Diagnose EOF on memory BIOs (or you just get mysterious errors with no error

message).

crypto/bio/bio.h

@@ -638,6 +638,7 @@ int BIO_vsnprintf(char *buf, size_t n, const char *format, va_list args);
 #define BIO_F_CONN_CTRL					 127
 #define BIO_F_CONN_STATE				 115
 #define BIO_F_FILE_CTRL					 116
+#define BIO_F_MEM_READ					 128
 #define BIO_F_MEM_WRITE					 117
 #define BIO_F_SSL_NEW					 118
 #define BIO_F_WSASTARTUP				 119
@@ -648,6 +649,7 @@ int BIO_vsnprintf(char *buf, size_t n, const char *format, va_list args);
 #define BIO_R_BAD_HOSTNAME_LOOKUP			 102
 #define BIO_R_BROKEN_PIPE				 124
 #define BIO_R_CONNECT_ERROR				 103
+#define BIO_R_EOF_ON_MEMORY_BIO				 127
 #define BIO_R_ERROR_SETTING_NBIO			 104
 #define BIO_R_ERROR_SETTING_NBIO_ON_ACCEPTED_SOCKET	 105
 #define BIO_R_ERROR_SETTING_NBIO_ON_ACCEPT_SOCKET	 106

crypto/bio/bio_err.c

@@ -91,6 +91,7 @@ static ERR_STRING_DATA BIO_str_functs[]=
 {ERR_PACK(0,BIO_F_CONN_CTRL,0),	"CONN_CTRL"},
 {ERR_PACK(0,BIO_F_CONN_STATE,0),	"CONN_STATE"},
 {ERR_PACK(0,BIO_F_FILE_CTRL,0),	"FILE_CTRL"},
+{ERR_PACK(0,BIO_F_MEM_READ,0),	"MEM_READ"},
 {ERR_PACK(0,BIO_F_MEM_WRITE,0),	"MEM_WRITE"},
 {ERR_PACK(0,BIO_F_SSL_NEW,0),	"SSL_new"},
 {ERR_PACK(0,BIO_F_WSASTARTUP,0),	"WSASTARTUP"},
@@ -104,6 +105,7 @@ static ERR_STRING_DATA BIO_str_reasons[]=
 {BIO_R_BAD_HOSTNAME_LOOKUP               ,"bad hostname lookup"},
 {BIO_R_BROKEN_PIPE                       ,"broken pipe"},
 {BIO_R_CONNECT_ERROR                     ,"connect error"},
+{BIO_R_EOF_ON_MEMORY_BIO                 ,"eof on memory bio"},
 {BIO_R_ERROR_SETTING_NBIO                ,"error setting nbio"},
 {BIO_R_ERROR_SETTING_NBIO_ON_ACCEPTED_SOCKET,"error setting nbio on accepted socket"},
 {BIO_R_ERROR_SETTING_NBIO_ON_ACCEPT_SOCKET,"error setting nbio on accept socket"},

crypto/bio/bss_mem.c

@@ -166,6 +166,8 @@ static int mem_read(BIO *b, char *out, int outl)
 		if (b->num != 0)
 			BIO_set_retry_read(b);
 		ret= b->num;
+		if(ret < 0)
+		    BIOerr(BIO_F_MEM_READ,BIO_R_EOF_ON_MEMORY_BIO);
 		}
 	return(ret);
 	}