Online SHA1 hash Generator

I am in the quite fortunate position to say that my code for a simple SHA1 Hash generator seems to work well. Unfortunately I know that this Arduino Program runs with Little Endianness and the description on the method to generate a hash requires the original message length to be appended as Big Endian integer.

1. This means for the message char m[] = "Applecake" I would have 9*8 bits, expressed as a 64-bit unsigned integer that is 0x0000 0000 0000 0048. That means, stored with Little Endian, the memory would look like this: 0x0048 0000 0000 0000.

2. As described in Section 4 of RFC 3174 Step c) I have to

   Obtain the 2-word representation of l, the number of bits in the original message. If l < 2^32 then the first word is all zeroes. Append these two words to the padded message.

   So with my memory as described above, I would have to convert it to Big Endian first and then append the lower 32 bits to the padded message.

The problem is, that if I do convert the Endianness of the length, which I know is Little Endian, I get the wrong padding and therefore the wrong hash.

Why is my code working without conversion of the Endianness?
Which limitations does my code have concerning the compatibility across different Arduinos, microcontrollers and compilers?

// initialize variablesh0 = 0x67452301;h1 = 0xEFCDAB89;h2 = 0x98BADCFE;h3 = 0x10325476;h4 = 0xC3D2E1F0;// calculate the number of required cycles and create a blocks arrayuint32_t numCycles = ((ml+65)/512)+1;uint32_t blocks[numCycles*16] = {};// copy messageuint32_t messageBytes = ml/8 + (ml%8!=0 ? 1 : 0);for (uint32_t i = 0; i < messageBytes; i++) {    blocks[i/4] |= ((uint32_t) message[i]) << (8*(3-(i%4)));}// append the 1 bitblocks[ml/32] |= ((uint32_t) 0b1) << (31-(ml%32));// append the 64-bit big endian ml at the endif (ml < 0x80000000)    blocks[(numCycles*16)-1] = (uint32_t) ml;else {    blocks[(numCycles*16)-2] = (uint32_t) ml;    blocks[(numCycles*16)-1] = (uint32_t) (ml >> 32);}for (uint32_t iCycle = 0; iCycle < numCycles; iCycle++) {    // initalize locals    uint32_t w[80] = {};    uint32_t a = h0, b = h1, c = h2, d = h3, e = h4;    for (uint8_t i = 0; i < 80; i++) {        // convert words to big-endian and copy to 80-elem array        if (i < 16)            w[i] = blocks[(iCycle*16)+i];        else            w[i] = rotL((w[i-3]^w[i-8]^w[i-14]^w[i-16]), 1);        // run defined formulas        uint32_t f, k, temp;        if (i < 20) {            f = (b & c) | ((~b) & d);            k = 0x5A827999;        }        else if (i < 40) {            f = b ^ c ^ d;            k = 0x6ED9EBA1;        }        else if (i < 60) {            f = (b & c) | (b & d) | (c & d);            k = 0x8F1BBCDC;        }        else {            f = b ^ c ^ d;            k = 0xCA62C1D6;        }        temp = rotL(a, 5) + f + e + k + w[i];        e = d; d = c; c = rotL(b, 30); b = a; a = temp;    }    // write back the results    h0 += a; h1 += b; h2 += c; h3 += d; h4 += e;}

I have generated my SHA1 code from my keystore but when I try to create an OAuth client 2.0, Google game console is giving me the error: "Certificate fingerprint is invalid".

http://oi68.tinypic.com/23lgt2g.jpg

http://oi64.tinypic.com/iqy2rb.jpg

Anyone knows why this happens?How do I fix this?

I was trying to work with hashcash to generate hash with certain number of leading zeros for a random string. I cannot find much resource online. If any help is possible.

When you sign and distribute your Xamarin Android apps the wizard helps you create keystore for your app. However, wherever I looked on my mac I could not find the actual .keystore file anywhere. So how am I supposed to get the SHA-1 fingerprint for that keystore?

I've created a MongoDB user with the password "86f5ec4fd396195a99b6c2545180676bbb62b86327314399829b4ea00c53":

@mongo_client.command(  {    createUser: "my_user",    pwd:        "86f5ec4fd396195a99b6c2545180676bbb62b86327314399829b4ea00c53",    roles:      ["readWrite"]  })

When I check the SCRAM hashed password in MongoDB:

pp @mongo_client.command({usersInfo: 1, showCredentials: true}).documents.first["users"]

the output is:

[{"_id"=>"5cecd7773ab42f4cff2f08dd.myuser",  "user"=>"myuser",  "db"=>"5cecd7773ab42f4cff2f08dd",  "credentials"=>   {"SCRAM-SHA-1"=>     {"iterationCount"=>10000,      "salt"=>"PLoIONQY4paDiiCdwiyBMQ==",      "storedKey"=>"joVFIIyEgI9sE9nXXS4RXcBeLv4=",      "serverKey"=>"C3AZBq9hTuwMQtpJXdqZa3ZYKK8="},    "SCRAM-SHA-256"=>     {"iterationCount"=>15000,      "salt"=>"foJnBgfiaKjhAkg9KFSqKGuyb4uhbfvgPoqgpA==",      "storedKey"=>"8TsZfXwIz9XEKtFY0Ug0XjSn9QAwB7/6XpFc4AjW7Wc=",      "serverKey"=>"9R9Mj9u4cymqqHGdHBAm4xOjmkuDYQso+jECik4n+Gw="}},  "roles"=>[{"role"=>"readWrite", "db"=>"5cecd7773ab42f4cff2f08dd"}],  "mechanisms"=>["SCRAM-SHA-1", "SCRAM-SHA-256"]}]

How do I (using Ruby) convert my original cleartext password to the SCRAM-SHA-1/SCRAM-SHA-256 versions seen above?

The docs writes this about SCRAM:

In the implementation of SCRAM authentication mechanisms (e.g. SCRAM-SHA-1 and SCRAM-SHA-256), drivers MUST maintain a cache of computed SCRAM credentials. The cache entries SHOULD be identified by the password, salt, iteration count, and a value that uniquely identifies the authentication mechanism (e.g. "SHA1" or "SCRAM-SHA-256").

The cache entry value MUST be either the saltedPassword parameter or the combination of the clientKey and serverKey parameters.