From 0edf1d179824fa6400031c6d05b3f464f01abf36 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Wed, 22 Feb 2017 15:38:16 +0100
Subject: [PATCH 2/2] rtmpdh: Stop using OpenSSL-provided DH functions to
 support 1.1.0

DH (struct dh_st) was made private in the 1.1 series, instead
DH is now done the same way as with gcrypt / libgmp.
---
 libavformat/rtmpdh.c | 94 ++++++++++++++++++++++++----------------------------
 libavformat/rtmpdh.h | 13 +++-----
 2 files changed, 49 insertions(+), 58 deletions(-)

diff --git a/libavformat/rtmpdh.c b/libavformat/rtmpdh.c
index 1876fd44f9..1ec1286d23 100644
--- a/libavformat/rtmpdh.c
+++ b/libavformat/rtmpdh.c
@@ -54,7 +54,6 @@
     "F71C35FDAD44CFD2D74F9208BE258FF324943328F67329C0" \
     "FFFFFFFFFFFFFFFF"
 
-#if CONFIG_GMP || CONFIG_GCRYPT
 #if CONFIG_GMP
 #define bn_new(bn)                      \
     do {                                \
@@ -93,7 +92,11 @@
         else                                        \
             ret = 1;                                \
     } while (0)
-#define bn_modexp(bn, y, q, p)      mpz_powm(bn, y, q, p)
+#define bn_modexp(bn, y, q, p, ret) \
+    do {                            \
+        mpz_powm(bn, y, q, p);      \
+        ret = 1;                    \
+    } while(0)
 #define bn_random(bn, num_bits)                       \
     do {                                              \
         int bits = num_bits;                          \
@@ -125,8 +128,34 @@
 #define bn_bn2bin(bn, buf, len)     gcry_mpi_print(GCRYMPI_FMT_USG, buf, len, NULL, bn)
 #define bn_bin2bn(bn, buf, len)     gcry_mpi_scan(&bn, GCRYMPI_FMT_USG, buf, len, NULL)
 #define bn_hex2bn(bn, buf, ret)     ret = (gcry_mpi_scan(&bn, GCRYMPI_FMT_HEX, buf, 0, 0) == 0)
-#define bn_modexp(bn, y, q, p)      gcry_mpi_powm(bn, y, q, p)
+#define bn_modexp(bn, y, q, p, ret) \
+    do {                            \
+        cry_mpi_powm(bn, y, q, p);  \
+        ret = 1;                    \
+    } while (0)
 #define bn_random(bn, num_bits)     gcry_mpi_randomize(bn, num_bits, GCRY_WEAK_RANDOM)
+#elif CONFIG_OPENSSL
+#define bn_new(bn)                  bn = BN_new()
+#define bn_free(bn)                 BN_free(bn)
+#define bn_set_word(bn, w)          BN_set_word(bn, w)
+#define bn_cmp(a, b)                BN_cmp(a, b)
+#define bn_copy(to, from)           BN_copy(to, from)
+#define bn_sub_word(bn, w)          BN_sub_word(bn, w)
+#define bn_cmp_1(bn)                BN_cmp(bn, BN_value_one())
+#define bn_num_bytes(bn)            BN_num_bytes(bn)
+#define bn_bn2bin(bn, buf, len)     BN_bn2bin(bn, buf)
+#define bn_bin2bn(bn, buf, len)     bn = BN_bin2bn(buf, len, 0)
+#define bn_hex2bn(bn, buf, ret)     ret = BN_hex2bn(&bn, buf)
+#define bn_modexp(bn, y, q, p, ret)              \
+    do {                                         \
+        BN_CTX *ctx = BN_CTX_new();              \
+        if (!ctx)                                \
+            ret = 0;                             \
+        else                                     \
+            ret = BN_mod_exp(bn, y, q, p, ctx);  \
+        BN_CTX_free(ctx);                        \
+    } while (0)
+#define bn_random(bn, num_bits)    BN_rand(bn, num_bits, 0, 0)
 #endif
 
 #define MAX_BYTES 18000
@@ -135,7 +164,7 @@
 
 static FFBigNum dh_generate_key(FF_DH *dh)
 {
-    int num_bytes;
+    int num_bytes, ret;
 
     num_bytes = bn_num_bytes(dh->p) - 1;
     if (num_bytes <= 0 || num_bytes > MAX_BYTES)
@@ -152,7 +181,9 @@ static FFBigNum dh_generate_key(FF_DH *dh)
         return NULL;
     }
 
