#

# Replace MD5 use in rcache with SHA1.

#

# rcache uses an unkeyed MD5 hash of the authenticator to distinguish 

# between different request with equal client principal, server principal 

# and microsecond time. When OpenSSL crypto provider is used and 

# underlying OpenSSL is run in FIPS mode, MD5 algorithm is disabled and 

# gss_accept_sec_context() results in an abort in rcache processing

#

# This patch effectively implements a different rcache extension.

# The new extension identifier is 'SHA1:' (instead of 'HASH:')

# and the checksum type is CKSUMTYPE_NIST_SHA (instead of CKSUMTYPE_RSA_MD5).

#

# This change has been brought for discussion with upstream:

# http://mailman.mit.edu/pipermail/krbdev/2015-December/012508.html

# Patch source: in-house

#

     *out = NULL;

     /* Calculate the binary checksum. */

-    retval = krb5_c_make_checksum(context, CKSUMTYPE_RSA_MD5, 0, 0,

+    retval = krb5_c_make_checksum(context, CKSUMTYPE_NIST_SHA, 0, 0,

                                   message, &cksum);

     if (retval)

         return retval;

 /*

  * Hash extension records have the format:

  *  client = <empty string>

- *  server = HASH:<msghash> <clientlen>:<client> <serverlen>:<server>

+ *  server = SHA1:<msghash> <clientlen>:<client> <serverlen>:<server>

  * Spaces in the client and server string are represented with

  * with backslashes.  Client and server lengths are represented in

  * ASCII decimal (which is different from the 32-bit binary we use

     /* Check if this appears to match the hash extension format. */

     if (*rep->client)

         return 0;

-    if (strncmp(rep->server, "HASH:", 5) != 0)

+    if (strncmp(rep->server, "SHA1:", 5) != 0)

         return 0;

     /* Parse out the message hash. */

         /* Format the extension value so we know its length. */

         k5_buf_init_dynamic(&extbuf);

-        k5_buf_add_fmt(&extbuf, "HASH:%s %lu:%s %lu:%s", rep->msghash,

+        k5_buf_add_fmt(&extbuf, "SHA1:%s %lu:%s %lu:%s", rep->msghash,

                        (unsigned long)clientlen, rep->client,

                        (unsigned long)serverlen, rep->server);

         if (k5_buf_status(&extbuf) != 0)