Fix DefaultOidcUser.equals()

Closes gh-18622

oauth2/oauth2-core/src/main/java/org/springframework/security/oauth2/core/oidc/user/DefaultOidcUser.java

@@ -19,6 +19,7 @@ package org.springframework.security.oauth2.core.oidc.user;
 import java.io.Serial;
 import java.util.Collection;
 import java.util.Map;
+import java.util.Objects;
 
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.oauth2.core.oidc.IdTokenClaimNames;
@@ -114,4 +115,38 @@ public class DefaultOidcUser extends DefaultOAuth2User implements OidcUser {
 		return this.userInfo;
 	}
 
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj) {
+			return true;
+		}
+		if (obj == null || this.getClass() != obj.getClass()) {
+			return false;
+		}
+		DefaultOidcUser that = (DefaultOidcUser) obj;
+		if (!this.getName().equals(that.getName())) {
+			return false;
+		}
+		if (!this.getAuthorities().equals(that.getAuthorities())) {
+			return false;
+		}
+		if (this.getIdToken().getIssuer() == null || that.getIdToken().getIssuer() == null) {
+			return false;
+		}
+		return Objects.equals(this.getIdToken().getIssuer().toExternalForm(),
+				that.getIdToken().getIssuer().toExternalForm())
+				&& Objects.equals(this.getIdToken().getSubject(), that.getIdToken().getSubject());
+	}
+
+	@Override
+	public int hashCode() {
+		int result = this.getName().hashCode();
+		result = 31 * result + this.getAuthorities().hashCode();
+		result = 31 * result + ((this.getIdToken().getIssuer() != null)
+				? this.getIdToken().getIssuer().toExternalForm().hashCode() : 0);
+		result = 31 * result
+				+ ((this.getIdToken().getSubject() != null) ? this.getIdToken().getSubject().hashCode() : 0);
+		return result;
+	}
+
 }

oauth2/oauth2-core/src/test/java/org/springframework/security/oauth2/core/oidc/user/DefaultOidcUserTests.java

@@ -17,6 +17,7 @@
 package org.springframework.security.oauth2.core.oidc.user;
 
 import java.time.Instant;
+import java.time.temporal.ChronoUnit;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -147,4 +148,31 @@ public class DefaultOidcUserTests {
 				StandardClaimNames.NAME, StandardClaimNames.EMAIL);
 	}
 
+	// gh-18622
+	@Test
+	public void equalsWhenOidcUserPrincipalSameThenTrue() {
+		String issuer = "https://example.com";
+		String subject = "subject-1";
+
+		// @formatter:off
+		OidcIdToken idToken1 = OidcIdToken.withTokenValue("id-token-value-1")
+				.issuer(issuer)
+				.subject(subject)
+				.issuedAt(Instant.now())
+				.expiresAt(Instant.now().plus(30, ChronoUnit.MINUTES))
+				.build();
+
+		OidcIdToken idToken2 = OidcIdToken.withTokenValue("id-token-value-2")
+				.issuer(issuer)
+				.subject(subject)
+				.issuedAt(Instant.now())
+				.expiresAt(Instant.now().plus(30, ChronoUnit.MINUTES))
+				.build();
+		// @formatter:on
+
+		DefaultOidcUser user1 = new DefaultOidcUser(AUTHORITIES, idToken1, USER_INFO);
+		DefaultOidcUser user2 = new DefaultOidcUser(AUTHORITIES, idToken2, USER_INFO);
+		assertThat(user1).isEqualTo(user2);
+	}
+
 }