From e0c89df9e424e681cf523fac718c425f9b5e6c27 Mon Sep 17 00:00:00 2001 From: Rich Salz Date: Sat, 8 Jul 2017 14:45:15 -0400 Subject: [PATCH] Rewrite RAND_egd Use stdio and its buffering. Limit to 255 bytes (could remove that if neceessary). Reviewed-by: Paul Dale (Merged from https://github.com/openssl/openssl/pull/3888) --- crypto/rand/rand_egd.c | 225 ++++++++++++----------------------------- doc/man3/RAND_egd.pod | 2 +- 2 files changed, 68 insertions(+), 159 deletions(-) diff --git a/crypto/rand/rand_egd.c b/crypto/rand/rand_egd.c index 1b091e848c..657a3bc5aa 100644 --- a/crypto/rand/rand_egd.c +++ b/crypto/rand/rand_egd.c @@ -1,5 +1,5 @@ /* - * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -16,41 +16,8 @@ NON_EMPTY_TRANSLATION_UNIT # include # include -/*- - * Query the EGD . - * - * This module supplies three routines: - * - * RAND_query_egd_bytes(path, buf, bytes) - * will actually query "bytes" bytes of entropy form the egd-socket located - * at path and will write them to buf (if supplied) or will directly feed - * it to RAND_seed() if buf==NULL. - * The number of bytes is not limited by the maximum chunk size of EGD, - * which is 255 bytes. If more than 255 bytes are wanted, several chunks - * of entropy bytes are requested. The connection is left open until the - * query is competed. - * RAND_query_egd_bytes() returns with - * -1 if an error occurred during connection or communication. - * num the number of bytes read from the EGD socket. This number is either - * the number of bytes requested or smaller, if the EGD pool is - * drained and the daemon signals that the pool is empty. - * This routine does not touch any RAND_status(). This is necessary, since - * PRNG functions may call it during initialization. - * - * RAND_egd_bytes(path, bytes) will query "bytes" bytes and have them - * used to seed the PRNG. - * RAND_egd_bytes() is a wrapper for RAND_query_egd_bytes() with buf=NULL. - * Unlike RAND_query_egd_bytes(), RAND_status() is used to test the - * seed status so that the return value can reflect the seed state: - * -1 if an error occurred during connection or communication _or_ - * if the PRNG has still not received the required seeding. - * num the number of bytes read from the EGD socket. This number is either - * the number of bytes requested or smaller, if the EGD pool is - * drained and the daemon signals that the pool is empty. - * - * RAND_egd(path) will query 255 bytes and use the bytes retrieved to seed - * the PRNG. - * RAND_egd() is a wrapper for RAND_egd_bytes() with numbytes=255. +/* + * Query an EGD */ # if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_VOS) || defined(OPENSSL_SYS_UEFI) @@ -61,14 +28,16 @@ int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes) int RAND_egd(const char *path) { - return -1; + return (-1); } int RAND_egd_bytes(const char *path, int bytes) { - return -1; + return (-1); } + # else + # include # include OPENSSL_UNISTD # include @@ -91,157 +60,97 @@ struct sockaddr_un { int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes) { - int ret = 0; + FILE *fp = NULL; struct sockaddr_un addr; - int len, num, numbytes; - int fd = -1; - int success; - unsigned char egdbuf[2], tempbuf[255], *retrievebuf; + int mybuffer, ret = -1, i, numbytes, fd; + unsigned char tempbuf[255]; + if (bytes > (int)sizeof(tempbuf)) + return -1; + + /* Make socket. */ memset(&addr, 0, sizeof(addr)); addr.sun_family = AF_UNIX; if (strlen(path) >= sizeof(addr.sun_path)) - return -1; + return (-1); strcpy(addr.sun_path, path); - len = offsetof(struct sockaddr_un, sun_path) + strlen(path); + i = offsetof(struct sockaddr_un, sun_path) + strlen(path); fd = socket(AF_UNIX, SOCK_STREAM, 0); - if (fd == -1) - return -1; - success = 0; - while (!success) { - if (connect(fd, (struct sockaddr *)&addr, len) == 0) - success = 1; - else { - switch (errno) { -# ifdef EINTR - case EINTR: -# endif -# ifdef EAGAIN - case EAGAIN: -# endif -# ifdef EINPROGRESS - case EINPROGRESS: -# endif -# ifdef EALREADY - case EALREADY: -# endif - /* No error, try again */ - break; + if (fd == -1 || (fp = fdopen(fd, "r+")) == NULL) + return (-1); + + /* Try to connect */ + for ( ; ; ) { + if (connect(fd, (struct sockaddr *)&addr, i) == 0) + break; # ifdef EISCONN - case EISCONN: - success = 1; - break; + if (errno == EISCONN) + break; # endif - default: - ret = -1; - goto err; /* failure */ - } - } - } - - while (bytes > 0) { - egdbuf[0] = 1; - egdbuf[1] = bytes < 255 ? bytes : 255; - numbytes = 0; - while (numbytes != 2) { - num = write(fd, egdbuf + numbytes, 2 - numbytes); - if (num >= 0) - numbytes += num; - else { - switch (errno) { + switch (errno) { # ifdef EINTR - case EINTR: + case EINTR: # endif # ifdef EAGAIN - case EAGAIN: + case EAGAIN: # endif - /* No error, try again */ - break; - default: - ret = -1; - goto err; /* failure */ - } - } - } - numbytes = 0; - while (numbytes != 1) { - num = read(fd, egdbuf, 1); - if (num == 0) - goto err; /* descriptor closed */ - else if (num > 0) - numbytes += num; - else { - switch (errno) { -# ifdef EINTR - case EINTR: +# ifdef EINPROGRESS + case EINPROGRESS: # endif -# ifdef EAGAIN - case EAGAIN: +# ifdef EALREADY + case EALREADY: # endif - /* No error, try again */ - break; - default: - ret = -1; - goto err; /* failure */ - } - } - } - if (egdbuf[0] == 0) + /* No error, try again */ + break; + default: + ret = -1; goto err; - if (buf) - retrievebuf = buf + ret; - else - retrievebuf = tempbuf; - numbytes = 0; - while (numbytes != egdbuf[0]) { - num = read(fd, retrievebuf + numbytes, egdbuf[0] - numbytes); - if (num == 0) - goto err; /* descriptor closed */ - else if (num > 0) - numbytes += num; - else { - switch (errno) { -# ifdef EINTR - case EINTR: -# endif -# ifdef EAGAIN - case EAGAIN: -# endif - /* No error, try again */ - break; - default: - ret = -1; - goto err; /* failure */ - } - } } - ret += egdbuf[0]; - bytes -= egdbuf[0]; - if (!buf) - RAND_seed(tempbuf, egdbuf[0]); } + + /* Make request, see how many bytes we can get back. */ + tempbuf[0] = 1; + tempbuf[1] = bytes; + if (fwrite(tempbuf, sizeof(char), 2, fp) != 2 || fflush(fp) == EOF) + goto err; + if (fread(tempbuf, sizeof(char), 1, fp) != 1 || tempbuf[0] == 0) + goto err; + numbytes = tempbuf[0]; + + /* Which buffer are we using? */ + mybuffer = buf == NULL; + if (mybuffer) + buf = tempbuf; + + /* Read bytes. */ + i = fread(buf, sizeof(char), numbytes, fp); + if (i < numbytes) + goto err; + ret = numbytes; + if (mybuffer) + RAND_seed(tempbuf, i); + err: - if (fd != -1) - close(fd); + if (fp != NULL) + fclose(fp); return ret; } int RAND_egd_bytes(const char *path, int bytes) { - int num, ret = -1; + int num; num = RAND_query_egd_bytes(path, NULL, bytes); if (num < 0) - goto err; - if (RAND_status() == 1) - ret = num; - err: - return ret; + return -1; + if (RAND_status() != 1) + return -1; + return num; } int RAND_egd(const char *path) { - return RAND_egd_bytes(path, 255); + return (RAND_egd_bytes(path, 255)); } # endif diff --git a/doc/man3/RAND_egd.pod b/doc/man3/RAND_egd.pod index e2c7b3f0e1..e68eb8fd7c 100644 --- a/doc/man3/RAND_egd.pod +++ b/doc/man3/RAND_egd.pod @@ -26,7 +26,7 @@ specified socket B, and passes the data it receives into RAND_add(). RAND_egd() is equivalent to RAND_egd_bytes() with B set to 255. RAND_query_egd_bytes() requests B bytes of randomness from an EGD at -the specified socket B. +the specified socket B, where B must be less than 256. If B is B, it is equivalent to RAND_egd_bytes(). If B is not B, then the data is copied to the buffer and RAND_add() is not called. -- 2.25.1