Implement __hash__ for ASN.1 wrapper types

src/cryptography/hazmat/bindings/_rust/declarative_asn1.pyi

@@ -81,30 +81,35 @@ class PrintableString:
     def __new__(cls, inner: str) -> PrintableString: ...
     def __repr__(self) -> str: ...
     def __eq__(self, other: object) -> bool: ...
+    def __hash__(self) -> int: ...
     def as_str(self) -> str: ...
 
 class IA5String:
     def __new__(cls, inner: str) -> IA5String: ...
     def __repr__(self) -> str: ...
     def __eq__(self, other: object) -> bool: ...
+    def __hash__(self) -> int: ...
     def as_str(self) -> str: ...
 
 class UTCTime:
     def __new__(cls, inner: datetime.datetime) -> UTCTime: ...
     def __repr__(self) -> str: ...
     def __eq__(self, other: object) -> bool: ...
+    def __hash__(self) -> int: ...
     def as_datetime(self) -> datetime.datetime: ...
 
 class GeneralizedTime:
     def __new__(cls, inner: datetime.datetime) -> GeneralizedTime: ...
     def __repr__(self) -> str: ...
     def __eq__(self, other: object) -> bool: ...
+    def __hash__(self) -> int: ...
     def as_datetime(self) -> datetime.datetime: ...
 
 class BitString:
     def __new__(cls, data: bytes, padding_bits: int) -> BitString: ...
     def __repr__(self) -> str: ...
     def __eq__(self, other: object) -> bool: ...
+    def __hash__(self) -> int: ...
     def as_bytes(self) -> bytes: ...
     def padding_bits(self) -> int: ...
 

src/rust/src/declarative_asn1/types.rs

@@ -254,6 +254,10 @@ impl PrintableString {
         (**self.inner.bind(py)).eq(other.inner.bind(py))
     }
 
+    fn __hash__(&self, py: pyo3::Python<'_>) -> pyo3::PyResult<isize> {
+        (**self.inner.bind(py)).hash()
+    }
+
     pub fn __repr__<'py>(
         &self,
         py: pyo3::Python<'py>,
@@ -301,6 +305,10 @@ impl IA5String {
         (**self.inner.bind(py)).eq(other.inner.bind(py))
     }
 
+    fn __hash__(&self, py: pyo3::Python<'_>) -> pyo3::PyResult<isize> {
+        (**self.inner.bind(py)).hash()
+    }
+
     pub fn __repr__<'py>(
         &self,
         py: pyo3::Python<'py>,
@@ -359,6 +367,10 @@ impl UtcTime {
         (**self.inner.bind(py)).eq(other.inner.bind(py))
     }
 
+    fn __hash__(&self, py: pyo3::Python<'_>) -> pyo3::PyResult<isize> {
+        (**self.inner.bind(py)).hash()
+    }
+
     pub fn __repr__<'py>(
         &self,
         py: pyo3::Python<'py>,
@@ -404,6 +416,10 @@ impl GeneralizedTime {
         (**self.inner.bind(py)).eq(other.inner.bind(py))
     }
 
+    fn __hash__(&self, py: pyo3::Python<'_>) -> pyo3::PyResult<isize> {
+        (**self.inner.bind(py)).hash()
+    }
+
     pub fn __repr__<'py>(
         &self,
         py: pyo3::Python<'py>,
@@ -453,6 +469,12 @@ impl BitString {
             && self.padding_bits == other.padding_bits)
     }
 
+    fn __hash__(&self, py: pyo3::Python<'_>) -> pyo3::PyResult<isize> {
+        (self.data.bind(py), self.padding_bits)
+            .into_pyobject(py)?
+            .hash()
+    }
+
     pub fn __repr__<'py>(
         &self,
         py: pyo3::Python<'py>,

tests/hazmat/asn1/test_api.py

@@ -29,6 +29,14 @@ def test_invalid_printable_string(self) -> None:
         with pytest.raises(ValueError, match="invalid PrintableString: café"):
             asn1.PrintableString("café")
 
+    def test_hash_printable_string(self) -> None:
+        assert hash(asn1.PrintableString("MyString")) == hash(
+            asn1.PrintableString("MyString")
+        )
+        assert hash(asn1.PrintableString("MyString")) != hash(
+            asn1.PrintableString("OtherString")
+        )
+
     def test_repr_ia5_string(self) -> None:
         my_string = "MyString"
         assert repr(asn1.IA5String(my_string)) == f"IA5String({my_string!r})"
@@ -41,6 +49,14 @@ def test_invalid_ia5_string(self) -> None:
         with pytest.raises(ValueError, match="invalid IA5String: café"):
             asn1.IA5String("café")
 
+    def test_hash_ia5_string(self) -> None:
+        assert hash(asn1.IA5String("MyString")) == hash(
+            asn1.IA5String("MyString")
+        )
+        assert hash(asn1.IA5String("MyString")) != hash(
+            asn1.IA5String("OtherString")
+        )
+
     def test_utc_time_as_datetime(self) -> None:
         dt = datetime.datetime(
             2000, 1, 1, 10, 10, 10, tzinfo=datetime.timezone.utc
@@ -53,6 +69,16 @@ def test_repr_utc_time(self) -> None:
         )
         assert repr(asn1.UTCTime(dt)) == f"UTCTime({dt!r})"
 
+    def test_hash_utc_time(self) -> None:
+        dt = datetime.datetime(
+            2000, 1, 1, 10, 10, 10, tzinfo=datetime.timezone.utc
+        )
+        other_dt = datetime.datetime(
+            2001, 1, 1, 10, 10, 10, tzinfo=datetime.timezone.utc
+        )
+        assert hash(asn1.UTCTime(dt)) == hash(asn1.UTCTime(dt))
+        assert hash(asn1.UTCTime(dt)) != hash(asn1.UTCTime(other_dt))
+
     def test_invalid_utc_time(self) -> None:
         with pytest.raises(
             ValueError,
@@ -107,6 +133,18 @@ def test_repr_generalized_time(self) -> None:
         )
         assert repr(asn1.GeneralizedTime(dt)) == f"GeneralizedTime({dt!r})"
 
+    def test_hash_generalized_time(self) -> None:
+        dt = datetime.datetime(
+            2000, 1, 1, 10, 10, 10, 300000, tzinfo=datetime.timezone.utc
+        )
+        other_dt = datetime.datetime(
+            2001, 1, 1, 10, 10, 10, 300000, tzinfo=datetime.timezone.utc
+        )
+        assert hash(asn1.GeneralizedTime(dt)) == hash(asn1.GeneralizedTime(dt))
+        assert hash(asn1.GeneralizedTime(dt)) != hash(
+            asn1.GeneralizedTime(other_dt)
+        )
+
     def test_invalid_generalized_time(self) -> None:
         with pytest.raises(
             ValueError,
@@ -129,6 +167,17 @@ def test_repr_bitstring(self) -> None:
             == f"BitString(data={data!r}, padding_bits=2)"
         )
 
+    def test_hash_bitstring(self) -> None:
+        assert hash(asn1.BitString(b"\x01\x02\x30", 2)) == hash(
+            asn1.BitString(b"\x01\x02\x30", 2)
+        )
+        assert hash(asn1.BitString(b"\x01\x02\x30", 2)) != hash(
+            asn1.BitString(b"\x01\x02\x40", 2)
+        )
+        assert hash(asn1.BitString(b"\x01\x02\x30", 2)) != hash(
+            asn1.BitString(b"\x01\x02\x30", 3)
+        )
+
     def test_invalid_bitstring(self) -> None:
         with pytest.raises(
             ValueError,