rust/src/libstd/sha1.rs

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#[doc ="
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An implementation of the SHA-1 cryptographic hash.
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First create a `sha1` object using the `sha1` constructor, then
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feed it input using the `input` or `input_str` methods, which may be
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called any number of times.
After the entire input has been fed to the hash read the result using
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the `result` or `result_str` methods.
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The `sha1` object may be reused to create multiple hashes by calling
the `reset` method.
"];
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/*
* A SHA-1 implementation derived from Paul E. Jones's reference
* implementation, which is written for clarity, not speed. At some
* point this will want to be rewritten.
*/
export sha1;
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#[doc = "The SHA-1 interface"]
iface sha1 {
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#[doc = "Provide message input as bytes"]
fn input(~[u8]);
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#[doc = "Provide message input as string"]
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fn input_str(str);
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#[doc = "
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Read the digest as a vector of 20 bytes. After calling this no further
input may be provided until reset is called.
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"]
fn result() -> ~[u8];
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#[doc = "
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Read the digest as a hex string. After calling this no further
input may be provided until reset is called.
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"]
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fn result_str() -> str;
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#[doc = "Reset the SHA-1 state for reuse"]
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fn reset();
}
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// Some unexported constants
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const digest_buf_len: uint = 5u;
const msg_block_len: uint = 64u;
const work_buf_len: uint = 80u;
const k0: u32 = 0x5A827999u32;
const k1: u32 = 0x6ED9EBA1u32;
const k2: u32 = 0x8F1BBCDCu32;
const k3: u32 = 0xCA62C1D6u32;
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#[doc = "Construct a `sha` object"]
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fn sha1() -> sha1 {
type sha1state =
{h: ~[mut u32],
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mut len_low: u32,
mut len_high: u32,
msg_block: ~[mut u8],
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mut msg_block_idx: uint,
mut computed: bool,
work_buf: @~[mut u32]};
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fn add_input(st: sha1state, msg: ~[u8]) {
/* FIXME: Should be typestate precondition (#2345) */
assert (!st.computed);
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for vec::each(msg) |element| {
st.msg_block[st.msg_block_idx] = element;
st.msg_block_idx += 1u;
st.len_low += 8u32;
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if st.len_low == 0u32 {
st.len_high += 1u32;
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if st.len_high == 0u32 {
// FIXME: Need better failure mode (#2346)
fail;
}
}
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if st.msg_block_idx == msg_block_len { process_msg_block(st); }
}
}
fn process_msg_block(st: sha1state) {
// FIXME: Make precondition (#2345)
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assert (vec::len(st.h) == digest_buf_len);
assert (vec::len(*st.work_buf) == work_buf_len);
let mut t: int; // Loop counter
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let w = st.work_buf;
// Initialize the first 16 words of the vector w
t = 0;
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while t < 16 {
let mut tmp;
tmp = (st.msg_block[t * 4] as u32) << 24u32;
tmp = tmp | (st.msg_block[t * 4 + 1] as u32) << 16u32;
tmp = tmp | (st.msg_block[t * 4 + 2] as u32) << 8u32;
tmp = tmp | (st.msg_block[t * 4 + 3] as u32);
