Remove -lmd. Use dlopen() and dlsym() instead for calls to the MD5* and

SHA* routines so that callers of libcrypt are not exposed to the internal
implementation.

1 files changed, 44 insertions, 1 deletions

diff --git a/lib/libcrypt/crypt-md5.c b/lib/libcrypt/crypt-md5.c
index 95255e4..004ba60 100644
--- a/lib/libcrypt/crypt-md5.c
+++ b/lib/libcrypt/crypt-md5.c
@@ -11,15 +11,29 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static const char rcsid[] = "$FreeBSD$";
+static const char rcsid[] = \
+"$FreeBSD$";
 #endif /* LIBC_SCCS and not lint */
 
 #include <unistd.h>
 #include <stdio.h>
 #include <string.h>
 #include <md5.h>
+#include <err.h>
 #include "crypt.h"
 
+#ifdef __PIC__
+#include <dlfcn.h>
+
+#define	MD5Init(ctx)			dl_MD5Init(ctx)
+#define	MD5Update(ctx, data, len)	dl_MD5Update(ctx, data, len)
+#define	MD5Final(dgst, ctx)		dl_MD5Final(dgst, ctx)
+
+static void (*dl_MD5Init)(MD5_CTX *);
+static void (*dl_MD5Update)(MD5_CTX *, const unsigned char *, unsigned int);
+static void (*dl_MD5Final)(unsigned char digest[16], MD5_CTX *);
+#endif
+
 /*
  * UNIX password
  */
@@ -41,6 +55,9 @@ crypt_md5(pw, salt)
 	int sl,pl,i;
 	MD5_CTX	ctx,ctx1;
 	unsigned long l;
+#ifdef __PIC__
+	void *libmd;
+#endif
 
 	/* Refine the Salt first */
 	sp = salt;
@@ -56,6 +73,29 @@ crypt_md5(pw, salt)
 	/* get the length of the true salt */
 	sl = ep - sp;
 
+#ifdef __PIC__
+	libmd = dlopen("libmd.so", RTLD_NOW);
+	if (libmd == NULL)
+		return NULL;
+	dl_MD5Init = dlsym(libmd, "MD5Init");
+	if (dl_MD5Init == NULL) {
+		warnx("libcrypt-md5: looking for MD5Init: %s\n", dlerror());
+		dlclose(libmd);
+		return NULL;
+	}
+	dl_MD5Update = dlsym(libmd, "MD5Update");
+	if (dl_MD5Update == NULL) {
+		warnx("libcrypt-md5: looking for MD5Update: %s\n", dlerror());
+		dlclose(libmd);
+		return NULL;
+	}
+	dl_MD5Final = dlsym(libmd, "MD5Final");
+	if (dl_MD5Final == NULL) {
+		warnx("libcrypt-md5: looking for MD5Final: %s\n", dlerror());
+		dlclose(libmd);
+		return NULL;
+	}
+#endif
 	MD5Init(&ctx);
 
 	/* The password first, since that is what is most unknown */
@@ -118,6 +158,9 @@ crypt_md5(pw, salt)
 		MD5Final(final,&ctx1);
 	}
 
+#ifdef __PIC__
+	dlclose(libmd);
+#endif
 	p = passwd + strlen(passwd);
 
 	l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];