Convert SCT_new_from_base64() to use CBS for o2i_SCT_signature().

Remove the existing o2i_SCT_signature() function and rename
o2i_SCT_signature_internal() to replace it.

ok inoguchi@ tb@

3 files changed, 16 insertions, 33 deletions

diff --git a/src/lib/libcrypto/ct/ct_b64.c b/src/lib/libcrypto/ct/ct_b64.c
index cc1fecbc30..bfc69a7da3 100644
--- a/src/lib/libcrypto/ct/ct_b64.c
+++ b/src/lib/libcrypto/ct/ct_b64.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ct_b64.c,v 1.5 2021/12/18 16:34:52 tb Exp $ */
+/*      $OpenBSD: ct_b64.c,v 1.6 2021/12/20 17:19:19 jsing Exp $ */
 /*
  * Written by Rob Stradling (rob@comodo.com) and Stephen Henson
  * (steve@openssl.org) for the OpenSSL project 2014.
@@ -64,6 +64,7 @@
 #include <openssl/err.h>
 #include <openssl/evp.h>
 
+#include "bytestring.h"
 #include "ct_local.h"
 
 /*
@@ -119,12 +120,12 @@ SCT_new_from_base64(unsigned char version, const char *logid_base64,
     ct_log_entry_type_t entry_type, uint64_t timestamp,
     const char *extensions_base64, const char *signature_base64)
 {
-        SCT *sct = SCT_new();
         unsigned char *dec = NULL;
-        const unsigned char* p = NULL;
         int declen;
+        SCT *sct;
+        CBS cbs;
 
-        if (sct == NULL) {
+        if ((sct = SCT_new()) == NULL) {
                 CTerror(ERR_R_MALLOC_FAILURE);
                 return NULL;
         }
@@ -161,8 +162,8 @@ SCT_new_from_base64(unsigned char version, const char *logid_base64,
                 goto err;
         }
 
-        p = dec;
-        if (o2i_SCT_signature(sct, &p, declen) <= 0)
+        CBS_init(&cbs, dec, declen);
+        if (!o2i_SCT_signature(sct, &cbs))
                 goto err;
         free(dec);
         dec = NULL;
diff --git a/src/lib/libcrypto/ct/ct_local.h b/src/lib/libcrypto/ct/ct_local.h
index bfc074a13a..cd19ed096a 100644
--- a/src/lib/libcrypto/ct/ct_local.h
+++ b/src/lib/libcrypto/ct/ct_local.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ct_local.h,v 1.7 2021/12/18 17:26:54 tb Exp $ */
+/*      $OpenBSD: ct_local.h,v 1.8 2021/12/20 17:19:19 jsing Exp $ */
 /*
  * Written by Rob Percival (robpercival@google.com) for the OpenSSL project.
  */
@@ -55,9 +55,11 @@
 
 #include <openssl/ct.h>
 #include <openssl/evp.h>
+#include <openssl/safestack.h>
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>
-#include <openssl/safestack.h>
+
+#include "bytestring.h"
 
 /* Number of bytes in an SCT v1 LogID - see RFC 6962 section 3.2. */
 #define CT_V1_LOG_ID_LEN        32
@@ -250,7 +252,7 @@ int i2o_SCT_signature(const SCT *sct, unsigned char **out);
  * If an error occurs, the SCT's signature NID may be updated whilst the
  * signature field itself remains unset.
  */
-int o2i_SCT_signature(SCT *sct, const unsigned char **in, size_t len);
+int o2i_SCT_signature(SCT *sct, CBS *cbs);
 
 /*
  * Handlers for Certificate Transparency X509v3/OCSP extensions
diff --git a/src/lib/libcrypto/ct/ct_oct.c b/src/lib/libcrypto/ct/ct_oct.c
index 773e62a254..3dae7d8456 100644
--- a/src/lib/libcrypto/ct/ct_oct.c
+++ b/src/lib/libcrypto/ct/ct_oct.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ct_oct.c,v 1.6 2021/12/18 16:34:52 tb Exp $ */
+/*      $OpenBSD: ct_oct.c,v 1.7 2021/12/20 17:19:19 jsing Exp $ */
 /*
  * Written by Rob Stradling (rob@comodo.com) and Stephen Henson
  * (steve@openssl.org) for the OpenSSL project 2014.
@@ -72,8 +72,8 @@
 #include "bytestring.h"
 #include "ct_local.h"
 
-static int
-o2i_SCT_signature_internal(SCT *sct, CBS *cbs)
+int
+o2i_SCT_signature(SCT *sct, CBS *cbs)
 {
         uint8_t hash_alg, sig_alg;
         CBS signature;
@@ -119,26 +119,6 @@ o2i_SCT_signature_internal(SCT *sct, CBS *cbs)
         return 0;
 }
 
-int
-o2i_SCT_signature(SCT *sct, const unsigned char **in, size_t len)
-{
-        size_t sig_len;
-        CBS cbs;
-
-        CBS_init(&cbs, *in, len);
-
-        if (!o2i_SCT_signature_internal(sct, &cbs))
-                return -1;
-
-        sig_len = len - CBS_len(&cbs);
-        if (sig_len > INT_MAX)
-                return -1;
-
-        *in = CBS_data(&cbs);
-
-        return sig_len;
-}
-
 static int
 o2i_SCT_internal(SCT **out_sct, CBS *cbs)
 {
@@ -182,7 +162,7 @@ o2i_SCT_internal(SCT **out_sct, CBS *cbs)
                 if (!CBS_stow(&extensions, &sct->ext, &sct->ext_len))
                         goto err;
 
-                if (!o2i_SCT_signature_internal(sct, cbs))
+                if (!o2i_SCT_signature(sct, cbs))
                         goto err;
 
                 if (CBS_len(cbs) != 0)