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base64.h File Reference
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Functions

int pg_b64_encode (const char *src, int len, char *dst, int dstlen)
 
int pg_b64_decode (const char *src, int len, char *dst, int dstlen)
 
int pg_b64_enc_len (int srclen)
 
int pg_b64_dec_len (int srclen)
 

Function Documentation

◆ pg_b64_dec_len()

int pg_b64_dec_len ( int  srclen)

Definition at line 239 of file base64.c.

Referenced by parse_scram_secret(), read_client_final_message(), read_server_final_message(), read_server_first_message(), and scram_verify_plain_password().

240 {
241  return (srclen * 3) >> 2;
242 }

◆ pg_b64_decode()

int pg_b64_decode ( const char *  src,
int  len,
char *  dst,
int  dstlen 
)

Definition at line 116 of file base64.c.

References Assert, b64lookup, buf, and error().

Referenced by parse_scram_secret(), read_client_final_message(), read_server_final_message(), read_server_first_message(), and scram_verify_plain_password().

117 {
118  const char *srcend = src + len,
119  *s = src;
120  char *p = dst;
121  char c;
122  int b = 0;
123  uint32 buf = 0;
124  int pos = 0,
125  end = 0;
126 
127  while (s < srcend)
128  {
129  c = *s++;
130 
131  /* Leave if a whitespace is found */
132  if (c == ' ' || c == '\t' || c == '\n' || c == '\r')
133  goto error;
134 
135  if (c == '=')
136  {
137  /* end sequence */
138  if (!end)
139  {
140  if (pos == 2)
141  end = 1;
142  else if (pos == 3)
143  end = 2;
144  else
145  {
146  /*
147  * Unexpected "=" character found while decoding base64
148  * sequence.
149  */
150  goto error;
151  }
152  }
153  b = 0;
154  }
155  else
156  {
157  b = -1;
158  if (c > 0 && c < 127)
159  b = b64lookup[(unsigned char) c];
160  if (b < 0)
161  {
162  /* invalid symbol found */
163  goto error;
164  }
165  }
166  /* add it to buffer */
167  buf = (buf << 6) + b;
168  pos++;
169  if (pos == 4)
170  {
171  /*
172  * Leave if there is an overflow in the area allocated for the
173  * decoded string.
174  */
175  if ((p - dst + 1) > dstlen)
176  goto error;
177  *p++ = (buf >> 16) & 255;
178 
179  if (end == 0 || end > 1)
180  {
181  /* overflow check */
182  if ((p - dst + 1) > dstlen)
183  goto error;
184  *p++ = (buf >> 8) & 255;
185  }
186  if (end == 0 || end > 2)
187  {
188  /* overflow check */
189  if ((p - dst + 1) > dstlen)
190  goto error;
191  *p++ = buf & 255;
192  }
193  buf = 0;
194  pos = 0;
195  }
196  }
197 
198  if (pos != 0)
199  {
200  /*
201  * base64 end sequence is invalid. Input data is missing padding, is
202  * truncated or is otherwise corrupted.
203  */
204  goto error;
205  }
206 
207  Assert((p - dst) <= dstlen);
208  return p - dst;
209 
210 error:
211  memset(dst, 0, dstlen);
212  return -1;
213 }
static void error(void)
Definition: sql-dyntest.c:147
char * c
static char * buf
Definition: pg_test_fsync.c:67
unsigned int uint32
Definition: c.h:359
static const int8 b64lookup[128]
Definition: base64.c:30
#define Assert(condition)
Definition: c.h:739

◆ pg_b64_enc_len()

int pg_b64_enc_len ( int  srclen)

Definition at line 224 of file base64.c.

Referenced by build_client_final_message(), build_client_first_message(), build_server_final_message(), build_server_first_message(), mock_scram_secret(), read_client_final_message(), and scram_build_secret().

225 {
226  /* 3 bytes will be converted to 4 */
227  return (srclen + 2) * 4 / 3;
228 }

◆ pg_b64_encode()

int pg_b64_encode ( const char *  src,
int  len,
char *  dst,
int  dstlen 
)

Definition at line 49 of file base64.c.

References _base64, Assert, buf, and error().

Referenced by build_client_final_message(), build_client_first_message(), build_server_final_message(), build_server_first_message(), mock_scram_secret(), read_client_final_message(), and scram_build_secret().

50 {
51  char *p;
52  const char *s,
53  *end = src + len;
54  int pos = 2;
55  uint32 buf = 0;
56 
57  s = src;
58  p = dst;
59 
60  while (s < end)
61  {
62  buf |= (unsigned char) *s << (pos << 3);
63  pos--;
64  s++;
65 
66  /* write it out */
67  if (pos < 0)
68  {
69  /*
70  * Leave if there is an overflow in the area allocated for the
71  * encoded string.
72  */
73  if ((p - dst + 4) > dstlen)
74  goto error;
75 
76  *p++ = _base64[(buf >> 18) & 0x3f];
77  *p++ = _base64[(buf >> 12) & 0x3f];
78  *p++ = _base64[(buf >> 6) & 0x3f];
79  *p++ = _base64[buf & 0x3f];
80 
81  pos = 2;
82  buf = 0;
83  }
84  }
85  if (pos != 2)
86  {
87  /*
88  * Leave if there is an overflow in the area allocated for the encoded
89  * string.
90  */
91  if ((p - dst + 4) > dstlen)
92  goto error;
93 
94  *p++ = _base64[(buf >> 18) & 0x3f];
95  *p++ = _base64[(buf >> 12) & 0x3f];
96  *p++ = (pos == 0) ? _base64[(buf >> 6) & 0x3f] : '=';
97  *p++ = '=';
98  }
99 
100  Assert((p - dst) <= dstlen);
101  return p - dst;
102 
103 error:
104  memset(dst, 0, dstlen);
105  return -1;
106 }
static void error(void)
Definition: sql-dyntest.c:147
static const char _base64[]
Definition: base64.c:27
static char * buf
Definition: pg_test_fsync.c:67
unsigned int uint32
Definition: c.h:359
#define Assert(condition)
Definition: c.h:739