PEM: constify PEM_write_ routines

There's no reason why the object to be written, or the key string
given by the caller should be non-const.

This makes the IMPLEMENT_PEM_..._const and  DECLARE_PEM_..._const
macros superfluous, so we keep them around but mark them deprecated.

In all places where IMPLEMENT_PEM_..._const and  DECLARE_PEM_..._const
are used, they are replaced with the corresponding macros without
'_const'.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10452)

7 files changed, 54 insertions, 53 deletions

diff --git a/crypto/pem/pem_all.c b/crypto/pem/pem_all.c
index 4c3f5f0df2..975e62e9f7 100644
--- a/crypto/pem/pem_all.c
+++ b/crypto/pem/pem_all.c
@@ -79,14 +79,9 @@ RSA *PEM_read_RSAPrivateKey(FILE *fp, RSA **rsa, pem_password_cb *cb, void *u)
 
 # endif
 
-IMPLEMENT_PEM_write_cb_const(RSAPrivateKey, RSA, PEM_STRING_RSA,
-                             RSAPrivateKey)
-
-
-IMPLEMENT_PEM_rw_const(RSAPublicKey, RSA, PEM_STRING_RSA_PUBLIC,
-                       RSAPublicKey) IMPLEMENT_PEM_rw(RSA_PUBKEY, RSA,
-                                                      PEM_STRING_PUBLIC,
-                                                      RSA_PUBKEY)
+IMPLEMENT_PEM_write_cb(RSAPrivateKey, RSA, PEM_STRING_RSA, RSAPrivateKey)
+IMPLEMENT_PEM_rw(RSAPublicKey, RSA, PEM_STRING_RSA_PUBLIC, RSAPublicKey)
+IMPLEMENT_PEM_rw(RSA_PUBKEY, RSA, PEM_STRING_PUBLIC, RSA_PUBKEY)
 #endif
 #ifndef OPENSSL_NO_DSA
 static DSA *pkey_get_dsa(EVP_PKEY *key, DSA **dsa)
@@ -113,9 +108,8 @@ DSA *PEM_read_bio_DSAPrivateKey(BIO *bp, DSA **dsa, pem_password_cb *cb,
     return pkey_get_dsa(pktmp, dsa); /* will free pktmp */
 }
 
-IMPLEMENT_PEM_write_cb_const(DSAPrivateKey, DSA, PEM_STRING_DSA,
-                             DSAPrivateKey)
-    IMPLEMENT_PEM_rw(DSA_PUBKEY, DSA, PEM_STRING_PUBLIC, DSA_PUBKEY)
+IMPLEMENT_PEM_write_cb(DSAPrivateKey, DSA, PEM_STRING_DSA, DSAPrivateKey)
+IMPLEMENT_PEM_rw(DSA_PUBKEY, DSA, PEM_STRING_PUBLIC, DSA_PUBKEY)
 # ifndef OPENSSL_NO_STDIO
 DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **dsa, pem_password_cb *cb, void *u)
 {
@@ -126,7 +120,7 @@ DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **dsa, pem_password_cb *cb, void *u)
 
 # endif
 
-IMPLEMENT_PEM_rw_const(DSAparams, DSA, PEM_STRING_DSAPARAMS, DSAparams)
+IMPLEMENT_PEM_rw(DSAparams, DSA, PEM_STRING_DSAPARAMS, DSAparams)
 #endif
 #ifndef OPENSSL_NO_EC
 static EC_KEY *pkey_get_eckey(EVP_PKEY *key, EC_KEY **eckey)
@@ -153,8 +147,8 @@ EC_KEY *PEM_read_bio_ECPrivateKey(BIO *bp, EC_KEY **key, pem_password_cb *cb,
     return pkey_get_eckey(pktmp, key); /* will free pktmp */
 }
 
-IMPLEMENT_PEM_rw_const(ECPKParameters, EC_GROUP, PEM_STRING_ECPARAMETERS,
-                       ECPKParameters)
+IMPLEMENT_PEM_rw(ECPKParameters, EC_GROUP, PEM_STRING_ECPARAMETERS,
+                 ECPKParameters)
 
 
 IMPLEMENT_PEM_write_cb(ECPrivateKey, EC_KEY, PEM_STRING_ECPRIVATEKEY,
@@ -175,7 +169,7 @@ EC_KEY *PEM_read_ECPrivateKey(FILE *fp, EC_KEY **eckey, pem_password_cb *cb,
 
