Program address generator (#8995)

sdk/src/pubkey.rs

@@ -1,4 +1,7 @@
-use crate::{hash::hashv, program_utils::DecodeError};
+use crate::{
+    hash::{hashv, Hasher},
+    program_utils::DecodeError,
+};
 use num_derive::{FromPrimitive, ToPrimitive};
 #[cfg(not(feature = "program"))]
 use std::error;
@@ -79,6 +82,22 @@ impl Pubkey {
         ))
     }
 
+    pub fn create_program_address(
+        seeds: &[&str],
+        program_id: &Pubkey,
+    ) -> Result<Pubkey, PubkeyError> {
+        let mut hasher = Hasher::default();
+        for seed in seeds.iter() {
+            if seed.len() > MAX_SEED_LEN {
+                return Err(PubkeyError::MaxSeedLengthExceeded);
+            }
+            hasher.hash(seed.as_ref());
+        }
+        hasher.hashv(&[program_id.as_ref(), "ProgramDerivedAddress".as_ref()]);
+
+        Ok(Pubkey::new(hashv(&[hasher.result().as_ref()]).as_ref()))
+    }
+
     #[cfg(not(feature = "program"))]
     pub fn new_rand() -> Self {
         Self::new(&rand::random::<[u8; 32]>())
@@ -220,6 +239,45 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_create_program_address() {
+        let exceeded_seed = from_utf8(&[127; MAX_SEED_LEN + 1]).unwrap();
+        let max_seed = from_utf8(&[0; MAX_SEED_LEN]).unwrap();
+        let program_id = Pubkey::new(b"BPFLoader11111111111111111111111");
+
+        assert_eq!(
+            Pubkey::create_program_address(&[exceeded_seed], &program_id),
+            Err(PubkeyError::MaxSeedLengthExceeded)
+        );
+        assert_eq!(
+            Pubkey::create_program_address(&["short_seed", exceeded_seed], &program_id),
+            Err(PubkeyError::MaxSeedLengthExceeded)
+        );
+        assert!(Pubkey::create_program_address(&[max_seed], &Pubkey::new_rand(),).is_ok());
+        assert_eq!(
+            Pubkey::create_program_address(&[""], &program_id),
+            Ok("FXjJsFsMXM8LFXynZvEkED7yECADnaEgAzWD6yyg91QG"
+                .parse()
+                .unwrap())
+        );
+        assert_eq!(
+            Pubkey::create_program_address(&["☉"], &program_id),
+            Ok("MAuKBzPvme5QmCNALp5iAEasZeazkpRyCZbwtJVkJEG"
+                .parse()
+                .unwrap())
+        );
+        assert_eq!(
+            Pubkey::create_program_address(&["Talking", "Squirrels"], &program_id),
+            Ok("3beXgJ9MfstiGfzav45bicJ7ygiwUEoCfsM4W94EuRii"
+                .parse()
+                .unwrap())
+        );
+        assert_ne!(
+            Pubkey::create_program_address(&["Talking", "Squirrels"], &program_id),
+            Pubkey::create_program_address(&["Talking"], &program_id),
+        );
+    }
+
     #[test]
     fn test_read_write_pubkey() -> Result<(), Box<dyn error::Error>> {
         let filename = "test_pubkey.json";