SHA384 online Hash Generator

Is it possible to decrypt(retain the actual string) the password which is saved in db using SHA1 algorithm.

Example:If password is "password" and it is stored in db as "sha1$4fb4c$2bc693f8a86e2d87f757c382a32e3d50fc945b24",is any chance to retain the same "password"(string) from "sha1$4fb4c$2bc693f8a86e2d87f757c382a32e3d50fc945b24"

I read Hash collision in gitfrom this it appears what very unlikely what two different commits in git will have same hash.

But what about all commits not only git? My application working with git,svn,hg - can i assume that there will be no different commits with same hash?

For now i'm trying to deside how stop my application from creation same commits from different forks of one repo in db.I figure out what i can do hash column in db unique and if i already have commit with this hash - just skip it.But i dont know is there is a big/small chance that i will skip unique commit and not the duplicate of already existing commit.

I have an old version of netbsd which I am using. I wanted to configure the openssh to use strong ciphers and macs, but when saw the available macs it did not have support for SHA256 and higher. macs supported are

macs[] = {    { "hmac-sha1",          SSH_EVP, EVP_sha1, 0, -1, -1 },    { "hmac-sha1-96",       SSH_EVP, EVP_sha1, 96, -1, -1 },    { "hmac-md5",           SSH_EVP, EVP_md5, 0, -1, -1 },    { "hmac-md5-96",        SSH_EVP, EVP_md5, 96, -1, -1 },    { "hmac-ripemd160",     SSH_EVP, EVP_ripemd160, 0, -1, -1 },    { "hmac-ripemd160@openssh.com", SSH_EVP, EVP_ripemd160, 0, -1, -1 },#ifdef UMAC_HAS_BEEN_UNBROKEN    { "umac-64@openssh.com",    SSH_UMAC, NULL, 0, 128, 64 },#endif    { NULL,             0, NULL, 0, -1, -1 }};

But when I check for supported ciphers for key exchange, I find that SHA256 can be used

#define KEX_DH1         "diffie-hellman-group1-sha1"#define KEX_DH14        "diffie-hellman-group14-sha1"#define KEX_DHGEX_SHA1      "diffie-hellman-group-exchange-sha1"#define KEX_DHGEX_SHA256    "diffie-hellman-group-exchange-sha256"

How is that. If there is an implementation of SHA256 in my netbsd openssh, why isn't it available as a mac cipher?

I'm following on this tutorial and in part 2 (picture below) it shows that the SHA256 yields a result different than what I get when I ran my python code:

the string is: 0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B23522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582BA6

While the tutorial SHA256 comes to: 600FFE422B4E00731A59557A5CCA46CC183944191006324A447BDB2D98D4B408

My short python shows:

sha_result = sha256(bitconin_addresss).hexdigest().upper()print sha_result32511E82D56DCEA68EB774094E25BAB0F8BDD9BC1ECA1CEEDA38C7A43ACEDDCE

in fact, any online sha256 shows the same python result; so am I missing here something?

Which is the standard size of the MAC generated with SHA-2?

it is safe if I trunk the message and then send it to destination ?

Thank you in advance for your consideration