Constify ASN1_generate_v3

Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1074)

crypto/asn1/asn1_gen.c

@@ -62,7 +62,7 @@ typedef struct {
     int exp_count;
 } tag_exp_arg;
 
-static ASN1_TYPE *generate_v3(char *str, X509V3_CTX *cnf, int depth,
+static ASN1_TYPE *generate_v3(const char *str, X509V3_CTX *cnf, int depth,
                               int *perr);
 static int bitstr_cb(const char *elem, int len, void *bitstr);
 static int asn1_cb(const char *elem, int len, void *bitstr);
@@ -86,7 +86,7 @@ ASN1_TYPE *ASN1_generate_nconf(char *str, CONF *nconf)
     return ASN1_generate_v3(str, &cnf);
 }
 
-ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf)
+ASN1_TYPE *ASN1_generate_v3(const char *str, X509V3_CTX *cnf)
 {
     int err = 0;
     ASN1_TYPE *ret = generate_v3(str, cnf, 0, &err);
@@ -95,7 +95,7 @@ ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf)
     return ret;
 }
 
-static ASN1_TYPE *generate_v3(char *str, X509V3_CTX *cnf, int depth,
+static ASN1_TYPE *generate_v3(const char *str, X509V3_CTX *cnf, int depth,
                               int *perr)
 {
     ASN1_TYPE *ret;

doc/crypto/ASN1_generate_nconf.pod

@@ -9,7 +9,7 @@ ASN1_generate_nconf, ASN1_generate_v3 - ASN1 generation functions
  #include <openssl/asn1.h>
 
  ASN1_TYPE *ASN1_generate_nconf(char *str, CONF *nconf);
- ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf);
+ ASN1_TYPE *ASN1_generate_v3(const char *str, X509V3_CTX *cnf);
 
 =head1 DESCRIPTION
 

include/openssl/asn1.h

@@ -799,7 +799,7 @@ void ASN1_add_oid_module(void);
 void ASN1_add_stable_module(void);
 
 ASN1_TYPE *ASN1_generate_nconf(char *str, CONF *nconf);
-ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf);
+ASN1_TYPE *ASN1_generate_v3(const char *str, X509V3_CTX *cnf);
 int ASN1_str2mask(const char *str, unsigned long *pmask);
 
 /* ASN1 Print flags */