 #ifndef OPENSSL_NO_DH
 
-IMPLEMENT_PEM_write_const(DHparams, DH, PEM_STRING_DHPARAMS, DHparams)
-    IMPLEMENT_PEM_write_const(DHxparams, DH, PEM_STRING_DHXPARAMS, DHxparams)
+IMPLEMENT_PEM_write(DHparams, DH, PEM_STRING_DHPARAMS, DHparams)
+IMPLEMENT_PEM_write(DHxparams, DH, PEM_STRING_DHXPARAMS, DHxparams)
 #endif
 IMPLEMENT_PEM_rw(PUBKEY, EVP_PKEY, PEM_STRING_PUBLIC, PUBKEY)
diff --git a/crypto/pem/pem_info.c b/crypto/pem/pem_info.c
index ad1dba3f0d..919769ae4f 100644
--- a/crypto/pem/pem_info.c
+++ b/crypto/pem/pem_info.c
@@ -244,15 +244,15 @@ STACK_OF(X509_INFO) *PEM_X509_INFO_read_bio(BIO *bp, STACK_OF(X509_INFO) *sk,
 }
 
 /* A TJH addition */
-int PEM_X509_INFO_write_bio(BIO *bp, X509_INFO *xi, EVP_CIPHER *enc,
-                            unsigned char *kstr, int klen,
+int PEM_X509_INFO_write_bio(BIO *bp, const X509_INFO *xi, EVP_CIPHER *enc,
+                            const unsigned char *kstr, int klen,
                             pem_password_cb *cb, void *u)
 {
     int i, ret = 0;
     unsigned char *data = NULL;
     const char *objstr = NULL;
     char buf[PEM_BUFSIZE];
-    unsigned char *iv = NULL;
+    const unsigned char *iv = NULL;
 
     if (enc != NULL) {
         objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc));
@@ -301,7 +301,7 @@ int PEM_X509_INFO_write_bio(BIO *bp, X509_INFO *xi, EVP_CIPHER *enc,
             buf[0] = '\0';
             PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
             PEM_dek_info(buf, objstr, EVP_CIPHER_iv_length(enc),
-                         (char *)iv);
+                         (const char *)iv);
 
             /* use the normal code to write things out */
             i = PEM_write_bio(bp, PEM_STRING_RSA, buf, data, i);
diff --git a/crypto/pem/pem_lib.c b/crypto/pem/pem_lib.c
index 020a030334..e059328aee 100644
--- a/crypto/pem/pem_lib.c
+++ b/crypto/pem/pem_lib.c
@@ -80,7 +80,7 @@ void PEM_proc_type(char *buf, int type)
     BIO_snprintf(p, PEM_BUFSIZE - (size_t)(p - buf), "Proc-Type: 4,%s\n", str);
 }
 
-void PEM_dek_info(char *buf, const char *type, int len, char *str)
+void PEM_dek_info(char *buf, const char *type, int len, const char *str)
 {
     long i;
     char *p = buf + strlen(buf);
@@ -288,8 +288,9 @@ int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
 
 #ifndef OPENSSL_NO_STDIO
 int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
-                   void *x, const EVP_CIPHER *enc, unsigned char *kstr,
-                   int klen, pem_password_cb *callback, void *u)
+                   const void *x, const EVP_CIPHER *enc,
+                   const unsigned char *kstr, int klen,
+                   pem_password_cb *callback, void *u)
 {
     BIO *b;
     int ret;
@@ -306,8 +307,9 @@ int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
 #endif
 
 int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
-                       void *x, const EVP_CIPHER *enc, unsigned char *kstr,
-                       int klen, pem_password_cb *callback, void *u)
+                       const void *x, const EVP_CIPHER *enc,
+                       const unsigned char *kstr, int klen,
+                       pem_password_cb *callback, void *u)
 {
     EVP_CIPHER_CTX *ctx = NULL;
     int dsize = 0, i = 0, j = 0, ret = 0;
diff --git a/crypto/pem/pem_pk8.c b/crypto/pem/pem_pk8.c
index 642d4f6e24..6b7840508b 100644
--- a/crypto/pem/pem_pk8.c
+++ b/crypto/pem/pem_pk8.c
@@ -18,12 +18,14 @@
 
 static int do_pk8pkey(BIO *bp, const EVP_PKEY *x, int isder,
                       int nid, const EVP_CIPHER *enc,
-                      char *kstr, int klen, pem_password_cb *cb, void *u);
+                      const char *kstr, int klen,
+                      pem_password_cb *cb, void *u);
 
 #ifndef OPENSSL_NO_STDIO
 static int do_pk8pkey_fp(FILE *bp, const EVP_PKEY *x, int isder,
                          int nid, const EVP_CIPHER *enc,
-                         char *kstr, int klen, pem_password_cb *cb, void *u);
+                         const char *kstr, int klen,
+                         pem_password_cb *cb, void *u);
 #endif
 /*
  * These functions write a private key in PKCS#8 format: it is a "drop in"
@@ -33,35 +35,35 @@ static int do_pk8pkey_fp(FILE *bp, const EVP_PKEY *x, int isder,
  */
 
