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base64: Reformat

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Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Sahana Prasad <sahana@redhat.com>
Reviewed-by: Eshan Kelkar <eshankelkar@galorithm.com>
This commit is contained in:
Jakub Jelen
2024-07-15 14:19:54 +02:00
committed by Sahana Prasad
parent 8ed9f5e69b
commit 9ddde3803e
1 changed files with 131 additions and 127 deletions
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258
src/base64.c
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@@ -57,119 +57,120 @@ static int get_equals(char *string);
* @returns A buffer containing the decoded string, NULL if something went * @returns A buffer containing the decoded string, NULL if something went
* wrong (e.g. incorrect char). * wrong (e.g. incorrect char).
*/ */
ssh_buffer base64_to_bin(const char *source) { ssh_buffer base64_to_bin(const char *source)
ssh_buffer buffer = NULL; {
unsigned char block[3]; ssh_buffer buffer = NULL;
char *base64; unsigned char block[3];
char *ptr; char *base64 = NULL;
size_t len; char *ptr = NULL;
int equals; size_t len;
int equals;
base64 = strdup(source); base64 = strdup(source);
if (base64 == NULL) { if (base64 == NULL) {
return NULL; return NULL;
}
ptr = base64;
/* Get the number of equals signs, which mirrors the padding */
equals = get_equals(ptr);
if (equals > 2) {
SAFE_FREE(base64);
return NULL;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
SAFE_FREE(base64);
return NULL;
}
/*
* The base64 buffer often contains sensitive data. Make sure we don't leak
* sensitive data
*/
ssh_buffer_set_secure(buffer);
len = strlen(ptr);
while (len > 4) {
if (_base64_to_bin(block, ptr, 3) < 0) {
goto error;
} }
if (ssh_buffer_add_data(buffer, block, 3) < 0) { ptr = base64;
goto error;
}
len -= 4;
ptr += 4;
}
/* /* Get the number of equals signs, which mirrors the padding */
* Depending on the number of bytes resting, there are 3 possibilities equals = get_equals(ptr);
* from the RFC. if (equals > 2) {
*/ SAFE_FREE(base64);
switch (len) { return NULL;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
SAFE_FREE(base64);
return NULL;
}
/*
* The base64 buffer often contains sensitive data. Make sure we don't leak
* sensitive data
*/
ssh_buffer_set_secure(buffer);
len = strlen(ptr);
while (len > 4) {
if (_base64_to_bin(block, ptr, 3) < 0) {
goto error;
}
if (ssh_buffer_add_data(buffer, block, 3) < 0) {
goto error;
}
len -= 4;
ptr += 4;
}
/*
* Depending on the number of bytes resting, there are 3 possibilities
* from the RFC.
*/
switch (len) {
/* /*
* (1) The final quantum of encoding input is an integral multiple of * (1) The final quantum of encoding input is an integral multiple of
* 24 bits. Here, the final unit of encoded output will be an integral * 24 bits. Here, the final unit of encoded output will be an integral
* multiple of 4 characters with no "=" padding * multiple of 4 characters with no "=" padding
*/ */
case 4: case 4:
if (equals != 0) { if (equals != 0) {
goto error; goto error;
} }
if (_base64_to_bin(block, ptr, 3) < 0) { if (_base64_to_bin(block, ptr, 3) < 0) {
goto error; goto error;
} }
if (ssh_buffer_add_data(buffer, block, 3) < 0) { if (ssh_buffer_add_data(buffer, block, 3) < 0) {
goto error; goto error;
} }
SAFE_FREE(base64); SAFE_FREE(base64);
return buffer; return buffer;
/* /*
* (2) The final quantum of encoding input is exactly 8 bits; here, the * (2) The final quantum of encoding input is exactly 8 bits; here, the
* final unit of encoded output will be two characters followed by * final unit of encoded output will be two characters followed by
* two "=" padding characters. * two "=" padding characters.
*/ */
case 2: case 2:
if (equals != 2){ if (equals != 2) {
goto error; goto error;
} }
if (_base64_to_bin(block, ptr, 1) < 0) { if (_base64_to_bin(block, ptr, 1) < 0) {
goto error; goto error;
} }
if (ssh_buffer_add_data(buffer, block, 1) < 0) { if (ssh_buffer_add_data(buffer, block, 1) < 0) {
goto error; goto error;
} }
SAFE_FREE(base64); SAFE_FREE(base64);
return buffer; return buffer;
/* /*
* The final quantum of encoding input is exactly 16 bits. Here, the final * The final quantum of encoding input is exactly 16 bits. Here, the final
* unit of encoded output will be three characters followed by one "=" * unit of encoded output will be three characters followed by one "="
* padding character. * padding character.
