InvalidCiphertextException when decrypt AWL Lambda environment variable using AWS go sdk - go

Question

I'm stuck on this issue for days and have tried all the methods I can find online. I am trying to decrypt (using AWS go sdk) the AWS lambda environment variable encrypted with KMS. I encrypted the env variables in transit and at rest using the same KMS key.
Screenshot of environment variables encryption
I had also added the policy to lambda function to allow it to have permission to decrypt the variables.
The attached policy looks like the below:
"Version": "2012-10-17",
"Statement": {
"Effect": "Allow",
"Action": "kms:*",
"Resource": "arn:aws:kms:us-west-2:602487775829:key/f91a9f1a-9b53-4544-xxxxxxxx",
"Condition": {
"StringEquals": {
"kms:EncryptionContext:LambdaFunctionName": "eLead"
}
}
}
}
And here is my Go code snippet for decrypting the variables(KeyId is not necessary for decrypting, I added it just to ensure it uses the same KMS key to encrypt and decrypt):
import (
"os"
"context"
"encoding/base64"
"github.com/aws/aws-sdk-go-v2/service/kms"
"github.com/aws/aws-lambda-go/lambda"
"github.com/aws/aws-sdk-go-v2/config"
)
var API_key = os.Getenv("API_key")
var API_Secret = os.Getenv("API_Secret")
func Handler(ctx context.Context) error {
cfg, err := config.LoadDefaultConfig(context.TODO(),config.WithRegion("us-west-2"))
API_key_blob, err := base64.StdEncoding.DecodeString(API_key)
API_Secret_blob, err := base64.StdEncoding.DecodeString(API_Secret)
keyID := "arn:aws:kms:us-west-2:602487775829:key/f91a9f1a-9b53-4544-a05b-xxxxxx"
API_key_result, err := kmsClient.Decrypt(context.TODO(), &kms.DecryptInput{
CiphertextBlob: API_key_blob,
KeyId:aws.String(keyID),
})
API_Secret_result, err := kmsClient.Decrypt(context.TODO(),&kms.DecryptInput{
CiphertextBlob: API_Secret_blob,
KeyId:aws.String(keyID),
})
if err != nil {
fmt.Println("Got error decrypting data: ", err)
return err
}
func main() {
lambda.Start(Handler)
}
The error message is:
Got error decrypting data: operation error KMS: Decrypt, https response error StatusCode: 400, RequestID: 629a64b2-ce53-46ad-88fb-1f6ac684919e, InvalidCiphertextException:
I don't understand what else can cause this error.
Any suggestion would help! Thanks!