w[t] = tmp;
t += 1;
}
// Initialize the rest of vector w
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while t < 80 {
let val = w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16];
w[t] = circular_shift(1u32, val);
t += 1;
}
let mut a = st.h[0];
let mut b = st.h[1];
let mut c = st.h[2];
let mut d = st.h[3];
let mut e = st.h[4];
let mut temp: u32;
t = 0;
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while t < 20 {
temp = circular_shift(5u32, a) + (b & c | !b & d) + e + w[t] + k0;
e = d;
d = c;
c = circular_shift(30u32, b);
b = a;
a = temp;
t += 1;
}
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while t < 40 {
temp = circular_shift(5u32, a) + (b ^ c ^ d) + e + w[t] + k1;
e = d;
d = c;
c = circular_shift(30u32, b);
b = a;
a = temp;
t += 1;
}
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while t < 60 {
temp =
circular_shift(5u32, a) + (b & c | b & d | c & d) + e + w[t] +
k2;
e = d;
d = c;
c = circular_shift(30u32, b);
b = a;
a = temp;
t += 1;
}
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while t < 80 {
temp = circular_shift(5u32, a) + (b ^ c ^ d) + e + w[t] + k3;
e = d;
d = c;
c = circular_shift(30u32, b);
b = a;
a = temp;
t += 1;
}
st.h[0] = st.h[0] + a;
st.h[1] = st.h[1] + b;
st.h[2] = st.h[2] + c;
st.h[3] = st.h[3] + d;
st.h[4] = st.h[4] + e;
st.msg_block_idx = 0u;
}
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fn circular_shift(bits: u32, word: u32) -> u32 {
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ret word << bits | word >> 32u32 - bits;
}
fn mk_result(st: sha1state) -> ~[u8] {
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if !st.computed { pad_msg(st); st.computed = true; }
let mut rs: ~[u8] = ~[];
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for vec::each(st.h) |hpart| {
let a = (hpart >> 24u32 & 0xFFu32) as u8;
let b = (hpart >> 16u32 & 0xFFu32) as u8;
let c = (hpart >> 8u32 & 0xFFu32) as u8;
let d = (hpart & 0xFFu32) as u8;
rs = vec::append(rs, ~[a, b, c, d]);
}
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ret rs;
}
/*
* According to the standard, the message must be padded to an even
* 512 bits. The first padding bit must be a '1'. The last 64 bits
* represent the length of the original message. All bits in between
* should be 0. This function will pad the message according to those
* rules by filling the msg_block vector accordingly. It will also
* call process_msg_block() appropriately. When it returns, it
* can be assumed that the message digest has been computed.
*/
fn pad_msg(st: sha1state) {
// FIXME: Should be a precondition (#2345)
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assert (vec::len(st.msg_block) == msg_block_len);
/*
* Check to see if the current message block is too small to hold
* the initial padding bits and length. If so, we will pad the
* block, process it, and then continue padding into a second block.
*/
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if st.msg_block_idx > 55u {
st.msg_block[st.msg_block_idx] = 0x80u8;
st.msg_block_idx += 1u;
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while st.msg_block_idx < msg_block_len {
st.msg_block[st.msg_block_idx] = 0u8;
st.msg_block_idx += 1u;
}
process_msg_block(st);
} else {
st.msg_block[st.msg_block_idx] = 0x80u8;
st.msg_block_idx += 1u;
}
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while st.msg_block_idx < 56u {
st.msg_block[st.msg_block_idx] = 0u8;
st.msg_block_idx += 1u;
}
// Store the message length as the last 8 octets
st.msg_block[56] = (st.len_high >> 24u32 & 0xFFu32) as u8;
st.msg_block[57] = (st.len_high >> 16u32 & 0xFFu32) as u8;
st.msg_block[58] = (st.len_high >> 8u32 & 0xFFu32) as u8;
st.msg_block[59] = (st.len_high & 0xFFu32) as u8;
st.msg_block[60] = (st.len_low >> 24u32 & 0xFFu32) as u8;
st.msg_block[61] = (st.len_low >> 16u32 & 0xFFu32) as u8;
st.msg_block[62] = (st.len_low >> 8u32 & 0xFFu32) as u8;
st.msg_block[63] = (st.len_low & 0xFFu32) as u8;
process_msg_block(st);
}
impl of sha1 for sha1state {
fn reset() {
// FIXME: Should be typestate precondition (#2345)
assert (vec::len(self.h) == digest_buf_len);
self.len_low = 0u32;
self.len_high = 0u32;
self.msg_block_idx = 0u;
self.h[0] = 0x67452301u32;
self.h[1] = 0xEFCDAB89u32;
self.h[2] = 0x98BADCFEu32;
self.h[3] = 0x10325476u32;
self.h[4] = 0xC3D2E1F0u32;
self.computed = false;
}
fn input(msg: ~[u8]) { add_input(self, msg); }
fn input_str(msg: str) { add_input(self, str::bytes(msg)); }