*/ */
case 3: case 3:
if (equals != 1) { if (equals != 1) {
goto error; goto error;
} }
if (_base64_to_bin(block, ptr, 2) < 0) { if (_base64_to_bin(block, ptr, 2) < 0) {
goto error; goto error;
} }
if (ssh_buffer_add_data(buffer,block,2) < 0) { if (ssh_buffer_add_data(buffer, block, 2) < 0) {
goto error; goto error;
} }
SAFE_FREE(base64); SAFE_FREE(base64);
return buffer; return buffer;
default: default:
/* 4,3,2 are the only padding size allowed */ /* 4,3,2 are the only padding size allowed */
goto error; goto error;
} }
error: error:
SAFE_FREE(base64); SAFE_FREE(base64);
SSH_BUFFER_FREE(buffer); SSH_BUFFER_FREE(buffer);
return NULL; return NULL;
} }
#define BLOCK(letter, n) do {ptr = strchr((const char *)alphabet, source[n]); \ #define BLOCK(letter, n) do {ptr = strchr((const char *)alphabet, source[n]); \
@@ -179,59 +180,62 @@ error:
} while(0) } while(0)
/* Returns 0 if ok, -1 if not (ie invalid char into the stuff) */ /* Returns 0 if ok, -1 if not (ie invalid char into the stuff) */
static int to_block4(unsigned long *block, const char *source, int num) { static int to_block4(unsigned long *block, const char *source, int num)
const char *ptr = NULL; {
unsigned int i; const char *ptr = NULL;
unsigned int i;
*block = 0;
if (num < 1) {
return 0;
}
BLOCK(A, 0); /* 6 bit */
BLOCK(B, 1); /* 12 bit */
if (num < 2) {
return 0;
}
BLOCK(C, 2); /* 18 bit */
if (num < 3) {
return 0;
}
BLOCK(D, 3); /* 24 bit */
*block = 0;
if (num < 1) {
return 0; return 0;
}
BLOCK(A, 0); /* 6 bit */
BLOCK(B,1); /* 12 bit */
if (num < 2) {
return 0;
}
BLOCK(C, 2); /* 18 bit */
if (num < 3) {
return 0;
}
BLOCK(D, 3); /* 24 bit */
return 0;
} }
/* num = numbers of final bytes to be decoded */ /* num = numbers of final bytes to be decoded */
static int _base64_to_bin(unsigned char dest[3], const char *source, int num) { static int _base64_to_bin(unsigned char dest[3], const char *source, int num)
unsigned long block; {
unsigned long block;
if (to_block4(&block, source, num) < 0) { if (to_block4(&block, source, num) < 0) {
return -1; return -1;
} }
dest[0] = GET_A(block); dest[0] = GET_A(block);
dest[1] = GET_B(block); dest[1] = GET_B(block);
dest[2] = GET_C(block); dest[2] = GET_C(block);
return 0; return 0;
} }
/* Count the number of "=" signs and replace them by zeroes */ /* Count the number of "=" signs and replace them by zeroes */
static int get_equals(char *string) { static int get_equals(char *string)
char *ptr = string; {
int num = 0; char *ptr = string;
int num = 0;
while ((ptr=strchr(ptr,'=')) != NULL) { while ((ptr = strchr(ptr, '=')) != NULL) {
num++; num++;
*ptr = '\0'; *ptr = '\0';
ptr++; ptr++;
} }
return num; return num;
} }
/* thanks sysk for debugging my mess :) */ /* thanks sysk for debugging my mess :) */
@@ -283,7 +287,7 @@ uint8_t *bin_to_base64(const uint8_t *source, size_t len)
} }
ptr = base64; ptr = base64;
while(len > 0){ while (len > 0) {
_bin_to_base64(ptr, source, len > 3 ? 3 : len); _bin_to_base64(ptr, source, len > 3 ? 3 : len);
ptr += 4; ptr += 4;
if (len < 3) { if (len < 3) {