 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, const EVP_PKEY *x, int nid,
-                                      char *kstr, int klen,
+                                      const char *kstr, int klen,
                                       pem_password_cb *cb, void *u)
 {
     return do_pk8pkey(bp, x, 0, nid, NULL, kstr, klen, cb, u);
 }
 
 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, const EVP_PKEY *x, const EVP_CIPHER *enc,
-                                  char *kstr, int klen,
+                                  const char *kstr, int klen,
                                   pem_password_cb *cb, void *u)
 {
     return do_pk8pkey(bp, x, 0, -1, enc, kstr, klen, cb, u);
 }
 
 int i2d_PKCS8PrivateKey_bio(BIO *bp, const EVP_PKEY *x, const EVP_CIPHER *enc,
-                            char *kstr, int klen,
+                            const char *kstr, int klen,
                             pem_password_cb *cb, void *u)
 {
     return do_pk8pkey(bp, x, 1, -1, enc, kstr, klen, cb, u);
 }
 
 int i2d_PKCS8PrivateKey_nid_bio(BIO *bp, const EVP_PKEY *x, int nid,
-                                char *kstr, int klen,
+                                const char *kstr, int klen,
                                 pem_password_cb *cb, void *u)
 {
     return do_pk8pkey(bp, x, 1, nid, NULL, kstr, klen, cb, u);
 }
 
 static int do_pk8pkey(BIO *bp, const EVP_PKEY *x, int isder, int nid,
-                      const EVP_CIPHER *enc, char *kstr, int klen,
+                      const EVP_CIPHER *enc, const char *kstr, int klen,
                       pem_password_cb *cb, void *u)
 {
     X509_SIG *p8;
@@ -149,34 +151,35 @@ EVP_PKEY *d2i_PKCS8PrivateKey_bio(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
 #ifndef OPENSSL_NO_STDIO
 
 int i2d_PKCS8PrivateKey_fp(FILE *fp, const EVP_PKEY *x, const EVP_CIPHER *enc,
-                           char *kstr, int klen, pem_password_cb *cb, void *u)
+                           const char *kstr, int klen,
+                           pem_password_cb *cb, void *u)
 {
     return do_pk8pkey_fp(fp, x, 1, -1, enc, kstr, klen, cb, u);
 }
 
 int i2d_PKCS8PrivateKey_nid_fp(FILE *fp, const EVP_PKEY *x, int nid,
-                               char *kstr, int klen,
+                               const char *kstr, int klen,
                                pem_password_cb *cb, void *u)
 {
     return do_pk8pkey_fp(fp, x, 1, nid, NULL, kstr, klen, cb, u);
 }
 
 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, const EVP_PKEY *x, int nid,
-                                  char *kstr, int klen,
+                                  const char *kstr, int klen,
                                   pem_password_cb *cb, void *u)
 {
     return do_pk8pkey_fp(fp, x, 0, nid, NULL, kstr, klen, cb, u);
 }
 
 int PEM_write_PKCS8PrivateKey(FILE *fp, const EVP_PKEY *x, const EVP_CIPHER *enc,
-                              char *kstr, int klen, pem_password_cb *cb,
-                              void *u)
+                              const char *kstr, int klen,
+                              pem_password_cb *cb, void *u)
 {
     return do_pk8pkey_fp(fp, x, 0, -1, enc, kstr, klen, cb, u);
 }
 
 static int do_pk8pkey_fp(FILE *fp, const EVP_PKEY *x, int isder, int nid,
-                         const EVP_CIPHER *enc, char *kstr, int klen,
+                         const EVP_CIPHER *enc, const char *kstr, int klen,
                          pem_password_cb *cb, void *u)
 {
     BIO *bp;
diff --git a/crypto/pem/pem_pkey.c b/crypto/pem/pem_pkey.c
index a4c60a354d..6f89759f1e 100644
--- a/crypto/pem/pem_pkey.c
+++ b/crypto/pem/pem_pkey.c
@@ -64,19 +64,20 @@ EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
     return ret;
 }
 
-int PEM_write_bio_PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc,
-                             unsigned char *kstr, int klen,
+int PEM_write_bio_PrivateKey(BIO *bp, const EVP_PKEY *x,
+                             const EVP_CIPHER *enc,
+                             const unsigned char *kstr, int klen,
                              pem_password_cb *cb, void *u)
 {
     if (x->ameth == NULL || x->ameth->priv_encode != NULL)
         return PEM_write_bio_PKCS8PrivateKey(bp, x, enc,
-                                             (char *)kstr, klen, cb, u);
+                                             (const char *)kstr, klen, cb, u);
     return PEM_write_bio_PrivateKey_traditional(bp, x, enc, kstr, klen, cb, u);
 }
 
