const for PEM_write{,_bio}()

[Theo Buehler]

Add const to the 'name', 'header' and 'data' arguments of PEM_write(3)
and PEM_write_bio(3). Tested in sthen's bulk with no fallout.

Index: lib/libcrypto/pem/pem.h
===================================================================
RCS file: /var/cvs/src/lib/libcrypto/pem/pem.h,v
retrieving revision 1.17
diff -u -p -r1.17 pem.h
--- lib/libcrypto/pem/pem.h     4 Sep 2016 16:22:54 -0000       1.17
+++ lib/libcrypto/pem/pem.h     13 May 2018 07:13:43 -0000
@@ -385,8 +385,8 @@ int PEM_do_header (EVP_CIPHER_INFO *ciph
 #ifndef OPENSSL_NO_BIO
 int    PEM_read_bio(BIO *bp, char **name, char **header,
            unsigned char **data, long *len);
-int    PEM_write_bio(BIO *bp, const char *name, char *hdr, unsigned char *data,
-           long len);
+int    PEM_write_bio(BIO *bp, const char *name, const char *hdr,
+           const unsigned char *data, long len);
 int    PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
            const char *name, BIO *bp, pem_password_cb *cb, void *u);
 void * PEM_ASN1_read_bio(d2i_of_void *d2i, const char *name, BIO *bp,
@@ -403,8 +403,8 @@ int PEM_X509_INFO_write_bio(BIO *bp, X50
 
 int    PEM_read(FILE *fp, char **name, char **header,
            unsigned char **data, long *len);
-int    PEM_write(FILE *fp, char *name, char *hdr, unsigned char *data,
-           long len);
+int    PEM_write(FILE *fp, const char *name, const char *hdr,
+           const unsigned char *data, long len);
 void *  PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x,
            pem_password_cb *cb, void *u);
 int    PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
Index: lib/libcrypto/pem/pem_lib.c
===================================================================
RCS file: /var/cvs/src/lib/libcrypto/pem/pem_lib.c,v
retrieving revision 1.46
diff -u -p -r1.46 pem_lib.c
--- lib/libcrypto/pem/pem_lib.c 14 Apr 2018 07:09:21 -0000      1.46
+++ lib/libcrypto/pem/pem_lib.c 13 May 2018 07:13:43 -0000
@@ -564,7 +564,8 @@ load_iv(char **fromp, unsigned char *to,
 }
 
 int
-PEM_write(FILE *fp, char *name, char *header, unsigned char *data, long len)
+PEM_write(FILE *fp, const char *name, const char *header,
+    const unsigned char *data, long len)
 {
        BIO *b;
        int ret;
@@ -580,8 +581,8 @@ PEM_write(FILE *fp, char *name, char *he
 }
 
 int
-PEM_write_bio(BIO *bp, const char *name, char *header, unsigned char *data,
-    long len)
+PEM_write_bio(BIO *bp, const char *name, const char *header,
+    const unsigned char *data, long len)
 {
        int nlen, n, i, j, outl;
        unsigned char *buf = NULL;