Use pyo3 warning helper (#7433)

Much simpler than importing the warnings module

Author: alex

src/rust/src/x509/certificate.rs

@@ -351,13 +351,11 @@ impl Certificate {
         let cryptography_warning = py
             .import("cryptography.utils")?
             .getattr(crate::intern!(py, "DeprecatedIn35"))?;
-        let warnings = py.import("warnings")?;
-        warnings.call_method1(
-            "warn",
-            (
-                "This version of cryptography contains a temporary pyOpenSSL fallback path. Upgrade pyOpenSSL now.",
-                cryptography_warning,
-            ),
+        pyo3::PyErr::warn(
+            py,
+            cryptography_warning,
+            "This version of cryptography contains a temporary pyOpenSSL fallback path. Upgrade pyOpenSSL now.",
+            1
         )?;
         let backend = py
             .import("cryptography.hazmat.backends.openssl.backend")?
@@ -415,13 +413,11 @@ fn warn_if_negative_serial(py: pyo3::Python<'_>, bytes: &'_ [u8]) -> pyo3::PyRes
         let cryptography_warning = py
             .import("cryptography.utils")?
             .getattr(crate::intern!(py, "DeprecatedIn36"))?;
-        let warnings = py.import("warnings")?;
-        warnings.call_method1(
-            "warn",
-            (
-                "Parsed a negative serial number, which is disallowed by RFC 5280.",
-                cryptography_warning,
-            ),
+        pyo3::PyErr::warn(
+            py,
+            cryptography_warning,
+            "Parsed a negative serial number, which is disallowed by RFC 5280.",
+            1,
         )?;
     }
     Ok(())

src/rust/src/x509/crl.rs

@@ -407,13 +407,11 @@ impl CertificateRevocationList {
         let cryptography_warning = py
             .import("cryptography.utils")?
             .getattr(crate::intern!(py, "DeprecatedIn35"))?;
-        let warnings = py.import("warnings")?;
-        warnings.call_method1(
-            "warn",
-            (
-                "This version of cryptography contains a temporary pyOpenSSL fallback path. Upgrade pyOpenSSL now.",
-                cryptography_warning,
-            ),
+        pyo3::PyErr::warn(
+            py,
+            cryptography_warning,
+            "This version of cryptography contains a temporary pyOpenSSL fallback path. Upgrade pyOpenSSL now.",
+            1
         )?;
         let backend = py
             .import("cryptography.hazmat.backends.openssl.backend")?

src/rust/src/x509/csr.rs

@@ -207,13 +207,11 @@ impl CertificateSigningRequest {
         let cryptography_warning = py
             .import("cryptography.utils")?
             .getattr(crate::intern!(py, "DeprecatedIn36"))?;
-        let warnings = py.import("warnings")?;
-        warnings.call_method1(
-            "warn",
-            (
-                "CertificateSigningRequest.get_attribute_for_oid has been deprecated. Please switch to request.attributes.get_attribute_for_oid.",
-                cryptography_warning,
-            ),
+        pyo3::PyErr::warn(
+            py,
+            cryptography_warning,
+            "CertificateSigningRequest.get_attribute_for_oid has been deprecated. Please switch to request.attributes.get_attribute_for_oid.",
+            1,
         )?;
         let rust_oid = py_oid_to_oid(oid)?;
         for attribute in self
@@ -309,13 +307,11 @@ impl CertificateSigningRequest {
         let cryptography_warning = py
             .import("cryptography.utils")?
             .getattr(crate::intern!(py, "DeprecatedIn35"))?;
-        let warnings = py.import("warnings")?;
-        warnings.call_method1(
-            "warn",
-            (
-                "This version of cryptography contains a temporary pyOpenSSL fallback path. Upgrade pyOpenSSL now.",
-                cryptography_warning,
-            ),
+        pyo3::PyErr::warn(
+            py,
+            cryptography_warning,
+            "This version of cryptography contains a temporary pyOpenSSL fallback path. Upgrade pyOpenSSL now.",
+            1,
         )?;
         let backend = py
             .import("cryptography.hazmat.backends.openssl.backend")?

src/rust/src/x509/sign.rs

@@ -101,13 +101,11 @@ fn identify_hash_type(
             let cryptography_warning = py
                 .import("cryptography.utils")?
                 .getattr(crate::intern!(py, "DeprecatedIn38"))?;
-            let warnings = py.import("warnings")?;
-            warnings.call_method1(
-                "warn",
-                (
-                    "MD5 signatures are deprecated and support for them will be removed in the next version.",
-                    cryptography_warning,
-                ),
+            pyo3::PyErr::warn(
+                py,
+                cryptography_warning,
+                "MD5 signatures are deprecated and support for them will be removed in the next version.",
+                1
             )?;
 
             Ok(HashType::Md5)
@@ -116,14 +114,13 @@ fn identify_hash_type(
             let cryptography_warning = py
                 .import("cryptography.utils")?
                 .getattr(crate::intern!(py, "DeprecatedIn38"))?;
-            let warnings = py.import("warnings")?;
-            warnings.call_method1(
-                "warn",
-                (
-                    "SHA1 signatures are deprecated and support for them will be removed in the next version.",
-                    cryptography_warning,
-                ),
+            pyo3::PyErr::warn(
+                py,
+                cryptography_warning,
+                "SHA1 signatures are deprecated and support for them will be removed in the next version.",
+                1
             )?;
+
             Ok(HashType::Sha1)
         }
         "sha224" => Ok(HashType::Sha224),