Remove configure test & compat code for ripemd160.

RIPEMD160 support was removed upstream in 2017, however we still had
a configure test and compat code for it, so clean those up now.

configure.ac

@@ -2915,15 +2915,6 @@ if test "x$openssl" = "xyes" ; then
 	# Check for SHA256, SHA384 and SHA512 support in OpenSSL
 	AC_CHECK_FUNCS([EVP_sha256 EVP_sha384 EVP_sha512])
 
-	# Search for RIPE-MD support in OpenSSL
-	AC_CHECK_FUNCS([EVP_ripemd160], ,
-	    [unsupported_algorithms="$unsupported_algorithms \
-		hmac-ripemd160 \
-		hmac-ripemd160@openssh.com \
-		hmac-ripemd160-etm@openssh.com"
-	     ]
-	)
-
 	# Check complete ECC support in OpenSSL
 	AC_MSG_CHECKING([whether OpenSSL has NID_X9_62_prime256v1])
 	AC_LINK_IFELSE(

digest-openssl.c

@@ -32,9 +32,6 @@
 #include "digest.h"
 #include "ssherr.h"
 
-#ifndef HAVE_EVP_RIPEMD160
-# define EVP_ripemd160 NULL
-#endif
 #ifndef HAVE_EVP_SHA256
 # define EVP_sha256 NULL
 #endif

openbsd-compat/Makefile.in

@@ -44,7 +44,6 @@ OPENBSD=base64.o \
 	readpassphrase.o \
 	reallocarray.o \
 	recallocarray.o \
-	rmd160.o \
 	rresvport.o \
 	setenv.o \
 	setproctitle.o \

openbsd-compat/openbsd-compat.h

@@ -44,7 +44,6 @@
 #include "getrrsetbyname.h"
 #include "sha1.h"
 #include "sha2.h"
-#include "rmd160.h"
 #include "md5.h"
 #include "blf.h"
 #include "fnmatch.h"

openbsd-compat/openssl-compat.h

@@ -87,12 +87,6 @@ void ssh_aes_ctr_iv(EVP_CIPHER_CTX *, int, u_char *, size_t);
 # endif
 #endif
 
-#if defined(HAVE_EVP_RIPEMD160)
-# if defined(OPENSSL_NO_RIPEMD) || defined(OPENSSL_NO_RMD160)
-#  undef HAVE_EVP_RIPEMD160
-# endif
-#endif
-
 /* LibreSSL/OpenSSL 1.1x API compat */
 #ifndef HAVE_DSA_GET0_PQG
 void DSA_get0_pqg(const DSA *d, const BIGNUM **p, const BIGNUM **q,