1 files changed, 46 insertions, 4 deletions

diff --git a/libmincrypt/rsa_e_3.c b/libmincrypt/rsa_e_3.c
index c8c02c41e..012a35717 100644
--- a/libmincrypt/rsa_e_3.c
+++ b/libmincrypt/rsa_e_3.c
@@ -27,6 +27,7 @@
 
 #include "mincrypt/rsa.h"
 #include "mincrypt/sha.h"
+#include "mincrypt/sha256.h"
 
 /* a[] -= mod */
 static void subM(const RSAPublicKey *key, uint32_t *a) {
@@ -134,7 +135,7 @@ static void modpow3(const RSAPublicKey *key,
 ** other flavor which omits the optional parameter entirely). This code does not
 ** accept signatures without the optional parameter.
 */
-static const uint8_t padding[RSANUMBYTES - SHA_DIGEST_SIZE] = {
+static const uint8_t sha_padding[RSANUMBYTES - SHA_DIGEST_SIZE] = {
     0x00,0x01,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
     0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
     0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
@@ -156,15 +157,56 @@ static const uint8_t padding[RSANUMBYTES - SHA_DIGEST_SIZE] = {
     0x04,0x14
 };
 
+static const uint8_t sha256_padding[RSANUMBYTES - SHA256_DIGEST_SIZE] = {
+    0x00,0x01,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+
+    0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x00,0x30,0x31,0x30,
+    0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,
+    0x00,0x04,0x20
+};
+
+
 /* Verify a 2048 bit RSA e=3 PKCS1.5 signature against an expected SHA-1 hash.
 ** Returns 0 on failure, 1 on success.
 */
 int RSA_e_3_verify(const RSAPublicKey *key,
                    const uint8_t *signature,
                    const int len,
-                   const uint8_t *sha) {
+                   const uint8_t *hash,
+                   const int hash_len) {
     uint8_t buf[RSANUMBYTES];
     int i;
+    int padding_size;
+    const uint8_t* padding;
+
+    switch (hash_len) {
+        case SHA_DIGEST_SIZE:
+            padding = sha_padding;
+            padding_size = sizeof(sha_padding);
+            break;
+        case SHA256_DIGEST_SIZE:
+            padding = sha256_padding;
+            padding_size = sizeof(sha256_padding);
+            break;
+        default:
+            return 0;  // unsupported hash
+    }
 
     if (key->len != RSANUMWORDS) {
         return 0;  /* Wrong key passed in. */
@@ -185,7 +227,7 @@ int RSA_e_3_verify(const RSAPublicKey *key,
     modpow3(key, buf);
 
     /* Check pkcs1.5 padding bytes. */
-    for (i = 0; i < (int) sizeof(padding); ++i) {
+    for (i = 0; i < padding_size; ++i) {
         if (buf[i] != padding[i]) {
             return 0;
         }
@@ -193,7 +235,7 @@ int RSA_e_3_verify(const RSAPublicKey *key,
 
     /* Check sha digest matches. */
     for (; i < len; ++i) {
-        if (buf[i] != *sha++) {
+        if (buf[i] != *hash++) {
             return 0;
         }
     }