Fix base64 implementation in pmix framework.

In the commit 80f07b65f1 setting of '-' marker used
as the string termination sign was moved from base64 code:
from: 80f07b65f1 (diff-1b10896c267d2591dc2c08fd0542ab67L491)
to: 80f07b65f1 (diff-1b10896c267d2591dc2c08fd0542ab67R189)

However the decoding function wasn't fixed and still expects on extra
byte at the end of the encoded string which leads to data truncation
during extraction (was noticed on standalone code that was using base64
from OMPI).

opal/mca/pmix/base/pmix_base_fns.c

@@ -5,6 +5,8 @@
  * Copyright (c) 2014-2015 Intel, Inc. All rights reserved.
  * Copyright (c) 2014-2015 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2016      Mellanox Technologies, Inc.
+ *                         All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -556,7 +558,7 @@ int opal_pmix_base_cache_keys_locally(const opal_process_name_t* id, const char*
     }
 
     /* search for each key in the decoded data */
-    for (offset = 0 ; offset < len && '\0' != tmp_val[offset] ; ) {
+    for (offset = 0 ; offset < len ; ) {
         /* type */
         tmp = tmp_val + offset + strlen (tmp_val + offset) + 1;
         /* size */
@@ -669,11 +671,11 @@ static inline unsigned char pmi_base64_encsym (unsigned char value) {
     assert (value < 64);
 
     if (value < 26) {
-	return 'A' + value;
+        return 'A' + value;
     } else if (value < 52) {
-	return 'a' + (value - 26);
+        return 'a' + (value - 26);
     } else if (value < 62) {
-	return '0' + (value - 52);
+        return '0' + (value - 52);
     }
 
     return (62 == value) ? '+' : '/';
@@ -681,19 +683,18 @@ static inline unsigned char pmi_base64_encsym (unsigned char value) {
 
 static inline unsigned char pmi_base64_decsym (unsigned char value) {
     if ('+' == value) {
-	return 62;
+        return 62;
     } else if ('/' == value) {
-	return 63;
+        return 63;
     } else if (' ' == value) {
-	return 64;
+        return 64;
     } else if (value <= '9') {
-	return (value - '0') + 52;
+        return (value - '0') + 52;
     } else if (value <= 'Z') {
-	return (value - 'A');
+        return (value - 'A');
     } else if (value <= 'z') {
-	return (value - 'a') + 26;
+        return (value - 'a') + 26;
     }
-
     return 64;
 }
 
@@ -715,12 +716,12 @@ static inline int pmi_base64_decode_block (const char in[4], unsigned char out[3
 
     out[0] = in_dec[0] << 2 | in_dec[1] >> 4;
     if (64 == in_dec[2]) {
-	return 1;
+        return 1;
     }
 
     out[1] = in_dec[1] << 4 | in_dec[2] >> 2;
     if (64 == in_dec[3]) {
-	return 2;
+        return 2;
     }
 
     out[2] = ((in_dec[2] << 6) & 0xc0) | in_dec[3];
@@ -736,7 +737,7 @@ static char *pmi_encode(const void *val, size_t vallen)
 
     outdata = calloc (((2 + vallen) * 4) / 3 + 2, 1);
     if (NULL == outdata) {
-	return NULL;
+        return NULL;
     }
 
     for (i = 0, tmp = outdata ; i < vallen ; i += 3, tmp += 4) {
@@ -750,7 +751,7 @@ static char *pmi_encode(const void *val, size_t vallen)
 
 static uint8_t *pmi_decode (const char *data, size_t *retlen)
 {
-    size_t input_len = (strlen (data) - 1) / 4;
+    size_t input_len = strlen (data) / 4;
     unsigned char *ret;
     int out_len;
     size_t i;
@@ -758,16 +759,13 @@ static uint8_t *pmi_decode (const char *data, size_t *retlen)
     /* default */
     *retlen = 0;
 
-    ret = calloc (1, 3 * input_len + 1);
+    ret = calloc (1, 3 * input_len);
     if (NULL == ret) {
         return ret;
     }
-
     for (i = 0, out_len = 0 ; i < input_len ; i++, data += 4) {
-	out_len += pmi_base64_decode_block(data, ret + 3 * i);
+        out_len += pmi_base64_decode_block(data, ret + 3 * i);
     }
-
-    ret[out_len] = '\0';
     *retlen = out_len;
     return ret;
 }