Fix escaping code for string printing. If *any* escaping is enabled we
must escape the escape character itself (backslash).

CHANGES

diff --git a/CHANGES b/CHANGES
index c75e514..7c44f0d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -166,7 +166,14 @@
        Add command line options to s_client/s_server.
      [Steve Henson]
 
- Changes between 1.0.0b and 1.0.0c  [xx XXX xxxx]
+ Changes between 1.0.0c and 1.0.0d [xx XXX xxxx]
+
+  *) Fix bug in string printing code: if *any* escaping is enabled we must
+     escape the escape character (backslash) or the resulting string is
+     ambiguous.
+     [Steve Henson]
+
+ Changes between 1.0.0b and 1.0.0c  [2 Dec 2010]
 
   *) Fixed J-PAKE implementation error, originally discovered by
      Sebastien Martini, further info and confirmation from Stefan

crypto/asn1/a_strex.c

diff --git a/crypto/asn1/a_strex.c b/crypto/asn1/a_strex.c
index 7fc14d3..264ebf2 100644
--- a/crypto/asn1/a_strex.c
+++ b/crypto/asn1/a_strex.c
@@ -74,6 +74,11 @@
 
 #define CHARTYPE_BS_ESC		(ASN1_STRFLGS_ESC_2253 | CHARTYPE_FIRST_ESC_2253 | CHARTYPE_LAST_ESC_2253)
 
+#define ESC_FLAGS (ASN1_STRFLGS_ESC_2253 | \
+		  ASN1_STRFLGS_ESC_QUOTE | \
+		  ASN1_STRFLGS_ESC_CTRL | \
+		  ASN1_STRFLGS_ESC_MSB)
+
 
 /* Three IO functions for sending data to memory, a BIO and
  * and a FILE pointer.
@@ -148,6 +153,13 @@
 		if(!io_ch(arg, tmphex, 3)) return -1;
 		return 3;
 	}
+	/* If we get this far and do any escaping at all must escape 
+	 * the escape character itself: backslash.
+	 */
+	if (chtmp == '\\' && flags & ESC_FLAGS) {
+		if(!io_ch(arg, "\\\\", 2)) return -1;
+		return 2;
+	}
 	if(!io_ch(arg, &chtmp, 1)) return -1;
 	return 1;
 }
@@ -292,11 +304,6 @@
 	4, -1, 2		/* 28-30 */
 };
 
-#define ESC_FLAGS (ASN1_STRFLGS_ESC_2253 | \
-		  ASN1_STRFLGS_ESC_QUOTE | \
-		  ASN1_STRFLGS_ESC_CTRL | \
-		  ASN1_STRFLGS_ESC_MSB)
-
 /* This is the main function, print out an
  * ASN1_STRING taking note of various escape
  * and display options. Returns number of