Const-correct X509_ALGOR_get0.

Matches the OpenSSL 1.1.0 spelling, which is what we advertise in
OPENSSL_VERSION_NUMBER now. Otherwise third-party code which uses it
will, in the long term, need ifdefs. Note this will require updates to
any existing callers (there appear to only be a couple of them), but it
should be straightforward.

Change-Id: I9dd1013609abca547152728a293529055dacc239
Reviewed-on: https://boringssl-review.googlesource.com/23325
Reviewed-by: Adam Langley <agl@google.com>

crypto/x509/x_algor.c

diff --git a/crypto/x509/x_algor.c b/crypto/x509/x_algor.c
index abacd06..13c9a8c 100644
--- a/crypto/x509/x_algor.c
+++ b/crypto/x509/x_algor.c
@@ -105,8 +105,8 @@
     return 1;
 }
 
-void X509_ALGOR_get0(ASN1_OBJECT **paobj, int *pptype, void **ppval,
-                     X509_ALGOR *algor)
+void X509_ALGOR_get0(const ASN1_OBJECT **paobj, int *pptype, const void **ppval,
+                     const X509_ALGOR *algor)
 {
     if (paobj)
         *paobj = algor->algorithm;

include/openssl/base.h

diff --git a/include/openssl/base.h b/include/openssl/base.h
index 9445556..cc962f3 100644
--- a/include/openssl/base.h
+++ b/include/openssl/base.h
@@ -151,7 +151,7 @@
 // A consumer may use this symbol in the preprocessor to temporarily build
 // against multiple revisions of BoringSSL at the same time. It is not
 // recommended to do so for longer than is necessary.
-#define BORINGSSL_API_VERSION 5
+#define BORINGSSL_API_VERSION 6
 
 #if defined(BORINGSSL_SHARED_LIBRARY)
 

include/openssl/x509.h

diff --git a/include/openssl/x509.h b/include/openssl/x509.h
index 7db9466..430ffc0 100644
--- a/include/openssl/x509.h
+++ b/include/openssl/x509.h
@@ -680,8 +680,9 @@
 OPENSSL_EXPORT X509_REQ *X509_REQ_dup(X509_REQ *req);
 OPENSSL_EXPORT X509_ALGOR *X509_ALGOR_dup(X509_ALGOR *xn);
 OPENSSL_EXPORT int X509_ALGOR_set0(X509_ALGOR *alg, const ASN1_OBJECT *aobj, int ptype, void *pval);
-OPENSSL_EXPORT void X509_ALGOR_get0(ASN1_OBJECT **paobj, int *pptype, void **ppval,
-						X509_ALGOR *algor);
+OPENSSL_EXPORT void X509_ALGOR_get0(const ASN1_OBJECT **paobj, int *pptype,
+                                    const void **ppval,
+                                    const X509_ALGOR *algor);
 OPENSSL_EXPORT void X509_ALGOR_set_md(X509_ALGOR *alg, const EVP_MD *md);
 OPENSSL_EXPORT int X509_ALGOR_cmp(const X509_ALGOR *a, const X509_ALGOR *b);