-    bn_modexp(dh->pub_key, dh->g, dh->priv_key, dh->p);
+    bn_modexp(dh->pub_key, dh->g, dh->priv_key, dh->p, ret);
+    if (!ret)
+        return NULL;
 
     return dh->pub_key;
 }
@@ -161,12 +192,15 @@ static int dh_compute_key(FF_DH *dh, FFBigNum pub_key_bn,
                           uint32_t secret_key_len, uint8_t *secret_key)
 {
     FFBigNum k;
+    int ret;
 
     bn_new(k);
     if (!k)
         return -1;
 
-    bn_modexp(k, pub_key_bn, dh->priv_key, dh->p);
+    bn_modexp(k, pub_key_bn, dh->priv_key, dh->p, ret);
+    if (!ret)
+        return -1;
     bn_bn2bin(k, secret_key, secret_key_len);
     bn_free(k);
 
@@ -184,53 +218,11 @@ void ff_dh_free(FF_DH *dh)
     bn_free(dh->priv_key);
     av_free(dh);
 }
-#elif CONFIG_OPENSSL
-#define bn_new(bn)                  bn = BN_new()
-#define bn_free(bn)                 BN_free(bn)
-#define bn_set_word(bn, w)          BN_set_word(bn, w)
-#define bn_cmp(a, b)                BN_cmp(a, b)
-#define bn_copy(to, from)           BN_copy(to, from)
-#define bn_sub_word(bn, w)          BN_sub_word(bn, w)
-#define bn_cmp_1(bn)                BN_cmp(bn, BN_value_one())
-#define bn_num_bytes(bn)            BN_num_bytes(bn)
-#define bn_bn2bin(bn, buf, len)     BN_bn2bin(bn, buf)
-#define bn_bin2bn(bn, buf, len)     bn = BN_bin2bn(buf, len, 0)
-#define bn_hex2bn(bn, buf, ret)     ret = BN_hex2bn(&bn, buf)
-#define bn_modexp(bn, y, q, p)               \
-    do {                                     \
-        BN_CTX *ctx = BN_CTX_new();          \
-        if (!ctx)                            \
-            return AVERROR(ENOMEM);          \
-        if (!BN_mod_exp(bn, y, q, p, ctx)) { \
-            BN_CTX_free(ctx);                \
-            return AVERROR(EINVAL);          \
-        }                                    \
-        BN_CTX_free(ctx);                    \
-    } while (0)
-
-#define dh_new()                                DH_new()
-#define dh_generate_key(dh)                     DH_generate_key(dh)
-
-static int dh_compute_key(FF_DH *dh, FFBigNum pub_key_bn,
-                          uint32_t secret_key_len, uint8_t *secret_key)
-{
-    if (secret_key_len < DH_size(dh))
-        return AVERROR(EINVAL);
-    return DH_compute_key(secret_key, pub_key_bn, dh);
-}
-
-void ff_dh_free(FF_DH *dh)
-{
-    if (!dh)
-        return;
-    DH_free(dh);
-}
-#endif
 
 static int dh_is_valid_public_key(FFBigNum y, FFBigNum p, FFBigNum q)
 {
     FFBigNum bn = NULL;
-    int ret = AVERROR(EINVAL);
+    int ret = AVERROR(EINVAL), ret2;
 
     bn_new(bn);
     if (!bn)
@@ -254,7 +246,9 @@ static int dh_is_valid_public_key(FFBigNum y, FFBigNum p, FFBigNum q)
      * random data.
      */
     /* y must fulfill y^q mod p = 1 */
-    bn_modexp(bn, y, q, p);
+    bn_modexp(bn, y, q, p, ret2);
+    if (!ret2)
+        goto fail;
 
     if (bn_cmp_1(bn))
         goto fail;
diff --git a/libavformat/rtmpdh.h b/libavformat/rtmpdh.h
index 2b250f595d..3f01e6b17b 100644
--- a/libavformat/rtmpdh.h
+++ b/libavformat/rtmpdh.h
@@ -26,7 +26,6 @@
 
 #include "config.h"
 
-#if CONFIG_GMP || CONFIG_GCRYPT
 #if CONFIG_GMP
 #include <gmp.h>
 
@@ -35,6 +34,11 @@ typedef mpz_ptr FFBigNum;
 #include <gcrypt.h>
 
 typedef gcry_mpi_t FFBigNum;
+
+#elif CONFIG_OPENSSL
+#include <openssl/bn.h>
+
+typedef BIGNUM *FFBigNum;
 #endif
 
 typedef struct FF_DH {
@@ -45,13 +49,6 @@ typedef struct FF_DH {
     long length;
 } FF_DH;
 
-#elif CONFIG_OPENSSL
-#include <openssl/bn.h>
-#include <openssl/dh.h>
-
-typedef BIGNUM *FFBigNum;
-typedef DH FF_DH;
-#endif
 
 /**
  * Initialize a Diffie-Hellmann context.
-- 
2.11.1

