Merge pull request #418 from bonzini/without-libgcrypt

allow choosing between libgcrypt, gnutls or embedded MD5

configure.ac

@@ -78,8 +78,43 @@ AM_CONDITIONAL([BUILD_EXAMPLES],
 
 AC_CONFIG_HEADERS([config.h])
 
-AC_CHECK_LIB([gcrypt], [gcry_control])
+AC_ARG_WITH([gnutls],
-AM_CONDITIONAL([HAVE_LIBGCRYPT], [test $ac_cv_lib_gcrypt_gcry_control = yes])
+	    [AS_HELP_STRING([--with-gnutls],
+			    [Use gnutls to compute MD5])],
+	    [WITH_GNUTLS=$withval],
+	    [WITH_GNUTLS=auto])
+
+AC_ARG_WITH([libgcrypt],
+	    [AS_HELP_STRING([--with-libgcrypt],
+			    [Use libgcrypt to compute MD5])],
+	    [WITH_LIBGCRYPT=$withval],
+	    [WITH_LIBGCRYPT=auto])
+
+if test "$WITH_GNUTLS" != no; then
+  AC_CHECK_LIB([gnutls], [gnutls_hash_init])
+  if test "$WITH_GNUTLS" = yes && test "$ac_cv_lib_gnutls_gnutls_hash_init" != yes; then
+    AC_MSG_ERROR([gnutls not found])
+  fi
+  WITH_GNUTLS=$ac_cv_lib_gnutls_gnutls_hash_init
+fi
+if test "$WITH_GNUTLS" = yes; then
+  WITH_LIBGCRYPT=no
+fi
+
+if test "$WITH_LIBGCRYPT" != no; then
+  AC_CHECK_LIB([gcrypt], [gcry_control])
+  if test "$WITH_LIBGCRYPT" = yes && test "$ac_cv_lib_gcrypt_gcry_control" != yes; then
+    AC_MSG_ERROR([libgcrypt not found])
+  fi
+  WITH_LIBGCRYPT=$ac_cv_lib_gcrypt_gcry_control
+fi
+
+NEED_MD5=no
+if test "$WITH_GNUTLS" = no && test "$WITH_LIBGCRYPT" = no; then
+  NEED_MD5=yes
+fi
+AM_CONDITIONAL([NEED_MD5],
+	       [expr "$NEED_MD5" : yes > /dev/null 2>&1])
 
 # For MinGW.
 AC_CHECK_LIB([ws2_32], [gethostbyname])

lib/Makefile.am

@@ -12,7 +12,7 @@ if TARGET_OS_IS_WIN32
 libiscsipriv_la_SOURCES += ../win32/win32_compat.c
 endif
 
-if !HAVE_LIBGCRYPT
+if NEED_MD5
 libiscsipriv_la_SOURCES += md5.c
 endif
 

lib/login.c

@@ -44,6 +44,10 @@
 #include "iscsi-private.h"
 #include "scsi-lowlevel.h"
 #include "md5.h"
+
+#ifdef HAVE_LIBGNUTLS
+#include <gnutls/crypto.h>
+#endif
 #ifdef HAVE_LIBGCRYPT
 #include <gcrypt.h>
 #endif
@@ -681,41 +685,61 @@ i2h(int i)
 	return i + '0';
 }
 
-#ifndef HAVE_LIBGCRYPT
+#if defined HAVE_LIBGNUTLS
-typedef struct MD5Context *gcry_md_hd_t;
+#define md5_context_t gnutls_hash_hd_t
-#define gcry_md_write MD5Update
+#define md5_open(hd)  gnutls_hash_init(hd, GNUTLS_DIG_MD5)
-#define GCRY_MD_MD5 1
+#define md5_write     gnutls_hash
+#define md5_read      gnutls_hash_output
 
-static void gcry_md_open(gcry_md_hd_t *hd, int algo, unsigned int flags)
+static void md5_close(md5_context_t h)
+{
+       unsigned char digest[16];
+
+       gnutls_hash_deinit(h, digest);
+}
+
+#elif defined HAVE_LIBGCRYPT
+typedef gcry_md_hd_t md5_context_t;
+#define md5_open(hd) gcry_md_open(hd, GCRY_MD_MD5, 0)
+#define md5_write gcry_md_write
+#define md5_close gcry_md_close
+
+static void md5_read(md5_context_t h, uint8_t *result)
+{
+	memcpy(result, gcry_md_read(h, 0), 16);
+}
+#else
+typedef struct MD5Context *md5_context_t;
+#define md5_write MD5Update
+
+static void md5_open(md5_context_t *hd)
 {
-	assert(algo == GCRY_MD_MD5 && flags == 0);
 	*hd = malloc(sizeof(struct MD5Context));
 	if (*hd) {
 		MD5Init(*hd);
 	}
 }
 
