Was the iOS SSL Flaw Deliberate?(schneier.com)

  Security-55471/libsecurity_ssl/security_ssl/tls_digest.c
  
  #ifdef KERNEL
  
  static int HashSHA1Update(SSLBuffer *digestCtx, const SSLBuffer *data)
  {
      return ccHashUpdate(ccsha1_di(), digestCtx, data);
  }
  
  #else
  
  static int HashSHA1Update(SSLBuffer *digestCtx, const SSLBuffer *data)
  {
      /* 64 bits cast: safe, SSL records are always smaller than 2^32 bytes */
          assert(digestCtx->length >= sizeof(CC_SHA1_CTX));
          CC_SHA1_CTX *ctx = (CC_SHA1_CTX *)digestCtx->data;
          CC_SHA1_Update(ctx, data->data, (CC_LONG)data->length);
      return 0;
  }
  
  #endif
  
  const HashReference SSLHashSHA1 =
  {
      SSL_SHA1_DIGEST_LENGTH,
      40,
      SSL_SHA1_CONTEXT_SIZE,
      HashSHA1Init,
      HashSHA1Update,
      HashSHA1Final,
      HashSHA1Close,
      HashSHA1Clone
  };
  
  Security-55179.13/libsecurity_ssl/security_ssl/sslDigests.c
  
  static OSStatus HashSHA1Update(SSLBuffer *digestCtx, const SSLBuffer *data)
  {
      /* 64 bits cast: safe, SSL records are always smaller than 2^32 bytes */
          assert(digestCtx->length >= sizeof(CC_SHA1_CTX));
          CC_SHA1_CTX *ctx = (CC_SHA1_CTX *)digestCtx->data;
          CC_SHA1_Update(ctx, data->data, (CC_LONG)data->length);
      return noErr;
  }
  
  const HashReference SSLHashSHA1 =
          {
                  sizeof(CC_SHA1_CTX),
                  CC_SHA1_DIGEST_LENGTH,
                  40,
                  HashSHA1Init,
                  HashSHA1Update,
                  HashSHA1Final,
                  HashSHA1Close,
                  HashSHA1Clone
          };