Is there a hidden salt?And why the won't match with the hashes of Troy Hunt?

[Update] Meanwhile the php hash is matched in the list. I didn't limit the string to 40 chars and had "\r" and "\n" in it.