Avoid a race condition if another thread happens to remove the error
[openssl.git] / crypto / err / err.c
index cbbd326f74d4d75b55340f4360352fa0abc6b2e5..7ce9e8fb9aacd62b8f307032561a63daadcced4f 100644 (file)
 #include <openssl/crypto.h>
 #include "cryptlib.h"
 #include <openssl/buffer.h>
+#include <openssl/bio.h>
 #include <openssl/err.h>
-#include <openssl/crypto.h>
 
 
 static LHASH *error_hash=NULL;
@@ -137,6 +137,7 @@ static ERR_STRING_DATA ERR_str_libraries[]=
 {ERR_PACK(ERR_LIB_SYS,0,0)             ,"system library"},
 {ERR_PACK(ERR_LIB_BN,0,0)              ,"bignum routines"},
 {ERR_PACK(ERR_LIB_RSA,0,0)             ,"rsa routines"},
+{ERR_PACK(ERR_LIB_DSA,0,0)             ,"dsa routines"},
 {ERR_PACK(ERR_LIB_DH,0,0)              ,"Diffie-Hellman routines"},
 {ERR_PACK(ERR_LIB_EVP,0,0)             ,"digital envelope routines"},
 {ERR_PACK(ERR_LIB_BUF,0,0)             ,"memory buffer routines"},
@@ -227,7 +228,7 @@ static ERR_STRING_DATA SYS_str_reasons[NUM_SYS_STR_REASONS + 1];
 
 static void build_SYS_str_reasons()
        {
-       /* Malloc cannot be used here, use static storage instead */
+       /* OPENSSL_malloc cannot be used here, use static storage instead */
        static char strerror_tab[NUM_SYS_STR_REASONS][LEN_SYS_STR_REASON];
        int i;
 
@@ -264,7 +265,7 @@ static void build_SYS_str_reasons()
        if (((p)->err_data[i] != NULL) && \
                (p)->err_data_flags[i] & ERR_TXT_MALLOCED) \
                {  \
-               Free((p)->err_data[i]); \
+               OPENSSL_free((p)->err_data[i]); \
                (p)->err_data[i]=NULL; \
                } \
        (p)->err_data_flags[i]=0;
@@ -280,7 +281,7 @@ static void ERR_STATE_free(ERR_STATE *s)
                {
                err_clear_data(s,i);
                }
-       Free(s);
+       OPENSSL_free(s);
        }
 
 void ERR_load_ERR_strings(void)
@@ -477,13 +478,11 @@ static unsigned long get_error_values(int inc, const char **file, int *line,
        return(ret);
        }
 
-/* BAD for multi-threaded, uses a local buffer if ret == NULL */
-char *ERR_error_string(unsigned long e, char *ret)
+void ERR_error_string_n(unsigned long e, char *buf, size_t len)
        {
-       static char buf[256];
+       char lsbuf[64], fsbuf[64], rsbuf[64];
        const char *ls,*fs,*rs;
        unsigned long l,f,r;
-       int i;
 
        l=ERR_GET_LIB(e);
        f=ERR_GET_FUNC(e);
@@ -493,21 +492,50 @@ char *ERR_error_string(unsigned long e, char *ret)
        fs=ERR_func_error_string(e);
        rs=ERR_reason_error_string(e);
 
-       if (ret == NULL) ret=buf;
-
-       sprintf(&(ret[0]),"error:%08lX:",e);
-       i=strlen(ret);
-       if (ls == NULL)
-               sprintf(&(ret[i]),":lib(%lu) ",l);
-       else    sprintf(&(ret[i]),"%s",ls);
-       i=strlen(ret);
+       if (ls == NULL) 
+               BIO_snprintf(lsbuf, sizeof(lsbuf), "lib(%lu)", l);
        if (fs == NULL)
-               sprintf(&(ret[i]),":func(%lu) ",f);
-       else    sprintf(&(ret[i]),":%s",fs);
-       i=strlen(ret);
+               BIO_snprintf(fsbuf, sizeof(fsbuf), "func(%lu)", f);
        if (rs == NULL)
-               sprintf(&(ret[i]),":reason(%lu)",r);
-       else    sprintf(&(ret[i]),":%s",rs);
+               BIO_snprintf(rsbuf, sizeof(rsbuf), "reason(%lu)", r);
+
+       BIO_snprintf(buf, len,"error:%08lX:%s:%s:%s", e, ls?ls:lsbuf, 
+               fs?fs:fsbuf, rs?rs:rsbuf);
+       if (strlen(buf) == len-1)
+               {
+               /* output may be truncated; make sure we always have 5 
+                * colon-separated fields, i.e. 4 colons ... */
+#define NUM_COLONS 4
+               if (len > NUM_COLONS) /* ... if possible */
+                       {
+                       int i;
+                       char *s = buf;
+                       
+                       for (i = 0; i < NUM_COLONS; i++)
+                               {
+                               char *colon = strchr(s, ':');
+                               if (colon == NULL || colon > &buf[len-1] - NUM_COLONS + i)
+                                       {
+                                       /* set colon no. i at last possible position
+                                        * (buf[len-1] is the terminating 0)*/
+                                       colon = &buf[len-1] - NUM_COLONS + i;
+                                       *colon = ':';
+                                       }
+                               s = colon + 1;
+                               }
+                       }
+               }
+       }
+
+/* BAD for multi-threading: uses a local buffer if ret == NULL */
+/* ERR_error_string_n should be used instead for ret != NULL
+ * as ERR_error_string cannot know how large the buffer is */
+char *ERR_error_string(unsigned long e, char *ret)
+       {
+       static char buf[256];
+
+       if (ret == NULL) ret=buf;
+       ERR_error_string_n(e, buf, 256);
 
        return(ret);
        }
@@ -517,6 +545,7 @@ LHASH *ERR_get_string_table(void)
        return(error_hash);
        }
 
+/* not thread-safe */
 LHASH *ERR_get_err_state_table(void)
        {
        return(thread_hash);
@@ -529,7 +558,7 @@ const char *ERR_lib_error_string(unsigned long e)
 
        l=ERR_GET_LIB(e);
 
-       CRYPTO_r_lock(CRYPTO_LOCK_ERR_HASH);
+       CRYPTO_w_lock(CRYPTO_LOCK_ERR_HASH);
 
        if (error_hash != NULL)
                {
@@ -537,7 +566,7 @@ const char *ERR_lib_error_string(unsigned long e)
                p=(ERR_STRING_DATA *)lh_retrieve(error_hash,&d);
                }
 
-       CRYPTO_r_unlock(CRYPTO_LOCK_ERR_HASH);
+       CRYPTO_w_unlock(CRYPTO_LOCK_ERR_HASH);
 
        return((p == NULL)?NULL:p->string);
        }
@@ -550,7 +579,7 @@ const char *ERR_func_error_string(unsigned long e)
        l=ERR_GET_LIB(e);
        f=ERR_GET_FUNC(e);
 
-       CRYPTO_r_lock(CRYPTO_LOCK_ERR_HASH);
+       CRYPTO_w_lock(CRYPTO_LOCK_ERR_HASH);
 
        if (error_hash != NULL)
                {
@@ -558,7 +587,7 @@ const char *ERR_func_error_string(unsigned long e)
                p=(ERR_STRING_DATA *)lh_retrieve(error_hash,&d);
                }
 
-       CRYPTO_r_unlock(CRYPTO_LOCK_ERR_HASH);
+       CRYPTO_w_unlock(CRYPTO_LOCK_ERR_HASH);
 
        return((p == NULL)?NULL:p->string);
        }
@@ -571,7 +600,7 @@ const char *ERR_reason_error_string(unsigned long e)
        l=ERR_GET_LIB(e);
        r=ERR_GET_REASON(e);
 
-       CRYPTO_r_lock(CRYPTO_LOCK_ERR_HASH);
+       CRYPTO_w_lock(CRYPTO_LOCK_ERR_HASH);
 
        if (error_hash != NULL)
                {
@@ -584,7 +613,7 @@ const char *ERR_reason_error_string(unsigned long e)
                        }
                }
 
-       CRYPTO_r_unlock(CRYPTO_LOCK_ERR_HASH);
+       CRYPTO_w_unlock(CRYPTO_LOCK_ERR_HASH);
 
        return((p == NULL)?NULL:p->string);
        }
@@ -623,7 +652,16 @@ void ERR_remove_state(unsigned long pid)
                pid=(unsigned long)CRYPTO_thread_id();
        tmp.pid=pid;
        CRYPTO_w_lock(CRYPTO_LOCK_ERR);
-       p=(ERR_STATE *)lh_delete(thread_hash,&tmp);
+       if (thread_hash)
+               {
+               p=(ERR_STATE *)lh_delete(thread_hash,&tmp);
+               if (lh_num_items(thread_hash) == 0)
+                       {
+                       /* make sure we don't leak memory */
+                       lh_free(thread_hash);
+                       thread_hash = NULL;
+                       }
+               }
        CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
 
        if (p != NULL) ERR_STATE_free(p);
@@ -632,39 +670,25 @@ void ERR_remove_state(unsigned long pid)
 ERR_STATE *ERR_get_state(void)
        {
        static ERR_STATE fallback;
-       ERR_STATE *ret=NULL,tmp,*tmpp;
+       ERR_STATE *ret=NULL,tmp,*tmpp=NULL;
+       int thread_state_exists;
        int i;
        unsigned long pid;
 
        pid=(unsigned long)CRYPTO_thread_id();
 
-       CRYPTO_r_lock(CRYPTO_LOCK_ERR);
-       if (thread_hash == NULL)
-               {
-               CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
-               CRYPTO_w_lock(CRYPTO_LOCK_ERR);
-               if (thread_hash == NULL)
-                       {
-                       MemCheck_off();
-                       thread_hash=lh_new(pid_hash,pid_cmp);
-                       MemCheck_on();
-                       CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
-                       if (thread_hash == NULL) return(&fallback);
-                       }
-               else
-                       CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
-               }
-       else
+       CRYPTO_w_lock(CRYPTO_LOCK_ERR);
+       if (thread_hash != NULL)
                {
                tmp.pid=pid;
                ret=(ERR_STATE *)lh_retrieve(thread_hash,&tmp);
-               CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
                }
+       CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
 
        /* ret == the error state, if NULL, make a new one */
        if (ret == NULL)
                {
-               ret=(ERR_STATE *)Malloc(sizeof(ERR_STATE));
+               ret=(ERR_STATE *)OPENSSL_malloc(sizeof(ERR_STATE));
                if (ret == NULL) return(&fallback);
                ret->pid=pid;
                ret->top=0;
@@ -674,9 +698,29 @@ ERR_STATE *ERR_get_state(void)
                        ret->err_data[i]=NULL;
                        ret->err_data_flags[i]=0;
                        }
+
                CRYPTO_w_lock(CRYPTO_LOCK_ERR);
-               tmpp=(ERR_STATE *)lh_insert(thread_hash,ret);
+
+               /* no entry yet in thread_hash for current thread -
+                * thus, it may have changed since we last looked at it */
+               if (thread_hash == NULL)
+                       thread_hash = lh_new(pid_hash, pid_cmp);
+               if (thread_hash == NULL)
+                       thread_state_exists = 0; /* allocation error */
+               else
+                       {
+                       tmpp=(ERR_STATE *)lh_insert(thread_hash,ret);
+                       thread_state_exists = 1;
+                       }
+
                CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
+
+               if (!thread_state_exists)
+                       {
+                       ERR_STATE_free(ret); /* could not insert it */
+                       return(&fallback);
+                       }
+               
                if (tmpp != NULL) /* old entry - should not happen */
                        {
                        ERR_STATE_free(tmpp);
@@ -714,7 +758,7 @@ void ERR_add_error_data(int num, ...)
        char *str,*p,*a;
 
        s=64;
-       str=Malloc(s+1);
+       str=OPENSSL_malloc(s+1);
        if (str == NULL) return;
        str[0]='\0';
 
@@ -730,10 +774,10 @@ void ERR_add_error_data(int num, ...)
                        if (n > s)
                                {
                                s=n+20;
-                               p=Realloc(str,s+1);
+                               p=OPENSSL_realloc(str,s+1);
                                if (p == NULL)
                                        {
-                                       Free(str);
+                                       OPENSSL_free(str);
                                        return;
                                        }
                                else