X-Git-Url: https://diplodocus.org/git/nmh/blobdiff_plain/522c66eae1a144e0631dfaa61f1632e341ea7ce6..cf57870921b26703aad420c6741c524b33736ff1:/sbr/base64.c diff --git a/sbr/base64.c b/sbr/base64.c index 80ca86e0..a1e54c92 100644 --- a/sbr/base64.c +++ b/sbr/base64.c @@ -11,7 +11,7 @@ #include #include -static char nib2b64[0x40+1] = +static const char nib2b64[0x40+1] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; int @@ -113,7 +113,7 @@ writeBase64aux (FILE *in, FILE *out, int crlf) 4 * [length/3] + length/57 + 2 But double the length will certainly be sufficient. */ int -writeBase64 (unsigned char *in, size_t length, unsigned char *out) +writeBase64 (const unsigned char *in, size_t length, unsigned char *out) { unsigned int n = BPERLIN; @@ -121,7 +121,7 @@ writeBase64 (unsigned char *in, size_t length, unsigned char *out) unsigned long bits; unsigned char *bp; unsigned int cc; - for (cc = 0, bp = in; length > 0 && cc < 3; ++cc, ++bp, --length) + for (cc = 0; length > 0 && cc < 3; ++cc, --length) /* empty */ ; if (cc == 0) { @@ -168,13 +168,13 @@ writeBase64 (unsigned char *in, size_t length, unsigned char *out) */ int -writeBase64raw (unsigned char *in, size_t length, unsigned char *out) +writeBase64raw (const unsigned char *in, size_t length, unsigned char *out) { while (1) { unsigned long bits; unsigned char *bp; unsigned int cc; - for (cc = 0, bp = in; length > 0 && cc < 3; ++cc, ++bp, --length) + for (cc = 0; length > 0 && cc < 3; ++cc, --length) /* empty */ ; if (cc == 0) { @@ -209,7 +209,7 @@ writeBase64raw (unsigned char *in, size_t length, unsigned char *out) } -static unsigned char b642nib[0x80] = { +static const unsigned char b642nib[0x80] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, @@ -233,8 +233,8 @@ static unsigned char b642nib[0x80] = { * See description of arguments with declaration in h/prototypes.h. */ int -decodeBase64 (const char *encoded, const char **decoded, size_t *len, int skip_crs, - unsigned char *digest) { +decodeBase64 (const char *encoded, unsigned char **decoded, size_t *len, + int skip_crs, unsigned char *digest) { const char *cp = encoded; int self_delimiting = 0; int bitno, skip; @@ -243,7 +243,8 @@ decodeBase64 (const char *encoded, const char **decoded, size_t *len, int skip_c charstring_t decoded_c = charstring_create (strlen (encoded)); MD5_CTX mdContext; - if (digest) { MD5Init (&mdContext); } + if (digest) + MD5Init (&mdContext); bitno = 18; bits = 0L; @@ -259,7 +260,7 @@ decodeBase64 (const char *encoded, const char **decoded, size_t *len, int skip_c } if (skip || (((unsigned char) *cp) & 0x80) || (value = b642nib[((unsigned char) *cp) & 0x7f]) > 0x3f) { - advise (NULL, "invalid BASE64 encoding in %s", encoded); + advise (NULL, "invalid BASE64 encoding in %s", cp); charstring_free (decoded_c); *decoded = NULL; @@ -274,19 +275,22 @@ test_end: if (! skip_crs || b != '\r') { charstring_push_back (decoded_c, b); } - if (digest) { MD5Update (&mdContext, (unsigned char *) &b, 1); } + if (digest) + MD5Update (&mdContext, (unsigned char *) &b, 1); if (skip < 2) { b = (bits >> 8) & 0xff; if (! skip_crs || b != '\r') { charstring_push_back (decoded_c, b); } - if (digest) { MD5Update (&mdContext, (unsigned char *) &b, 1); } + if (digest) + MD5Update (&mdContext, (unsigned char *) &b, 1); if (skip < 1) { b = bits & 0xff; if (! skip_crs || b != '\r') { charstring_push_back (decoded_c, b); } - if (digest) { MD5Update (&mdContext, (unsigned char *) &b, 1); } + if (digest) + MD5Update (&mdContext, (unsigned char *) &b, 1); } } @@ -307,14 +311,19 @@ test_end: } if (! self_delimiting && bitno != 18) { - advise (NULL, "premature ending (bitno %d) in %s", bitno, encoded); + int i; + + /* Show some context for the error. */ + for (i = 0; i < 20 && cp > encoded; ++i, --cp) {} + advise (NULL, "premature ending (bitno %d) near %s", bitno, + cp ? cp : encoded); charstring_free (decoded_c); *decoded = NULL; return NOTOK; } - *decoded = charstring_buffer_copy (decoded_c); + *decoded = (unsigned char *) charstring_buffer_copy (decoded_c); *len = charstring_bytes (decoded_c); charstring_free (decoded_c); @@ -324,3 +333,35 @@ test_end: return OK; } + + +/* + * Prepare an unsigned char array for display by replacing non-printable + * ASCII bytes with their hex representation. Assumes ASCII input. output + * is allocated by the function and must be freed by the caller. + */ +void +hexify (const unsigned char *input, size_t len, char **output) { + /* Start with a charstring capacity that's arbitrarily larger than len. */ + const charstring_t tmp = charstring_create (2 * len); + const unsigned char *cp = input; + size_t i; + + for (i = 0; i < len; ++i, ++cp) { + if (isascii(*cp) && isprint(*cp)) { + charstring_push_back (tmp, (const char) *cp); + } else { + char s[16]; + const int num = snprintf(s, sizeof s, "[0x%02x]", *cp); + + if (num <= 0 || (unsigned int) num >= sizeof s) { + advise (NULL, "hexify failed to write nonprintable character, needed %d bytes", num + 1); + } else { + charstring_append_cstring (tmp, s); + } + } + } + + *output = charstring_buffer_copy (tmp); + charstring_free (tmp); +}