-int PEM_write_bio_PrivateKey_traditional(BIO *bp, EVP_PKEY *x,
+int PEM_write_bio_PrivateKey_traditional(BIO *bp, const EVP_PKEY *x,
                                          const EVP_CIPHER *enc,
-                                         unsigned char *kstr, int klen,
+                                         const unsigned char *kstr, int klen,
                                          pem_password_cb *cb, void *u)
 {
     char pem_str[80];
@@ -111,7 +112,7 @@ EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x)
     return ret;
 }
 
-int PEM_write_bio_Parameters(BIO *bp, EVP_PKEY *x)
+int PEM_write_bio_Parameters(BIO *bp, const EVP_PKEY *x)
 {
     char pem_str[80];
     if (!x->ameth || !x->ameth->param_encode)
@@ -139,8 +140,8 @@ EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
     return ret;
 }
 
-int PEM_write_PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc,
-                         unsigned char *kstr, int klen,
+int PEM_write_PrivateKey(FILE *fp, const EVP_PKEY *x, const EVP_CIPHER *enc,
+                         const unsigned char *kstr, int klen,
                          pem_password_cb *cb, void *u)
 {
     BIO *b;
diff --git a/crypto/pem/pem_sign.c b/crypto/pem/pem_sign.c
index 4be03a4794..c12afd5c3b 100644
--- a/crypto/pem/pem_sign.c
+++ b/crypto/pem/pem_sign.c
@@ -19,7 +19,8 @@ int PEM_SignInit(EVP_MD_CTX *ctx, EVP_MD *type)
     return EVP_DigestInit_ex(ctx, type, NULL);
 }
 
-int PEM_SignUpdate(EVP_MD_CTX *ctx, unsigned char *data, unsigned int count)
+int PEM_SignUpdate(EVP_MD_CTX *ctx,
+                   const unsigned char *data, unsigned int count)
 {
     return EVP_DigestUpdate(ctx, data, count);
 }
diff --git a/crypto/pem/pvkfmt.c b/crypto/pem/pvkfmt.c
index 6bcde93d6c..95bd4da3f5 100644
--- a/crypto/pem/pvkfmt.c
+++ b/crypto/pem/pvkfmt.c
@@ -424,7 +424,7 @@ static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *magic);
 static void write_rsa(unsigned char **out, RSA *rsa, int ispub);
 static void write_dsa(unsigned char **out, DSA *dsa, int ispub);
 
-static int do_i2b(unsigned char **out, EVP_PKEY *pk, int ispub)
+static int do_i2b(unsigned char **out, const EVP_PKEY *pk, int ispub)
 {
     unsigned char *p;
     unsigned int bitlen, magic = 0, keyalg;
@@ -473,7 +473,7 @@ static int do_i2b(unsigned char **out, EVP_PKEY *pk, int ispub)
     return outlen;
 }
 
-static int do_i2b_bio(BIO *out, EVP_PKEY *pk, int ispub)
+static int do_i2b_bio(BIO *out, const EVP_PKEY *pk, int ispub)
 {
     unsigned char *tmp = NULL;
     int outlen, wrlen;
@@ -599,12 +599,12 @@ static void write_dsa(unsigned char **out, DSA *dsa, int ispub)
     return;
 }
 
-int i2b_PrivateKey_bio(BIO *out, EVP_PKEY *pk)
+int i2b_PrivateKey_bio(BIO *out, const EVP_PKEY *pk)
 {
     return do_i2b_bio(out, pk, 0);
 }
 
-int i2b_PublicKey_bio(BIO *out, EVP_PKEY *pk)
+int i2b_PublicKey_bio(BIO *out, const EVP_PKEY *pk)
 {
     return do_i2b_bio(out, pk, 1);
 }
@@ -780,7 +780,7 @@ EVP_PKEY *b2i_PVK_bio(BIO *in, pem_password_cb *cb, void *u)
     return ret;
 }
 
-static int i2b_PVK(unsigned char **out, EVP_PKEY *pk, int enclevel,
+static int i2b_PVK(unsigned char **out, const EVP_PKEY *pk, int enclevel,
                    pem_password_cb *cb, void *u)
 {
     int outlen = 24, pklen;
@@ -865,7 +865,7 @@ static int i2b_PVK(unsigned char **out, EVP_PKEY *pk, int enclevel,
     return -1;
 }
 
-int i2b_PVK_bio(BIO *out, EVP_PKEY *pk, int enclevel,
+int i2b_PVK_bio(BIO *out, const EVP_PKEY *pk, int enclevel,
                 pem_password_cb *cb, void *u)
 {
     unsigned char *tmp = NULL;