Use typedefs in i2d and d2i_ASN1_BOOLEAN.

This makes it slightly clearer which ints are lengths and which are
substituting for T*. (ASN1_BOOLEAN is weird. It is the one non-pointer
representation in crypto/asn1.)

Change-Id: I93ff87264835e64c9f8613edae63e93731e77548
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49865
Reviewed-by: Adam Langley <agl@google.com>

crypto/asn1/a_bool.c

diff --git a/crypto/asn1/a_bool.c b/crypto/asn1/a_bool.c
index 15396ff..1282176 100644
--- a/crypto/asn1/a_bool.c
+++ b/crypto/asn1/a_bool.c
@@ -59,7 +59,7 @@
 #include <openssl/err.h>
 #include <openssl/mem.h>
 
-int i2d_ASN1_BOOLEAN(int a, unsigned char **pp)
+int i2d_ASN1_BOOLEAN(ASN1_BOOLEAN a, unsigned char **pp)
 {
     int r;
     unsigned char *p, *allocated = NULL;
@@ -88,36 +88,30 @@
     return r;
 }
 
-int d2i_ASN1_BOOLEAN(int *a, const unsigned char **pp, long length)
-{
-    int ret = -1;
-    const unsigned char *p;
+ASN1_BOOLEAN d2i_ASN1_BOOLEAN(ASN1_BOOLEAN *a, const unsigned char **pp,
+                              long length) {
+    const unsigned char *p = *pp;
     long len;
     int inf, tag, xclass;
-    int i = 0;
-
-    p = *pp;
     inf = ASN1_get_object(&p, &len, &tag, &xclass, length);
     if (inf & 0x80) {
-        i = ASN1_R_BAD_OBJECT_HEADER;
-        goto err;
+        OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_OBJECT_HEADER);
+        return -1;
     }
 
     if (tag != V_ASN1_BOOLEAN) {
-        i = ASN1_R_EXPECTING_A_BOOLEAN;
-        goto err;
+        OPENSSL_PUT_ERROR(ASN1, ASN1_R_EXPECTING_A_BOOLEAN);
+        return -1;
     }
 
     if (len != 1) {
-        i = ASN1_R_BOOLEAN_IS_WRONG_LENGTH;
-        goto err;
+        OPENSSL_PUT_ERROR(ASN1, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
+        return -1;
     }
-    ret = (int)*(p++);
-    if (a != NULL)
+    ASN1_BOOLEAN ret = (ASN1_BOOLEAN)*(p++);
+    if (a != NULL) {
         (*a) = ret;
+    }
     *pp = p;
-    return (ret);
- err:
-    OPENSSL_PUT_ERROR(ASN1, i);
-    return (ret);
+    return ret;
 }

include/openssl/asn1.h

diff --git a/include/openssl/asn1.h b/include/openssl/asn1.h
index f9d980f..799732d 100644
--- a/include/openssl/asn1.h
+++ b/include/openssl/asn1.h
@@ -1113,9 +1113,10 @@
                                                     const unsigned char **pp,
                                                     long length);
 
-OPENSSL_EXPORT int i2d_ASN1_BOOLEAN(int a, unsigned char **pp);
-OPENSSL_EXPORT int d2i_ASN1_BOOLEAN(int *a, const unsigned char **pp,
-                                    long length);
+OPENSSL_EXPORT int i2d_ASN1_BOOLEAN(ASN1_BOOLEAN a, unsigned char **pp);
+OPENSSL_EXPORT ASN1_BOOLEAN d2i_ASN1_BOOLEAN(ASN1_BOOLEAN *a,
+                                             const unsigned char **pp,
+                                             long length);
 
 DECLARE_ASN1_FUNCTIONS(ASN1_INTEGER)
 OPENSSL_EXPORT int i2c_ASN1_INTEGER(const ASN1_INTEGER *a, unsigned char **pp);