Implement AI code review suggestions

- Enhanced SSL function documentation with detailed examples and environment variable precedence
- Added CA bundle file format validation (.pem, .crt, .cer) with warnings for unsupported formats
- Improved error handling with structured solutions and current CA bundle path display
- Added comprehensive tests for file format validation and warning scenarios
- Enhanced user guidance for SSL certificate configuration issues

Addresses feedback from joaomdmoura's AI code review for better documentation,
error handling, and path validation as requested.

Co-Authored-By: João <joao@crewai.com>

src/crewai/cli/provider.py

@@ -170,11 +170,22 @@ def get_ssl_verify_config():
     Example:
         >>> get_ssl_verify_config()
         '/path/to/ca-bundle.pem'
+        
+        >>> os.environ['REQUESTS_CA_BUNDLE'] = '/custom/ca-bundle.pem'
+        >>> get_ssl_verify_config()
+        '/custom/ca-bundle.pem'
     """
     for env_var in ['REQUESTS_CA_BUNDLE', 'SSL_CERT_FILE', 'CURL_CA_BUNDLE']:
         ca_bundle = os.environ.get(env_var)
-        if ca_bundle and os.path.isfile(ca_bundle):
-            return ca_bundle
+        if ca_bundle:
+            ca_path = Path(ca_bundle)
+            if ca_path.is_file() and ca_path.suffix in ['.pem', '.crt', '.cer']:
+                return str(ca_path)
+            elif ca_path.is_file():
+                click.secho(f"Warning: CA bundle file {ca_bundle} may not be in expected format (.pem, .crt, .cer)", fg="yellow")
+                return str(ca_path)
+            else:
+                click.secho(f"Warning: CA bundle path {ca_bundle} from {env_var} does not exist", fg="yellow")
     
     return certifi.where()
 
@@ -200,7 +211,10 @@ def fetch_provider_data(cache_file):
     except requests.exceptions.SSLError as e:
         click.secho(f"SSL certificate verification failed: {e}", fg="red")
         click.secho(f"Current CA bundle path: {ssl_config}", fg="yellow")
-        click.secho("Try setting REQUESTS_CA_BUNDLE environment variable to your CA bundle path", fg="yellow")
+        click.secho("Solutions:", fg="cyan")
+        click.secho("  1. Set REQUESTS_CA_BUNDLE environment variable to your CA bundle path", fg="yellow")
+        click.secho("  2. Ensure your CA bundle file is in .pem, .crt, or .cer format", fg="yellow")
+        click.secho("  3. Contact your system administrator for the correct CA bundle", fg="yellow")
         return None
     except requests.RequestException as e:
         click.secho(f"Error fetching provider data: {e}", fg="red")

tests/cli/test_provider_ssl.py

@@ -71,6 +71,35 @@ class TestSSLConfiguration:
                 result = get_ssl_verify_config()
                 assert result == '/path/to/certifi/cacert.pem'
 
+    def test_get_ssl_verify_config_file_format_validation(self):
+        """Test that CA bundle file format validation works correctly."""
+        with tempfile.NamedTemporaryFile(suffix=".pem", delete=False) as temp_file:
+            temp_path = temp_file.name
+        
+        try:
+            with patch.dict(os.environ, {"REQUESTS_CA_BUNDLE": temp_path}):
+                result = get_ssl_verify_config()
+                assert result == temp_path
+        finally:
+            os.unlink(temp_path)
+
+    def test_get_ssl_verify_config_unsupported_format_warning(self):
+        """Test that unsupported file formats still work but show warning."""
+        with tempfile.NamedTemporaryFile(suffix=".txt", delete=False) as temp_file:
+            temp_path = temp_file.name
+        
+        try:
+            with patch.dict(os.environ, {"REQUESTS_CA_BUNDLE": temp_path}):
+                with patch('click.secho') as mock_secho:
+                    result = get_ssl_verify_config()
+                    assert result == temp_path
+                    mock_secho.assert_called_with(
+                        f"Warning: CA bundle file {temp_path} may not be in expected format (.pem, .crt, .cer)", 
+                        fg="yellow"
+                    )
+        finally:
+            os.unlink(temp_path)
+
 
 class TestFetchProviderDataSSL:
     def test_fetch_provider_data_uses_ssl_config(self):
@@ -99,7 +128,8 @@ class TestFetchProviderDataSSL:
                 
                 assert result is None
                 mock_secho.assert_any_call("SSL certificate verification failed: SSL verification failed", fg="red")
-                mock_secho.assert_any_call("Try setting REQUESTS_CA_BUNDLE environment variable to your CA bundle path", fg="yellow")
+                mock_secho.assert_any_call("Solutions:", fg="cyan")
+                mock_secho.assert_any_call("  1. Set REQUESTS_CA_BUNDLE environment variable to your CA bundle path", fg="yellow")
 
     def test_fetch_provider_data_general_request_error(self):
         cache_file = Path("/tmp/test_cache.json")