diff --git a/crypto/asn1/a_mbstr.c b/crypto/asn1/a_mbstr.c
index 260c1aff0..ce413ec3d 100644
--- a/crypto/asn1/a_mbstr.c
+++ b/crypto/asn1/a_mbstr.c
@@ -60,7 +60,7 @@
 #include "cryptlib.h"
 #include <openssl/asn1.h>
 
-static int traverse_string(unsigned char *p, int len, int inform,
+static int traverse_string(const unsigned char *p, int len, int inform,
 		 int (*rfunc)(unsigned long value, void *in), void *arg);
 static int in_utf8(unsigned long value, void *arg);
 static int out_utf8(unsigned long value, void *arg);
@@ -78,8 +78,8 @@ static int is_printable(unsigned long value);
  * Yes this is horrible: it has to be :-(
  */
 
-int ASN1_mbstring_copy(ASN1_STRING **out, unsigned char *in, int len,
-					int inform, unsigned long mask)
+int ASN1_mbstring_copy(ASN1_STRING **out, const unsigned char *in, int len,
+		       int inform, unsigned long mask)
 {
 	int str_type;
 	int ret;
@@ -206,7 +206,7 @@ int ASN1_mbstring_copy(ASN1_STRING **out, unsigned char *in, int len,
  * to an optional function along with a void * argument.
  */
 
-static int traverse_string(unsigned char *p, int len, int inform,
+static int traverse_string(const unsigned char *p, int len, int inform,
 		 int (*rfunc)(unsigned long value, void *in), void *arg)
 {
 	unsigned long value;
diff --git a/crypto/asn1/a_utf8.c b/crypto/asn1/a_utf8.c
index 45434be4f..b5125af22 100644
--- a/crypto/asn1/a_utf8.c
+++ b/crypto/asn1/a_utf8.c
@@ -100,9 +100,9 @@ ASN1_UTF8STRING *d2i_ASN1_UTF8STRING(ASN1_UTF8STRING **a, unsigned char **pp,
  * -4 = character encoded incorrectly (not minimal length).
  */
 
-int UTF8_getc(unsigned char *str, int len, unsigned long *val)
+int UTF8_getc(const unsigned char *str, int len, unsigned long *val)
 {
-	unsigned char *p;
+	const unsigned char *p;
 	unsigned long value;
 	int ret;
 	if(len <= 0) return 0;
diff --git a/crypto/asn1/asn1.h b/crypto/asn1/asn1.h
index 832611b71..fb2007322 100644
--- a/crypto/asn1/asn1.h
+++ b/crypto/asn1/asn1.h
@@ -563,7 +563,7 @@ ASN1_BMPSTRING *d2i_ASN1_BMPSTRING(ASN1_BMPSTRING **a, unsigned char **pp,
 	long length);
 
 
-int UTF8_getc(unsigned char *str, int len, unsigned long *val);
+int UTF8_getc(const unsigned char *str, int len, unsigned long *val);
 int UTF8_putc(unsigned char *str, int len, unsigned long value);
 
 int i2d_ASN1_PRINTABLE(ASN1_STRING *a,unsigned char **pp);
@@ -718,7 +718,7 @@ unsigned char *ASN1_seq_pack(STACK *safes, int (*i2d)(), unsigned char **buf,
 								 int *len );
 void *ASN1_unpack_string(ASN1_STRING *oct, char *(*d2i)());
 ASN1_STRING *ASN1_pack_string(void *obj, int (*i2d)(), ASN1_OCTET_STRING **oct);
-int ASN1_mbstring_copy(ASN1_STRING **out, unsigned char *in, int len,
+int ASN1_mbstring_copy(ASN1_STRING **out, const unsigned char *in, int len,
 					int inform, unsigned long mask);
 
 /* BEGIN ERROR CODES */