-static void gcry_md_putc(gcry_md_hd_t h, unsigned char c)
+static void md5_read(md5_context_t h, uint8_t *result)
-{
-	MD5Update(h, &c, 1);
-}
-
-static char *gcry_md_read(gcry_md_hd_t h, int algo)
 {
 	unsigned char digest[16];
-	assert(algo == 0 || algo == GCRY_MD_MD5);
 
 	MD5Final(digest, h);
-	return memcpy(h->buf, digest, sizeof(digest));
+	memcpy(result, digest, sizeof(digest));
 }
 
-static void gcry_md_close(gcry_md_hd_t h)
+static void md5_close(md5_context_t h)
 {
 	memset(h, 0, sizeof(*h));
 	free(h);
 }
 #endif
 
+static inline void md5_putc(md5_context_t h, unsigned char c)
+{
+	md5_write(h, &c, 1);
+}
+
 /* size of the challenge used for bidirectional chap */
 #define TARGET_CHAP_C_SIZE 32
 
@@ -726,7 +750,7 @@ iscsi_login_add_chap_response(struct iscsi_context *iscsi, struct iscsi_pdu *pdu
 	char * strp;
 	unsigned char c, cc[2];
 	unsigned char digest[CHAP_R_SIZE];
-	gcry_md_hd_t ctx;
+	md5_context_t ctx;
 	int i;
 
 	if (iscsi->current_phase != ISCSI_PDU_LOGIN_CSG_SECNEG
@@ -739,22 +763,22 @@ iscsi_login_add_chap_response(struct iscsi_context *iscsi, struct iscsi_pdu *pdu
 		return -1;
 	}
 
-	gcry_md_open(&ctx, GCRY_MD_MD5, 0);
+	md5_open(&ctx);
 	if (ctx == NULL) {
 		iscsi_set_error(iscsi, "Cannot create MD5 algorithm");
 		return -1;
 	}
-	gcry_md_putc(ctx, iscsi->chap_i);
+	md5_putc(ctx, iscsi->chap_i);
-	gcry_md_write(ctx, (unsigned char *)iscsi->passwd, strlen(iscsi->passwd));
+	md5_write(ctx, (unsigned char *)iscsi->passwd, strlen(iscsi->passwd));
 
 	strp = iscsi->chap_c;
 	while (*strp != 0) {
 		c = (h2i(strp[0]) << 4) | h2i(strp[1]);
 		strp += 2;
-		gcry_md_putc(ctx, c);
+		md5_putc(ctx, c);
 	}
-	memcpy(digest, gcry_md_read(ctx, 0), sizeof(digest));
+	md5_read(ctx, digest);
-	gcry_md_close(ctx);
+	md5_close(ctx);
 
 	strncpy(str,"CHAP_R=0x",MAX_STRING_SIZE);
 	if (iscsi_pdu_add_data(iscsi, pdu, (unsigned char *)str, strlen(str))
@@ -822,20 +846,19 @@ iscsi_login_add_chap_response(struct iscsi_context *iscsi, struct iscsi_pdu *pdu
 			return -1;
 		}
 
-		gcry_md_open(&ctx, GCRY_MD_MD5, 0);
+		md5_open(&ctx);
 		if (ctx == NULL) {
 			iscsi_set_error(iscsi, "Cannot create MD5 algorithm");
 			return -1;
 		}
-		gcry_md_putc(ctx, iscsi->target_chap_i);
+		md5_putc(ctx, iscsi->target_chap_i);
-		gcry_md_write(ctx, (unsigned char *)iscsi->target_passwd,
+		md5_write(ctx, (unsigned char *)iscsi->target_passwd,
 			      strlen(iscsi->target_passwd));
-		gcry_md_write(ctx, (unsigned char *)target_chap_c,
+		md5_write(ctx, (unsigned char *)target_chap_c,
 			      TARGET_CHAP_C_SIZE);
 
-		memcpy(iscsi->target_chap_r, gcry_md_read(ctx, 0),
+		md5_read(ctx, iscsi->target_chap_r);
-		       sizeof(iscsi->target_chap_r));
+		md5_close(ctx);
-		gcry_md_close(ctx);
 	}
 
 	return 0;