Rename the BIGNUM ASN.1 functions.

There's many ways to serialize a BIGNUM, so not including asn1 in the name is
confusing (and collides with BN_bn2cbb_padded). Since BN_asn12bn looks
ridiculous, match the parse/marshal naming scheme of other modules instead.

Change-Id: I53d22ae0537a98e223ed943e943c48cb0743cf51
Reviewed-on: https://boringssl-review.googlesource.com/6822
Reviewed-by: Adam Langley <alangley@gmail.com>

crypto/bn/bn_asn1.c

@@ -18,7 +18,7 @@
 #include <openssl/err.h>
 
 
-int BN_cbs2unsigned(CBS *cbs, BIGNUM *ret) {
+int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret) {
   CBS child;
   if (!CBS_get_asn1(cbs, &child, CBS_ASN1_INTEGER) ||
       CBS_len(&child) == 0) {
@@ -42,7 +42,7 @@ int BN_cbs2unsigned(CBS *cbs, BIGNUM *ret) {
   return BN_bin2bn(CBS_data(&child), CBS_len(&child), ret) != NULL;
 }
 
-int BN_cbs2unsigned_buggy(CBS *cbs, BIGNUM *ret) {
+int BN_parse_asn1_unsigned_buggy(CBS *cbs, BIGNUM *ret) {
   CBS child;
   if (!CBS_get_asn1(cbs, &child, CBS_ASN1_INTEGER) ||
       CBS_len(&child) == 0) {
@@ -58,7 +58,7 @@ int BN_cbs2unsigned_buggy(CBS *cbs, BIGNUM *ret) {
   return BN_bin2bn(CBS_data(&child), CBS_len(&child), ret) != NULL;
 }
 
-int BN_bn2cbb(CBB *cbb, const BIGNUM *bn) {
+int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn) {
   /* Negative numbers are unsupported. */
   if (BN_is_negative(bn)) {
     OPENSSL_PUT_ERROR(BN, BN_R_NEGATIVE_NUMBER);
@@ -66,28 +66,15 @@ int BN_bn2cbb(CBB *cbb, const BIGNUM *bn) {
   }
 
   CBB child;
-  if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER)) {
+  if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER) ||
+      /* The number must be padded with a leading zero if the high bit would
+       * otherwise be set or if |bn| is zero. */
+      (BN_num_bits(bn) % 8 == 0 && !CBB_add_u8(&child, 0x00)) ||
+      !BN_bn2cbb_padded(&child, BN_num_bytes(bn), bn) ||
+      !CBB_flush(cbb)) {
     OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR);
     return 0;
   }
 
-  /* The number must be padded with a leading zero if the high bit would
-   * otherwise be set (or |bn| is zero). */
-  if (BN_num_bits(bn) % 8 == 0 &&
-      !CBB_add_u8(&child, 0x00)) {
-    OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR);
-    return 0;
-  }
-
-  uint8_t *out;
-  if (!CBB_add_space(&child, &out, BN_num_bytes(bn))) {
-    OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR);
-    return 0;
-  }
-  BN_bn2bin(bn, out);
-  if (!CBB_flush(cbb)) {
-    OPENSSL_PUT_ERROR(BN, BN_R_ENCODE_ERROR);
-    return 0;
-  }
   return 1;
 }

crypto/bn/bn_test.cc

@@ -1823,7 +1823,7 @@ static bool test_asn1() {
     }
     CBS cbs;
     CBS_init(&cbs, reinterpret_cast<const uint8_t*>(test.der), test.der_len);
-    if (!BN_cbs2unsigned(&cbs, bn2.get()) || CBS_len(&cbs) != 0) {
+    if (!BN_parse_asn1_unsigned(&cbs, bn2.get()) || CBS_len(&cbs) != 0) {
       fprintf(stderr, "Parsing ASN.1 INTEGER failed.\n");
       return false;
     }
@@ -1838,7 +1838,7 @@ static bool test_asn1() {
     size_t der_len;
     CBB_zero(&cbb);
     if (!CBB_init(&cbb, 0) ||
-        !BN_bn2cbb(&cbb, bn.get()) ||
+        !BN_marshal_asn1(&cbb, bn.get()) ||
         !CBB_finish(&cbb, &der, &der_len)) {
       CBB_cleanup(&cbb);
       return false;
@@ -1852,7 +1852,7 @@ static bool test_asn1() {
 
     // |BN_cbs2unsigned_buggy| parses all valid input.
     CBS_init(&cbs, reinterpret_cast<const uint8_t*>(test.der), test.der_len);
-    if (!BN_cbs2unsigned_buggy(&cbs, bn2.get()) || CBS_len(&cbs) != 0) {
+    if (!BN_parse_asn1_unsigned_buggy(&cbs, bn2.get()) || CBS_len(&cbs) != 0) {
       fprintf(stderr, "Parsing ASN.1 INTEGER failed.\n");
       return false;
     }
@@ -1869,7 +1869,7 @@ static bool test_asn1() {
     }
     CBS cbs;
     CBS_init(&cbs, reinterpret_cast<const uint8_t*>(test.der), test.der_len);
-    if (BN_cbs2unsigned(&cbs, bn.get())) {
+    if (BN_parse_asn1_unsigned(&cbs, bn.get())) {
       fprintf(stderr, "Parsed invalid input.\n");
       return false;
     }
@@ -1878,7 +1878,7 @@ static bool test_asn1() {
     // All tests in kASN1InvalidTests are also rejected by
     // |BN_cbs2unsigned_buggy|.
     CBS_init(&cbs, reinterpret_cast<const uint8_t*>(test.der), test.der_len);
-    if (BN_cbs2unsigned_buggy(&cbs, bn.get())) {
+    if (BN_parse_asn1_unsigned_buggy(&cbs, bn.get())) {
       fprintf(stderr, "Parsed invalid input.\n");
       return false;
     }
@@ -1894,7 +1894,7 @@ static bool test_asn1() {
 
