Cleaning

0xPolygonZero · wborgeaud · Jan 31, 2023 · Nov 9, 2022 · Nov 10, 2022 · Nov 10, 2022
commit 05641440e7fbb3eb72f646b0fbd9ade444461000
@@ -215,30 +215,15 @@ retself:
 
 // Push the order of the Secp256k1 scalar field.
 %macro secp_base
-    PUSH 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f
+    PUSH @SECP_BASE
 %endmacro
 
-// Modular subtraction. Subtraction x-y underflows iff x<x-y, so can be computed as N*(x<x-y) + x-y.
+// Modular subtraction.
+// TODO: Use SUBMOD when it's ready
 %macro submod_secp_base
     // stack: x, y
-    SWAP1
-    // stack: y, x
-    DUP2
-    // stack: x, y, x
-    SUB
-    // stack: x - y, x
-    DUP1
-    // stack: x - y, x - y, x
-    SWAP2
-    // stack: x, x - y, x - y
-    LT
-    // stack: x < x - y, x - y
-    %secp_base
-    // stack: N, x < x - y, x - y
-    MUL
-    // stack: N * (x < x - y), x - y
-    ADD
-    // (x-y) % N
+    %stack (x, y) -> (@SECP_BASE, y, x, @SECP_BASE)
+    SUB ADDMOD
 %endmacro
 
 // Check if (x,y) is a valid curve point.

@@ -187,7 +187,7 @@ pubkey_to_addr:
 %endmacro
 
 %macro secp_scalar
-    PUSH 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
+    PUSH @SECP_SCALAR
 %endmacro
 
 // Return u256::MAX which is used to indicate the input was invalid.

@@ -9,7 +9,7 @@ global glv:
     // -(q1+q2) = -(k.b1.a1-k.b2.a2) = k2
     // k1 - k2\lambda = k
     // push group modulus n onto stack
-    PUSH 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141 dup1 dup1
+    PUSH @SECP_SCALAR dup1 dup1
     // we need to calculate k*b1. We require a full-width 512 bit multiplication,
     // see https://medium.com/wicketh/mathemagic-full-multiply-27650fec525d
     PUSH 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff // -1 n n n k
@@ -23,7 +23,7 @@ global glv:
     sub sub // top = (mm - bottom - (m < bottom)) n n n k
     PUSH 0x3086d221a7d46bcde86c90e49284eb15 mulmod // q2 n n k
 
-    PUSH 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141
+    PUSH @SECP_SCALAR
     PUSH 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff // -1 n q2 n n k
     PUSH 0x3086d221a7d46bcde86c90e49284eb15 dup7 mulmod // mm n q2 n n k
     PUSH 0x3086d221a7d46bcde86c90e49284eb15 dup7 mul    // bottom mm n q2 n n k
@@ -32,7 +32,7 @@ global glv:
     PUSH 0xfffffffffffffffffffffffffffffffdd66b5e10ae3a1813507ddee3c5765c7e mulmod // q1 q2 n n k
     add %sub_check_underflow      // k2 underflow n k
     swap3                   // k underflow n k2
-    PUSH 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141 // n k underflow n k2
+    PUSH @SECP_SCALAR // n k underflow n k2
     dup5 PUSH 0x5363ad4cc05c30e0a5261c028812645a122e22ea20816678df02967c1b23bd72 // s k2 n k underflow n k2
     mulmod // (s*k2)%n k underflow n k2
     SWAP2 DUP1 %jumpi(underflowed)