Merge pull request #943 from Zokrates/use-field-constants

Use field constants to avoid curve-dependant code

zokrates_cli/examples/runtime_errors/lt_overflow_max_plus_1.zok

@@ -1,12 +1,11 @@
-#pragma curve bn128
+from "field" import FIELD_SIZE_IN_BITS
 
 // we can compare numbers up to 2^(pbits - 2) - 1, ie any number which fits in (pbits - 2) bits
 // It should not work for the maxvalue = 2^(pbits - 2) - 1 augmented by one
 // /!\ should be called with a = 0
 
 def main(field a) -> bool:
-  field pbits = 254
-  // maxvalue = 2**252 - 1
-  field maxvalue = a + 7237005577332262213973186563042994240829374041602535252466099000494570602496 - 1
-  // we added a = 0 to prevent the condition to be evaluated at compile time
-  return a < (maxvalue + 1)
+    u32 pbits = FIELD_SIZE_IN_BITS
+    // we added a = 0 to prevent the condition to be evaluated at compile time
+    field maxvalue = a + (2**(pbits - 2) - 1)
+    return a < (maxvalue + 1)

zokrates_cli/examples/runtime_errors/lt_overflow_p_minus_one.zok

@@ -1,7 +1,9 @@
+from "field" import FIELD_MAX
+
 // as p - 1 is greater than p/2, comparing to it should fail
 // /!\ should be called with a = 0
 
 def main(field a) -> bool:
-  field p = 21888242871839275222246405745257275088548364400416034343698204186575808495616 + a
+  field p = FIELD_MAX + a
   // we added a = 0 to prevent the condition to be evaluated at compile time
   return a < p

zokrates_cli/examples/test_lt_max_value.zok

@@ -1,10 +1,9 @@
-#pragma curve bn128
+from "field" import FIELD_SIZE_IN_BITS
 
 // we can compare numbers up to 2^(pbits - 2) - 1, ie any number which fits in (pbits - 2) bits
 // lt should work for the maxvalue = 2^(pbits - 2) - 1
 
 def main(field a) -> bool:
-  field pbits = 254
-  // maxvalue = 2**252 - 1
-  field maxvalue = 7237005577332262213973186563042994240829374041602535252466099000494570602496 - 1
+  u32 pbits = FIELD_SIZE_IN_BITS
+  field maxvalue = 2**(pbits - 2) - 1
   return 0 < maxvalue

zokrates_core_test/tests/tests/native_le.zok

@@ -1,5 +1,6 @@
 from "utils/pack/bool/unpack.zok" import main as unpack
 from "utils/casts/u32_to_bits" import main as u32_to_bits
+from "field" import FIELD_MAX, FIELD_SIZE_IN_BITS
 
 // this comparison works for any N smaller than the field size, which is the case in practice
 def le<N>(bool[N] a_bits, bool[N] c_bits) -> bool:
@@ -17,11 +18,9 @@ def le<N>(bool[N] a_bits, bool[N] c_bits) -> bool:
 
     return verified_conditions == N // this checks that all conditions were verified
 
-// this instanciates comparison starting from field elements
+// this instantiates comparison starting from field elements
 def le<N>(field a, field c) -> bool:
-
-    field MAX = 21888242871839275222246405745257275088548364400416034343698204186575808495616
-    bool[N] MAX_BITS = unpack::<N>(MAX)
+    bool[N] MAX_BITS = unpack::<N>(FIELD_MAX)
 
     bool[N] a_bits = unpack(a)
     assert(le(a_bits, MAX_BITS))
@@ -38,10 +37,7 @@ def le(u32 a, u32 c) -> bool:
     return le(a_bits, c_bits)
 
 def main(field a, u32 b) -> (bool, bool):
-
-    u32 N = 254
     field c = 42
-
     u32 d = 42
 
-    return le::<N>(a, c), le(b, d)
+    return le::<FIELD_SIZE_IN_BITS>(a, c), le(b, d)

zokrates_core_test/tests/tests/split.zok

@@ -0,0 +1,6 @@
+from "EMBED" import unpack
+from "field" import FIELD_SIZE_IN_BITS
+
+def main(field a) -> bool[FIELD_SIZE_IN_BITS]:
+	bool[FIELD_SIZE_IN_BITS] b = unpack(a)
+	return b

zokrates_core_test/tests/tests/split_bls.json

@@ -1,5 +1,5 @@
 {
-	"entry_point": "./tests/tests/split_bls.zok",
+	"entry_point": "./tests/tests/split.zok",
 	"curves": ["Bls12_381"],
 	"tests": [
 		{

zokrates_core_test/tests/tests/split_bls.zok

@@ -1,7 +0,0 @@
-from "EMBED" import unpack
-
-def main(field a) -> (bool[255]):
-	
-	bool[255] b = unpack(a)
-
-	return b

zokrates_core_test/tests/tests/split_bn.json

@@ -1,5 +1,5 @@
 {
-	"entry_point": "./tests/tests/split_bn.zok",
+	"entry_point": "./tests/tests/split.zok",
 	"curves": ["Bn128"],
 	"tests": [
 		{

zokrates_core_test/tests/tests/split_bn.zok

@@ -1,7 +0,0 @@
-from "EMBED" import unpack
-
-def main(field a) -> (bool[254]):
-	
-	bool[254] b = unpack(a)
-
-	return b