== Why is this an issue?

The MD5 algorithm and its successor, SHA-1, are no longer considered secure, because it is too easy to create hash collisions with them. That is, it takes too little computational effort to come up with a different input that produces the same MD5 or SHA-1 hash, and using the new, same-hash value gives an attacker the same access as if he had the originally-hashed value. This applies as well to the other Message-Digest algorithms: MD2, MD4, MD6, HAVAL-128, HMAC-MD5, DSA (which uses SHA-1), RIPEMD, RIPEMD-128, RIPEMD-160, HMACRIPEMD160.


The following APIs are tracked for use of obsolete crypto algorithms:

* ``++java.security.AlgorithmParameters++``  (JDK)
* ``++java.security.AlgorithmParameterGenerator++`` (JDK)
* ``++java.security.MessageDigest++`` (JDK)
* ``++java.security.KeyFactory++`` (JDK)
* ``++java.security.KeyPairGenerator++`` (JDK)
* ``++java.security.Signature++`` (JDK)
* ``++javax.crypto.Mac++`` (JDK)
* ``++javax.crypto.KeyGenerator++`` (JDK)
* ``++org.apache.commons.codec.digest.DigestUtils++``  (Apache Commons Codec)
* ``++org.springframework.util.DigestUtils++``
* ``++com.google.common.hash.Hashing++`` (Guava)
* ``++org.springframework.security.authentication.encoding.ShaPasswordEncoder++`` (Spring Security 4.2.x)
* ``++org.springframework.security.authentication.encoding.Md5PasswordEncoder++`` (Spring Security 4.2.x)
* ``++org.springframework.security.crypto.password.LdapShaPasswordEncoder++`` (Spring Security 5.0.x)
* ``++org.springframework.security.crypto.password.Md4PasswordEncoder++`` (Spring Security 5.0.x)
* ``++org.springframework.security.crypto.password.MessageDigestPasswordEncoder++`` (Spring Security 5.0.x)
* ``++org.springframework.security.crypto.password.NoOpPasswordEncoder++`` (Spring Security 5.0.x)
* ``++org.springframework.security.crypto.password.StandardPasswordEncoder++`` (Spring Security 5.0.x)

Consider using safer alternatives, such as SHA-256, SHA-3 or adaptive one way functions like bcrypt or PBKDF2.

=== Noncompliant code example

[source,java]
----
MessageDigest md = MessageDigest.getInstance("SHA1");  // Noncompliant
----

=== Compliant solution

[source,java]
----
MessageDigest md = MessageDigest.getInstance("SHA-256");
----

include::../see.adoc[]

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== Implementation Specification
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include::../message.adoc[]

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== Comments And Links
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include::../comments-and-links.adoc[]

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