fn result() -> ~[u8] { ret mk_result(self); }
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fn result_str() -> str {
let r = mk_result(self);
let mut s = "";
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for vec::each(r) |b| { s += uint::to_str(b as uint, 16u); }
ret s;
}
}
let st = {
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h: vec::to_mut(vec::from_elem(digest_buf_len, 0u32)),
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mut len_low: 0u32,
mut len_high: 0u32,
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msg_block: vec::to_mut(vec::from_elem(msg_block_len, 0u8)),
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mut msg_block_idx: 0u,
mut computed: false,
work_buf: @vec::to_mut(vec::from_elem(work_buf_len, 0u32))
};
let sh = st as sha1;
sh.reset();
ret sh;
}
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#[cfg(test)]
mod tests {
#[test]
fn test() unsafe {
type test = {input: str, output: ~[u8]};
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fn a_million_letter_a() -> str {
let mut i = 0;
let mut rs = "";
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while i < 100000 { rs += "aaaaaaaaaa"; i += 1; }
ret rs;
}
// Test messages from FIPS 180-1
let fips_180_1_tests: ~[test] =
~[{input: "abc",
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output:
~[0xA9u8, 0x99u8, 0x3Eu8, 0x36u8,
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0x47u8, 0x06u8, 0x81u8, 0x6Au8,
0xBAu8, 0x3Eu8, 0x25u8, 0x71u8,
0x78u8, 0x50u8, 0xC2u8, 0x6Cu8,
0x9Cu8, 0xD0u8, 0xD8u8, 0x9Du8]},
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{input:
"abcdbcdecdefdefgefghfghighij" +
"hijkijkljklmklmnlmnomnopnopq",
output:
~[0x84u8, 0x98u8, 0x3Eu8, 0x44u8,
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0x1Cu8, 0x3Bu8, 0xD2u8, 0x6Eu8,
0xBAu8, 0xAEu8, 0x4Au8, 0xA1u8,
0xF9u8, 0x51u8, 0x29u8, 0xE5u8,
0xE5u8, 0x46u8, 0x70u8, 0xF1u8]},
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{input: a_million_letter_a(),
output:
~[0x34u8, 0xAAu8, 0x97u8, 0x3Cu8,
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0xD4u8, 0xC4u8, 0xDAu8, 0xA4u8,
0xF6u8, 0x1Eu8, 0xEBu8, 0x2Bu8,
0xDBu8, 0xADu8, 0x27u8, 0x31u8,
0x65u8, 0x34u8, 0x01u8, 0x6Fu8]}];
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// Examples from wikipedia
let wikipedia_tests: ~[test] =
~[{input: "The quick brown fox jumps over the lazy dog",
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output:
~[0x2fu8, 0xd4u8, 0xe1u8, 0xc6u8,
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0x7au8, 0x2du8, 0x28u8, 0xfcu8,
0xedu8, 0x84u8, 0x9eu8, 0xe1u8,
0xbbu8, 0x76u8, 0xe7u8, 0x39u8,
0x1bu8, 0x93u8, 0xebu8, 0x12u8]},
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{input: "The quick brown fox jumps over the lazy cog",
output:
~[0xdeu8, 0x9fu8, 0x2cu8, 0x7fu8,
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0xd2u8, 0x5eu8, 0x1bu8, 0x3au8,
0xfau8, 0xd3u8, 0xe8u8, 0x5au8,
0x0bu8, 0xd1u8, 0x7du8, 0x9bu8,
0x10u8, 0x0du8, 0xb4u8, 0xb3u8]}];
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let tests = fips_180_1_tests + wikipedia_tests;
fn check_vec_eq(v0: ~[u8], v1: ~[u8]) {
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assert (vec::len::<u8>(v0) == vec::len::<u8>(v1));
let len = vec::len::<u8>(v0);
let mut i = 0u;
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while i < len {
let a = v0[i];
let b = v1[i];
assert (a == b);
i += 1u;
}
}
// Test that it works when accepting the message all at once
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let sh = sha1::sha1();
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for vec::each(tests) |t| {
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sh.input_str(t.input);
let out = sh.result();
check_vec_eq(t.output, out);
sh.reset();
}
// Test that it works when accepting the message in pieces
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for vec::each(tests) |t| {
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let len = str::len(t.input);
let mut left = len;
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while left > 0u {
let take = (left + 1u) / 2u;
sh.input_str(str::slice(t.input, len - left,
take + len - left));
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left = left - take;
}
let out = sh.result();
check_vec_eq(t.output, out);
sh.reset();
}
}
}
// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End: