Q: Given the following code slice:
```
1 static inline void DecodeBase64Block(uint8_t ascii[ASCII_BLOCK], uint8_t b64[B64_BLOCK])
2 {
3     ascii[0] = (uint8_t) (b64[0] << 2) | (b64[1] >> 4);
4     ascii[1] = (uint8_t) (b64[1] << 4) | (b64[2] >> 2);
5     ascii[2] = (uint8_t) (b64[2] << 6) | (b64[3]);
6 }
7 Base64Ecode DecodeBase64(uint8_t *dest, uint32_t dest_size, const uint8_t *src, uint32_t len,
8         uint32_t *consumed_bytes, uint32_t *decoded_bytes, Base64Mode mode)
9 {
10     int val;
11     uint32_t padding = 0, bbidx = 0, sp = 0, leading_sp = 0;
12     uint8_t *dptr = dest;
13     uint8_t b64[B64_BLOCK] = { 0,0,0,0 };
14     bool valid = true;
15     Base64Ecode ecode = BASE64_ECODE_OK;
16     *decoded_bytes = 0;
17 
18     /* Traverse through each alpha-numeric letter in the source array */
19     for (uint32_t i = 0; i < len; i++) {
20         /* Get decimal representation */
21         val = GetBase64Value(src[i]);
22         if (val < 0) {
23             if (mode == BASE64_MODE_RFC2045 && src[i] != '=') {
24                 if (bbidx == 0) {
25                     /* Special case where last block of data has a leading space or invalid char */
26                     leading_sp++;
27                 }
28                 sp++;
29                 continue;
30             }
31             /* Invalid character found, so decoding fails */
32             if (src[i] != '=') {
33                 valid = false;
34                 ecode = BASE64_ECODE_ERR;
35                 if (mode == BASE64_MODE_STRICT) {
36                     *decoded_bytes = 0;
37                 }
38                 break;
39             }
40             padding++;
41         }
42 
43         /* For each alpha-numeric letter in the source array, find the numeric
44          * value */
45         b64[bbidx++] = (val > 0 ? val : 0);
46 
47         /* Decode every 4 base64 bytes into 3 ascii bytes */
48         if (bbidx == B64_BLOCK) {
49 
50             /* For every 4 bytes, add 3 bytes but deduct the '=' padded blocks */
51             uint32_t numDecoded_blk = ASCII_BLOCK - (padding < B64_BLOCK ? padding : ASCII_BLOCK);
52             if (dest_size < *decoded_bytes + numDecoded_blk) {
53                 SCLogDebug("Destination buffer full");
54                 ecode = BASE64_ECODE_BUF;
55                 break;
56             }
57 
58             /* Decode base-64 block into ascii block and move pointer */
59             DecodeBase64Block(dptr, b64);
60             dptr += numDecoded_blk;
61             *decoded_bytes += numDecoded_blk;
62             /* Reset base-64 block and index */
63             bbidx = 0;
64             padding = 0;
65             *consumed_bytes += B64_BLOCK + sp;
66             sp = 0;
67             leading_sp = 0;
68             memset(&b64, 0, sizeof(b64));
69         }
70     }
71 
72     if (bbidx > 0 && bbidx < 4 && ((!valid && mode == BASE64_MODE_RFC4648))) {
73         /* Decoded bytes for 1 or 2 base64 encoded bytes is 1 */
74         padding = bbidx > 1 ? B64_BLOCK - bbidx : 2;
75         uint32_t numDecoded_blk = ASCII_BLOCK - (padding < B64_BLOCK ? padding : ASCII_BLOCK);
76         if (dest_size < *decoded_bytes + numDecoded_blk) {
77             SCLogDebug("Destination buffer full");
78             ecode = BASE64_ECODE_BUF;
79             return ecode;
80         }
81         /* if the destination size is not at least 3 Bytes long, it'll give a dynamic
82          * buffer overflow while decoding, so, return and let the caller take care of the
83          * remaining bytes to be decoded which should always be < 4 at this stage */
84         if (dest_size - *decoded_bytes < 3)
85             return BASE64_ECODE_BUF;
86         *decoded_bytes += numDecoded_blk;
87         DecodeBase64Block(dptr, b64);
88         *consumed_bytes += bbidx;
89     }
90 
91     /* Finish remaining b64 bytes by padding */
92     if (valid && bbidx > 0 && (mode != BASE64_MODE_RFC2045)) {
93         /* Decode remaining */
94         *decoded_bytes += ASCII_BLOCK - (B64_BLOCK - bbidx);
95         DecodeBase64Block(dptr, b64);
96     }
97 
98     if (*decoded_bytes == 0) {
99         SCLogDebug("base64 decoding failed");
100     }
101 
102     *consumed_bytes += leading_sp;
103     return ecode;
104 }
105 static inline void DecodeBase64Block(uint8_t ascii[ASCII_BLOCK], uint8_t b64[B64_BLOCK])
106 {
107     ascii[0] = (uint8_t) (b64[0] << 2) | (b64[1] >> 4);
108     ascii[1] = (uint8_t) (b64[1] << 4) | (b64[2] >> 2);
109     ascii[2] = (uint8_t) (b64[2] << 6) | (b64[3]);
110 }
111 static inline int GetBase64Value(uint8_t c)
112 {
113     int val = -1;
114 
115     /* Pull from conversion table */
116     if (c <= BASE64_TABLE_MAX) {
117         val = b64table[(int) c];
118     }
119 
120     return val;
121 }
```
which has a vulnerability among CWE-787 and among lines:
```
69         }
```
Please generate five possible patches for the vulnerability.