Addition of ChangeLog and migration guide entry files.

Signed-off-by: TRodziewicz <tomasz.rodziewicz@mobica.com>
diff --git a/ChangeLog.d/issue4084.txt b/ChangeLog.d/issue4084.txt
new file mode 100644
index 0000000..c6a72f9
--- /dev/null
+++ b/ChangeLog.d/issue4084.txt
@@ -0,0 +1,27 @@
+Removals
+    * Remove MD2, MD4, RC4, Blowfish and XTEA cryptographic primitives and
+      ciphersuites. Remove the following library files: arc4.c/h, blowfish.c/h,
+      md2.c/h, md4.c/h, xtea.c/h and belonging csr/crt/pem files. Remove the
+      following defines: MBEDTLS_RC4_C, MBEDTLS_ARC4_C, MBEDTLS_ARC4_ALT,
+      PSA_WANT_KEY_TYPE_ARC4, PSA_WANT_ALG_STREAM_CIPHER,
+      MBEDTLS_PSA_ACCEL_KEY_TYPE_ARC4, MBEDTLS_CIPHER_ID_ARC4,
+      MBEDTLS_CIPHER_ARC4_128, MBEDTLS_BLOWFISH_C, MBEDTLS_BLOWFISH_ALT,
+      MBEDTLS_CIPHER_ID_BLOWFISH, MBEDTLS_CIPHER_BLOWFISH_ECB,
+      MBEDTLS_CIPHER_BLOWFISH_CBC, MBEDTLS_CIPHER_BLOWFISH_CFB64,
+      MBEDTLS_CIPHER_BLOWFISH_CTR, MBEDTLS_MD2_C, MBEDTLS_MD2_ALT,
+      MBEDTLS_MD2_PROCESS_ALT, PSA_ALG_MD2, PSA_WANT_ALG_MD2,
+      MBEDTLS_PSA_ACCEL_ALG_MD2, MBEDTLS_OID_PKCS1_MD2,
+      MBEDTLS_OID_DIGEST_ALG_MD2, MBEDTLS_OID_PKCS5_PBE_MD2_DES_CBC,
+      MBEDTLS_MD_MD2, MBEDTLS_MD4_C, MBEDTLS_MD4_ALT, MBEDTLS_MD4_PROCESS_ALT,
+      PSA_ALG_MD4, PSA_WANT_ALG_MD4, MBEDTLS_PSA_ACCEL_ALG_MD4,
+      MBEDTLS_OID_PKCS1_MD4, MBEDTLS_OID_DIGEST_ALG_MD4,
+      MBEDTLS_OID_PKCS5_PBE_MD2_RC2_CBC, MBEDTLS_MD_MD4, MBEDTLS_XTEA_C,
+      MBEDTLS_XTEA_ALT. Remove the following functions:
+      mbedtls_arc4_self_test(), mbedtls_md2_free(), mbedtls_md2_clone(),
+      mbedtls_md2_starts_ret(), mbedtls_md2_update_ret(),
+      mbedtls_md2_finish_ret(), mbedtls_md2_ret(), mbedtls_md2_self_test(),
+      mbedtls_internal_md2_process(), mbedtls_md4_free(), mbedtls_md4_clone(),
+      mbedtls_md4_starts_ret(), mbedtls_md4_update_ret(),
+      mbedtls_md4_finish_ret(), mbedtls_md4_ret(), mbedtls_md4_self_test(),
+      mbedtls_internal_md4_process(), mbedtls_xtea_self_test().
+      Remove the related tests and test suites and error codes. Fixes #4084.
diff --git a/docs/3.0-migration-guide.d/remove_MD2_MD4_RC4_Blowfish_XTEA.md b/docs/3.0-migration-guide.d/remove_MD2_MD4_RC4_Blowfish_XTEA.md
new file mode 100644
index 0000000..d7e116c
--- /dev/null
+++ b/docs/3.0-migration-guide.d/remove_MD2_MD4_RC4_Blowfish_XTEA.md
@@ -0,0 +1,8 @@
+Remove MD2, MD4, RC4, Blowfish and XTEA ciphersuites
+--
+
+This change affects users of the MD2, MD4, RC4, Blowfish and XTEA ciphersuites.
+
+They are already niche or obsolete and most of them are weak or broken. For
+those reasons possible users should consider switching to modern and safe
+alternatives to be found in literature.