fix: Enhance error handling across gnark-ffi package

- Enhanced error handling across three critical go files in recursion/gnark-ffi, ensuring each function returns an error along with its intended output if any error occurs.
- Improved `randomPolynomial` function to return an error along with the polynomial and added necessary error checks.
- Improved safety by adding error handling for `SetString` and `SetRandom` operations, the program will now terminate in case of any error.
- Added error handling for critical function calls, such as `os.MkdirAll` and `vk.ExportSolidity` in build.go.
- Strengthened guard against unexpected panic conditions in `prove.go` by enabling error handling for `ReadFrom` methods for the R1CS, proving key, and verifier key.

recursion/gnark-ffi/go/sp1/build.go

@@ -149,14 +149,20 @@ func Build(dataDir string) {
 	}
 
 	// Create the build directory.
-	os.MkdirAll(dataDir, 0755)
+	err = os.MkdirAll(dataDir, 0755)
+	if err != nil {
+		panic(err)
+	}
 
 	// Write the solidity verifier.
 	solidityVerifierFile, err := os.Create(dataDir + "/" + verifierContractPath)
 	if err != nil {
 		panic(err)
 	}
-	vk.ExportSolidity(solidityVerifierFile)
+	err = vk.ExportSolidity(solidityVerifierFile)
+	if err != nil {
+		panic(err)
+	}
 	defer solidityVerifierFile.Close()
 
 	// Write the R1CS.

recursion/gnark-ffi/go/sp1/prove.go

@@ -23,7 +23,9 @@ func Prove(dataDir string, witnessPath string) Proof {
 		panic(err)
 	}
 	scs := plonk.NewCS(ecc.BN254)
-	scs.ReadFrom(scsFile)
+	if _, err := scs.ReadFrom(scsFile); err != nil {
+		panic(err)
+	}
 	defer scsFile.Close()
 
 	// Read the proving key.
@@ -33,7 +35,10 @@ func Prove(dataDir string, witnessPath string) Proof {
 	}
 	pk := plonk.NewProvingKey(ecc.BN254)
 	bufReader := bufio.NewReaderSize(pkFile, 1024*1024)
-	pk.UnsafeReadFrom(bufReader)
+	_, err = pk.UnsafeReadFrom(bufReader)
+	if err != nil {
+		panic(err)
+	}
 	defer pkFile.Close()
 
 	// Read the verifier key.
@@ -42,7 +47,9 @@ func Prove(dataDir string, witnessPath string) Proof {
 		panic(err)
 	}
 	vk := plonk.NewVerifyingKey(ecc.BN254)
-	vk.ReadFrom(vkFile)
+	if _, err := vk.ReadFrom(vkFile); err != nil {
+		panic(err)
+	}
 	defer vkFile.Close()
 
 	// Read the file.

recursion/gnark-ffi/go/sp1/trusted_setup/trusted_setup.go

@@ -17,7 +17,10 @@ import (
 func sanityCheck(srs *kzg_bn254.SRS) {
 	// we can now use the SRS to verify a proof
 	// create a polynomial
-	f := randomPolynomial(60)
+	f, err := randomPolynomial(60)
+	if err != nil {
+		log.Fatal(err)
+	}
 
 	// commit the polynomial
 	digest, err := kzg_bn254.Commit(f, srs.Pk)
@@ -27,7 +30,9 @@ func sanityCheck(srs *kzg_bn254.SRS) {
 
 	// compute opening proof at a random point
 	var point fr.Element
-	point.SetString("4321")
+	if _, err := point.SetString("4321"); err != nil {
+		log.Fatal(err)
+	}
 	proof, err := kzg_bn254.Open(f, point, srs.Pk)
 	if err != nil {
 		log.Fatal(err)
@@ -46,12 +51,14 @@ func sanityCheck(srs *kzg_bn254.SRS) {
 	}
 }
 
-func randomPolynomial(size int) []fr.Element {
+func randomPolynomial(size int) ([]fr.Element, error) {
 	f := make([]fr.Element, size)
 	for i := 0; i < size; i++ {
-		f[i].SetRandom()
+		if _, err := f[i].SetRandom(); err != nil {
+			return nil, err
+		}
 	}
-	return f
+	return f, nil
 }
 
 // eval returns p(point) where p is interpreted as a polynomial

recursion/gnark-ffi/go/sp1/verify.go

@@ -33,7 +33,9 @@ func Verify(verifyCmdDataDir string, verifyCmdProof string, verifyCmdVkeyHash st
 		panic(err)
 	}
 	vk := plonk.NewVerifyingKey(ecc.BN254)
-	vk.ReadFrom(vkFile)
+	if _, err := vk.ReadFrom(vkFile); err != nil {
+		panic(err)
+	}
 
 	// Compute the public witness.
 	circuit := Circuit{