     CBS cbs;
     CBS_init(&cbs, reinterpret_cast<const uint8_t*>(test.der), test.der_len);
-    if (BN_cbs2unsigned(&cbs, bn.get())) {
+    if (BN_parse_asn1_unsigned(&cbs, bn.get())) {
       fprintf(stderr, "Parsed invalid input.\n");
       return false;
     }
@@ -1907,7 +1907,7 @@ static bool test_asn1() {
     }
 
     CBS_init(&cbs, reinterpret_cast<const uint8_t*>(test.der), test.der_len);
-    if (!BN_cbs2unsigned_buggy(&cbs, bn.get()) || CBS_len(&cbs) != 0) {
+    if (!BN_parse_asn1_unsigned_buggy(&cbs, bn.get()) || CBS_len(&cbs) != 0) {
       fprintf(stderr, "Parsing (invalid) ASN.1 INTEGER failed.\n");
       return false;
     }
@@ -1926,7 +1926,7 @@ static bool test_asn1() {
   CBB cbb;
   CBB_zero(&cbb);
   if (!CBB_init(&cbb, 0) ||
-      BN_bn2cbb(&cbb, bn.get())) {
+      BN_marshal_asn1(&cbb, bn.get())) {
     fprintf(stderr, "Serialized negative number.\n");
     CBB_cleanup(&cbb);
     return false;

crypto/ecdsa/ecdsa_asn1.c

@@ -115,8 +115,8 @@ ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs) {
   }
   CBS child;
   if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
-      !BN_cbs2unsigned(&child, ret->r) ||
-      !BN_cbs2unsigned(&child, ret->s) ||
+      !BN_parse_asn1_unsigned(&child, ret->r) ||
+      !BN_parse_asn1_unsigned(&child, ret->s) ||
       CBS_len(&child) != 0) {
     OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_BAD_SIGNATURE);
     ECDSA_SIG_free(ret);
@@ -140,8 +140,8 @@ ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in, size_t in_len) {
 int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig) {
   CBB child;
   if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
-      !BN_bn2cbb(&child, sig->r) ||
-      !BN_bn2cbb(&child, sig->s) ||
+      !BN_marshal_asn1(&child, sig->r) ||
+      !BN_marshal_asn1(&child, sig->s) ||
       !CBB_flush(cbb)) {
     OPENSSL_PUT_ERROR(ECDSA, ECDSA_R_ENCODE_ERROR);
     return 0;

crypto/rsa/rsa_asn1.c

@@ -76,9 +76,9 @@ static int parse_integer_buggy(CBS *cbs, BIGNUM **out, int buggy) {
     return 0;
   }
   if (buggy) {
-    return BN_cbs2unsigned_buggy(cbs, *out);
+    return BN_parse_asn1_unsigned_buggy(cbs, *out);
   }
-  return BN_cbs2unsigned(cbs, *out);
+  return BN_parse_asn1_unsigned(cbs, *out);
 }
 
 static int parse_integer(CBS *cbs, BIGNUM **out) {
@@ -91,7 +91,7 @@ static int marshal_integer(CBB *cbb, BIGNUM *bn) {
     OPENSSL_PUT_ERROR(RSA, RSA_R_VALUE_MISSING);
     return 0;
   }
-  return BN_bn2cbb(cbb, bn);
+  return BN_marshal_asn1(cbb, bn);
 }
 
 static RSA *parse_public_key(CBS *cbs, int buggy) {

include/openssl/bn.h

@@ -303,17 +303,17 @@ OPENSSL_EXPORT BN_ULONG BN_get_word(const BIGNUM *bn);
 
 /* ASN.1 functions. */
 
-/* BN_cbs2unsigned parses a non-negative DER INTEGER from |cbs| writes the
- * result to |ret|. It returns one on success and zero on failure. */
-OPENSSL_EXPORT int BN_cbs2unsigned(CBS *cbs, BIGNUM *ret);
+/* BN_parse_asn1_unsigned parses a non-negative DER INTEGER from |cbs| writes
+ * the result to |ret|. It returns one on success and zero on failure. */
+OPENSSL_EXPORT int BN_parse_asn1_unsigned(CBS *cbs, BIGNUM *ret);
 
-/* BN_cbs2unsigned_buggy acts like |BN_cbs2unsigned| but tolerates some invalid
- * encodings. Do not use this function. */
-OPENSSL_EXPORT int BN_cbs2unsigned_buggy(CBS *cbs, BIGNUM *ret);
+/* BN_parse_asn1_unsigned_buggy acts like |BN_parse_asn1_unsigned| but tolerates
+ * some invalid encodings. Do not use this function. */
+OPENSSL_EXPORT int BN_parse_asn1_unsigned_buggy(CBS *cbs, BIGNUM *ret);
 
-/* BN_bn2cbb marshals |bn| as a non-negative DER INTEGER and appends the result
- * to |cbb|. It returns one on success and zero on failure. */
-OPENSSL_EXPORT int BN_bn2cbb(CBB *cbb, const BIGNUM *bn);
+/* BN_marshal_asn1 marshals |bn| as a non-negative DER INTEGER and appends the
+ * result to |cbb|. It returns one on success and zero on failure. */
+OPENSSL_EXPORT int BN_marshal_asn1(CBB *cbb, const BIGNUM *bn);
 
 
 /* Internal functions.