crypto/src/main/java/org/springframework/security/crypto/password/LdapShaPasswordEncoder.java
private String extractPrefix(String encPass) {
		if (!encPass.startsWith("{")) {
			return null;
		}

		int secondBrace = encPass.lastIndexOf('}');

		if (secondBrace < 0) {
			throw new IllegalArgumentException(
					"Couldn't find closing brace for SHA prefix");
		}

		return encPass.substring(0, secondBrace + 1);
	}
private String extractPrefix(String encPass) {
		if (!encPass.startsWith("{")) {
			return null;
		}

		int secondBrace = encPass.lastIndexOf('}');

		if (secondBrace < 0) {
			throw new IllegalArgumentException(
					"Couldn't find closing brace for SHA prefix");
		}

		return encPass.substring(0, secondBrace + 1);
	}
Returns the hash prefix or null if there isn't one.