Merge branch '19-add-tiny-hash-function-for-small-prime-fields'

Author: steven-varga

src/TinyCrypto.jl

@@ -3,17 +3,20 @@ module TinyCrypto
 include("macroes.jl")
 include("utils.jl")
 include("field.jl")
+include("core/hash.jl")
 
 using .Macroes
 using .Field
 using .Utils
+using .Hash
 
 include("core/ecpoint.jl")
 include("curves/weierstrass.jl")
 include("curves/montgomery.jl")
 include("curves/edwards.jl")
     # Re-export core symbols for public API
     export @define, @attach
+    export H, H₈, H₁₆, H8, H16
     export Fp, 𝔽ₚ
     export is_prime, primes, mod_inverse
     export Point, ∞, Curve, ECPoint, Infinity

src/core/hash.jl

@@ -0,0 +1,70 @@
+module Hash
+    export H, H₈,H₁₆, H8, H16
+
+    const INIT8 = UInt8[0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0]
+    const K8 = UInt8[0x1f, 0x2b, 0x3c, 0x4d, 0x5e, 0x6a, 0x7d, 0x8e]
+
+    rotate(x::UInt8, n::Int) = ((x >> n) | (x << (8 - n))) % UInt8
+    rotate(x::UInt16, n::Int) = ((x >> n) | (x << (16 - n))) % UInt16
+
+    function pad8(msg::Vector{UInt8})
+        len = length(msg)
+        padded = copy(msg)
+        push!(padded, 0x80)
+        while (length(padded) % 8) != 7
+            push!(padded, 0x00)
+        end
+        push!(padded, UInt8(len % 256))
+        return padded
+    end
+
+    function compress_block8(block::Vector{UInt8}, state::Vector{UInt8})
+        W = copy(block)
+        for i in 1:8
+            W[i] ⊻= K8[i]
+            W[i] = rotate(W[i], i % 8 + 1)
+        end
+        for i in 1:8
+            state[i] = rotate(state[i] ⊻ W[i], i)
+        end
+    end
+
+    function tiny_hash8(msg::Vector{UInt8})
+        padded = pad8(msg)
+        state = copy(INIT8)
+        for i in 1:8:length(padded)
+            block = padded[i:i+7]
+            compress_block8(block, state)
+        end
+        result = state[1]
+        for i in 2:8
+            result ⊻= rotate(state[i], i)
+        end
+        return result
+    end
+    tiny_hash8(msg::String) = tiny_hash8(Vector{UInt8}(codeunits(msg)))
+
+    function tiny_hash16(msg::Vector{UInt8})
+        acc = UInt16(0xabcd)
+        for (i, byte) in enumerate(msg)
+            acc ⊻= UInt16(byte) << (i % 8)
+            acc = (acc << 5) ⊻ (acc >> 3)
+        end
+        return acc
+    end
+    tiny_hash16(msg::String) = tiny_hash16(Vector{UInt8}(codeunits(msg)))
+
+    function H8(msg::Union{String, Vector{UInt8}})
+        bytes = msg isa String ? Vector{UInt8}(codeunits(msg)) : msg
+        return tiny_hash8(bytes)
+    end
+
+    function H16(msg::Union{String, Vector{UInt8}})
+        bytes = msg isa String ? Vector{UInt8}(codeunits(msg)) : msg
+        return tiny_hash16(bytes)
+    end
+
+    H(msg::Union{String, Vector{UInt8}}) = H8(msg)
+    H₈(msg::Union{String, Vector{UInt8}}) = H8(msg)
+    H₁₆(msg::Union{String, Vector{UInt8}}) = H16(msg)
+end

test/runtests.jl

@@ -2,6 +2,7 @@ using Test
 using TinyCrypto
 
 @testset "Curve tests" begin
+    include("test_hash.jl")
     include("test_field.jl")
     include("test_montgomery.jl")
     include("test_edwards.jl")

test/test_hash.jl

@@ -0,0 +1,56 @@
+using Test
+using TinyCrypto: H, H8, H16, H₈, H₁₆
+
+@testset "Hash - TinyHash API" begin
+
+    @testset "Determinism" begin
+        @test H("msg") == H("msg")
+        @test H8("abc") == H8("abc")
+        @test H16("abc") == H16("abc")
+    end
+
+    @testset "Types & Output Range" begin
+        @test H8("") isa UInt8
+        @test H16("") isa UInt16
+        @test 0x00 <= H8("abc") <= 0xff
+        @test 0x0000 <= H16("abc") <= 0xffff
+    end
+
+    @testset "Unicode and Multibyte Strings" begin
+        @test H("𝒞rypto") isa UInt8
+        @test H16("éçüΩ") != H16("ecuo")
+    end
+
+    @testset "Empty input" begin
+        @test H8("") == H(collect(UInt8, ""))
+        @test H16("") == H16(UInt8[])
+    end
+
+    @testset "Single and Repeated Characters" begin
+        @test H8("a") == H("a")
+        @test H8("aaaaaaaa") != H8("aaaaaaaaa")  # should trigger padding into another block
+        @test H16("z"^1000) isa UInt16
+    end
+
+    @testset "Vectors of UInt8" begin
+        @test H8(UInt8[0x61, 0x62, 0x63]) == H8("abc")
+        @test H16(UInt8[0x61, 0x62, 0x63]) == H16("abc")
+    end
+
+    @testset "Aliases" begin
+        str = "hello world"
+        @test H(str) == H8(str)
+        @test H₈(str) == H8(str)
+        @test H₁₆(str) == H16(str)
+    end
+
+    @testset "Corner padding boundaries" begin
+        # Pad to block sizes: exact 7, 8, 14, 15, etc.
+        for n in (0, 1, 6, 7, 8, 13, 14, 15, 16, 100)
+            msg = "a"^n
+            @test H8(msg) isa UInt8
+            @test H16(msg) isa UInt16
+        end
+    end
+
+end