diff options
| -rw-r--r-- | crypto/asn1/a_int.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/crypto/asn1/a_int.c b/crypto/asn1/a_int.c index e154343925..6c8046c410 100644 --- a/crypto/asn1/a_int.c +++ b/crypto/asn1/a_int.c @@ -149,6 +149,8 @@ static size_t c2i_ibuf(unsigned char *b, int *pneg, const unsigned char *p, size_t plen) { int neg, pad; + size_t i; + /* Zero content length is illegal */ if (plen == 0) { ASN1err(ASN1_F_C2I_IBUF, ASN1_R_ILLEGAL_ZERO_CONTENT); @@ -167,6 +169,22 @@ static size_t c2i_ibuf(unsigned char *b, int *pneg, } return 1; } + /* leading 0xFF is not a padding if all the following bytes are zero */ + if (p[0] == 0xFF) { + /* check is any following octets are non zero */ + for (i = 1; i < plen; i++) { + if (p[i] != 0) + break; + } + /* if all bytes are zero handle as special case */ + if (i == plen) { + if (b != NULL) { + b[0] = 1; + memset(b + 1, 0, plen - 1); + } + return plen; + } + } if (p[0] == 0 || p[0] == 0xFF) pad = 1; else |