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authorrsiddharth <s@ricketyspace.net>2021-02-24 18:09:52 -0500
committerrsiddharth <s@ricketyspace.net>2021-02-24 18:09:52 -0500
commit7db89aa66b95d67a82963996b26dccbc7384a926 (patch)
treeb3eca8abf1f482e85a61bca201a4395aec466f70
parent1347de40f45ec0402ac61fcd86e8f87adf3473ad (diff)
lib: put rand functions in rand.go
-rw-r--r--lib/oracle.go61
-rw-r--r--lib/rand.go47
2 files changed, 59 insertions, 49 deletions
diff --git a/lib/oracle.go b/lib/oracle.go
index 005e392..8c7a52b 100644
--- a/lib/oracle.go
+++ b/lib/oracle.go
@@ -3,32 +3,29 @@
package lib
-import (
- "crypto/rand"
- "math/big"
-)
-
var oracleUnknown string = `Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkg
aGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBq
dXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUg
YnkK`
-var OracleKey []byte = make([]byte, 16)
-var OracleIV []byte = make([]byte, 16)
-var oracleRandom []byte = make([]byte, RandomInt(1, 4096))
+var OracleKey []byte
+var OracleIV []byte
+var oracleRandom []byte
func init() {
- _, err := rand.Read(OracleKey)
+ var err error
+
+ OracleKey, err = RandomKey(16)
if err != nil {
panic(err)
}
- _, err = rand.Read(OracleIV)
+ OracleIV, err = RandomKey(16)
if err != nil {
panic(err)
}
- _, err = rand.Read(oracleRandom)
+ oracleRandom, err = RandomKey(int(RandomInt(1, 4096)))
if err != nil {
panic(err)
}
@@ -39,14 +36,12 @@ func init() {
// cipher.
func OracleAESRandomEncrypt(in []byte) []byte {
// Generate random key.
- key := make([]byte, 16)
- _, err := rand.Read(key)
+ key, err := RandomKey(16)
if err != nil {
panic(err)
}
// Generate random initialization vector; needed for AES CBC.
- iv := make([]byte, 16)
- _, err = rand.Read(iv)
+ iv, err := RandomKey(16)
if err != nil {
panic(err)
}
@@ -56,12 +51,9 @@ func OracleAESRandomEncrypt(in []byte) []byte {
in = append(in, randomBytes(5, 10)...)
// Randomly encrypt `in` with AES in ECB or CBC mode.
- m, err := rand.Int(rand.Reader, big.NewInt(2))
- if err != nil {
- panic(err)
- }
+ m := RandomInt(0, 1)
var out []byte
- if m.Int64() == 0 {
+ if m == 0 {
// Encrypt with AES in ECB mode.
out = AESEncryptECB(in, key)
} else {
@@ -80,32 +72,3 @@ func OracleAESVarEncryptECB(in []byte) []byte {
in = append(in, Base64ToBytes(oracleUnknown)...)
return AESEncryptECB(in, OracleKey)
}
-
-// Return a random number from range [min, max]
-func RandomInt(min, max int64) int64 {
- if min >= max {
- panic("RandomInt: min cannot be >= max!")
- }
-
- var rn *big.Int
- var err error
- for {
- rn, err = rand.Int(rand.Reader, big.NewInt(max+1))
- if err != nil {
- panic(err)
- }
- if rn.Int64() >= min {
- return rn.Int64()
- }
- }
-}
-
-// Randomly generates `min` to `max` bytes.
-func randomBytes(min, max int64) []byte {
- bs := make([]byte, RandomInt(min, max))
- _, err := rand.Read(bs)
- if err != nil {
- panic(err)
- }
- return bs
-}
diff --git a/lib/rand.go b/lib/rand.go
new file mode 100644
index 0000000..03fd651
--- /dev/null
+++ b/lib/rand.go
@@ -0,0 +1,47 @@
+// Copyright © 2020 rsiddharth <s@ricketyspace.net>
+// SPDX-License-Identifier: ISC
+
+package lib
+
+import (
+ "crypto/rand"
+ "math/big"
+)
+
+// Return a random number from range [min, max]
+func RandomInt(min, max int64) int64 {
+ if min >= max {
+ panic("RandomInt: min cannot be >= max!")
+ }
+
+ var rn *big.Int
+ var err error
+ for {
+ rn, err = rand.Int(rand.Reader, big.NewInt(max+1))
+ if err != nil {
+ panic(err)
+ }
+ if rn.Int64() >= min {
+ return rn.Int64()
+ }
+ }
+}
+
+func RandomKey(size int) ([]byte, error) {
+ k := make([]byte, size)
+ _, err := rand.Read(k)
+ if err != nil {
+ return []byte{}, err
+ }
+ return k, nil
+}
+
+// Randomly generates `min` to `max` bytes.
+func randomBytes(min, max int64) []byte {
+ bs := make([]byte, RandomInt(min, max))
+ _, err := rand.Read(bs)
+ if err != nil {
+ panic(err)
+ }
+ return bs
+}